The effect of organic fertilization with cattle manure on fertility properties of soils with different clay contents was evaluated; as well as the influence of cattle manure fertilization on the production of lettuce, and on subsequent arugula and common chicory grown in these soils. The experiment with pot plants was arranged in randomized blocks and analyzed in a 3x6 factorial design with four replications. The treatments consisted of three soil types with different clay contents (166; 362; 565 g kg-1) and six cattle manure rates (0; 10; 20; 40; 80, and 160 t ha-1). Batches of each soil were manured, limed, filled in pots, moistened, and incubated for 30 days. Then, mineral base fertilization was applied and one lettuce seedling per each pot was grown. After lettuce harvest, the residual effect of organic fertilization was assessed in two subsequent crops, first arugula and then common chicory. The application of up to 160 t ha-1 cattle manure reduces soil acidity and increases nutrient contents, particularly of P, K and Zn, in soils with 165 to 565 g kg-1 clay content. Fertilization with cattle manure at rates of up to 160 t ha-1 increases electrical conductivity of soils, without affecting growth and yield of the leafy vegetables. Cattle manuring increases the yield of lettuce, as well as of arugula and common chicory grown afterwards.

The effect of organic fertilization with cattle manure on fertility properties of soils with different clay contents was evaluated; as well as the influence of cattle manure fertilization on the production of lettuce, and on subsequent arugula and common chicory grown in these soils. The experiment with pot plants was arranged in randomized blocks and analyzed in a 3x6 factorial design with four replications. The treatments consisted of three soil types with different clay contents (166; 362; 565 g kg-1) and six cattle manure rates (0; 10; 20; 40; 80, and 160 t ha-1). Batches of each soil were manured, limed, filled in pots, moistened, and incubated for 30 days. Then, mineral base fertilization was applied and one lettuce seedling per each pot was grown. After lettuce harvest, the residual effect of organic fertilization was assessed in two subsequent crops, first arugula and then common chicory. The application of up to 160 t ha-1 cattle manure reduces soil acidity and increases nutrient contents, particularly of P, K and Zn, in soils with 165 to 565 g kg-1 clay content. Fertilization with cattle manure at rates of up to 160 t ha-1 increases electrical conductivity of soils, without affecting growth and yield of the leafy vegetables. Cattle manuring increases the yield of lettuce, as well as of arugula and common chicory grown afterwards. | O presente trabalho teve como objetivos avaliar o efeito da adubação com esterco bovino em atributos de fertilidade de solos com diferentes teores de argila e, verificar a influência da adubação com esterco bovino na produção de alface americana, e da rúcula e almeirão, cultivados de forma sucessiva a alface. O experimento foi realizado em vasos, em delineamento em blocos ao acaso, com os tratamentos arranjados em esquema fatorial 3x6 com quatro repetições. Os tratamentos foram constituídos por três solos com diferentes teores de argila (166; 362; 565 g kg-1) e seis doses de esterco bovino (0; 10; 20; 40; 80 e 160 t ha-1). Porções de cada solo receberam esterco bovino e calcário, foram transferidas para vasos, umedecidas e incubadas por 30 dias. A seguir, efetuou-se adubação mineral de plantio e cada vaso recebeu uma muda de alface. Após a colheita da alface, para avaliar o efeito residual da adubação orgânica foram realizados dois cultivos sucessivos, um de rúcula e outro de almeirão. A aplicação de até 160 t ha-1 de esterco bovino diminui a acidez e, aumenta os teores de nutrientes, particularmente P, K e Zn em solos com teores de argila de 165 a 565 g kg-1. A adubação com esterco bovino em doses de até 160 t ha-1 aumenta a condutividade elétrica dos solos, e esse acréscimo não prejudica o crescimento e a produção de hortaliças folhosas. A adubação com esterco bovino aumenta a produção de alface, como também a de rúcula e almeirão, cultivados de forma sucessiva.

Forage cactus species may belong to different genera (such as Opuntia and Nopalea), which can result in different water dynamics at the biosphere-atmosphere interface. The objective of this study was to analyze the water balance in soil cultivated with forage cactus clones under different conditions of soil water availability in the Brazilian semi-arid. The experiment was conducted in the municipality of Serra Talhada, State of Pernambuco. The crop was subjected to nine treatments arranged in a randomized complete block design with three replications in a factorial arrangement of 3x3. The plots were composed of three water availability conditions, with the application of a water depth of 7.5 mm at intervals of 7, 14, and 28 days, and the subplots consisted of three forage cactus clones (IPA Sertânia, Miúda, and Orelha de Elefante Mexicana). The soil water balance (SWB) method was applied, and the ET/ETo ratio was estimated (ET is the actual crop evapotranspiration, and ETo is the reference evapotranspiration) at intervals of 14 days; the results were represented in nine periods of 28 days. There was a difference between SWB components along the cycle and between irrigation conditions (p < 0.05). Nevertheless, ET and rainfall were the most important components in SWB when irrigation was performed. There was no difference in water consumption between forage cactus clones belonging to different genera, resulting in an average of 1.50 mm day-1. The ET/ETo ratio had low magnitude (0.29 ± 0.12), indicating that the ET was more dependent on the water regime than on the atmospheric demand.

