ABSTRACT The application of a bionematicide based on chlamydospores of Pochonia chlamydosporia (Pc-10) can be an important strategy for reducing the damage caused by Meloidogyne incognita on carrot. Based on this perspective, the nematicidal effects of 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kg ha -1 of Pc-10 were evaluated on carrot cv. Juliana under field conditions. Carrot yield and nematode population were influenced by increasing doses of Pc-10. The application of 3.0 kg ha-1 of Pc-10 increased the marketable production of carrot roots by 41.7% compared to the untreated control, whereas the production of unmarketable roots and the nematode population in the soil were reduced by 48.7% and 61.4%. The application of 3.0 kg ha -1 of Pc-10 reduces M. incognita population and improves carrot quality and yield. | RESUMO A aplicação de um bionematicida à base de clamidósporos de Pochonia chlamydosporia (Pc-10) pode se tornar uma importante estratégia para reduzir os danos causados por Meloidogyne incognita em cenoura. Baseado nessa perspectiva, o efeito nematicida de 0; 0,5; 1,0; 1,5; 2,0; 2.5 e 3,0 kg ha -1 de Pc-10 foi avaliado em área de produção de cenoura cv. Juliana em condições de campo. A produtividade de cenoura e a população do nematoide foram influenciados por doses crescentes de Pc-10. A aplicação de 3,0 kg ha-1 de Pc-10 aumentou a produção de raízes comerciais de cenoura em 41,7% comparada com aquela obtida na testemunha não tratada, enquanto que a produção de raízes não-comerciais e a população do nematoide no solo foram reduzidos em 48,7% e 61,4%, respectivamente. A aplicação de 3,0 kg ha -1 de Pc-10 reduz a população de M. incognita e aumenta a qualidade e a produtividade das raízes de cenoura.

The application of a bionematicide based on chlamydospores of Pochonia chlamydosporia (Pc-10) can be an important strategy for reducing the damage caused by Meloidogyne incognita on carrot. Based on this perspective, the nematicidal effects of 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kg ha-1 of Pc-10 were evaluated on carrot cv. Juliana under field conditions. Carrot yield and nematode population were influenced by increasing doses of Pc-10. The application of 3.0 kg ha-1 of Pc-10 increased the marketable production of carrot roots by 41.7% compared to the untreated control, whereas the production of unmarketable roots and the nematode population in the soil were reduced by 48.7% and 61.4%. The application of 3.0 kg ha-1 of Pc-10 reduces M. incognita population and improves carrot quality and yield.

