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  • Data: 29/01/2024
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  • The present study aimed to evaluate and identify the efficiency of different vegetation indexes (VI) in distinguishing the phenological stages of soybean crops, using images collected by sensor systems, with different spatial resolutions. The research was carried out in a soybean cultivation area irrigated by central pivot, in Balsas, MA, Brazil, where weekly assessments of phenology and leaf area index were carried out. Throughout the crop cycle, spectral data from the study area were collected from the MSI and WFI sensors onboard the Sentinel-2 and Amazonia-1 satellites, respectively. The images obtained were processed to obtain vegetation indexes based on NIR (NDVI, NDWI and SAVI) and RGB (VARI, IV GREEN and GLI), for the different phenological stages of the crop. The efficiency in identifying soybean phenological stages using vegetation indexes was determined using Anderson's discriminant analysis, where the best classifications were those with the lowest apparent error rate (AER). The difference in spatial resolution of the sensors is not a determining factor in the correct identification of soybean phenological stages. Although no vegetation index obtained from the Amazonia-1 and Sentinel-2 sensor systems was 100% effective in identifying all phenological stages of the soybean crop, specific RGB and NIR indexes can be used to identify some phenological stages. keys to soybean cultivation are the flowering of the crop (R1 and R2), the end of pod development (R4) and the stages that characterize the development of grains within the pods (R4 to R5.2). This demonstrates that vegetation indexes obtained from orbital sensors are effective in identifying soybean phenological stages quickly and cheaply.

  • POTENCIAL ANTIFÚNGICO DAS NANOEMULSSÕES DE ÓLEOS ESSENCIAIS DE Ocimum basilicum, Ocimum gratissimum, e Mentha villosa PARA MANEJO DE Fusarium oxysporum F. sp. tracheiphilum

  • Data: 29/05/2024
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  • O uso intensivo e indiscriminado do controle químico, incluindo agentes de alta toxicidade, para combate de pragas, tem afetado negativamente o meio ambiente e o ser humano. Os óleos essenciais são conhecidos por possuírem propriedades antifúngicas naturais, tornando-se uma alternativa para o controle fitossanitário. No entanto, os óleos essenciais são voláteis e fotodegradáveis, o que reduz suas atividades a longo prazo. Sendo assim este trabalho teve como objetivo avaliar o perfil químico e o potencial antifúngico dos óleos essenciais das partes aéreas de Ocimum basilicum, Ocimum gratissimum e Mentha villosa sobre o fungo Fusarium Oxysporum f. sp. tracheiphillum em condições laboratoriais. Os óleos essenciais foram extraídos das folhas de alfavaca, hortelã, manjericão por meio de hidrodestilação e diluído nas concentrações de 25, 50, 75, 100, 250 e 500μL/Ml. Os constituintes químicos dos foram identificados por cromatografia gasosa acoplada a espectrometria de massas e ressonância magnética nucelar. A análise química demonstrou uma grande variedade de compostos, sendo os constituintes majoritários, Estragol e Linalool do O. basilicum; Estragol e 1,8-Cineol, do O.gratissmum e Rotundifolona da Mentha villosa. O potencial antifúngico de cada óleo foi avaliado durante 7 dias por meio de testes in vitro. Resultados preliminares constaram que em comparação ao controle, a solução contendo o óleo essencial de O.gratissmum na concentração de 500μL/Ml inibiu por completo o crescimento micelial do F.Oxysporum f. sp. tracheiphillum.

  • Brassinosteroid and salicylic acid in the development of grain sorghum under water stress in the pre-flowering stage.

  • Data: 16/04/2024
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  • Water stress negatively affects vegetables. It causes changes in the physiological and biochemical aspects of plants, leading to reduced productivity. Despite being resistant to low water availability, sorghum production is significantly reduced under these conditions. Therefore, it is necessary to evaluate the use of mitigators of this stress, such as Brassinosteroid (BR) and Salicylic Acid (SA). The objective of the work was to evaluate the effect of the isolated and combined application of brassinosteroids and salicylic acid on sorghum plants subjected to water stress. The study was implemented using a randomized block design (RBD), with a 2x4 factorial scheme, including two levels of water in the substrate (irrigated and water stress) and four ways of using bioregulators (Control - without the bioregulator; application of BR in concentration of 0.1 μM; application of SA at a concentration of 1 mM; and the combination of the two bioregulators (BR and SA), totaling eight treatments, five replications and 40 experimental units. Sowing was carried out with ten seeds per pot, with thinning carried out and maintaining two plants. The moisture of the substrate was maintained close to field capacity until 50 days after sowing (DAS), when the plants reached pre-flowering (the most sensitive phase), and were then subjected to water stress treatment with the gradual suspension of irrigation. From 51 to 56 DAS, the plants were subjected to moderate stress, with 50% of field capacity. From 57 to 62 DAS, severe stress began, with the substrate at 20% of field capacity. Plants in the control treatment remained irrigated close to field capacity until physiological maturation of the grains. Water stress and the application of bioregulators influenced growth variables. The BR+SA treatment proved to be more efficient, as it achieved a greater increase in stem height and diameter, in addition to greater leaf dry mass, stem dry mass, root dry mass and total seed weight. The joint application of bioregulators was also responsible for increasing the green index in leaves, the maximum quantum efficiency of photosystem II, the primary efficiency of photosystem II and the content of photosynthetic pigments compared to control treatments (without application of bioregulators).

  • Socio and environmental Dynamics of Attalea speciosa Production in Maranhão as a Subsidy for Sustainable Development

  • Data: 31/03/2023
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  • The state of Maranhão has the largest production of babassu in Brazil, a crop that performed an important socioeconomic role for extractive families. Until the middle 1980s, this culture was an escape from the crisis that reached the State, after the decline of textile-cotton production. However, this situation changed after the introduction of laws that legitimized the privatization and expropriation of public lands, restricting the access of babassu nut breakers to the babassu groves. This fact initiated conflicts over access to this natural resource, which has been accompanied by the introduction of activities and the implementation of agricultural products, pasture and an increase in deforested areas, which may have influenced the production of babassu almonds. Therefore, the objective of the present study was to identify what has happened to babassu trees over three decades and what has affected the increase and/or decrease in the production of this palm tree in the mesoregions of the state of Maranhão. Identifying these factors is highest importance, since babassu is classified as a palm tree that generates income for several families. The data for the development of the research were acquired from the IBGE/SIDRA database, MapBiomas and Lapig, where geoprocessing techniques were integrated into the QGIS software for the spatial analysis of the dynamics of babassu production in the State. This information will be able to update cartographic data on babassu production and reconstruct the historical evolution of this palm tree, which is so important for the livelihood of many families. In addition to contributing to public policies capable of preserving these areas and instigating greater inspection and punishment for not properly preserving these environments.

  • Use of digital leaf imaging as a tool to diagnose nitrogen in cowpea

  • Data: 15/02/2023
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  • The cowpea crop is important as a source of food, employment and income generation, in addition to stimulating the economy in the North and Northeast of Brazil. However, the low productivity of the crop is an obstacle to be overcome, through efficient technologies and management that increase production without generating excessive costs for farmers. The objective was to evaluate, through digital images of cowpea leaves, the indexes of plant color would be correlated with the nitrogenous status of the plants. Along with evaluation of vegetation indexes that correlate with the productivity of different cowpea genotypes. Twenty genotypes of cowpea were used in the experimental conduction, in order to determine an index that adapts to different genotypes of cowpea. The indexes that improved correlated with Leaf Nitrogen Content was the DGCI, which had a strong positive correlation of 0.7. As for productivity, it was not possible to determine a vegetation index capable of predicting productivity. This demonstrated that it is possible to reliably determine the leaf nitrogen of several genotypes of cowpea in reality, but it is not feasible to use these indexes for productivity.

  • Sustainability, leguminous biomass, total organic carbon, polyvalent cations.

  • Data: 27/06/2023
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  • In order for soil sustainability to be achieved in the humid tropics, the use of management practices capable of increasing the content of stable organic matter are essential. Practices such as the use of leguminous biomass and fertilization with cations help in this process. Thus, the objective of this work was to evaluate the effect of the interaction between high quality biomass and the polyvalent cations Ca2+ and Si2+ on carbon use efficiency and how this effect interferes with the accumulation of the stable fraction of soil organic matter. For this, microbial biomass activity and soil organic carbon have been used as indicators. The experimental design used was randomized blocks, with eight treatments and four replications. The treatments consisted of arrangements of legumes with calcium, silicon and urea. The combination of silicon plus leguminous biomass was the treatment that showed the highest carbon use efficiency and the highest incorporation of organic carbon in the microbial biomass. However, the results indicated that the combination of leguminous biomass in association with both polyvalent cations benefited the activity of microorganisms, which was reflected in the accumulation and stabilization of OC in soil organic matter.

  • Distribution of Odonata Assembly in Streams in the Legal Amazon of Maranhão due to Environmental Variation

  • Data: 30/03/2023
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  • The Amazon biome has been suffering recurrent degradation and great loss of its biodiversity, and there are still many studies that need to be done to learn more about its fauna and flora. Dragonflies are a small group of aquatic insects classified in the order Odonata, they are sensitive organisms to changes in habitat, so they are known as good indicators of environmental conditions, and are used in several ecological studies to measure impacts caused by anthropic activities that cause degradation of ecosystem resources and especially of aquatic resources. The first chapter of this work studies which mechanisms can influence the Odonata metacommunity in a landscape cover loss gradient. The study also aims to find out whether the factors of space and variation in the environment can influence the two suborders of Odonata (Anisoptera and Zygoptera). The second chapter evaluates the response of dragonfly diversity (abundance and richness) to environmental changes in streams located in the Legal Amazon of Maranhão, and in view of this assessment, identify which factors most influence the richness and abundance of the sampled species. This study was carried out in streams located in the Pindaré River basin in the legal Amazon of Maranhão in an environmental gradient that suffers from degradation and loss of biodiversity. Our results showed that Odonata species presented a distinction in distribution between the two suborders of the order in view of this environmental gradient and also due to the body characteristics of the species of each suborder. And we were also able to perceive differences in species richness and abundance when comparing the two suborders (Anisoptera and Zygoptera), showing that the abundance was lower in the species of the suborder Zygoptera due to their relationship with environments with greater vegetation cover. In view of our findings, monitoring and preservation of these environments are necessary to reduce the loss of aquatic biodiversity that inhabits them and especially of species that are restricted to environments with greater vegetation cover, since they are of great importance.


  • Data: 01/03/2023
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  • The barbatimão, [Stryphnodendron adstringens (Mart.) Coville], belonging to the Fabaceae family and subfamily Mimosoidae, has a wide distribution in Brazil and occurs in the North, Northeast, Midwest, Southeast and South. This species has great economic importance, with medicinal potential, which demonstrates to be a valuable biological resource, the wood can be used in construction and the recovery of degraded areas. Its exploitation is developed through extractivism and the bark of its stem is widely used in traditional medicine. This work aimed to evaluate the in vitro development of barbatimão using plant growth promoting bacteria (PGPB). For this, the experiment was conducted in an entirely randomized design, with five treatments (T1: MS without growth regulator (applications of autoclaved distilled water), 2: applications of Bacillus methylotrophicus, T3: applications of Serratia marcescens, T4: applications of B. methylotrophicus and S. marcescens and T5: MS + 21.48 µM of naphthaleneacetic acid (applications of autoclaved distilled water), totaling five treatments, with six repetitions, each flask representing one repetition. In the experiment, barbatimão (Stryphnodendron astringens) seeds were used, and after 15 days of in vitro cultivation, BPCPs applications were made to the seedlings. For this, the strains used were diluted to 10-6 (Bacillus methylotrophicus and Serratia marcescens) and applied twice to the seedlings, at 15 and 30 days. At 30 days of in vitro cultivation, leaf number, leaf area (cm²), plant height (cm), root fresh matter (g), aerial fresh matter (g), root dry matter (g), aerial dry matter (g) were evaluated, percentage of survival (%), root to aerial part ratio, maximum quantum yield of photosystem II (PSII, Fv/Fm), photosynthetic index (IF) and the density of photosystem II active reaction centers per unit of absorbed photons (RC/ABS). Growth-promoting bacteria were observed to have positive effects on the growth of barbatimon seedlings under in vitro conditions and subsequent ex vitro acclimatization. These results indicate that in vitro propagation associated with inoculation of PGPBs (MS + B. methylotrophicus and MS+ S. marcescens) is a viable method for the production of Stryphnodendron astringens seedlings.

  • Regeneration of the Herbaceous Stratum after Experimental Burns in Campos Amazônicos National Park

  • Orientador : TIAGO MASSI FERRAZ
  • Data: 30/04/2023
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  • Fire in the Cerrado plays an important role in nutrient cycling and in maintaining the diversity and structure of habitats, but the increase in anthropic pressures has significantly altered its natural regimes, impacting the functioning of these ecosystems. The Campos Amazônicos National Park (PNCA) protects a significant part of the largest enclave of Cerrado in the south of the Amazon, areas that are frequently affected by fire and require a lot of effort for their proper management. As part of a broader proposal for monitoring the effects of fire in experimental burnings to be carried out in the PNCA, this project seeks to evaluate the responses of the herbaceous stratum in plant formations subjected to burnings in different periods within two experimental zones (Zones A and B). Each experimental zone has 15 plots of 40x40m where 6 plots will be burned at the beginning of the dry season (May); 6 plots between the middle and end of the dry season (August); and 3 excluded from fire. Before applying these treatments, more precisely in February 2019, a survey of 8 permanent plots of 1x1 m (randomly distributed) was carried out in each plot to then collect data on species richness, abundance and regeneration. In May 2021, two years after the pre-fire survey, data were collected again. Thus, the effects of fire on herbaceous vegetation were evaluated, since this is the stratum mainly affected by fire. It is the first research to report a set of experimental burnings in cerrado environments in the Amazon, within a context of integrated fire management, which made it possible to advance in understanding the similarities and differences in the relationships between fire and vegetation in the comparison with results obtained in other experiments conducted in core areas of the Brazilian Cerrado.

  • Chlorophyll Index and Soluble Sugar Contents in the Stem of Sorghum Cultivars in Southern Maranhão: A Possible Relationship with Growth and Productivity

  • Data: 27/02/2023
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  • Sorghum (Sorghum L. moench) is a grass of African origin and is one of the most planted cereals in the world, and, with regard to tolerance to biotic and abiotic stresses, this species is one of the most versatile. The information about the correlation between characters is of great importance to optimize the simultaneous selection of characters. However, quantification and interpretation of the magnitude of a correlation can result in mistakes in the selection strategy. In turn, path analysis is based on evaluating the effect of an independent variable on a dependent variable, after removing the influence of all other independent variables included in the analysis. Thus, this research aimed to verify whether the SPAD index (associated with the concentration of chlorophylls in the leaves) and the concentration of sugars in the stem (BRIX) (associated with an osmotic adjustment), are related to some agronomic variables in different cultivars of sorghum cultivated in the south of the state of Maranhão. The experiment was carried out at the agricultural research unit of the State University of Maranhão, located in the municipality of Balsas-MA, with an experimental design in randomized blocks and three replications, with the experiment being repeated in the 2021 and 2022 harvests. treatments, being the treatments composed by the cultivars SUDAN 4202, AGRI 001-E, AGRI 002-E, BRS 658, BRS 810, BRS Ponta Negra, BRS 373, BR 509, BR 506 and IPA 467-4-2. The variables studied were plant height, stem diameter, number of leaves, leaf area, days to flowering, cycle (count of days from the sowing day, until the plants reach the phenological stage of pasty grain .), the final stand, the fresh mass, the dry mass, the SPAD index and the sugar content in the stem estimated by the °Brix index. For path analysis, the GENES software was used. The variables fresh mass, stem diameter, height and number of leaves were efficient in increasing the production of soluble solids (BRIX), which indicates the presence of cause and effect. Among all the analyzed variables, the leaf area was the only one that had a direct effect on the main one, the SPAD index, with a magnitude greater than the residual effect. Path analysis proved to be an efficient tool in the selection of productive traits of sorghum cultivars associated with chlorophyll content and soluble solids.