Forage cactus species may belong to different genera (such as Opuntia and Nopalea), which can result in different water dynamics at the biosphere-atmosphere interface. The objective of this study was to analyze the water balance in soil cultivated with forage cactus clones under different conditions of soil water availability in the Brazilian semi-arid. The experiment was conducted in the municipality of Serra Talhada, State of Pernambuco. The crop was subjected to nine treatments arranged in a randomized complete block design with three replications in a factorial arrangement of 3x3. The plots were composed of three water availability conditions, with the application of a water depth of 7.5 mm at intervals of 7, 14, and 28 days, and the subplots consisted of three forage cactus clones (IPA Sertânia, Miúda, and Orelha de Elefante Mexicana). The soil water balance (SWB) method was applied, and the ET/ETo ratio was estimated (ET is the actual crop evapotranspiration, and ETo is the reference evapotranspiration) at intervals of 14 days; the results were represented in nine periods of 28 days. There was a difference between SWB components along the cycle and between irrigation conditions (p < 0.05). Nevertheless, ET and rainfall were the most important components in SWB when irrigation was performed. There was no difference in water consumption between forage cactus clones belonging to different genera, resulting in an average of 1.50 mm day-1. The ET/ETo ratio had low magnitude (0.29 ± 0.12), indicating that the ET was more dependent on the water regime than on the atmospheric demand. | A palma é uma espécie pertencente aos gêneros Nopalea e Opuntia, o que pode resultar em dinâmicas de água diferentes na interface biosfera-atmosfera. Assim, objetivou-se analisar o balanço de água no solo cultivado com clones de palma forrageira em diferentes condições de disponibilidade hídrica no Semiárido brasileiro. O experimento foi conduzido em Serra Talhada, PE. A cultura foi submetida a nove tratamentos, dispostos em delineamento em blocos ao acaso, com três repetições, em arranjo fatorial 3x3. As parcelas foram constituídas por três condições de disponibilidade hídrica com a aplicação de uma lâmina de 7,5 mm em intervalos 7; 14 e 28 dias, e as subparcelas por três clones de palma (IPA Sertânia, Miúda e Orelha de Elefante Mexicana). O método do balanço de água no solo (BAS) foi aplicado e a razão ET/ETo estimada (sendo, ET a evapotranspiração real da cultura e ETo a evapotranspiração de referência), em intervalos de 14 dias, e os resultados foram representados em nove períodos de 28 dias. Houve diferença dos componentes do BAS ao longo do ciclo e entre as condições de irrigação (p < 0,05). Embora sob irrigação, a ET e a precipitação foram os componentes mais importantes no BAS. Não houve diferença no consumo de água entre os clones, ainda que pertencentes a diferentes gêneros, resultando média de 1,50 mm dia-1. A razão ET/ETo possuiu baixa magnitude (0,29±0,12), indicando que a ET foi mais dependente do regime hídrico do que da demanda atmosférica.

The use of chemical seed treatment is an important tool in the protection of seedlings and has contributed to the increase of rice yield (Oryza sativa L.). The objective of this study was to evaluate the physiological quality and quantify the retention of chemical products in rice seeds treated with insecticide and fungicide coated with polymers. Six seed treatments were used: control, phytosanitary treatment and phytosanitary treatment and coating with the polymers, Florite 1127®, GV5® Solid Resin, Polyseed CF® and VermDynaseed®. The physiological quality was evaluated by the test of germination and vigor by first count tests, germination speed index, shoot length, radicle length, seedling dry mass and sand emergence. To determine the retention of the active ingredients metalaxyl-M and thiamethoxam, an equipment called extractor was used. The experiment was organized in a completely randomized design (DIC) and the averages were separated by the Scott Knott test (p≤0.05). Seed treatment with the fungicide and insecticide, coated with the polymers, Florite 1127®, Solid Resin GV5®, Polyseed CF® and VermDynaseed®, did not affect the physiological quality of rice seeds. Solid Resin GV5®, Polyseed CF® and VermDynaseed® polymers were efficient at retaining thiamethoxam in the rice seeds, preventing some of the active ingredients of the insecticide from being leached through the sand columns immediately after the simulated pluvial precipitation.