ABSTRACT The proper soil use and management are essential for a sustainable production, thus the pursuit for systems that minimize damages to the environment and improve soil fertility is continuous. The objective of this study was to evaluate changes in soil fertility by the use and management of an Oxisol (Latossolo Vermelho-amarelo, SiBCS) in the Amazon biome. The soil uses and management systems evaluated were native forest, native pasture, minimum tillage system and conventional tillage system. The chemical atributes of the soil layers 0.00-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.40 m were evaluated. The soil pH (CaCl2) and the contents of organic matter, available phosphorus and exchangeable potassium, calcium, magnesium and aluminum were evaluated and the saturation by Al, effective cation exchange capacity and soil potential were determined. The highest pH values were found in the native pasture area, and the highest exchangeable aluminum contents were found in the layers 0.00-0.10 and 0.10-0.20 m of the conventional tillage system. The highest phosphorus availability was found in the layer 0.00-0.10 m of the native forest area. The highest potassium availability was found in the minimum tillage system. The lowest calcium and magnesium values were found in the layers 0.00-0.10 and 0.10-0.20 m of the conventional tillage system. The highest soil organic matter content was found in the layer 0.00-0.10 m of the native forest area. The nutrient availability for plants decreases in soils managed using the conventional tillage system. Soil uses and management systems of little soil disturbance are recommended to minimize environmental degradation in the Amazon biome. | RESUMO O uso e manejo do solo adequados são fundamentais para a produção sustentável, sendo constante a busca por sistemas que minimizem os danos causados ao ambiente e que melhorem a fertilidade do solo. Objetivou-se avaliar as alterações nos atributos de fertilidade em decorrência do uso e manejo em Latossolo Vermelho-Amarelo (LVA) na Amazônia. Os seguintes sistemas de uso e manejo do solo num LVA foram avaliados: floresta nativa, pastagem nativa e áreas preparadas por sistema de cultivo mínimo e cultivo convencional. As avaliações dos atributos químicos do solo foram realizadas nas profundidades de 0 -0,10, 0,10-0,20, 0,20-0,30 e 0,30-0,40 m. Foram avaliados o pH do solo (CaCl2), o teor de matéria orgânica do solo, os teores de fósforo disponível e potássio trocável, cálcio, magnésio e alumino trocáveis, sendo ainda determinados a saturação por Al, a capacidade de troca catiônica efetiva e potencial do solo. Os valores de pH mais elevados foram verificados no sistema de pastagem nativa e os maiores teores de alumínio trocável nas profundidades de 0-0,10 e 0,10-0,20 m foram verificadas no sistema de cultivo convencional. O sistema de floresta nativa apresentou a maior disponibilidade de fósforo na profundidade de 0-0,10 m. As maiores disponibilidades de potássio foram verificadas no sistema de cultivo mínimo. Os menores valores de cálcio e magnésio nas profundidades de 0-0,10 e 0,10-0,20 m ocorreram no sistema de cultivo convencional. O sistema de floresta nativa apresentou o maior teor de matéria orgânica do solo na profundidade de 0-0,10 m. A disponibilidade de nutrientes para as plantas é reduzida em solos manejados em sistema de plantio convencional. Os sistemas de uso e manejo de menor revolvimento do solo são indicados para minimizar a degradação ambiental na Amazônia.

The proper soil use and management are essential for a sustainable production, thus the pursuit for systems that minimize damages to the environment and improve soil fertility is continuous. The objective of this study was to evaluate changes in soil fertility by the use and management of an Oxisol (Latossolo Vermelho - amarelo, SiBCS) in the Amazon biome. The soil uses and management systems evaluated were native forest, native pasture, minimum tillage system and conventional tillage system. The chemical atributes of the soil layers 0.00 - 0.10, 0.10 - 0.20, 0.20 - 0.30 and 0.30 - 0.40 m were evaluated. The soil pH (CaCl 2 ) and the contents of organic matter, available phosphorus and exchangeable potassium, calcium, magnesium and aluminum were evaluated and the saturation by Al, effective cation exchange capacity and soil potential were determined. The highest pH values were found in the native pasture area, and the highest exchangeable aluminum contents were found in the layers 0.00 - 0.10 and 0.10 - 0.20 m of the conventional tillage system. The highest phosphorus availability was found in the layer 0.00 - 0.10 m of the native forest area. The highest potassium availability was found in the minimum tillage system. The lowest calcium and magnesium values were found in the layers 0.00 - 0.10 and 0.10 - 0.20 m of the conventional tillage system. The highest soil organic matter content was found in the layer 0.00 - 0.10 m of the native forest area. The nutrient availability for plants decreases in soils managed using the conventional tillage system. Soil uses and management systems of little soil disturbance are recommended to minimize environmental degradation in the Amazon biome.