  • Community of Scarabaeid Beetles (Coleoptera: Scarabaeidae: Scarabaeinae) in Different Landscapes in the Lajeado River Basin Region, Maranhão

  • Data: 31/03/2023
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  • The Brazilian Cerrado is considered one of the world's biodiversity hotspots, conserving this landscape has become a major challenge for scientists and conservationists. In this biome, the variation in environmental conditions due to high rates of deforestation, fragmentation and intensification of land use can influence the distribution of species, which are associated with some environmental characteristics. Dung beetles (Coleoptera: Scarabaeinae) are insects sensitive to habitat disturbances and have been used to monitor environmental changes. The objective of this research was to study the diversity of the dung beetle communities (composition patterns, richness and abundance) in the face of landscape changes (gallery forests, forest fragments and pastures) in the Lajeado river basin region, Cerrado of the state of Maranhão. Sampling (through pitfall traps) was carried out in 30 areas located in the municipalities of São João do Paraíso, Porto Franco, Lajeado Novo, Campestre do Maranhão and Ribamar Fizene, Maranhão, Brazil. We collected 2,855 dung beetles belonging to 17 genera, 32 species and 30 morphospecies. The most abundant species were Canthon histrio (Le Peletier & Serville, 1828) (28.12%, n = 803), Onthophagus aff. rubrescens (Blanchard, 1846) (13.6%, n = 390) and Eurysternus caribaeus (Herbst, 1789) (5.11%, n = 146). The highest species richness and abundance were recorded in the forest fragment, followed by pasture, while the gallery forest had lower species richness, but similar abundance to pasture. Species composition was dissimilar between forest and pasture environments. The species Canthon aff. xanthopus (Blanchard, 1846) and Deltochilum enceladus (kolbe, 1893) were associated with forest fragments. Canthidium aff. barbacenicum (Preudhomme de Borre, 1886), Canthon octodentatus (Schmidt, 1920), Coprophanaeus magnoi (Arnaud, 2002), Dichotomius bos (Blanchard, 1846), Dichotomius nisus (Olivier, 1789) and Pseudocanthon xanthurus (Blanchard, 1846) had strong relationship with pastures. The species Eurysternus caribaeus (Herbst, 1789) was associated with forest fragments and gallery forests. Our results provide evidence that there are significant distributions and associations between beetle species and the environmental structure of the different phytophysiognomies of the Lajeado river basin. In view of this, we encourage environmental management to develop measures aimed at preserving areas in the study region that are currently suffering from anthropic processes, in order to minimize the impacts caused on scarab beetle communities.

  • Data: 29/07/2022
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  • Agricultural production systems, due to the high demand for food production, need sustainable strategies that aim to maintain the balance of ecosystems. For pest management, an alternative is to manipulate the environment, using spontaneous plants that are capable of providing important resources for the conservation of natural enemies. Thus, the objective of this work will be to evaluate the effect of the presence (absence) of the weeding interval and composition of weeds as a strategy for the conservation of arthropod diversity and regulation of pest infestation in cowpea plants. The work will be conducted at Fazenda Escola and at the Entomology Laboratory of the Department of Phytotechnics and Plant Health at the State University of Maranhão – UEMA, São Luís, Maranhão. The planting of cowpea beans was carried out in rows, in an area of 841 m2 which was divided into parcels. The experiment was laid out in a randomized complete block design, with 6 treatments and 5 replications. The treatments were the weeding intervals, where t1: without weeding, and the other treatments were be represented by weeding after the emergence of cowpea, where t2 received weeding at 7 days, t3 weeding at 14 days, t4 weeding at 14 days 21 days, t5 one weed at 28 days and t6 one weed at 35 days after cowpea emergence. Entomofauna sampling was carried out both in cowpea bean plants and in spontaneous vegetation where the collected insects were sorted and later identified taxonomically. The floristic composition of spontaneous plants was also evaluated, and their data served to carry out a phytosociological analysis. Shannon diversity (h’) and species richness (s) indices were generated and submitted to the Shapiro-Wilk normality test. The relative abundances (%) of each taxon was also calculated, grouping them according to functional guild (predators, parasitoids and phytophagous).


  • Data: 27/07/2022
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  • With the growing need for more sustainable agricultural production and reduced dependence on pesticides, there is a need to improve biological control techniques and their effective application. Thus, the application of fungi in the endophytic form is a promising technique. Therefore, the present work aimed to select isolates of entomopathogenic fungi with high virulence against Spodoptera frugiperda, a key pest of corn, aiming to control this pest via endophytic colonization of plants with these fungi. Two Beauveria bassiana isolates (LPP 129 and LPP SP1) and two Metarhizium anisopliae isolates (ESALQ 818 and LPP M1) were tested for virulence against S. frugiperda larvae via contact. Corn plants were then inoculated with fungal conidia through foliar spray and the presence of the fungi in different plant tissues was evaluated 7, 14, 21, 28 and 90 days after inoculation. After confirmation of endophytic colonization in leaf tissues, corn leaves were offered to third instar S. frugiperda and survival was monitored over 10 days. Agronomic parameters related to plant growth were also evaluated. The results showed variability in virulence of the four isolates against S. frugiperda larvae, in which LPPM1 isolate was considered to have low virulence, LPP 129 median virulence and both ESALQ 818 and LPP SP1 were highly virulent, killing >90% of the larvae in 5-6 days. The two most virulent isolates were used for inoculation via foliar spraying in maize plants. Endophytic colonization of plants with ESALQ 818 and LPPSP1 were efficient in reducing the survival of S. frugiperda larvae that fed on leaves. The treatments differed significantly (P<0.0001) from the control group. Larvae exposed to corn leaves colonized with the fungi showed a mean survival of 3 days (S50), and 96% mortality on the 7th day of evaluation. The control group had a survival rate of approximately 90%. As for the agronomic parameters evaluated, significant increases were observed in the variables root length, stem diameter, plant height, leaf area and number of leaves. LPPSP1 and ESALQ 818 efficiently colonized maize plants via foliar inoculation, and was detected for up to 90 days after inoculation. Plants colonized with fungi in the endophytic form proved to be efficient and virulent against S. frugiperda larvae, as well as causing positive effects on plant growth, indicating the potential of endophytic colonization for biological control strategies.

  • ACARICIDAL, REPELLENT AND ANTIHELMINTHIC ACTIVITY OF ESSENTIAL OIL FROM Lippia origanoides KUNTH "CAMPHOR CHEMOTYPE" ON Rhipicephalus (Boophilus) microplus, Haemonchus contortus and Caenorhabditis elegans

  • Data: 10/03/2022
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  • One of the biggest challenges for ranchers today is associated with the search for effective products to control parasites in herds of cattle, goats and sheep. However, populations of ectoparasites and endoparasites end up creating drug resistance due to chemical substances present in their compositions, as well as influencing the quality of products derived from animals. In this sense, the search for alternative methods found in natural products has grown significantly in recent decades. Thus, the present study aims to evaluate the in vitro activity of the essential oil of Lippia origanoides "Camphora Chemotype" in ticks of the species Rhipicephalus (Boophilus) microplus and in Helminths of the species Haemonchus contortus and Caenorhabditis elegans. For this, fresh leaves of Rosemary-pimenta (L. origanoides) were obtained from naturally occurring adult plants in the municipality of Montes Altos, Maranhão, Brazil. The essential oil was extracted from the leaves of L. origanoides by means of hydrodistillation and the analysis of the chemical constituents was performed by gas chromatography (GC-MS). To evaluate the acaricide activity on R. (B.) microplus, the Larval Immersion Test was performed using concentrations of L. origanoides essential oil ranging from 10 to 0.40 mg/mL in a solution of 1% ethanol + 0.02 % Triton, where a 50% Lethal Concentration (LC50) of 7.48 mg/mL was obtained. To evaluate the repellent activity on R. (B.) microplus, the Vertical Repelence Test was performed at concentrations ranging from 1.25 to 0.001 mg/mL and for the positive control, N,N-Diethyl-m-toluamide was used. (DEET) at different times, obtaining for L. origanoides 50% Repellent Concentration (RC50) of 0.5844 mg/cm² (10min), 0.101 mg/cm² (20min) and 0.310 mg/cm² (30min). For the species H. contortus, the Egg Hatchability Test was performed, where eggs of H. contortus were counted and distributed in 96-well plates, at the rate of 100 eggs per well. Essential oil concentrations ranging from 10 to 0.005 mg/mL were used in 3% Tween, obtaining an LC50 of 0.67 mg/mL. For the species C. elegans, the adult mortality test was performed using essential oil concentrations ranging from 10 to 0.005 mg/mL in 96-well plates containing 100 µL of M9, obtaining an LC50 of 2.23 mg/mL. The Lethal and Repellent Concentrations of the tests carried out confirmed the acaricidal, repellency and nematicide activity of the essential oil of L. origanoides and its effectiveness against R. (B.) microplus, H. contortus and C. elegans.

  • Soil Chemical Indicators of the Humid Tropic that Determine Crop Productivity.

  • Data: 21/10/2022
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  • In soils of the humid tropics, specifically in the north of Maranhão, soil organic matter (SOM) and the sum of basic cations such as calcium (Ca), magnesium (Mg) and potassium (K) are one of the main indicators of soil quality. soil to assess sustainability and viability in agroecosystems. Therefore, the objective of this work was to identify chemical indicators in the soil of the humid tropics that correlate with corn productivity and that can contribute to the ecological intensification of agriculture in the region. The experiment was carried out in the community of Santa Rita do Vale, in the municipality of Santa Rita, in the northern region of the state of Maranhão, Brazil. The experiment consisted of evaluating two areas with a size of 1,680 m2 each, 24 points were evaluated at each depth, 24 points (0-15 cm) and 24 points (15-30 cm). In order to evaluate the attributes Ca, Mg, K, P, MOS, COT, COP, COAM and ECOT, four soil samples were collected per point, each repetition with a distance of two meters to the central point, to form a sample. composed. Corn yield was sampled in a 4 m2 (2m x 2m) area around each sampling point. Corn yield showed positive correlations with the variables COAM, Ca, Mg, Ca+Mg and P, in both soil depths. Except for K, which showed a positive correlation with productivity only at 15-30 cm depth. The MOS and COAM variables showed a positive correlation with the cations (calcium and calcium+magnesium) in the 0-15 cm soil layer. In the 15-30 cm layer of soil, only the COAM showed a positive correlation with calcium and calcium+magnesium. Overall, at 0-15 cm depth of soil, productivity showed a positive correlation with the indicators, COAM, Mg, Ca+Mg, Ca and K and negatively correlated with COP. The mean ratio of COAM:clay at 0-15 cm depth was (1:8.56). At a depth of 15-30 cm the average COAM:clay ratio was (1:8.67). The chemical indicators that determine corn productivity are organic carbon associated with minerals, magnesium, calcium and calcium+magnesium, potassium and phosphorus. MOS and COAM showed interactions with calcium and calcium+magnesium. The COAM:clay ratio at 0-15 cm depth was 1:8.34 and at 15-30 cm depth it was 1:8.76, considering the soil of good structural quality. We determined that the critical value of calcium is 20 mmolc dm-3 and that of COAM is 15 g kg-1 for the depth of 0-15 cm and in the depth of 15-30 cm the critical value of calcium is 20 mmolc dm- 3 and COAM of 15 g kg-1.

  • Impacts Caused by Anthropogenic Changes in Soil Under Different Managements in the Cerrado Maranhense

  • Data: 28/01/2022
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  • The Cerrado is the last agricultural frontier in Brazil and its biodiversity is threatened by the degradation of extensive pastures. The aim of this study was to evaluate the chemical, physical and biological attributes of extensive pasture (PE), abandoned pasture (PA) and forest (FL) in the Cerrado Maranhense, in order to measure anthropogenic impacts. In a completely randomized experimental design, with three areas and five replications, the atributes evaluated, at depths of 0-5 cm, 5-10 cm, 10-20 cm and 20-30 cm, were: soil density (DS), total porosity (PR), mass-based moisture (UMM), volumetric moisture (UMV), mechanical resistance to penetration (RSP) and basic infiltration velocity (Vib), potassium (K+), calcium (Ca+2) , exchangeable magnesium (Mg+2) and aluminum (Al+3), phosphorus (P), hydrogen potential (pH), potential acidity (H+Al), organic matter (MO), organic carbon stock (ECO), sum of bases (SB), effective cation exchange capacity (t), cation exchange capacity at pH 0.7 (T), base saturation (V) and aluminum saturation (m), litter and macrofauna. The results were compared by ANOVA and difference of means by Tukey (p&gt;0.05), with Principal Component Analysis (PCA) as complementary analysis for the chemical attributes. The PA and PE land uses were positively correlated with the sorting complex, while FL was positively correlated with the acidity indices. There was a significant interaction between land use and depth only for the chemical attributes Al+3, m, M.O. and P and ECO with PA area standing out from other surface treatments. For physical attributes, only RSP showed statistical difference, with the greatest resistance in PA at 5-10 cm, and greater resistance in FL under depth. The smallest means of RSP were observed in PE. There was no statistical difference between the density and richness of individuals for macrofauna, in the evaluated land uses, but the greatest abundance of Hymenoptera and Blattodea was observed in FL.