The use of chemical seed treatment is an important tool in the protection of seedlings and has contributed to the increase of rice yield (Oryza sativa L.). The objective of this study was to evaluate the physiological quality and quantify the retention of chemical products in rice seeds treated with insecticide and fungicide coated with polymers. Six seed treatments were used: control, phytosanitary treatment and phytosanitary treatment and coating with the polymers, Florite 1127®, GV5® Solid Resin, Polyseed CF® and VermDynaseed®. The physiological quality was evaluated by the test of germination and vigor by first count tests, germination speed index, shoot length, radicle length, seedling dry mass and sand emergence. To determine the retention of the active ingredients metalaxyl-M and thiamethoxam, an equipment called extractor was used. The experiment was organized in a completely randomized design (DIC) and the averages were separated by the Scott Knott test (p≤0.05). Seed treatment with the fungicide and insecticide, coated with the polymers, Florite 1127®, Solid Resin GV5®, Polyseed CF® and VermDynaseed®, did not affect the physiological quality of rice seeds. Solid Resin GV5®, Polyseed CF® and VermDynaseed® polymers were efficient at retaining thiamethoxam in the rice seeds, preventing some of the active ingredients of the insecticide from being leached through the sand columns immediately after the simulated pluvial precipitation. | O uso do tratamento químico de sementes é uma importante ferramenta na proteção de plântulas e tem contribuído com a elevação da produtividade de arroz (Oryza sativa L.). Objetivou-se avaliar a qualidade fisiológica e quantificar a retenção de produtos químicos em sementes de arroz tratadas com inseticida e fungicida recobertas com polímeros. Foram utilizados seis tratamentos de sementes: controle, tratamento fitossanitário e tratamento fitossanitário e recobrimento com os polímeros, Florite 1127®, Resina Sólida GV5®, Polyseed CF® e o VermDynaseed®. A qualidade fisiológica foi avaliada pelo teste de germinação e vigor pelos testes de primeira contagem, índice de velocidade de germinação, comprimento de parte aérea, comprimento de radícula, massa seca de plântulas e emergência em areia. Para determinar a retenção dos ingredientes ativos metalaxil-M e thiamethoxam, utilizou-se equipamento denominado extrator. O experimento foi organizado no delineamento inteiramente casualizado (DIC) e as médias foram separadas pelo Scott Knott (p≤0,05).O tratamento de sementes com o fungicida e inseticida, recobertos com os polímeros,Florite 1127®, ResinSolid GV5®, Polyseed CF® e o VermDynaseed®, não afetaram a qualidade fisiológica de sementes de arroz. Os polímeros ResinSolid GV5®, Polyseed CF® e o VermDynaseed® foram eficientes na retenção do thiamethoxam junto às sementes de arroz, impedindo que parte do ingrediente ativo do inseticida fosse lixiviado, através das colunas de areia, logo após a precipitação pluvial simulada.

The present study was conducted with the objective of analyzing the covariance structure and repeatability estimates of the variables related to guava productivity, such as fruit weight (FW), fruit number (FN) and fruit production (FP) of three harvests, in 95 genotypes of a segregating population. The study also aims to choose the most appropriate covariance structure of the observations within the same individual by means of AIC (Akaike's Information Criterion) and SBC (Schwarz's Bayesian Criterion) criteria. A covariance structure between repeated measures could be incorporated into the statistical model, with the self-regression and compound symmetry forms being the most adequate. The values of repeatability coefficients obtained for FW (0.25), FN (0.14), and FP (0.29) were considered low, indicating that the three harvests were not sufficient to select the best individuals with greater accuracy for the study population. For the variables PF and FP, estimates of accuracy around 0.50 could be obtained from five measurements, while for the variable FN more harvests would be necessary. These values indicate that in guava-segregating populations, evaluations in the first harvests are not enough to select more stable genotypes for the variables considered in this study.

The present study was conducted with the objective of analyzing the covariance structure and repeatability estimates of the variables related to guava productivity, such as fruit weight (FW), fruit number (FN) and fruit production (FP) of three harvests, in 95 genotypes of a segregating population. The study also aims to choose the most appropriate covariance structure of the observations within the same individual by means of AIC (Akaike's Information Criterion) and SBC (Schwarz's Bayesian Criterion) criteria. A covariance structure between repeated measures could be incorporated into the statistical model, with the self-regression and compound symmetry forms being the most adequate. The values of repeatability coefficients obtained for FW (0.25), FN (0.14), and FP (0.29) were considered low, indicating that the three harvests were not sufficient to select the best individuals with greater accuracy for the study population. For the variables PF and FP, estimates of accuracy around 0.50 could be obtained from five measurements, while for the variable FN more harvests would be necessary. These values indicate that in guava-segregating populations, evaluations in the first harvests are not enough to select more stable genotypes for the variables considered in this study. | O presente estudo foi conduzido com o objetivo de analisar estrutura de covariância e estimativas de repetibilidade das variáveis relacionadas à produtividade da goiabeira como massa dos frutos (MF), número de frutos (NF) e produção de frutos (PROD) de três safras, em 95 genótipos de uma população segregante. E por meio dos critérios de AIC (Akaike’s Information Criterion) e SBC (Schwarz’s Bayesian Criterion) escolher a estrutura de covariância mais adequada das observações dentro de um mesmo indivíduo. Foi possível incorporar ao modelo estatístico, uma estrutura de covariância entre medidas repetidas, sendo as formas autorregressiva e simetria composta as mais adequadas. Os valores dos coeficientes de repetibilidade obtidos para PF (0,25), NF (0,14) e PROD (0,29) foram considerados baixos, indicando que para a população em estudo as três safras realizadas não foram suficientes para selecionar os melhores indivíduos com maior acurácia. Para as variáveis PF e PROD, a partir de cinco medições seria possível a obtenção de estimativas de acurácias em torno de 0,50. Enquanto que para a variável NF, observou-se que mais safras seriam necessárias. Estes valores indicam que em populações segregantes de goiabeira, avaliações nas primeiras safras, não são suficientes para seleção de genótipos mais estáveis para as variáveis consideradas neste estudo.

The precocity of cowpea is important because it indicates the possibility of increasing and/or stabilizing production in regions with long periods of drought. The aim of this study was to evaluate genetic variability and select extra-early cowpea progenies. Fifteen F3:6 progenies were evaluated in 2014 while sixty-two F7 progenies were evaluated in 2015. Two commercial cultivars were used in experiments performed in the irrigated perimeter of Baixo Acaraú, in Marco, CE. The following characteristics were evaluated: number of days for flowering (NDF), number of days for maturity (NDM), plant height (PH), pod length (PL), number of seeds per pod (NSP), number of grains per plant (NGP), weight of 100 grains (W100G) and total weight (MTOT). Data were analyzed in lattice and RBD, according to the methodology of mixed models by the REML/BLUP procedure. Also, the components of variance and genetic values were estimated. Variability among progenies, high heritability and high accuracy were identified for all traits. For NDF and NDM, the progenies presented higher behavior than the controls. The lattice arrangement contributed to a greater gain with the selection of NDF, NDM, PH, NSP, NGP and WTOT. The genotypes 12, 15, 30, 33, 41, 43 and 52 are among the top ten because they have high genetic values in three or more traits. The genotypes 12, 15, 30, 33, 43 and 52 highlight extra-earliness (precocity).

The precocity of cowpea is important because it indicates the possibility of increasing and/or stabilizing production in regions with long periods of drought. The aim of this study was to evaluate genetic variability and select extra-early cowpea progenies. Fifteen F3:6 progenies were evaluated in 2014 while sixty-two F7 progenies were evaluated in 2015. Two commercial cultivars were used in experiments performed in the irrigated perimeter of Baixo Acaraú, in Marco, CE. The following characteristics were evaluated: number of days for flowering (NDF), number of days for maturity (NDM), plant height (PH), pod length (PL), number of seeds per pod (NSP), number of grains per plant (NGP), weight of 100 grains (W100G) and total weight (MTOT). Data were analyzed in lattice and RBD, according to the methodology of mixed models by the REML/BLUP procedure. Also, the components of variance and genetic values were estimated. Variability among progenies, high heritability and high accuracy were identified for all traits. For NDF and NDM, the progenies presented higher behavior than the controls. The lattice arrangement contributed to a greater gain with the selection of NDF, NDM, PH, NSP, NGP and WTOT. The genotypes 12, 15, 30, 33, 41, 43 and 52 are among the top ten because they have high genetic values in three or more traits. The genotypes 12, 15, 30, 33, 43 and 52 highlight extra-earliness (precocity). | A precocidade é importante para o feijão-caupi por representar a possibilidade de aumentar e/ou estabilizar a produção em regiões com longos períodos de estiagem. Objetivou- se avaliar a variabilidade genética e selecionar progênies de feijão-caupi extraprecoces. Foram avaliadas 15 progênies F3:6 em 2014 e 62 progênies F7 em 2015, juntamente com duas cultivares comerciais em experimentos conduzidos no perímetro irrigado Baixo Acaraú, localizado no município de Marco, CE. Foram avaliados os caracteres: número de dias para o florescimento (NDF), número de dias para a maturação (NDM), altura de planta (ALT), comprimento de vagem (CPV), número de grãos por vagem (NGV), número de grãos por planta (NGP), massa de 100 grãos (M100G) e massa total (MTOT). Os dados foram analisados em DBIL e DBC, segundo a metodologia de modelos mistos, via procedimento REML/BLUP. Foram estimados os componentes de variância e os valores genéticos. Identificou-se variabilidade entre as progênies, alta herdabilidade e elevada acurácia em todos os caracteres avaliados. As progênies apresentaram comportamento superior às testemunhas para NDF e NDM. O arranjo em látice apresentou maior eficiência que o DBC, pelo maior ganho obtido com a seleção nos caracteres NDF, NDM, ALT, NGV, NGP e MTOT. Os genótipos 12, 15, 30, 33, 41, 43 e 52 encontram-se entre os dez superiores, por apresentarem valores genéticos elevados em três ou mais caracteres. Os genótipos 12, 15, 30, 33, 43 e 52 destacam-se como os mais precoces.