  • Data: 21/12/2022
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  • Adequate levels of nitrogen supplementation in Agrosilvopastoral systems can provide mutual gains between system components. The objective was to evaluate the soil attributes and chemical composition of Megathyrsus maximus cv. Massai in an agrosilvopastoral system. The experiment was established in 2017 in 3 ha with the planting of massai (Megathyrsus maximus Jacq. cv. Massai) in intercropping with corn (Zea mays L.) between double rows of thrush (Mimosa caesalpiniaefolia Benth), in the spacing of 30 × 3 × 2 m, and babassu (Atallea speciosa Mart.). The experimental design was randomized in blocks with three replications. Each block of 1 ha was subdivided into four paddocks of 0.25 ha, with an average of 35 babassu palm trees/ha and 276 sabiá trees/ha. The treatments were 0, 100, 200 and 400 kg ha-1 year-1 of nitrogen (N), the fertilizations were with urea. Ring steers were used, with initial average body weight (BW) of 200 ± 35 kg, according to the put-and-take technique, with two test animals per paddock, and adjustment animals according to forage availability [2 kg green matter (MVS) kg PC-1]. Two soil collections were carried out (Aug/2020 and July/2021). The evaluation of soil attributes was carried out at five distances (0; 3.5; 7.0; 10.5 and 14 m) perpendicular to the double rows of thrush. Mini trenches (30 x 30 x 30 cm) were opened to collect undisturbed samples at depths of 0 ±10, 10 ±20, 20 ±30 cm, and density, macroporosity, microporosity and total porosity were analyzed. Deformed samples at the same depths perpendicular to the mini-trenches were collected for soil chemical analysis (P, K+, Mg+2 and Ca+2). The masai was evaluated from Jun/2021 to Feb/2022 every 28 days, and the total forage mass (MFT), percentage of green (%FV) and senescent (%FS), forage height and density (DF), green forage crude protein (PBFV) and senescent (PBFS), green forage mineral matter (MMFV) and senescent (MMFS); neutral detergent fiber from green (FDNFV) and senescent (FDNFS) forage; green (FDAFV) and senescent (FDAFS) forage acid detergent fiber, green (LIGFV) and senescent (LIGFS) forage (LIGFS) lignin. The SAS Proc Mixed program was used and the means of each treatment were compared using Tukey's test, at a 5% probability level. The distance from the tree component did not significantly influence (P<0.05) the physical attributes of the soil, however, there was a difference (P<0.05) for microporosity, treatments 0 and 100 Kg N ha-1 year- 1 showed values 11.2% higher than the other treatments. For the chemical attributes of the soil, there was no difference (P<0.05) between the treatments, since the depths differed, the superficial layer (0-10 cm), were 31%, 8.82% and 23.53% of P, Ca2+ and k+ respectively higher than the other evaluated layers. The year 2020 showed lower concentrations of P, Mg+2 and K+ in the interaction of fertilization and distances. Forage mass was not influenced by fertilization levels (variation from 2128.21 Kg N ha-1 year-1 to 2203.03 Kg N ha-1 year -1. Lower percentage of green forage (51.50%) and higher senescent (48.89%) was observed in the treatment without fertilization. The percentages of MM, PB, NDF and LIG were not influenced by fertilization. January 2022 showed a higher value of MM (17.54% more), LIG was also higher in this month (31.07% more, together with the months of August and October 2022. The lowest value of PB was in July 2021 (24.43% lower). FDN was higher in August 2021 and February 2022 (15% and 12.15% higher respectively. The agrosivilpastoral systems under nitrogen fertilization, improves the physical and chemical conditions of the soil, providing the formation of macroaggregates. The chemical attributes, on the other hand, present relevant results, but require more time to be observed. Nitrogen fertilization had a positive influence on the production of MSV in agrosivilpastoral systems, as well as on the crude protein content of the forage, with treatments with higher protein applications having higher concentrations in the forage.


  • Data: 29/07/2022
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  • Psychoculture is an important economic activity that, in addition to generating income, produces food rich in protein, but it can be a polluting source, due to the presence of potentially toxic metals in its residues, these potentially toxic metals, when found in high concentration, contaminate soils and bodies. water receivers of these effluents cause several environmental problems. The biosorption process has proved to be effective to treat these effluents. This work aims to evaluate the biosorption potential of the biomass obtained from açaí (Euterpe oleracea) and cupuaçu (Theobroma grandiflorum) epicarp in the form of activated carbon with an acid solution of hydrochloric acid in a filter in the treatment of this effluent. The biomasses were characterized by the following chemical variables: pH in water, pH in KCl, zero charge point, and determination of acid and basic groups present on the surface. First, an assay was carried out in a fixed-bed column, with distilled water, until there was saturation of the biosorbents, after which the biosorption assay was started. The filtration system was kept in continuous flow until there was saturation of the biosorbents, the effluent was collected after obtaining a volume of 50 mL and stored in dark-colored flasks to determine the concentrations of the metallic species Cu2+, Cd2+, Zn2+, and Mn2+ by Flame Atomic Absorption Spectrometry (FASS). The test performed observed considerable efficiency of the biomasses in the removal of the investigated metallic species.


  • Data: 16/12/2022
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  • There are several methodologies available to analyze the GxE interaction and the choice will depend of several factors. The GGE Biplot and REML/BLUP methods have been used together to investigate the interaction in several annual crops, however there are no reports for sorghum. In view of this, the objective is to evaluate the adaptability and stability of sorghum genotypes aiming at biomass production in the cerrado of southern Maranhão by the REML/BLUP method and GGE biplot. The trials were conducted in Balsas - MA in the second harvest of 2021 and 2022, arranged in DBC with three replications and ten treatments, with the following cultivars: Sudão, AGRI 001-E, AGRI 002-E, BRS 658, BRS 810, BRS Ponta Negra, BRS 373, BR 509, BR 506 e IPA 467-4-2. The production of green matter and dry matter in t ha-1 were evaluated. Model significance was estimated by deviance analysis. The estimates of variance components were determined by the REML (Restricted Maximum Likelihood) procedure and adaptability and stability of genotypes were determined by the BLUP (Best Linear Unbiased Prediction) procedure under harmonic means and by biplot GGE techniques. For analysis under harmonic means, the SELEGEN REML/BLUP program was used. For the GGE biplot analysis, the R statistical software was used. Through the simultaneous evaluation of productivity, stability and adaptability (MHPRVG), the genotypes BRS Ponta Negra, AGRI 002-E, BRS 506 and BRS 509 remained among the first positions in the ranking, demonstrating increased adaptability, stability and productivity. Through the GGE biplot it was possible to identify four genotypes with performance above the average of the environments, namely G6 (BRS Ponta Negra), G9 (BRS 506), G3 (AGRI 002-E) and G2 (AGRI 001-E), however, G9 and G2 had high instability. Thus, for the environmental conditions of Balsas-MA and considering both methodologies under study, the BRS Ponta Negra cultivar proved to be the cultivar with the greatest potential for recommendation, followed by the AGRI 002-E and BRS 506 cultivars


  • Data: 28/07/2022
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  • The brown stink bug, Euschistus heros (Fabr., 1974) (Hemiptera, Pentatomidae) is considered one of the most important soybean pests and has chemical control as the main management method. However, with the many problems that chemical control can cause, the use of the association of biological control agents such as entomopathogenic fungi and the egg parasitoid, Telenomus podisi (Ashmead, 1893) (Hymenoptera: Scelionidae) in soybean crops can be a sustainable alternative. In this sense, the objective of the research is to evaluate entomopathogenic fungi that are efficient in the developmental stages of E. heros (egg, 3rd nymphal instar and adult) so that they do not affect the parasitism carried out by T. podisi. The entomopathogenic fungal isolates used were from the species of Metarhizium anisopliae (CG 168, IBCB 425) and Beauveria bassiana (LPP 129, LPP SP1). The research was carried out in the Entomology and Phytopathology laboratories of the Universidade Estadual do Maranhão, Campus São Luís, MA. The insects used in the experiments came from breeding maintained in the Entomology laboratory and the entomopathogenic fungal isolates were acquired from Instituto Biológico de São Paulo, Embrapa Arroz e Feijão and Universidade Estadual do Norte Fluminense. The entomopathogenic isolates were cultivated in potato-dextrose-agar (PDA) medium for 15 days and later multiplied in parboiled rice used as substrate. After multiplication, suspensions of fungal isolates were prepared at a concentration of 1 × 108 viable conidia/mL+ 0.01% Tween 80® from rice washing. The suspensions were used in two experiments, that of pathogenicity and virulence of isolates on the brown stink bug and that of selectivity of M. anisopliae on T. podisi. In the first experiment, 50 eggs, 25 third instar nymphs and 25 couples of E. heros were treated with the fungal suspensions. In the second experiment, two bioassays were set up using 50 non-parasitized (pre-parasitism) and parasitized (post-parasitism) eggs fixed with white glue on a cardboard sheet (n=20) treated with 2.5 mL of M. anisopliae (CG 168 and IBCB 425). E. heros eggs were susceptible to CG 168 and IBCB 425 isolates. All isolates were pathogenic for 3rd instar nymphs, with LPP 129 and CG 168 being the most virulent with a mortality rate of 82% and 86%, respectively within four days. The proportion of viability of 4th instar nymphs was higher in isolates IBCB 425 (0.62) and LPP S1 (0.79). The treatments Tween 80® (16,30) and LPP 129 decreased the number of eggs in females. The isolates IBCB 425 and LPP S1 increased the number of E. heros females laying. The isolate CG 168 caused a mortality of 96% in adults of E. heros in seven days. The parasitoid T. podisi parasitizes and develops in eggs of E. heros previously treated and not treated with M. anisopliae, with the isolate IBCB 425 being selective for the natural enemy of E. heros. All isolates were pathogenic for E. heros in the 3rd instar and adult nymph stages, however with different levels of virulence. The egg parasitoid, T. podisi, parasitizes and develops in E. heros eggs previously treated and untreated with M. anisopliae; The isolate M. anisopliae CG 168 was efficient in controlling E. heros in all stages of development (eggs, 3rd instar nymphs and adult), not being selective for T. podisi because it compromises the development of the parasitoid. The isolate M. anisopliae IBCB 425 was efficient in controlling eggs and adults of E. heros and selective for the parasitoid of T. podisi eggs in E. heros eggs.

  • Potential of Tree Legumes and Nitrogen Fertilization in Agrosilvopastoral System, in the Humid Tropic - MA

  • Data: 12/02/2022
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  • The presence of leguminous trees with the potential for biological nitrogen fixation can increase forage production and reduce dependence on chemical inputs in agrosilvopastoral systems. The objective was to quantify the biomass and nutrients of Massai and Sabiá grass and estimate the natural abundance of δ13C and δ15N via leguminous trees under different levels of nitrogen fertilization in an agrosilvopastoral system, in the humid tropics of Maranhão. The experiment was carried out at the Technological Reference Unit (URT) in Lavoura Pecuária Floresta Integration (ILPF) of the Brazilian Agricultural Research Corporation (EMBRAPA), Cocais unit, in the municipality of Pindaré Mirim - MA, Brazil. The experiment was established in 2017 on 3 ha with the planting of massai (Megathyrsus maximus cv. Massai) intercropped with corn (Zea mays L.) between double rows of sabiá (Mimosa caesalpiniaefolia Benth) at a spacing of 30 x 3 x 2 m. The experimental design was randomized in blocks with three replications. Each 1 ha block was subdivided into four 0.25 ha paddocks. The treatments were 0, 100, 200 and 400 kg/ha/year of N. Fertilizations were carried out with urea, in the rainy season. Nelore steers were used, with an average initial weight of 200 ± 35 kg, adopting the continuous grazing method with variable stocking rate, according to the put-and-take technique. adjustments according to forage availability. In the trees, the dendrometric variables (plant stand, stem length (CF), diameter at the base (DB), diameter at breast height (DBH), Lorey height (hL) and Volume), total aerial biomass (leaves and branches), basic density at the base (0.5 m) and at breast height (1.3 m), chemical composition (dry matter (DM), mineral matter (MM), organic matter (OM), crude protein ( CP), nitrogen (N), carbon (C), C:N ratio, neutral detergent fiber (NDF), acid detergent fiber (ADF) and Natural abundance of δ13C and δ15N, and derived nitrogen of air (Ndda). Animal performance was evaluated through stocking rate (TL), average daily gain (ADG), average gain per area (GPA) and forage through total forage mass (MFT), percentage of green forage (%FV). ) and senescent (%FS), forage density (DF), green forage crude protein (PBFV) and senescent (PBFS) and green forage mineral matter (MMFV) and senescent (MMFS). The SAS Proc Mixed program was used and the means of each treatment were compared using the Tukey test, at a 5% probability level. There was no significant difference (P>0.05) between the levels of fertilization for the dendrometric variables, total area biomass, basic density, chemical composition and δ13C, but there was a difference (P<0.05) between the evaluation periods. The stand reduced from 180 to 165 plants/ha, between the first and second evaluations, respectively. The CF (5 to 7 m); DB (8 to 9 cm); DAP (6 to 7 cm); hL (5 to 7 m); volume (0.5 to 0.9 m3); biomass in the leaf fraction (23 to 206 kg.ha-1); biomass in branches with circumference <4.9 cm (675 to 996 kg.ha-1); with circumference 5-10 cm (696 to 1164 kg) and circumference >10 cm (increase from 2014 to 3716 kg) were higher in the second evaluation. The basic density at the base and at breast height varied from 0.7 and 0.5 g/cm³, in the first evaluation, to 0.79 and 0.72 (g/cm³, in the second evaluation. In the chemical composition of the leaves, the MM, N and CP concentrations were higher in the second evaluation period with 108, 26 and 165 g kg-1, compared to the first (65, 19 and 129 g kg-1 respectively). was higher in the first evaluation compared to the second (13).In the branch fraction < 4.9 cm, the DM, MM and C:N contents were higher in the first evaluation with 46.47, 492.0 and 74 g kg-1 , in relation to the second (36, 27 g kg-1 and 56), while OM and N (973 and 8 g kg-1 respectively) were higher in the second evaluation compared to the first (952 and 6 g kg-1 respectively In the branch fraction 5 -10 cm, MS and C:N were higher in the first evaluation with 52 g kg-1 and 77 than in the second one (42 g kg-1 and 62 respectively), and the N was higher in the second evaluation. with 7.2 g kg-1. In the branch fraction >10, there was significance for variables, MM concentrations, MO and N with 20; 980; 7 g kg-1 respectively were higher in the second evaluation compared to the first (15, 985 and 6 g kg-1 respectively). δ13C did not differ between fertilization levels, but δ15N was higher in treatments of 200 and 400 kg/N/ha/year with 1.04 and 1.73 ‱ respectively, Ndda was higher in treatments of 0 (76, 77%) and 100 (56.84%) kg/N/ha/year. There was no significant difference (P>0.05) between the levels of fertilization for animal performance (TL, ADG and GPA), MFT, %FV, %FS and chemical composition. Between the evaluation periods there was significance (P<0.05) for all variables, the TL ranged from 3.4 to 5.1 Ua between June/2020 and February/2021. The GMD and GPA were higher in the periods with the highest rainfall, ranging from 0.03 and 0.1 to 0.75 and 3.4 in the months of August/2020 and April/2021 respectively. The MFT ranged from 552 (August/2020) to 2216 kg/ha (February/2021). The %FV in the months of November and December/2020 and January and March/2021 was higher than the other months, reaching 87, 94, 81.86%, on the other hand, %FS was higher in the months of August, September and October with 64 , 62, 70%. The DF ranged from 14 (December/2020) to 84 kg of DM ha-1 cm-1 (February/2021). PBF concentrations ranged from 83 (October/2020) to 118 g kg-1 (March/2021), while PBFS differed only in June/2020 with 47 g kg-1. The MMFV differed only in March and April/2020 with 124 and 127 g kg-1, and the MMFS was lower in the months of Nov/2020 and Jan/2021. Fertilization did not differ in forage production and animal performance. In the agrosilvopastoral system, the different levels of nitrogen fertilization did not influence the dendrometry, biomass area, basic density and chemical composition of the thrush. The biological N fixation of the sabiá in the agrosilvopastoral system was higher at the levels of 0 and 100 kg of N ha-1 yr-1. The inclusion of leguminous trees in massai pastures resulted in significant increases in the CP contents of the pasture.

  • In vitro cultivation of Barbatimão: Native plant with medicinal properties.

  • Data: 29/10/2021
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  • Stryphnodendron astringens (Mart.) Coville, with popular name barbatimão, is native to the Brazilian cerrado with prominence in herbal medicine due to medicinal properties attributed by secondary metabolites present in the species. This study aimed to verify the influence of the culture medium on germination and production of phenolic acids and flavonoids of barbatimão, using the in vitro propagation technique, and the results compared to cultivation under greenhouse conditions. In the first experiment, barbatimão seeds obtained by donation and preserved under aseptic conditions were germinated in vegetation house conditions (control)
    and in vitro using as culture media: MS + 100 mg L-1 myo-inositol + 30 g L-1 sucrose + 6.5 g agar (T1); Distilled water + 30 g L-1 sucrose + 6.5 g agar (T2); MS + 11.09 μM 6- benzylaminopurine (BAP) + 0.54 μM naphthalene acetic acid (ANA) (T3); MS + 1.44 μM of gibberellic acid (GA3) + 0.54 μM of ANA + 100 mg L-1 of myo-inositol + 30 g L-1 of sucrose + 6.5 g L -1 of agar-agar (T4); MS + 11.09 μM BAP + 0.54 μM ANA + 100 mg L-1 of myo- inositol + 6.5 g L -1 of agar-agar + 1 g L-1 of activated carbon (T5). After 60 days germination, the following variables were evaluated: number of leaves (NF, units), height of the aerial part (APA, cm), length of the largest root (CR, cm), difference between fresh and dry mass of the aerial part (MPA, g), difference between fresh and dry mass of the root (MR, g) and average width of the leaves (LF, cm). The data were submitted to Dunnet's test at 5% possibility. In the second experiment, the methanolic extracts (hydromodule 1:8) of barbatimão leaves were obtained for the control and T1 to T5 treatments, and then the chromatographic profiles were obtained from the readings of the extracts by means of high-performance liquid chromatography (HPLC-PDA), where the representative peaks of the spectra in the UV for phenolic acids and flavonoids were verified. The results obtained indicated differences between treatments for the variables APA, CR and MR, where the in vitro treatment T5 was superior in the development of the aerial part and root length of the seedlings. The data obtained for the variable MR showed that the in vitro treatments were not efficient for root mass production compared to the control. The T5 treatment was superior in the production of phenolic acids and flavonoids compared to the other in vitro treatments, with results close to control, indicating promising results to produce secondary metabolites of medicinal interest in homogeneous conditions and low environmental impact in barbatimão.

  • Efficiency of Brachiaria (Urochoa brizanta) associated with arbuscular mycorrhizal fungi as a potential for phytoremediation of soils contaminated with zinc, manganese and copper  

  • Data: 29/10/2021
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  • The use of fertilizers and other pesticides to meet the nutritional requirements of crops and increase production has, in some cases, generated an increase of hundreds of tons of potentially toxic metals to the soil, thus contributing to its impoverishment. However, some plant species are able to survive and adapt to environments contaminated with potentially toxic metals, in addition to removing large amounts of pollutants, characterized as phytoremediation plants. Experimental used was completely randomized (DIC) in a 5x2 factorial, with 5 doses of metallic species in the form of PA salts (0, 10, 20, 40 and 80 mg kg-1 ) and 2 inoculations of FMA (with and without FMA), totaling 10 treatments with 4 repetitions, resulting in 40 experimental units. The soils were incubated with the metallic species investigated in the form of P.A salts at doses 0, 10, 20, 40 and 80 mg kg-1. The determination of the percentage of organic matter was made by calcination at 550°C. In determining the cation exchange capacity, the method proposed by Cotta et al. (2006). Parameters were also determined: plant height, root length, chlorophyll index, shoot fresh matter, shoot dry matter, root dry matter, % root colonization and uptake of phosphorus, nitrogen and potassium. The extraction of bioavailable metals from the soil before and after planting was carried out using a 1 mol L-1 HCl extracting solution. Data were subjected to analysis of variance using the R statistical program and the comparison of means was performed using the Tukey test at 5% probability. Urochiloa brizantha showed good development in soil contaminated with different dosages of heavy metals. The soil had a low percentage of organic matter, characterizing itself as an inorganic soil. The metal that represented more bioavailability was Zn2+ with 473.867 mg kg-1 in doping and 80 mg kg-1 followed by Mn2+ with 190.508 mg kg-1 in 10 mg kg-1 doping and the one that was less bioavailable was Cu2+ with 2 mg kg-1. It was also observed that in the 20 and 40 mg kg-1 dopings, the F.M.A influenced the metal complexation in the soil, causing it to leach a lower concentration of metals.

  • Morphophysiology of Pineapple CV. Pearl in Photomixotrophic Culture in Vitro and in Ex Vitro Condition
  • Data: 29/10/2021
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  • Pineapple (Ananas comosus) is a fruit consumed worldwide and represents a source of employment and income for several countries. To meet the demand for fruit, it is always necessary to have an intense supply of seedlings. Micropropagation is a technique used to increase the production and quality of seedlings in less time. Thus, this research aimed to verify whether the photoautotrophic/photomixotrophic environment can provide, in explants, optimization of photosynthetic capacity and growth, by reducing the concentration of sucrose in the culture medium, optimizing gas exchange and increasing photosynthetically active radiation (RFA). The experiment was carried out in a completely randomized design (DIC), 2x4 factorial scheme, with two types of sealing (covers with gas-permeable membranes and without this membrane) and four concentrations of sucrose (0, 10, 20 and 30 g L- 1), totaling 8 treatments, with five repetitions each. The experimental unit consisted of a flask containing 3 plants. After 90 days of in vitro cultivation, shoot length (CPA, cm), number of leaves (NF), length of the longest root (CMR, cm), leaf area (AF, cm2), specific leaf mass ( MFE, g m-2), fresh and dry mass of aerial and root parts (MFPA, MSPA, MFR, MSR, g, respectively), total dry mass (MST, g), photoassimilates partition for root (PFR, %) , photoassimilate partition for shoot (PFPA, %), shoot dry mass to root dry mass ratio (MSPA/MSPR), maximum quantum yield of photosystem II (PSII, Fv/Fm), the "Photosynthetic Index" (photosynthetic index) (IF), density of active PSII reaction centers per unit of absorbed photons (RC/ABS), net photosynthetic rate (A, μmol CO2 m-2 s-1), SPAD index, photosynthetic pigments (chlorophyll a, b, total, carotenoids, chlorophyll a/b, chlorophyll (a+b)/carotenoids (μg mm-2) and stomatal index (%) At the end of 90 days of in vitro cultivation, five plants of each treatment o were acclimatized in a greenhouse. During acclimatization, the net photosynthetic rate (A), the maximum quantum yield of photosystem II (PSII) (Fv/Fm), the photosynthetic index (IF) and the SPAD index at 5, 10 and 15 days after acclimatization ex vitro. In this work, it was possible to verify that the total elimination of sucrose from the in vitro culture medium, even using permeable membranes, the pineapple cv. Pearl did not produce biomass. With the use of permeable membranes and the reduction of sucrose to 10 g L-1 in the culture medium, there was a greater length of shoot, leaf area, increase in shoot fresh mass, a higher photosynthetic index, and larger torso of chlorophyll a, total and carotenoids. This gain in biomass production in the treatment flask with membranes and 10 g L-1 was not associated with greater photosynthetic carbon assimilation. For the photomyxotrophic cultivation of pineapple in vitro, the use of permeable membranes and sucrose concentration in the culture medium of 10 g L-1 is indicated.

  • Ecophysiological responses of Eucalyptus under Inoculation of Ceratocystis fimbriata
  • Data: 23/12/2021
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  • Eucalyptus is a kind of fast growing cycle and widely used for the production of cellulose and paper. In recent decades, the expansion of cultivation has registered an aggressive increase in diseases in nurseries and forest plantations. And one of the most serious diseases that the Eucalyptus crop has been facing is wilt caused by the fungus Ceratocystis fimbriata. This fungus, when colonizing the plant, will obstruct the vascular system, and in response the plant forms tylos, gels or fungal material, which will promote the physical blockage of the xylem vessels and increase the resistance to the flow of water from the roots to the leaves, inducing the plant to water stress. As a result, the physiological functioning of the plant will be affected and its growth reduced, causing the plant to have symptoms such as wilt, cankers and root rot, which may even lead to death. Thus, this study aimed to evaluate the ecophysiological responses of Eucalyptus spp. inoculated with the fungus C. fimbriata. The treatments used were the isolates LPF 1512, 1806, 1607, 1657, from São Paulo, Minas Gerais, Bahia, Mato Grosso do Sul, respectively, and a control treatment, using only distilled water. Isolates of C. fimbriata were cultivated in a Petri dish filled with PDA culture medium (200g of potato, 20g of dextrose, 17g of Agar and one liter of distilled water), in a BOD-type incubator, at a temperature of 25 ± 1 °C and 12-hour photoperiod for 15 days. At the end of the fungal growth period, the suspension for inoculation was prepared, adding 10 mL of distilled and sterilized water to the plates with the fungal growth. With the aid of a sterilized Drigalsk loop, the surface of the fungal colony was scraped to obtain the suspension of the spores. Inoculation was carried out on the plants 60 days after planting. With the aid of a scalpel, a longitudinal incision was made in the epidermis of the plants with approximately 1 cm in length and 0.2 cm in depth and at a height of three centimeters from the plant's neck. 500 μL of conidia suspension is applied with an automatic pipette. After inoculation, analyzes of growth, gas exchange, leaf temperature and chlorophyll a fluorescence were performed. The study suggests that the resistance to water flow in the xylem vessels, imposed by colonization by C. fimbriata in the Eucalyptus clone VCC 795, regardless of the isolate used, resulted in a water deficit in the leaves and resulted in a reduction in gas exchange, in addition to impair photosynthetic performance, observed through reductions in active reaction center density (RC/ABS) and photosynthetic index (Pi), and all these triggered mechanisms resulted in a reduction in plant growth. In addition, the fungus severity analysis indicates that of the isolates used in the study, LPF 1657 was the one that most affected the physiology and growth of plants of the Eucalyptus clone VCC 795, a fact that was confirmed by the lower height values, A , gs and E, in plants inoculated with this isolate.


  • Data: 08/07/2021
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  • Knowing the influence of mineral nitrogen fertilization on agroforestry systems and its effects on soil attributes and forage production, as well as its role in the nutrient cycling process, is essential to promote the efficient use of nutrients in this ecosystem. Thus, the objective was to evaluate the effects of mineral nitrogen fertilization and forestry component on forage production, physical attributes and soil organic carbon fractions, on decomposition and chemical composition of Marandu grass litter and bovine excreta, in an agrosilvopastoral system , in the humid tropics of Maranhão. The experiment was conducted in 2019 and 2020, at the Technological Reference Unit - URT in ILPF of EMBRAPA Cocais in Pindaré Mirim - MA. A randomized block design was used, with four nitrogen fertilization treatments (0, 100, 200 and 400 kg of N ha -1 year-1
    ) and three replications in a total area of 3 ha divided into twelve equal plots kept under continuous stocking with two “tersters” animals, and with a variable stocking rate with “adjustment” animals, annealed steers with an average weight of 150 to 180 kg. For the purpose of evaluating forage production and soil attributes, samples were taken through transects perpendicular to the double rows of eucalyptus in each experimental plot. This
    was divided into five points: P1 (0 m), P2 (1.75 m), P3 (5.25 m), P4 (8.75 m) and P5 (12.25 m), which corresponded to the distances of the eucalyptus row. For each of these distances, the forage was collected to evaluate the production of dry matter of green forage (MSFV) and dry (MSFS) and then the mini trenches of 30 x 30 x 30 cm were opened to collect undeformed samples in the depths: 0 - 10, 10 - 20, 20 - 30 cm, to
    determine physical attributes (density, macroporosity, microporosity and total porosity).
    For the chemical attributes of the soil (organic carbon fractions), deformed samples were collected at the same depths perpendicular to the mini-trenches. To evaluate the decomposition of Marandu grass litter and bovine excreta, samples of senescent leaves and feces were used, which were incubated in nylon bags, in exclusion areas, and removed with 2, 4, 8, 16, 32, 64, 128 and 256 days, in 2019 and 2020. The chemical composition of Dry Matter (DM), Organic Matter (OM), Fiber in Neutral Detergent (NDF), Fiber in Acid Detergent (FDA), N, C, and C:N ratio were determined. The results of forage mass production in the green and dry fractions of the marandu grass did not differ (P> 0.05) due to nitrogen fertilization, however the green forage mass was influenced by the distance of the double row of eucalyptus, with less production of 1733 kg DM ha-1 , 49% of the total mass, closer to the trees. The different fertilization doses influenced the fractions of organic carbon, with values of 10.32 g kg-1 and 7.56 g kg-1 for COt, 1.94 and 4.13 g kg-1 for COp with the greatest increase in estimated dose of 203 kg of N ha-1 yr-1 and a decrease in COam with doses up to 278 kg of N ha-1 yr-1. The same happens with the physical attributes, with the exception of the microporosity that was not altered. Attribute values ranged from 0.54 to 0.56 m3 m-3 for total porosity, from 0.12 to 0.15 m3 m-3 for macroporosity and from 1.45 to 1.49g cm-3 for ulk density. ground. Forage production is reduced near the double row eucalyptus trees. Nitrogen fertilization modifies the physical fractions of the SOC, reducing its depth levels. The physical attributes were influenced under agrosilvopastoral system, improving the physical quality of the soil, in depth and along the distance of the planting lines. Litter decomposition between the years 2019 and 2020 was influenced by nitrogen fertilization, with a triple effect (P<0.0001) between the levels of fertilization x time x year. The average speed of decomposition was lower in the second year, with k = 0.00589925 g.g-1.day-1 against k = 0.00798675 g.g-1.day-1 in the first year. The average N mineralization in litter was 74% and 17% in feces, which provided an annual input of 146 kg N ha-1 yr-1 and 5 kg N ha-1 yr-1 kg N, respectively. There were no differences in the decomposition and chemical composition of excreta (P > 0.05) between doses and incubation time for the analyzed variables. Both materials, litter and excreta, presented a high C:N ratio, above 30:1, revealing the greater difficulty of degradation of the material. The different decomposition rate behaviors of litter and faeces fractions revealed the distinct capacity to support nutrients through environmental services, since the contribution via decomposition of these materials constitutes a promising production input against the possibility of cost reduction with mineral source of N.

  • Light intensity, type of sealing and sucrose concentrations in growth and development in vitro of pata-de-vaca (Bauhinia forficata Link)
  • Data: 28/10/2021
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  • The objective was to evaluate the light intensity, type of sealing and sucrose levels in the morphogenic parameters of the “Pata de vaca” (Bauhinia forficata Link) crop. A completely randomized design was used, in a 2x2x3 factorial scheme (two light intensities - IL, two types of sealing - TV and three levels of sucrose - NS). The light intensity being 43 or 70 μmol m-2s-1, the type of sealing with or without membrane and the sucrose concentrations of 0, 20 and 30 g L-1, totaling 12 treatments and 4 repetitions for each. B. forficata were obtained by donation, submitted to processes under aseptic conditions and packaged in paper bags for subsequent conservation in a refrigerator at 2 oC. In the laboratory, the seeds were subjected to aseptic conditions, then germinated in 350 mL disinfected glass bottles and kept for 30 days in a growth room. After these procedures, the evaluation began for a period of 45 days, using three nodal segments of the seedlings germinated in a 350 mL glass bottle, each bottle representing a repetition, which were distributed and submitted according to each treatment. At 30 days of culture, the shoot fresh mass (MFPA, g), shoot dry mass (MSPA,g), root fresh mass (MFR, g), root dry mass (MSR, g), plant length (CP, cm), leaf width (LF, mm), leaf length (CF, mm), number of leaves per plant (NF) and number of shoots (NB), were assessed. There were no significant differences in the ILxTVxNS interaction for any of the evaluated parameters. Significant differences were observed for the TVxNS interaction for the MRS variable, for the ILxNS interaction for the MPAS, MRS, LF and CF variables, and for the ILxTV interaction for the MPAS variable. A positive linear increase (P ≤ 0.05) was observed as the NS increased in the NB, CP, MPAF and MRF variables. TV influenced weight and size (P ≤ 0.05), with higher values being observed in the use of CM when compared to SM in the variables CP, MPAF, MRF, LF, CF and NF. Greater amount, size and weight (P ≤ 0.05) were observed in IL, in I70 they had more NB, CP, MPAF and MRF when compared to I43.