The goal of this work was to evaluate the physiological responses of cowpea under water stress and rehydration in conventional and no-tillage systems. We evaluated two crop systems (conventional and no tillage) and three water conditions (no stress, moderate stress and severe stress). The following were determined: leaf area, total dry matter, photosynthetic rate, stomatal conductance, transpiration rate, internal CO2 concentration and leaf water potential. Water stress affected all variables evaluated, with the exception of leaf water potential. Cowpea recovered with respect to all variables after rehydration at both stress levels. Stomatal closure is an important drought tolerance mechanism, and cowpea can be considered a conservative species (i.e., one that prioritizes water status maintenance rather than photosynthetic rate). Planting systems did not affect photosynthetic rate. The tillage system promoted greater accumulation of biomass and higher leaf area.

The goal of this work was to evaluate the physiological responses of cowpea under water stress and rehydration in conventional and no-tillage systems. We evaluated two crop systems (conventional and no tillage) and three water conditions (no stress, moderate stress and severe stress). The following were determined: leaf area, total dry matter, photosynthetic rate, stomatal conductance, transpiration rate, internal CO2 concentration and leaf water potential. Water stress affected all variables evaluated, with the exception of leaf water potential. Cowpea recovered with respect to all variables after rehydration at both stress levels. Stomatal closure is an important drought tolerance mechanism, and cowpea can be considered a conservative species (i.e., one that prioritizes water status maintenance rather than photosynthetic rate). Planting systems did not affect photosynthetic rate. The tillage system promoted greater accumulation of biomass and higher leaf area. | O objetivo do trabalho foi avaliar as respostas fisiológicas em feijão-caupi sob efeito de estresse hídrico e reidratação nos sistemas de plantio direto (PD) e convencional (PC). Foram avaliados dois sistemas de plantio (direto e convencional) e três condições hídricas (sem estresse, estresse moderado e estresse severo). Foram determinados: área foliar, matéria seca total, fotossíntese, condutância estomática, transpiração, concentração interna de CO2 e potencial hídrico foliar. O estresse hídrico afetou todas as variáveis avaliadas, com exceção do potencial hídrico foliar. Houve recuperação de todas as variáveis após reidratação em ambos níveis de estresse. O fechamento estomático é um importante mecanismo de tolerância à seca, sendo que o feijão-caupi pode ser considerado uma espécie conservadora, i.e. que prioriza a manutenção do status hídrico em detrimento da produção fotossintética. Os sistemas de plantio não afetaram as taxas fotossintéticas. O sistema de plantio direto promove maior acúmulo de biomassa e maior área foliar.

The goal of this work was to evaluate the physiological responses of cowpea under water stress and rehydration in conventional and no-tillage systems. We evaluated two crop systems (conventional and no tillage) and three water conditions (no stress, moderate stress and severe stress). The following were determined: leaf area, total dry matter, photosynthetic rate, stomatal conductance, transpiration rate, internal CO2 concentration and leaf water potential. Water stress affected all variables evaluated, with the exception of leaf water potential. Cowpea recovered with respect to all variables after rehydration at both stress levels. Stomatal closure is an important drought tolerance mechanism, and cowpea can be considered a conservative species (i.e., one that prioritizes water status maintenance rather than photosynthetic rate). Planting systems did not affect photosynthetic rate. The tillage system promoted greater accumulation of biomass and higher leaf area. | O objetivo do trabalho foi avaliar as respostas fisiológicas em feijão-caupi sob efeito de estresse hídrico e reidratação nos sistemas de plantio direto (PD) e convencional (PC). Foram avaliados dois sistemas de plantio (direto e convencional) e três condições hídricas (sem estresse, estresse moderado e estresse severo). Foram determinados: área foliar, matéria seca total, fotossíntese, condutância estomática, transpiração, concentração interna de CO2 e potencial hídrico foliar. O estresse hídrico afetou todas as variáveis avaliadas, com exceção do potencial hídrico foliar. Houve recuperação de todas as variáveis após reidratação em ambos níveis de estresse. O fechamento estomático é um importante mecanismo de tolerância à seca, sendo que o feijão-caupi pode ser considerado uma espécie conservadora, i.e. que prioriza a manutenção do status hídrico em detrimento da produção fotossintética. Os sistemas de plantio não afetaram as taxas fotossintéticas. O sistema de plantio direto promove maior acúmulo de biomassa e maior área foliar.