  • Use of  Rhizobacteria Isolates (Pseudomonas fluorescens) in the Removal of Cadmium in Agricultural Soils in the Region of Senador La Rocque-MA.

  • Data: 11/11/2021
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  • The objective was to evaluate the cadmium removal capacity through the rhizobacteria isolate Pseudomonas fluorescens, in soils with different cultivation intervals of a horticulture located in the municipality of Senador La Rocque-Ma. pHKCL, PHH2O, cation exchange capacity (CTC), organic matter content, zero charge point (PCZ). From the results obtained, it was possible to observe that the soils of the studied places have an acidic or very acidic character, thus retaining cations, presence of inorganic matter, low average cation exchange. The design used was in randomized blocks (DBC) consisted of 6 treatments (time 0, 2, 5, 10, 15 and 21 days), and 3 repetitions (area 1, area 2, 2 area 3), resulting in 54 sampling units, in a 6x3 factorial. After the experimental phase, the extraction of the investigated species was carried out, determined by Flame Atomic Absorption Spectrometry (FAAS), after which the removal rate and biosorption capacity were calculated and the averages observed were submitted to a factorial analysis of variance. Data were analyzed using the SISVAR® Program (Ferreira, 2019), using the Student's t test at 5% probability (LSD) to compare the obtained means. Among the investigated areas, areas 1 and 2 had the greatest decrease in cadmium concentrations by the bacterium Pseudomonas fluorescens, when compared to area 3 during the 21-day period. Area 1 achieved a maximum removal rate of 61.3% of cadmium with an equilibrium time of 21 days. In area, II the removal rate was 65.52% at 15 days and area III had the lowest removal rate with a maximum value of 27.42% removal at 21 days. The bacterium species used in the P. fluorescens study had a slow remedial potential, a fact that is probably related to particularities of the causative agent and the metal under study.

  • Detection of Babassu Palm Populations in Different Environments of the Maranhense Amazon Using Remote Sensing Techniques

  • Data: 29/10/2021
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  • Babassu extractivism has already stood out as one of the three main productive activities in the agriculture context in Maranhão state, which had relevance concentrated in the ecological, conservationist, political and social areas. But from the 70's onwards, this scenario began to change, giving rise to a historical conflict between farmers and agro-collectors of Babassu coconut. In the 90's the process of organizing and articulating women-coconut-breakers began, generating the first “Encontro Interestadual das Quebradeiras de Coco Babaçu”, which resulted in the “Movimento Interestadual das Quebradeiras de Coco Babaçu” – MIQCB. This movement contributed to an agenda of struggle for these women, which prioritized issues related to the preservation of the environment and guarantees of free access and common use of palm trees. Thus, the breakers got more force in the “free babaçu” laws. However, even though the MIQCB has united the breakers and gained strength in recent years, they still cannot control the pressure that acquired babassu areas are suffering from large agricultural enterprises. Given this assumption, the creation of public policies for the protection of the palm tree may be a way to perpetuate this traditional culture in Maranhão that generates livelihood mainly for these families that depend on Babaçu.

  • Performance of the Agrosilvopastoral System under Nitrogen Fertilization.
  • Data: 30/07/2021
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  • The objective of this study was to evaluate forage production, chemical composition and animal performance, biomass and carbon stock of trees and economic viability in an Agrosilvopastoral system under nitrogen fertilization. The research was carried out in the years 2019 and 2020 at the Technological Reference Unit (URT) of Integration Crop Livestock Flotesta (ILPF) of the Brazilian Agricultural Research Corporation (EMBRAPA), Cocais unit, located in the municipality of Pindaré-Mirim / MA, Brazil. An experimental area has about 3.0 ha, formed in pasture of Urochloa brizantha cv Marandu, formed in intercropping with corn (Zea mays L.) and eucalyptus (Eucalyptus ssp.). Divided equally into three blocks, each block with an area of 1 ha, which were subdivided into four paddocks of approximately 0.250 ha. Each paddock corresponded to a treatment: (I) control, without nitrogen fertilization; (II) application of 100 kg / ha / year of nitrogen (N), (III) application of 200 kg / ha / year of N; (IV) Application of 400 kg / ha / year of N. Fertilization with urea was divided into four equal doses during the rainy season, in May, June, July and August 2019 and in 2020, in the months of April, May, June and July, manually distributed. The paste method was continuous stocking, with variable load. The steers used had an average weight of 150 to 180 kg, with two animals "tersters" that will remain fixed in the plots, and a variable number of "adjustment" animals according to a forage offer that was adjusted every 28 days, together with the weighing of the animals for performance evaluation. The news from marandu was formed in the months of October, November and December 2019 and in the months of January, February, June, July, August and September 2020, where it obtained the Total Forage Mass (TFM), percentage of green forage and senescent. In the determined chemical composition, Dry Matter (DM), Ash (CIN), Crude Protein (CP) and Fiber in Neutral Detergent (NDF). No animals were measured Average Daily Weight Gain (GMD), Average Daily Gain per Area (GMA) and Stocking Rate (SR). In the arboreal component, 10 trees were selected per paddock, for the determination of diameter at breast height (DBH) of the bole, diameter at the base (DB), and one tree for estimation of total aerial biomass, fraction (leaves and bole), plant volume (V), CIN and Carbon (C) contents. In the economic evaluation, the calculation of the production cost was carried out, consisting of: Effective Operating Cost (COE); Total Operating Cost (TOC); and, Total Cost (CT). As a measure of economic result, the following calculations were performed: Gross Income (RB); Gross Margin (MB); Net Margin (ML); Net Income (RL); and, Leveling Point (PN). And the economic indicators: Net Present Value (NPV), Internal Rate of Return (IRR) and Benefit Cost Ratio (RBC). The highest value of dry green forage mass was observed in January with an average of 9.9 ton/ha and the lowest in July and August with an average of 2.0 ton/ha. There was no statistical difference (P>0.005) between nitrogen fertilization and forage mass production, as well as for GMD (highest gain in January with 0.61 kg UA-1 day-1) and GMA (highest gain in January with 3.5 kg AU-1 day-1). The TL were 4.2, 4.09, 4.07 and 3.87 AU/ha, in treatments 0, 100, 200 and 400 N kg/ha/year. The highest levels of CP were found in the treatment of 200 and 400 kg N/ha/year for green forage (14.07 and 14.48 g/g N) and for dry forage (10.56 and 10.45 g/ g N, respectively). The highest contents of CIN were in the doses of 100 kg N/ha/year (14.44%) and 400 kg N/ha/year (14.55%) in senescent forage and in green forage o better contents were in the doses of 200 kg N/ha/year (14.72%) and 400 kg N/ha/year (14.88%). NDF was higher in 400 kg N/ha/year (64.28%). The use of nitrogen fertilization in agrosilvopastoral system Formatado: Inglês (EUA) presented itself as an economically viable alternative. The dose that presented the maximum value of economic viability was 100 kg of N/ha/year. Because it obtained a lower cost than treatments with a dose of 200 kg of N/ha/year and treatment with 400 kg of N/ha/year. Where it presented better values for NPV considering the TMA of 19%, 27% and 40%; IRR with 103.59% and RBC of R$ 2.04.

  • Growth, tolerance and phytoremediation potential of Canavalia ensiformes L. in copper and zinc contaminated soil

  • Data: 27/10/2021
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  • Phytoremediation is an innovative proposal as an alternative methodology for the removal of organic pollutants, and the success of the technique depends on the careful selection of plants with favorable characteristics. Legume species exhibit favorable characteristics for growing rapidly in degraded soils, which is an important quality when considering the potential for phytoremediation of these contaminants. To reach the objective, bibliographical and experimental researches were carried out, organized in four chapters. Thus, this study aimed to valuate the physiological response, determine the tolerance and phytoremediation potential of C. ensiformes L. in increasing doses of copper and zinc in the soil. The experiment was carried out in a greenhouse, in a completely randomized design for both metals. The experiment was carried out in a greenhouse, in a completely randomized design for both metals. The soil was treated with four doses, in addition to the control of copper and zinc equivalent to (0, 10, 20, 40 and 80 mg kg-1), with four replications, the species used was C. ensiformes. The first chapter is a literature review on potentially toxic metals, copper, zinc, phytoremediation and C. ensiformes. The second chapter aimed to evaluate the physiological responses of C. ensiformes cultivated in soil with increasing doses of copper and zinc. The variables analyzed were: green intensity, photosynthetic index (PI) and count of the number of nodules. In addition, chlorophyll a fluorescence variables were analyzed: initial fluorescence (F0), maximum fluorescence (Fm), variable fluorescence (Fv) and maximum PSII quantum efficiency (Fv/Fm). The results were submitted to ANOVA and regression test (p<0.05). Regarding the chlorophyll a fluorescence, it was found that the individuals presented rates outside normal, indicating a stress condition, there was a decrease in the Fv/Fm ratio and in the intensity of green at the dose 80 mg kg-1. Photosynthetic indices revealed that C. ensiformes plants are sensitive to Zn and Cu contamination. Higher doses of metals caused fewer nodules. Therefore, it can be concluded that copper and zinc metals at high levels cause damage to physiological metabolism in C. ensiformes plants. The third chapter aimed to evaluate the phytoremediation potential of the species C. ensiformes cultivated in soil with increasing doses of copper and zinc. The variables analyzed were the growth morphometric: height, stem diameter and number of leaves, dry biomass and copper and zinc contents of shoot and root, translocation indexes and factors, bioaccumulation and tolerance. The plants of C. ensiformes during the experimental period were tolerant to the treatments used, however, doses of copper and zinc in the soil above 20 mg kg-1 reduced their growth. Zinc and copper contents were higher in shoots. The FT was greater than 1 for Zn showing that for this metal the plant was phytoextractor. Therefore, it can be stated that C. ensiformes is an economic and ecological alternative for metal remediation.

  • Importance of Environmental Variables on the Abundance of Rupela albinella Cramer 1781 (Lepidoptera: Crambidae), Parasitism of Telenomus sp. (Hymenoptera: Scelionidae) in Rice Crop with Molecular Characterization of the Parasitoid

  • Data: 30/11/2021
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  • The moth Rupela albinella Cramer 1781 (Lepidoptera: Crambidae), popularly known as white borer, is a notorious rice pest in the lowlands of the Brazilian state of Maranhão (MA), accounting for significant losses in crop productivity. This study aimed to determine the importance of environmental variables (namely, air temperature, rainfall, and photoperiod) on the abundance of R. albinella individuals and Telenomus sp. parasitism. Besides, a new parasitoid species associated with R. albinella had its molecular characterization done. The research was conducted in Arari (MA), during the 2019/2020 crop, between January and April, in a commercial irrigated rice field at different phenological phases (development stages). A light trap (“Model Esalq, 220) was employed to help collect the moths; whereas masses of R. albinella eggs were gathered manually, at different phenological rice stages. The abundance variation in R. albinella and Telenomus sp. was assessed through analysis of variance (one-way ANOVA). A simple linear regression analysis was applied to check the possible effects of abiotic variables (air temperature, rainfall, and photoperiod) on the abundance of these species. Furthermore, the COI barcode was used to identify Telenomus sp. The abundance of R. albinella did not differ as for the phenological stages of rice, and it showed no relationship with the abiotic variables. On the other hand, Telenomus sp. parasitism was distinct in the phenological rice stages, and a relationship with the photoperiod was noticed. Sequenced Telenomus sp. specimens exhibited an identical barcode region, with approximately 91% homology. In conclusion, the abundance of this new Telenomus sp. varied significantly in the R. albinella egg masses according to the phenological rice stages, and photoperiod alterations affected this parameter. The molecular characterization of Telenomus sp. indicated the need for taxonomic and systematic studies to update the of species that act as biological control agents in rice, aiming to establish the integrated pest management in the state.


  • Variation in Soil Attributes in Agrosystems in the Maranhense Amazon and its Relatios with the corn productivity.

  • Data: 30/07/2021
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  • The aim of this study was to determine the relationship between soil attributes, corn productivity and agroecosystem change, defining a management capable of increasing the potential for corn production in structurally fragile soils in the Amazon region of Maranhão. The experiment was carried out between November and May, between the years 2019 and 2020, in the municipality of Pindaré-Mirim, MA, Brazil. This study was divided into two experimental tests: Experiment 1 - Determined which and how soil attributes influence maize yield. For this evaluation, 119 georeferenced sampling points were delimited, in a uniform degree of 9m x 8m, totaling an experimental area of 1 ha. Corn production was sampled in 6 m2 around the sampling points. To determine the physical attributes, a 30x30x30cm trench was opened, close to each sampling point. Experiment 2 - Determined the influence of different agroecosystems on soil fertility. Four agroecosystems were taken, each with approximately 1 ha: Forest, Pasture, Crop and Agrosilvipastoral System. For this evaluation, three trenches similar to those of the previous experiment were opened, in each land use, distributed at random. To remove the deformed ones, twelve equidistant points were distributed around each trench on the four first cardinals. In both experiments, two layers were sampled: 0-15 and 15-30cm. The physical attributes (particle composition, Ds, PT, MIC and MAC and RP), the chemical attributes (pH, P, Ca, Mg, K, Na, H + Al, T, CTC and V%) and as fractions were superior physical organic carbon (COT, COP and COAM). In experiment 1, descriptive statistics of the data, the Shapiro-Wilk normality test and the Bartlett homogeneity of variance test, the Pearson correlation test and the multiple regression by the stepwise method were performed, both at 5% significance, in addition to of Ordinary Kriging with isoline maps. In experiment 2, the same normality and homogeneity of variance tests were performed, with subsequent analysis of means comparison using Tukey's test (α = 5%). The soil attributes that influenced maize yield were COAM, RP and pH, and indirectly the Ca contents. In fragile tropical soils, the agrosilvopastoral system represented an excellent strategy for conservation and environmental recovery.

  • Danilo Gualberto Zavarize
  • Synthesis of carbon-based heterogeneous acid catalyst obtained from Açai (Euterpe oleracea Mart.) seeds residues for the production of biodiesel from waste frying oil

  • Data: 17/02/2020
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  • The aim of this study was to conduct waste frying oil to biodiesel transesterification reactions with a carbon-based heterogeneous acid catalyst prepared from Açai (Euterpe oleracea Mart.) seed residues. The phases of the product (processed seeds, biochar, catalyst and spent catalyst) were physically, chemically and physicochemically characterized. Carbonization experiments considered the following factors: carbonization time (2.0, 4.0 or 6.0 h), carbonization temperature (180.0, 360.0 or 540.0 ºC), and chemical activator dosage (5.0, 7.5 or 10.0 wt.% of processed seeds), experimentally arranged in 27 observations in which their influence on the process was evaluated with statistical tests. For the experiments of biodiesel production, the following factors were chosen: oil to methanol molar ratio (10:30, 10:45 or 10:60), catalyst dosage (6.0, 8.0 or 10.0 wt.% of oil mass), reaction time (90, 150 or 210 minutes), temperature of reaction (55.0, 60.0 or 65.0 ºC), and stirring speed (400, 500 or 600 rpm), experimentally arranged in accord with Box-Behnken multivariate optimization method which resulted in 46 observations, evaluated with mathematical modeling and statistical tests. By applying the optimized data, experiments of optimization consistency, catalyst reuse, and performance comparison to conventional homogeneous catalyst were also conducted. The use of Acai seed residues as raw material for carbonization and acid synthesis was proven viable technically and financially, given the biochar yield of 84.21% and catalyst yield of 43.12%, costing about R$ 133,18 in local currency, with catalytic features equivalent and, per times, even superior, to that of other studies that explored different types of agroindustrial waste. Evidence of its catalytic power refers to the following points: (i) biodiesel yield varying from 45.90 to 97.14%, (ii) reuse capacity throughout 11 cycles with stable yield in the first five, (iii) higher yield compared to H2SO4 and KOH in homogeneous form catalyst (88.72, 84.95 and 52.93%, respectively), and (iv) the environmental advantages of using an agroindustrial waste that is often irregularly released into the environment. Furthermore, the multivariate numeric optimization showed that 37.64 mL of methanol, 8.25 wt.% of catalyst dosage, 209.9 min of reaction time, 60.7 ºC of reaction temperature, and 400 rpm of stirring speed would yield 89.0% of biodiesel, which was proven correct with consistency experiments that provided 88.73% of biodiesel yield, only 0.27% different from that suggested by the optimization.  

  • Data: 23/06/2020
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  • Studies on land use and occupation on larger scales are increasingly necessary, since they promote a more accurate diagnosis of the landscape, and thus contribute to the elaboration of plans for the land use, minimizing environmental degradation processes along hydrographic basins. The objective of this study is to identify and characterize the time-space dynamics of land use and occupation in the Rio Lajeado basin, state of Maranhão, which is fully inserted in the Cerrado Biome. Images from the Landsat-5 (TM) satellite, for the years 1986, 1996 and 2006 and Landsat-8 (OLI), for the year 2018 were used. The software QGIS 3.4.8 was used for the digital processing of the images and supervised classification of images using the Random Forest algorithm installed in this software. As for the accuracy of thematic maps, the AcATaMa plugin was used, in which we adopted the model of random sampling by extracts, that is, the samples generated take into consideration the proportion of the classified class in relation to the area. All classifications showed results of global accuracy greater than 80%. In the analyzed period, we noticed important changes, considering that in 1986 the area under study was occupied by 84.61% of natural formations, and as the years passed, this scenario was significantly modified, and in 2018 the natural formations represented 53.26% of the study area. There were also the emergence of two classes of land use and occupation, bananas and silviculture with eucalyptus plantations. Among the non-natural classes, pastures stood out, occupying an area of 43.18% in 2018, and becoming the largest driving force responsible for landscape changes in the Lajeado river basin. Therefore, the results obtained by remote sensing techniques are very important, since pasture, forestry and banana farming activities, close to water courses, can cause numerous environmental impacts, due to the deforestation process to introduce these new activities. Deforestation of natural formations can lead to loss of biodiversity and habitats, soil erosion, silting of streams and climate changing. Not only with deforestation, can there be environmental impacts, but we also have environmental impacts associated with the management of these activities, due to the use of pesticides, large use of water for irrigation of perennial crops, soil compaction due to cattle grazing, contamination of streams and soil by cattle faeces.

  • Implantation and growth of Khaya ivorensis in pure cultivation and consortium with agricultural crops

  • Data: 22/10/2020
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  • Agroforestry systems (SAF’s) represent socio-environmental concepts of great importance related to agricultural production, especially with regard to sustainability and biodiversity. In addition, the consortium production format enables productive diversification and the generation of income sources in many stages and sectors of production. One forest species used was Khaya ivorensis (African mahogany), which belongs to the family of meliáceas, and is in great expansion throughout Brazil. The objective was to evaluate the effects of intercropping agricultural crops (cowpea, corn and cassava) on the growth and survival of tree culture and the economic impact of this system on production. Three planting systems were studied: T1 - Conventional planting of African mahogany; T2 - Taungya system, composed of African mahogany + corn + manioc; and T3 - Taungya system, composed of African mahogany + beans + corn. To assess the economic return provided by agricultural crops, all production was sold on the local market. To evaluate the bean crop, the productivity of green pods was taken; average pod length; pod mass after harvest; number of grains per pod; productivity; dry mass of the aerial part of the plant. For corn, plant height was taken; ear productivity with and without straw; cob mass with and without straw; percentage of commercial ears; length, diameter and the mass of 20 commercial ears per plot. No cassava cultivation was obtained at plant height; stem diameter; number of bifurcations and root productivity. In the mahogany the rate of supply was evaluated, and the biometric data for height (m) and neck diameter (mm). The T2 treatment consortium system also differed from the conventional T1 treatment system. Treatments 2 and 3 (taungya systems), descriptively superior results for total soil bacteria, as well as amortized 25,23% and 20,63%, respectively, of the total costs of implementing maintenance of forest planting. There was no interference of agronomic crops in the growth of African mahogany. The results obtained that the cultivation of Khaya ivorensis in consortium with agricultural crops, when well managed, can be environmentally and economically advantageous for the rural producer.

  • Data: 29/05/2020
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  • In the municipality of Pindaré-Mirim and in other regions of the Amazon, the practice of converting native forests into pastures for traditional cattle ranching or agricultural areas, which quickly reach the stage of degradation, is predominant. In this sense, the work aims to measure the physical and chemical attributes of the soil in chronossequence of pasture in a crop-livestock-forest integration system, in Pindaré-Mirim, state of Maranhão, Brazil. For the purpose of evaluation, the experiment included two reference environments: capoeira with secondary vegetation in regeneration for approximately 20 years and native babassu forest with soils collected before the project started; and five succession seasons: degraded pasture, ILPF 2016, 2017, 2018 and 2019 that were compared with the reference environments. Undisturbed samples were collected to determine physical attributes (density, macroporosity, microporosity and total porosity) in the layers: 0-10, 10-20, 20-30 and 30-40 cm. For the chemical attributes (pH, MO, P, Al, H + Al, SB and V) of the soil, deformed samples were collected in the same layers. For the analysis of carbon content and stock, the analyzes included layers 0-10, 10-20, 20-30, 30-40, 40-60, 60-80 and 80-100 cm. With the data in hand, analysis of variance was performed and a means test was used (Tukey, 5% probability), and multivariate analysis (analysis of main components and grouping) was performed. Pasture in the second year of ILPF (2017) shows lower values of macroporosity and total porosity in all studied layers, however in ILPF 2019 it presented higher values of macroporosity. For layers 0-10, 10-20 and 30-40 cm, the phosphorus and base saturation variables showed higher values in ILPF 2018. The 20-30 cm layer in ILPF 2018 management showed higher values of P, MO, pH and microporosity. ILPF 2017 shows dissimilarity from other land uses from the point of view of soil physics variables, while ILPF 2018 was for chemical soil improvement. The increase in accumulated C stock (0-100 cm) in relation to Native Forest with the use of pasture in ILPF of 2018 after the corn-grass consortium was 16%. ILPF pasture in 2018 increased the carbon stock (0-100 cm) by 31% compared to degraded pasture (2016).


  • Data: 18/06/2020
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  • The rice stalk bug, Tibraca limbativentris Stal 1860, grain bug, Oebalus poecilus Dallas 1851(Hemiptera: Penatomidae), and the stalk borer, Rupella albinella Cramer 1781 (Lepidoptera: Crambidae), are reported as the most harmful pest insects for rice cultivation in Maranhão. The aim was to propose management strategies for T. limbativentris and O. poecilus from the diapause characterization, as well as to point out the parasitoid species of R. albinella eggs in the State of Maranhão. For this purpose, during the harvest and off-season (2018/2019) we performed monthly collections of T. limbativentris and O. poecilus in rice fields located in the municipality of Itapecuru-Mirim, MA. Collections were performed from the moment the species were observed in the field, 25 and 70 days after rice planting for T. limbativentris and O. poecilus, respectively. The stink bugs were collected through inspections on the plants and also with the aid of an entomological network. Subsequently, they were placed in glass containers, sacrificed in 70% alcohol and sent to the laboratory, where they were dissected for evaluation of the reproductive system and quantification of body fat content. Concomitantly, from January to April 2019, in rice fields located in the municipality of Arari, MA, R. albinella eggs were collected from inspections of rice plants. Collections were made 35 days after rice planting, when the species was observed in the field. The postures collected were followed up in the laboratory to record the emergence of parasitoids. After their death, they were preserved in 70% alcohol and sent to identify the species. Higher amount of T. limbativentris female stink bugs found during the harvest period presented 1/3 of fat, as well as a large amount of eggs, since the culture was present in the field. For males, it was noted that the abdominal cavity had 1/3 of fat and a developed reproductive system, indicating that the bedbugs were reproductive in this period. In the off-season, especially from June to September, there was a significant increase in the number of T. limbativentris females with 3/3 fat. For O. poecilus, it was observed that immature females showed population fluctuation similar to that of mature females. However, the number of mature females of O. poecilus was always higher. In all collections there was a predominance of O. poecilus males with 1/3 accumulation of fat and a developed reproductive system. For the first time the species T. podisi nov. sp. 1 was reported as a parasitoid of R. albinella eggs in Maranhão. A parasitism rate of 68.64% was observed and the number of parasitoids collected totaled 8,590 individuals. A parasitism rate of 68.64% was observed and the number of parasitoids collected totaled 8,590 individuals. It was concluded that T. limbativentris and O. poecilus migrate to the crop showing mature or immature reproductive organs, infest the crop during the harvest and, after harvest, can accumulate fat and present characteristics of diaphanous insects. It was also observed that T. podisi nov. sp. 1 occurs in Maranhão as an important parasitoid of R. albinella eggs, opening perspectives for this parasitoid to be studied in order to integrate biological control programs in rice crops in the state.



  • Data: 08/09/2020
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  • The objective of this study was to evaluate the behavior of different native plants from the Cerrado of Maranhão, ipe-purple (Tabebuia impetiginosa) and aroeira (Myracrodrun urundeuva) in phytoremediation of soil contaminated by Mn (II) and Zn (II) under greenhouse conditions. Soil collections were carried out in a preserved area in the city of Imperatriz-Ma and physical-chemical analyzes were performed: pH in water and KCl, cation exchange capacity, organic matter content, adsorption tests, efficiency calculations and analysis of their bioavailability. The results indicated that the soil has acidic characteristics, a tendency to retain cations, with low and medium cation exchange capacity, predominance of inorganic materials and minerals incorporated in the soil and that the metals Zn and Mn have a high content of bioavailability. For the phytoremediation experiment, Tabebuia impetiginosa and Myracrodrun urundeuva seedlings were grown in a greenhouse. A completely randomized design (DIC) was used, constituting 12 treatments with 3 repetitions, resulting in 36 experimental units. After the experimental period, metal extraction of the species was performed, metal determination by Flame Atomic Absorption Spectrometry (FAAS) and calculations of Bioconcentration Factor (BCF) and translocation factor (FT). The analyzes of variances for independent samples (ANOVA) were obtained, with the averages compared by the t test at 5% probability, the statistical analyzes were performed in the IBM SPSS Statistic.Among the species investigated, T. impetiginosa presented a biomass production (aerial part / root) greater than M. urundeuva in the period of 25 days. In the 45 day period, the root biomass was higher in T. impetiginosa in doped soil and the lower biomass production was verified in the control group of M. urundeuva. Regarding the content of Mn in the root, T. impetiginosa in the period of 45 days in doped soil obtained the highest concentration of the metal. With respect to T. impetiginosa, the Mn concentrations showed significant differences in the plant root over a 45-day period in doped soil 130.74 mg kg-1. In the aerial part, Mn showed higher concentrations in M. urundeuva in the period of 45 days in control soil, 335.80 mg kg-1 and in T. impetiginosa in the period of 25 days in doped soil, 256.10 mg kg-1. The highest concentrations of Zn in the root were observed in the 25 day periods of the doped soils of both species, with absorption of 142.10 mg kg-1 for T. impetiginosa and 150.57 mg kg-1 for M. urundeuva. In the aerial part the concentration of Zn was higher in the species M. urundeuva in doped soil in the period of 45 days 398.97 mg kg-1. For FT and BCF, T. impetiginosa showed efficiency in phytostabilization and
    phytoextraction for both metals. M. urundeuva had phytoextractive behavior during the 45 days of cultivation. In the period of 25 days in doped soil M. urundeuva behaved as a phyto-stabilizer, retaining and immobilizing metals in the soil. The two species studied showed good tolerance to manganese and zinc metals in soils.

  • Physical and chemical soil indicators as a result of land use change

  • Data: 05/08/2020
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  • Intensive land use has accelerated the loss of soil quality, a process that can be avoided by adopting conservationist production systems, such as the crop-livestock-forest (ilpf) systems. The effects of ilpf soil quality can be proven by evaluating various chemical, physical and of the soil during management. It is noteworthy that, in the southwest of the state of maranhão, a large part of the properties soils are degraded and in different stages of erosion, since these have been explored for decades with pastures implanted without using conservationist measures, or what a current situation degradation and low attempt. Therefore, the aim of this study is to evaluate the change in physical, chemical and biological attributes of the non-ecological cerrado-amazonian amazonian soil under the ilpf system, compared to the conventional pasture and secondary forest system. The study proposed here will be a pioneer in the region and may contribute to the inversion of the current degradation situation observed, allowing a sustainable exploration for the soils of a strategic region for the development of the state. The study will be carried out at fazenda monalisa, located in the municipality of são francisco de brejão, ma. The ilpf system was implemented in 2016, in an area of 70 ha, previously occupied with pasture. Adjacent to this area, there is a pasture area in the conventional system and a fragment of secondary forest. How the soil samples will be collected in the glove period and in the dry period, which includes the months of february and august 2019, at depths between 0-5, 5-10, 10-20 cm. The physical parameters will be selected: soil density, density density and total porosity, chemical products: ph in water and ph in cacl2, acidity potential, calcium, magnesium, phosphorus, potassium, exchangeable aluminum, organic carbon, cation exchange, sum of bases, base saturation and aluminum and biological saturation: soil respiration. The soil management systems will be compared between the multivariate analysis methods of the main components.