Cotton has great socio-economic importance due to its use in textile industry, edible oil and biodiesel production and animal feed. Thus, the objective of this work was to identify the best potassium rate and soil management for cotton crops and select among cultivars, the one that better develops in the climatic conditions of the Cerrado biome in the State of Goiás, Brazil. Thus, the effect of five potassium rates (100, 150, 200, 250 and 300 kg ha-1 of K2O) and two soil management systems (no-till and conventional tillage) on the growth, development and reproduction of four cotton cultivars (BRS-371, BRS-372, BRS-286 and BRS-201) was evaluated. The data on cotton growth and development were subjected to analysis of variance; the data on potassium rates were subjected to regression analysis; and the data on cultivars and soil management to mean test. The correlation between the vegetative and reproductive variables was also assessed. The conventional tillage system provides the best results for the herbaceous cotton, regardless of the others factors evaluated. The cultivar BRS-286 has the best results in the conditions evaluated. The cultivar BRS-371 under no-till system present the highest number of fruiting branches at a potassium rate of 105.5% and highest number of floral buds at a potassium rate of 96.16%. The specific leaf area was positively correlated with the number of bolls per plant at 120 days after emergence of the herbaceous cotton.

Cotton has great socio-economic importance due to its use in textile industry, edible oil and biodiesel production and animal feed. Thus, the objective of this work was to identify the best potassium rate and soil management for cotton crops and select among cultivars, the one that better develops in the climatic conditions of the Cerrado biome in the State of Goiás, Brazil. Thus, the effect of five potassium rates (100, 150, 200, 250 and 300 kg ha-1 of K2O) and two soil management systems (no-till and conventional tillage) on the growth, development and reproduction of four cotton cultivars (BRS-371, BRS-372, BRS-286 and BRS-201) was evaluated. The data on cotton growth and development were subjected to analysis of variance; the data on potassium rates were subjected to regression analysis; and the data on cultivars and soil management to mean test. The correlation between the vegetative and reproductive variables was also assessed. The conventional tillage system provides the best results for the herbaceous cotton, regardless of the others factors evaluated. The cultivar BRS-286 has the best results in the conditions evaluated. The cultivar BRS-371 under no-till system present the highest number of fruiting branches at a potassium rate of 105.5% and highest number of floral buds at a potassium rate of 96.16%. The specific leaf area was positively correlated with the number of bolls per plant at 120 days after emergence of the herbaceous cotton. | O algodão possui grande importância social e econômica, devido a sua utilização na indústria têxtil, produção de óleo comestível, biodiesel e alimentação animal, dessa forma é de grande importância selecionar a cultivar que apresenta o melhor desempenho nas condições climáticas do Cerrado goiano e estudar seu comportamento em função de doses de potássio pelas inúmeras funções na planta e ainda identificar o manejo do solo que proporcione as melhores condições visando um maior desempenho da cultura. Dessa forma, objetivou-se com o experimento, avaliar cinco doses de potássio (100; 150; 200; 250; 300 kg ha-1 de K2O), dois sistemas de manejo do solo (plantio direto e plantio convencional) no crescimento, desenvolvimento e reprodução de quatro cultivares de algodão (BRS-371, BRS-372, BRS-286 e BRS-201). Os dados de crescimento e desenvolvimento do algodoeiro foram submetidos à análise de variância e para os dados referentes às doses de potássio, realizou-se análise de regressão, e referentes às cultivares e sistemas de manejo do solo teste de média, ainda avaliou-se a correlação entre as variáveis vegetativas e reprodutivas analisadas. O sistema de plantio convencional proporciona melhores respostas ao algodoeiro herbáceo independentemente dos demais fatores avaliados. A cultivar BRS-286 apresenta melhor resposta nas condições avaliadas. A cultivar BRS-371 no sistema de plantio direto apresenta maior número de ramo frutífero na dose de potássio de 105,5% e botão floral na dose de potássio de 96,16%. A área foliar específica é positivamente correlacionada com o número de capulho aos 120 dias após emergência do algodoeiro herbáceo.

The common bean requires high levels of nitrogen (N) to achieve high productivity, which can be supplied, at least partially, by the biological nitrogen fixation (BFN). Two field experiments were carried out in the winter season of 2015 aiming to evaluate the effects of different cover crops, desiccation times and the agronomic performance of the common bean inoculated with rhizobia. The experiments were assembled in a randomized block design with four replications, in a factorial split-plot arrangement with two additional treatments (5x4x2+2). The factors were composed of five cover crops, four desiccation times, two seed inoculation treatments and two additional controls (TN = 90 Kg N ha-1 and T0 = without N and without inoculation). The variables analyzed in the cover crops were dry mass (DM) and total nitrogen (Total-N). With the common bean, the chlorophyll content (CC), the number of nodules (NN), the nodule dry weight (NDW), the shoot dry weight (SDW), the root dry weight (RDW) and the grain yield (GY) were evaluated. The results showed that the agronomic performance of the common bean was not affected by the desiccation times of the cover crops, although the amount of Total-N accumulated by cover crops was influenced by sowing times. Inoculation of the common bean promoted an increase in the NN, NDW, CC and SDW. Higher GY of the common bean was achieved with its cropping after Brachiaria brizantha, Brachiaria ruziziensis, millet and fallow.

The common bean requires high levels of nitrogen (N) to achieve high productivity, which can be supplied, at least partially, by the biological nitrogen fixation (BFN). Two field experiments were carried out in the winter season of 2015 aiming to evaluate the effects of different cover crops, desiccation times and the agronomic performance of the common bean inoculated with rhizobia. The experiments were assembled in a randomized block design with four replications, in a factorial split-plot arrangement with two additional treatments (5x4x2+2). The factors were composed of five cover crops, four desiccation times, two seed inoculation treatments and two additional controls (TN = 90 Kg N ha-1 and T0 = without N and without inoculation). The variables analyzed in the cover crops were dry mass (DM) and total nitrogen (Total-N). With the common bean, the chlorophyll content (CC), the number of nodules (NN), the nodule dry weight (NDW), the shoot dry weight (SDW), the root dry weight (RDW) and the grain yield (GY) were evaluated. The results showed that the agronomic performance of the common bean was not affected by the desiccation times of the cover crops, although the amount of Total-N accumulated by cover crops was influenced by sowing times. Inoculation of the common bean promoted an increase in the NN, NDW, CC and SDW. Higher GY of the common bean was achieved with its cropping after Brachiaria brizantha, Brachiaria ruziziensis, millet and fallow. | O feijoeiro-comum requer altos níveis de nitrogênio (N) para alcançar elevadas produtividades, os quais podem ser supridos, ao menos parcialmente, pela fixação biológica de N (FBN). Com o objetivo de avaliar os efeitos de diferentes plantas de cobertura e épocas de dessecação no desempenho agronômico do feijoeiro-comum inoculado com rizóbio, foram conduzidos dois experimentos em campo, na safra de inverno 2015. Os experimentos foram implantados em delineamento de blocos ao acaso com quatro repetições, em esquema fatorial de parcelas sub subdivididas com tratamentos adicionais (5x4x2+2). Os fatores foram: cinco plantas de cobertura, quatro épocas de dessecação, dois tratamentos de inoculação das sementes e duas testemunhas (TN = 90 Kg N ha-1 e T0 = sem N e sem inoculação). As variáveis analisadas nas plantas de cobertura foram massa seca (MS) e nitrogênio total (N-Total). No feijoeiro-comum avaliou-se teor de clorofila (TC), número de nódulos (NN), massa seca de nódulos (MSN), massa seca da parte aérea (MSPA), massa seca de raiz (MSR) e a produção de grãos (PG). Os resultados mostraram que o desempenho agronômico do feijoeiro-comum não foi afetado pelas épocas de dessecação das plantas de cobertura, embora a quantidade de N-Total acumulada pelas plantas de cobertura tenha sido influenciada pela época de semeadura. A inoculação do feijoeiro-comum promoveu aumento do NN e MSN, do TC e da MSPA do feijoeiro-comum. Em Santo Antônio de Goiás obteve-se maior PG do feijoeiro-comum em cultivo após braquiária brizanta, braquiária ruziziensis, milheto e pousio.

The objective of the present research is to characterize the phytotoxic activity of geopropolis from the Jandaira bee (Melipona subnitida Ducke) in the state of Ceará in Northeast Brazil and to analyze its effects. Extracts were prepared in 80% v/v grain alcohol at 0.25, 0.5, 0.75, and 1.0%. Their effects were determined on seed germination, radicle elongation, and hypocotyl growth of the pasture weeds malícia (Mimosa pudica) and mata-pasto (Senna obtusifolia). Extract phytotoxicity varied as functions of plant species, application dosage, and plant organ. M. pudica was more sensitive to the inhibitory effects of geopropolis than S. obtusifolia. There was a phytotoxic effect of 50% (PE50) for S. obtusifolia in terms of seed germination and in rootlet development near the maximum applied concentrations. M. pudica had PE50 and PE90 at the minimum concentration (0.25%) and near the maximum (1.00%), respectively. Thus, geopropolis extracts from the Jandaira bee (M. subnitida) are potentially phytotoxic to certain plant species.