  • Data: 03/08/2020
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  • Insects are excellent models to study the effects of modified ecosystem on diversity patterns and ecosystem functioning, modifications being either human made or naturally occurring events. In Class Insecta, dipterans are appointed as bioindicators to be used in impact assessment and environmental monitoring, as they can provide responses to changes caused in their habitat by anthropization, vegetation gradient modification, and possibly by fire events. Therefore, faunal and ecological studies carried out in Chapada das Mesas National Park region are essential, as this Conservation Unit is located in a biodiversity hotspot, and has been suffering from anthropogenic disturbances, native vegetation loss and fires. Thus, our aim was to study patterns of species composition, richness and abundance of necrophagous fly communities (Calliphoridae, Mesembrinellidae and Sarcophagidae), verifying the possible effects of vegetation cover and fire events on species composition, richness, abundance and diversity of this fauna in Chapada das Mesas National Park. We observed that the communities of the three families sampled had a different distribution pattern according to the vegetation cover of each phytophysiognomy. The most opened environments were those with the highest estimated species abundance and species richness for families Calliphoridae and Sarcophagidae. Mesembrinella bicolor (Fabricius, 1805), the only species from family Mesembrinellidae found in this study, occurred only in forest phytophysiognomies (seasonal forest and riparian forest) and showed as a good indicator for these areas. Sarcophagidae, in general, had a higher occurrence in open areas due to its heliophilic behavior. In relation to the environmental variables, califorids had a higher relationship with the types of phytophysiognomies found in the park, and showed higher abundance on rainy days, while arcophagids were better adapted to the areas that had more fire events. Therefore, this work suggests directing efforts towards the conservation and preservation of the protected areas of the Chapada das Mesas National Park, which have been undergoing anthropization processes, in order to minimize the impacts caused on the scavenger dipter communities, as well as to understand better how changes in the fire regime can affect these communities, since it was observed in this study that fire can be an exclusion factor for many species of the group califorids + mesembrinelids, while favoring the colonization of areas burned by species of sarcophagids.

  • Luana Ribeiro de Andrade

  • Orientador : TIAGO MASSI FERRAZ
  • Data: 17/06/2020
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  •  Table cassava is significantly preferred in the Northeastern diet, especially in Maranhão, however, the average yield of the crop in the state is still low, whose yield is less than 8.5 t ha-1. This low yield is attributed to the lack of scientific information regarding productive management, since the production occurs mainly through non-technical knowledge, and the management of the fertilization of the crop is one of the factors that most lack information. In this context, an experiment was installed, under field conditions, with the objective of evaluating the morphophysiological and productive behavior of table cassava as a function of organic and mineral fertilizing in Mesoregion South of Maranhão state. The experiment was carried out in a randomized block design, arranged in a 5 × 2 factorial scheme, with four replications. The treatments resulted from the combination of five doses of cattle manure, with a C / N = 18/1 ratio, applied to the soil (0, 2.5, 5.0, 7.5, and 10.0 t ha-1) and two conditions of mineral fertilization (with and without NPK fertilization). Biometric characteristics (Height, stem diameter and number of leaves per plant), physiological (Green intensity and photochemical efficiency) and productive characteristics (Number of commercial and non-commercial roots, length and diameter of roots, root mass per plant and productivity) were evaluated, as well as the nutritional status of the plants. The results indicated that the fertilizer sources did not increase the biometric variables and green intensity, did not influence the physiological characteristics and did little to interfere in the extraction of nutrients by the plants. On the other hand, all components of production and productivity were increased by increasing doses of cattle manure and fertilization with NPK. Based on the results of the present study, fertilization with 10 t ha-1 of cattle manure and with NPK is recommended, because although there is no interaction between fertilizers, they act in a complementary way, increasing the production and productivity components of cassava table.

  • HABITAT SIMPLIFICATION: the effects on the insect community and its implications for environmental services 
    in the region of Balsas-MA
  • Data: 05/08/2020
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  • Agricultural expansion in the South region of Maranhao state, Brazil, has been impoverishing Cerrado biome landscape with soybean monocultures. It exerts a negative effect on richness of insect species that have been noted from changes in their composition. Insects have an important role in ecosystem services and they are useful for measuring ecological quality of environments. The present work evaluated the effect of habitat impoverishment on richness, abundancy and composition standards of insect species present in the entomofauna of a soybean monoculture area, compared to a legally protected area, all located in Balsas, state of Maranhao, Brazil. Insect sampling was carried out with Provid and Moericke traps, and also with active collecting using entomological nets. There have been two collection periods during the soybean phenological cycle: one during inflorescence and another during maturation, at the same time of the collections in legally protected area. An amount of 9345 insect samples was collected and classified in 15 orders, 93 families and 383 morphospecies. More abundant orders were Hemiptera, Hymenoptera, Dipteran and Coleoptera. Overall, field observations suggested that habitat impoverishment significantly reduced richness of species in the soybean monoculture, but did not seem to have a negative effect on abundancy. Species composition in the entomofauna of the four main sampled orders showed similarities between insect communities in the soybean monoculture and legally protected area, suggesting existence of insect rotativity. Scarabaeidae and Formicidae have confirmed their bioindicator potential in this study, since they presented themselves more diversified and abundant in the legally protected area. This study suggests that ecosystem services in these areas have contributions from the following insect families: Dolichopodidae, Carabidae, Formicidae, and Apidae. Thus, it is emphasized the importance of conserving vegetation in native areas of Cerrado biome next to agricultural lands.


  • Data: 22/08/2019
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  • Studies in soil seed banks are important for the proper use of environmental restoration
    techniques, particularly, the transposition of soil seed banks from a conserved area for later
    deposition in a degraded area of the same plant typology. However, this technique has as a
    prerequisite the evaluation of the local soil seed bank to understand the limitations existing in the
    ecosystem to restore vegetation in degraded areas. Thus, this research aimed to evaluate the soil
    seed bank in five areas with different management techniques located in the municipality of
    Açailândia, state of Maranhão, northeastern Brazil. The evaluated areas were: T1 - regenerated
    forest, T2, secondary forest, T3 - degraded pasture T4 - eucalyptus plantation area and T5 - fallow
    corn cultivation area. The methodology used was germination in trays in the greenhouse. Floristic
    composition was evaluated by species and family identification, floristic similarity between areas by
    Jaccard Similarity Index and floristic diversity by the Shannon Diversity Index (H'). Additionally,
    phytosociological analysis was performed to determine which species were the most important in
    the soil seed bank in each area by computation of the parameters density, frequency and
    importance value of each species (VI). Germination, species identification and number of
    individuals per species, according to life style, were evaluated every fifteen days, for 150 days. We
    identified 3,674 individuals belonging to 51 species of 33 genera and 21 botanical families. All
    species that germinated in the assessed period have a herbaceous life form, considered in the
    literature as weeds. The families Asteraceae and Malvaceae had the highest floristic richness with
    six species each. The highest germination density of the soil seed bank was observed in the fallow
    corn cultivation area (T5), with 3,620 plants m-2 followed by degraded pasture area (T3), with 1,813
    plants m-2, capoeira in regeneration (T2), with 1,676 plants m-2, eucalyptus plantation (T4) with 845
    plants m-2 and the regenerated forest area (T1), with 183 plants m-2. The most important species
    were Chamaesyce hirta in T1 (VI = 65.1); Corchorus aestuans, in T2 (VI = 84.9); Cyperus sp., in T3
    (VI = 49.9); Chamaesyce prostrata in T4 (VI = 43.8 and Corchorus aestuans in T5 (VI = 46.1) The
    highest floristic similarity was observed between the secondary forest and the eucalyptus planting
    area (40%) and between the secondary forest and degraded pasture (38%) The greatest floristic
    diversity was observed in T4 (H' = 2.59).The absence of perennial species and the predominance
    of herbaceous life form species, considered as weeds in the soil seed bank imposes serious
    restrictions. Therefore, the soil transposition technique of the researched areas for the recovery of
    degraded areas that are intended for use in agricultural activities is not recommended. However, it
    can be beneficial for extremely degraded environments, to promote the attraction.of pollinating and
    seed dispersing fauna, controlling erosion and improving physical and chemical characteristics
    favoring soil conservation.

  • Effect of the application of kaolin-based particle film on eucalyptus plants

  • Data: 11/03/2019
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  • With the expansion of forest plantations in the national territory and the imminence of the increase in temperatures due to global warming, it becomes relevant to approach technologies that favor survival and greater growth of seedlings after planting and consequently increase productivity in the field. The application of particle films based on calcined kaolin has been used as a protective barrier against the deleterious effects of solar radiation and excess temperature. The present project aims to evaluate the effects of the application of particle film based on purified calcined kaolin in eucalyptus plants, in vase and field conditions. In the two cultivation conditions, five treatments will be established: control (without application of the particle film), 3%, 5% 7% and 10% syrup volume. The application will be performed on the adaxial part of the sheets. The experimental design will be completely randomized, presenting five treatments with 10 replicates, totaling 50 experimental units for each cultivation condition. The plants will be evaluated for height, diameter at soil level, leaf temperature, gas exchange (photosynthetic CO2 assimilation, stomatal conductance and transpiration), water use efficiency, maximum quantum yield of photosystem II, green intensity and foliar ontogeny.


  • Data: 23/07/2019
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  • The extraction of wood was one of the main activities in the 1980s in the western Maranhense region, known as the portal of the Amazon. After this large-scale deforestation in this region, the forest environments have given way to pasture (cattle raising) and Eucalyptus spp (paper and pulp industry) plantations. The objective of this study was to evaluate the effect of the landscapes on the structure of the community of Diphtherodic Calliphoridae and Sarcophagidae in the region of West Maranhão, Brazil, in the municipalities of Açailândia, Cidelândia, Imperatriz and São Francisco do Brejão. . The study was carried out in four different landscapes (Pasture with forest species-PF, conventional Pasture-PC, Eucalyptus Plantation-PE and Fragment of Forest-FF) from September 2017 to September 2018. The collections using specific traps for Diptera necrophages and Van Someren-Rydon traps, were carried out in 20 areas, with five replicates in each landscape. A total of 22,807 muscoid dipterans were collected from 21 families, and the Sarcophagidae (7,866 ind., 34.49%) and Calliphoridae (1,754 ind., 7.69%) families were the most abundant. The Sarcophagidae family with 6,386 individuals was represented by 11 genera, 14 subgenera and 44 species. The most abundant species were Tricharaea (Sarcophagula) occidua (Fabricius, 1794) with 4,697 (73,55%) individuals, Peckia (Sarcodexia) lambens (Wiedemann, 1830) with 802 (12.56%) individuals, followed by Oxysarcodexia thornax Walker, 1849) with 242 (3.79%). Only the abundance of species T. (Sarcophagula) occidua (H = 15.1685 p = 0.0017) and Oxysarcodexia thornax (H = 15.9491; p = 0.0012) differed between environments. Regarding Frequency and Constancy Indices, three species were considered Common (7%), 15, Intermediate (34%) and 26, Rare (59%). In the Calliphoridae family, six genera and nine species were recorded. Chrysomya albiceps (Wiedemann, 1819) was the most abundant, representing 34.15% of the total collected, followed by Cochliomyia macellaria (Fabricius, 1775) (30.22%) and Chloroprocta idioidea (Robineau-Desvoidy, 1830) (23.55%). The abundance of Chrysomya albiceps (F = 13.4586; p = 0.0003), C. macellaria (F = 16.5148; p = 0.0001) and C. Idioidea differed among all environments (H = 15.5803; p = 0.0014). Three species were considered Common (33.5%), four Intermediate (44.5%) and two Rare (22%). The analysis of ordering (NMDS) and similarity (ANOSIM) showed that communities are distinct among all environments with respect to the composition of Diptera families (R = 0.909) and Calliphoridae families ((R = 0.816).) For Sarcophagidae, (NMDS) demonstrated in Axis 1, the formation of two clusters, one with the Forest Fragment and Eucalyptus Plantation environments and the other with the pasture environments. Although communities are not distinct among all environments, similarity analysis (ANOSIM) presented a significant value (R = 0.699) .The research demonstrated the expressive environmental plasticity of these families of necrophagous dipterans, due to the capacity to adapt to different environments. It should be emphasized that the pasture environment with forest species, anthropogenic, is more heterogeneous than conventional pastures, a fact that influenced the patterns of abundance and richness of these taxa, representing in this way, an important one in the strategy in the understanding of the processes of maintenance and conservation of species in the region. The present work also presents an indicative of three probable new species of Sarcophagidae, making clear the need for more collections in this western region of Maranhão, as well as the development of strategies for conservation of the areas, with the objective of conserving possible undiscovered species.


  • Data: 12/12/2019
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  • The intensification of products consumption by humanity obtains as a result the making of great amounts of solid residues which are commonly discarded in open air places named "lixões"¹. Among the effluents deposited in lixões are the heavy metals that, in some conditions, may act in a harmful manner, justifying studies over such substances. The Diptera from the family Calliphoridae, known as flies, are also found in urban rural and forest areas, attracted by substances in the process of decaying. Therefore, these characteristics attribute them the capacity of being used as bioindicators of anthropogenic interferences in natural environments. Consequently, this study aims to resort to Synanthropic fly species from Calliphoridae family as bioindicators of the concentration of metals potentially hazardous in anthropized territories (lixões). There has been used 200 traps for the capture of necrophagous Diptera in the surroundings of Balsas and São Raimundo das Mangabeiras (MA), making 100 in the areas of the towns' solid residues (lixões) and another 100 in Brazilian's protected Cerrado area. Moreover, there were also collected soil samples in the spots of the settlement of the traps. Succeeding this process, there was made the analysis of levels of potentially toxic metals, both in flies and in the soil samples gathered. There were collected 27.933 Diptera belonging to 11 families, from which 17.767 were in anthropized environment and 10.166 in Brazilian's protected Cerrado. The most abundant families were Muscidae (35,4%), Calliphoridae (23,5%), Otitiidae (20,9%), Sarcophagidae (16,1%) and Faniidae (3%). Out of the Calliphoridae family were collected 6.560 specimen, making 4.550 in the anthropized environment and 2.010 in Cerrado, sorted in 04 genera and 06 species, giving due prominence to Chrysomya megacephala (45,53%), Chrysomya albiceps (27,52%), Cochliomyia macellaria (11,36%) and Chloroprocta idiodea (10,38%). Excluding an anthropized area where were presented 10,40 %, another areas presented organic material rating less than 10%. The water's pH indicates that in the analysed soils, in general, contain acidic character. The pH in water was higher than the pH in KCI. ∆pH and PCZ revealed occurrence of negative charges in both environments. The anthropized environment showed larger concentration of the metallic species analyzed (Cd, Pb, Cr, Mn e Zn) both on the soil and in the flies, considering that the Cadmium's were below the quantity of detection in the ground. The same has happened to lead in flies in preserved environment. Both three species investigated from the family Calliphoridae (Chrysomya megacephala, Chrysomya albiceps e Chrysomya putoria) presented high potential of bioaccumulation for Cr, Mn e Zn. There was a tendency of better indication of metals by female specimen.


    ¹ landfills or garbage dump (in informal language), however, the denomination is considered a proper name in Portuguese. Therefore, it may not be translated accurately.

  • Glycine max, Glycine max, Salinity, Drought, Chlorophyll fluorescence, Gas exchange.