The objective of the present research is to characterize the phytotoxic activity of geopropolis from the Jandaira bee (Melipona subnitida Ducke) in the state of Ceará in Northeast Brazil and to analyze its effects. Extracts were prepared in 80% v/v grain alcohol at 0.25, 0.5, 0.75, and 1.0%. Their effects were determined on seed germination, radicle elongation, and hypocotyl growth of the pasture weeds malícia (Mimosa pudica) and mata-pasto (Senna obtusifolia). Extract phytotoxicity varied as functions of plant species, application dosage, and plant organ. M. pudica was more sensitive to the inhibitory effects of geopropolis than S. obtusifolia. There was a phytotoxic effect of 50% (PE50) for S. obtusifolia in terms of seed germination and in rootlet development near the maximum applied concentrations. M. pudica had PE50 and PE90 at the minimum concentration (0.25%) and near the maximum (1.00%), respectively. Thus, geopropolis extracts from the Jandaira bee (M. subnitida) are potentially phytotoxic to certain plant species. | Este trabalho teve por objetivo caracterizar a atividade fitotóxica da geoprópolis de abelhas jandaira (Melipona subnitida Ducke), nativas do estado do Ceará, e analisar, comparativamente, seus efeitos. Os extratos obtidos com álcool cereal foram preparados em concentrações de 0,25, 0,5, 0,75 e 1,0%, tendo como eluente o etanol 80%, e testados sobre a germinação de sementes, alongamento da radícula e do hipocótilo das plantas daninhas de área de pastagens cultivadas, malícia (Mimosa pudica) e mata-pasto (Senna obtusifolia). Os extratos testados evidenciaram atividade fitotóxica em intensidades que variaram em função da planta receptora, concentração, e da parte da planta analisada. A espécie M. pudica apresentou maior sensibilidade aos efeitos inibitórios do que S. obtusifolia. A espécie S. obtusifolia, quando analisada isoladamente, apresentou Efeito Fitotóxico EF50 na germinação das sementes e no desenvolvimento da radícula em concentrações próximas à máxima utilizada, enquanto que a espécie M. pudica apresentou EF50 e EF90 nas concentrações mínimas e próximas à máxima, 0,25% e 1,00%. Os extratos da geoprópolis da abelha jandaira (M. subnitida) avaliados possuem em sua composição bioativos com potencial efeito fitotóxico às plantas daninhas estudadas.

The cowpea Vigna unguiculata (L.) Walp., also known as cowpea, is of fundamental socioeconomic importance to the northeast of Brazil, and has become one of the main sources of protein in the diet of the rural population. However, in this region, it has become necessary to identify genotypes that are better adapted to drought. In addition, research is needed regarding the action of substances that promote tolerance to stress factors. The aim of this study was to evaluate the antioxidative response of cowpea cultivars under osmotic stress conditions using potassium nitrate as an attenuator. Five osmotic potentials were tested in the substrate (0.0, −0.2, −0.4, −0.6, and −0.8 MPa), and three seed treatments (pre-soaking in distilled water, pre-soaking in potassium nitrate, and without pre-soaking) were tested in three cowpea cultivars (BRS Itaim, BRS Aracê, and BRS Potengi). The design was randomized with 45 treatments and four replications. The data were submitted to analysis of variance (P < 0.05), and in cases of significance, regression analysis was conducted to quantitate the factors. Our results indicate that an increase in proline content in cowpea plants may be seen as indicative of the intensity of water stress on germination and the initial stages of growth of the plant. The BRS Itaim cultivar best tolerates drought conditions with the application of potassium nitrate, given the increased activity of antioxidant enzymes such as superoxide dismutase, catalase, and ascorbate peroxidase.

The cowpea [Vigna unguiculata (L.) Walp.], also known as cowpea, is of fundamental socioeconomic importance to the northeast of Brazil, and has become one of the main sources of protein in the diet of the rural population. However, in this region, it has become necessary to identify genotypes that are better adapted to drought. In addition, research is needed regarding the action of substances that promote tolerance to stress factors. The aim of this study was to evaluate the antioxidative response of cowpea cultivars under osmotic stress conditions using potassium nitrate as an attenuator. Five osmotic potentials were tested in the substrate (0.0, −0.2, −0.4, −0.6, and −0.8 MPa), and three seed treatments (pre-soaking in distilled water, pre-soaking in potassium nitrate, and without pre-soaking) were tested in three cowpea cultivars (BRS Itaim, BRS Aracê, and BRS Potengi). The design was randomized with 45 treatments and four replications. The data were submitted to analysis of variance (P < 0.05), and in cases of significance, regression analysis was conducted to quantitate the factors. Our results indicate that an increase in proline content in cowpea plants may be seen as indicative of the intensity of water stress on germination and the initial stages of growth of the plant. The BRS Itaim cultivar best tolerates drought conditions with the application of potassium nitrate, given the increased activity of antioxidant enzymes such as superoxide dismutase, catalase, and ascorbate peroxidase. | O feijão-caupi [Vigna unguiculata (L.) Walp.], também conhecido como feijão macassar, representa fundamental importância socioeconômica para o Nordeste do Brasil, constituindo-se como uma das principais fontes proteicas na alimentação da população rural. Todavia, nessa região é necessário identificar genótipos mais adaptados ao déficit hídrico, bem como conhecer a ação de substâncias promotoras de tolerância a fatores de estresse. O objetivo desse trabalho foi avaliar a resposta antioxidativa de cultivares feijão-caupi sob condições de estresse osmótico, utilizando como atenuador o nitrato de potássio. Foram testados cinco potenciais osmóticos no substrato (0,0; -0,2; -0,4; -0,6 e -0,8 MPa) e três tratamentos de sementes (pré-embebição em água destilada; pré-embebição em nitrato de potássio e sem pré-embebição) em três cultivares (BRS Itaim, BRS Aracê e BRS Potengi). Foi adotado o delineamento inteiramente casualizado, com quatro repetições e sementes por repetição. Os dados obtidos foram submetidos à análise de variância (P