  • Data: 18/03/2019
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  • Soy has great value for the Brazilian agricultural sector, which, in turn, occupies a prominent position in the global scenario. However, abiotic effects of drought or salinity can have negative effects on plant development and productivity. Therefore, with the objective of selecting soybean genotypes with greater tolerance to water and saline stresses, two experiments were carried out, being water stress and saline stress in soybean genotypes, following a completely randomized experimental design, with a factorial arrangement of 8×3, with 5 replicates. For water stress, eight soybean genotypes and three stress treatments (control, moderate dry and severe dry) were used. For saline stress, the same water stress genotypes and three conductivity levels were used in the irrigation water, 0.8 dS m-1 (control), 4.0 dS m-1 (moderate salinity) and 8.0 dS m-1 (severe salinity). The parameters of growth, gas exchange, photochemical efficiency of photosystem II and photosynthetic pigments were evaluated. Stresses significantly reduced the physiological processes of photosynthesis and plant biomass productivity due to stomatal closure factors. Plants M8349, BMX Bonus and RK8317 obtained better performance in moderate drought conditions while M8808 plants can be grown under severe water stress. For salinity, BMX Bonus and RK8115 present high tolerance to irrigation with moderate salinity water and genotype M8349 developed better in severe salinity. The soybean genotypes studied presented a higher average tolerance to moderate salt stress than moderate drought. The genotypes M8349, BMX Bonus and RK8317 can be grown on soils with moderate water availability, and genotype M8808 can be grown under severe water stress. The BMX Bonus and RK8115 genotypes present high tolerance to irrigation with water with electrical conductivity ≤ 4.0 dS m-1 , and genotype M8349 is best developed when irrigated with water with electrical conductivity around 8.0 dS m-1 . Genotypes tolerant to water and saline stress can be widely used in breeding and breeding programs to develop new cultivars with higher yields in environments with adverse conditions.


  • Data: 02/09/2019
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  • Our objective was to develop nitrogen indices based on SPAD indices as a non-destructive tool to predict N state and corn yield throughout crop development. Five N rates (0, 30, 60, 120 or 180 kg ha-1) applied as cover were used to create variability in the nitrogen indices evaluated in corn plants. A randomized block design with four replications was used. The AG1051 corn hybrid was used. The SPAD value was obtained in four fully expanded leaves from the plant apex in five phases of vegetative growth (V5, V7, V11, anthesis and milky grain). Subsequently, the SPAD value was used to calculate Normalized SPAD Index (ISN), Relative SPAD Index (ISR), SPAD Index Difference (DIS), Relative SPAD Index Difference (DISR), and SPAD Index Difference normalized (DISN). Also, in each growth phase were determined leaf N (TNF) and plant N (TNP), nitrogen nutrition index (INN) and plant accumulated N (NA). INN values ranged from 0.47 to 1.53. INN values were greater than 1.0 for all doses of N at stage V5 except for N0 (INN = 0.99) and V7. This indicates that plant growth was not limited by N rates. N rates increased quadratically the grain yield. The 114.2 kg ha-1 N rate provided the maximum grain yield of 2955.4 kg ha-1. In phase V7, grain yield showed the highest correlation with the SPAD value obtained on leaf L1 (r = 0.72; p <0.01) and the lowest correlation with ISN2 (r = 0.52; p <0, 05). This indicates that 52% of grain yield was explained by the SPAD value. The results of correlations between SPAD and N indices indicate that leaves L1 and L2 are the most sensitive for SPAD reading in the early stages of maize. The initial stages V5 and V7, and leaves L1 and L2 were the ones that showed the highest significance and r2 of SPAD indices with the 4 N indicators, but with low or no significant relation for L1 leaf in V11.


  • Data: 28/03/2019
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  • The Cerrado is the second largest Brazilian biome, standing out from the other savannas in the world due to its great biodiversity and therefore it is considered one of the world hotspots. The Chapada das Mesas National Park (CMNP), located in the Cerrado biome, in the state of Maranhão, includes several phytophysiognomies, high scientific, ecological and tourism potential and was one of the first protection areas to be part of the Integrated Fire Management – IFM program - Cerrado Jalapão. Therefore, the goals of the study was to determine the reconstruction of the burn regime of the CMNP, covering the period 1990-2017, and analyze the relation with the types of physiognomies of the park. In this way, a temporal space study was carried out using tools and remote sensing data, in order to obtain data on the burn regime (frequency, area, season), being carried out also the mapping of the classification of vegetation types of CMNP using high resolution satellite imagery and spatial analysis of object-oriented classification. The study will be carried out using software (ArcGIS, QGIS), Rstudio and and algorithms implemented in libraries in Python, and vector and raster data. The use of computational methods and tools, such as geoprocessing and remote sensing, allowed the study to be carried out throughout the CMPN area and buffer for determination of the burned regime, and the mapping of the vegetation in the park area.Therefore, the research sought to contribute to the management and monitoring of the park, one of the greatest riches of the cerrado biome ecosystem in the state of Maranhão, besides subsidizing and stimulate future research.

  • Allelopathy; Phytotoxicity; Weeds; Bioherbicide.

  • Data: 28/03/2019
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  • Studies in the area of allelopathy in agriculture have increased due to searches of alternative methods in weed control over conventional herbicides. Lippia origanoides is a plant native to South and Central America that has several chemotypes and has been a major target for research due to its medicinal properties. Thus, the objective of this work was to evaluate the chemical composition and phytotoxicity of the essential oil of Lippia origanoides in weeds of the species Bidens subalternans, Euphorbia heterophylla and Macroptilium lathyroides in laboratory conditions and greenhouse. The essential oil was extracted from the leaves of L. origanoides by hydrodistillation and diluted at concentrations of 0.01%; 0.05%; 0.1%; 0.5% and 1%. The chemical composition was determined by gas chromatograph coupled to the mass spectrometer. Phytotoxic activity was evaluated in pre and post-emergence by germination, seedling growth, chlorophyll content and cellular respiration tests. The chemical analysis demonstrated an essential oil rich in monoterpenes, mainly oxygenated, with camphor, camphene and βBisabolene as major compounds. In general, both germination and seedling development were strongly inhibited by essential oil, decreasing with increasing concentrations. The concentrations 0.5 and 1.0% totally inhibited the germination of B. subalternans, but did not affect the germination of M. lathyroides. The essential oil sprayed on weed leaves had no effect on chlorophyll content but was able to induce visible lesions such as necrosis and chlorosis. Only the cellular respiration of E. heterophylla was affected by the essential oil. All phytotoxic effects observed are due to the high concentration of monoterpenes in the essential oil, mainly oxygenated, as well as the concentration used.


  • Data: 14/03/2019
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  • With the expansion of forest plantations in the national territory and the imminence of the increase in temperatures due to global warming, it becomes relevant to approach technologies that favor the growth and development of the clonal minijardim in order to guarantee nursery productivity. The application of particle films based on calcined kaolin has been used as a protective barrier against the negative effects of solar radiation and temperature. The present proposal seeks to evaluate the effects of the application of purified particle-calcined kaolin film, in clonal minijardim, in the production and quality of eucalyptus minicuttings. Five treatments will be established, being: control (without particle-film application), 3%, 5% 7% and 10% syrup volume. The application will be performed on the adaxial part of the sheets. The experimental design will be in randomized blocks with four replications. Each treatment will consist of 100 minicepas (01 m², spaced 10 cm x 10 cm), totaling 500 experimental units per block and 2000 in total. The minicepas will be evaluated for leaf temperature, gas exchange (liquid photosynthetic rate, conductance and transpiration), water use efficiency, maximum quantum yield of photosystem II, green intensity and minicut productivity. The minicuttings will be evaluated for length, diameter, specific foliar mass, nutritional evaluation (macro and micronutrients), rooting and survival. The seedlings will be evaluated for height and diameter, dry weight of shoot and root.


  • Data: 20/03/2019
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  • Bioremediation uses microbial metabolism to reduce or decontaminate pollutants. The herbicides, when used intensively, contaminate the soil, making necessary the degradation of these molecules. The objective of this work was to evaluate the bioremediation of soils supplemented with atrazine, glyphosate and pendimethalin by consortia of fungal lineages isolated from agricultural soils, in the biodegradation processes in microcosms in Imperatriz - MA. Soil samples were collected from three areas for physical-chemical analysis and fungal isolation. Isolation was by serial dilutions and selection was performed in KATAYAMA culture medium at the concentrations 0, 10, 20, 50 and 100 μg mL-1 of the herbicides. The microorganisms were selected by macroscopic observations after 14 days of incubation. These strains were plated in a 4% sabouraud dextrose culture medium supplemented with 0, 10, 20, 50 and 100 μg mL-1 of the herbicides and incubated for seven days at 28 ° C, then the mean mycelial growth of the lines. In order to detect the degradation activity, microcosmos tests with 0 and 50 μg mL-1 of the herbicides were carried out for 15 days. The consortia were formed based on the evaluation of the CO2 release of the isolated strains. From the calculations of respiration curves were constructed that indicated the metabolizaton of the herbicides. In the genotoxicity analysis, Allium cepa roots remained in contact with the elutriates of the soils supplemented with the herbicides in the contractions 0 and 50 μg mL-1 for 24 hours, then were collected and analyzed for mitotic index determination and occurrence of cell changes. The data were submitted to statistical analyzes at p <0.05%, with the aid of the Sisvar program. Three fungal strains proved to be suitable for the degradation of herbicides, namely: Aspergillus fumigatus, Fusarium verticillioides and Penicillium citrinum. In the mean of mycelial growth in the presence of atrazine, the fungus Fusarium verticillioides showed the highest growth and the concentrations 10 and 20 μg mL-1 were more favorable. The fungus Fusarium verticilliodes and Aspergillus fumigatus had the best means and the growth was more pronounced in 10 μg mL-1. In the presence of pendimethalin, the fungus Fusarium verticilliodes showed better performance and the best results were 10 μg mL-1. In the microcosms, Aspergillus fumigatus and Penicillium citrinum presented the best rates of CO2 release for atrazine; Aspergillus fumigatus presented greater CO2 release for glyphosate and Penicillium citrinum had the highest rates for pendimethalin. The consortium Aspergillus fumigatus - Penicillium citrinum presented higher release of CO2 in the presence of atrazine, but this consortium showed growth inhibition and was not efficient for glyphosate and pendimethalin. In the genotoxicity test, a delay in the mitotic index was observed in the treatments with 50 μg mL-1 of atrazine herbicide elutriates treated with the Fusarium verticillioides - Aspergillus fumigatus, Fusarium verticillioides - Penicillium citrinum and Aspergillus fumigatus - Penicillium citrinum and pendimethalin treated with the consortium Aspergillus fumigatus - Penicillium citrinum. In the treatment with glyphosate elutriate treated with the consortium Aspergillus fumigatus - Penicillium citrinum, no delay in the mitotic index was observed. Only disorganized cell division in the metaphase phase was found in the treatments with 50 μg mL-1 of the three herbicides, but the alterations were considered low, indicating that the herbicides were degraded.


  • Data: 28/02/2019
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  • The soybean cultivation is of great agricultural importance, both nationally and internationally. The increasing frequency and intensity of drought periods associated with high temperatures due to climate change has been causing substantial losses in agricultural areas. Thus, evaluations of the ecophysiological performance of the plants allow to understand the behaviour of the physiological variables (stomatal conductance, transpiration, photosynthesis and foliar temperature), as well as the responses in productive yield. The water use efficiency characterizes the connection of water and carbon cycles. Understanding the physiological mechanisms involved in this property, and being able to predict its behaviour in an environment of constant change is a fundamental challenge. Therefore, this study aimed to evaluate the ecophysiological behaviour of soybean cultivars. Were used three cultivars (CS01, CS02 e CS03), evaluated during the V5 and R5 stages. As the physiological parameters: photosynthetic assimilation CO2, transpiration, stomatal conductance, SPAD index, Fv/Fm and photosynthetic index (PI). With the gas exchanges values, the water use (WUE) efficiency and the water use intrinsic efficiency (WUEi) were determined. In addition, were obtained production components and biomass. The gas exchanges were significant at the R5 stage. The CS02 presented the highest mean values of the Fv/Fm ratio and PI. The WUE presented positive linear relationships for all cultivars. In both developmental stages, CS02 was more efficient in water use, obtaining a higher CO2 assimilation value for each gram of water transpired in the V5 stage (13,62 mg CO2 g-1 H2O). The WUEi maximum values were verified in CS03, presenting, 22,71 e 1,63 µmol CO2 mol-1 H2O, for V5 and R5, respectively. According to the results, CS02 obtained the best performance in the main analysed variables, being the most efficient in the water use and more productive of the studied cultivars, in field conditions in the southwest of Maranhão.


  • Data: 15/08/2019
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  • Understanding the spatial variability of soil attributes allows the farmer to implement precision farming on his property by ensuring optimization in the productive process and yield increases due to the proper management of specific sites and generation of yield maps. The objective of this paper was to determine and map spatial variation of soil physical attributes and maize productivity components in an area under no-tillage, as well as to characterize the relationship between these attributes to obtain variables with potential for the recognition of specific sites of management. The study was conducted at Fazenda Santa Luzia, located in the municipality of São Raimundo das Mangabeiras, MA, in an experimental area of approximately 0.7 ha, managed under no-tillage. The soil physical parameters and  maize crop yield were evaluated with the support of a 10 x 10 m grid, where the sampling points corresponded to the intersection between the rows and columns of the grid. In each sampling point, the geographical coordinates were recorded with GPS Garmin 76CSx, collection of undisturbed soil samples with volumetric rings of 100 cm³ in the depth 0.0-0.2 m, soil resistance measurement with penetrometer Falker PLG 1020 in the 0.05, 0.06-0.10, 0.11-0.15, 0.16-0.20 cm depth, collection of deformed samples at the depths of 0,0- 0.1 and 0.11-0.20 m to determining moisture at the time of sampling and harvesting of corn in an area of 4 m², totaling 100 samples. Soil density (Ds), total porosity (Pt), macroporosity (Ma), microporosity (Mi), fine sand content (AF), coarse sand content (AG), silt content (Si), clay content (Ar), penetration resistance (RP1, RP2, RP3, RP4), maximum  pressure (Pm), the maximum pressure depth (Ppm), moisture (UD1 and UD2), ear weight (PE), weight of one hundred grains (PCG), number of grains per ear (NGE), productivity (Prod). The data were submitted to descriptive analysis, exploratory analysis, Kolmogorov-Smirnov (K-S) normality test, Pearson's correlation, modeling and adjustment of semivariograms, ordinary kriging and generation of thematic maps. From the correlation analysis, positive correlation was obtained for the coarse sand and maximum pressure variables, and negative correlation for silt content and depth of maximum pressure. It was verified the occurrence of spatial dependence for most of the physical attributes of the soil and productivity components, with variation of the degree of spatial dependence between strong and moderate, except for moisture 0-10 cm, depth of maximum pressure, ear weight and number of grains per ear, which showed pure nugget effect. Ordinary Kriging was performed for the variables that exhibited spatial dependence, and generated isoline maps that allowed the visualization of the attributes variation of the studied and the identification of potential management areas.

  • Identification of predictive variables for maize production under long-term no-tillage

  • Data: 01/07/2019
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  • Precision agriculture has as its starting point the idea that it’s possible to identify predictive variables for the proper development of a crop, besides being able to quantify them and to locate them graphically in order to guide management decision-making. The objective of this work was to map and evaluate the spatial variation of chemical indicators of soil quality and components of corn crop productivity, to identify among chemical attributes those that behave as limiting maize productivity and to delineate specific sites that will deserve differentiated management posteriorly. The experiment was conducted in an area of 0.7 hectare with 100 sample points regularly dispersed in a 10 x 10 m sample grid. The data were analyzed in interconnected stages: Step 1) descriptive statistics, Step 2) normality test (Kolmogorov-Smirnov), Step 3) semivariogram parameters, Step 4) correlation analysis, Step 5) isoline maps. It was verified the presence of spatial variability for all soil chemical attributes and productivity components. The degree of spatial dependence ranged from moderate to strong, which allowed the potentialities and limitations of the long-term no-tillage system to be demonstrated through isolate maps. Positive correlation was verified between phosphorus and yield.

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