ABSTRACT Early blight (caused by Alternaria tomatophila) is a major disease of tomato with no resistant cultivars. Thus, it is necessary to identify sources of resistance and productive genotypes for the development of new cultivars. Therefore, this study aimed to evaluate the productive potential of cherry tomato genotypes grown in the summer / fall, the severity of early blight on leaves and the incidence of disease in fruits. The treatments consisted of Carolina tomato genotypes, Cereja Vermelho, CH 152 and CLN1561A. The experimental design consisted of randomized blocks with six replications, and the experimental plot had 16 plants. The following characteristics were evaluated: area under the disease progress curve (AUDPC), average number of microinjuries on the fruits (MF), average number of fruits per bunch (NFC), average number of bunches per plant (NCP), average number of fruits per plant (NFP), average yield, number of fruits with incidence of early blight per plant (NFI) and the severity of early blight in leaves (%). The cherry tomato genotype CH152 showed tolerance to early blight with a smaller area under the disease progress curve, lower severity and fruits with incidence of A. tomatophila were not observed in this genotype. The CH152 had the highest number of fruits per bunch, greater number of bunches per plant, higher number of fruits per plant and higher productivity. This line has great potential of being integrated into breeding programs. | RESUMO A pinta preta (Alternaria tomatophila) é uma das principais doenças do tomateiro não havendo cultivares resistentes à doença. Com isso, é necessário identificar fontes de resistência e genótipos produtivos na perspectiva de desenvolvimento de novas cultivares. Logo, objetivou com esse estudo avaliar o potencial produtivo de genótipos de tomateiro cereja cultivados no verão/outono, a severidade da pinta preta nas folhas e a incidência da doença nos frutos. Os tratamentos consistiram dos genótipos de tomateiro Carolina, Cereja Vermelho, CH 152 e CLN1561A. O delineamento experimental foi de blocos ao acaso com seis repetições, sendo a parcela experimental constituída por 16 plantas. Foram avaliadas as seguintes características: área abaixo da curva de progresso da doença (AACPD), número médio de microferimentos nos frutos (MF), número médio de frutos por cacho (NFC), número médio de cachos por planta (NCP), número médio de frutos por planta (NFP), produtividade média, número de frutos com incidência de pinta preta por planta (NFI) e a severidade da pinta preta nas folhas (%). O genótipo de tomateiro cereja CH152 apresentou tolerância à pinta preta com menor área abaixo da curva de progresso da doença, menor severidade e também não foram observados frutos com incidência de A. tomatophila nesse genótipo. O CH152 apresentou o maior número de frutos por cacho, maior número de cachos por planta, maior número de frutos por planta e maior produtividade. Esta linhagem tem grande potencial para ser integrada em programas de melhoramento genético.

Early blight (caused by Alternaria tomatophila ) is a major disease of tomato with no resistant cultivars. Thus, it is necessary to identify sources of resistance and productive genotypes for the development of new cultivars. Therefore, this study aimed to evaluate the productive potential of cherry tomato genotypes grown in the summer / fall, the severity of early blight on leaves and the incidence of disease in fruits. The treatments consisted of Carolina tomato genotypes, Cereja Vermelho, CH 152 and CLN1561A. The experimental design consisted of randomized blocks with six replications, and the experimental plot had 16 plants. The following characteristics were evaluated: area under the disease progress curve (AUDPC), average number of microinjuries on the fruits (MF), average number of fruits per bunch (NFC), average number of bunches per plant (NCP), average number of fruits per plant (NFP), average yield, number of fruits with incidence of early blight per plant (NFI) and the severity of early blight in leaves (%). The cherry tomato genotype CH152 showed tolerance to early blight with a smaller area under the disease progress curve, lower severity and fruits with incidence of A. tomatophila were not observed in this genotype. The CH152 had the highest number of fruits per bunch, greater number of bunches per plant, higher number of fruits per plant and higher productivity. This line has great potential of being integrated into breeding programs.

ABSTRACT The objective of this work was to evaluate the effect of applying mixtures of chemical ripeners on the technological quality and agricultural productivity of sugarcane. The experimental design consisted of randomized blocks arranged in split- split-plots with four blocks, the main plots being constituted by sugarcane varieties SP803280 and SP801842. The subplots consisted of the application of the following products with their respective mixtures: control - absence of ripener; Sulfometrom methyl + glyphosate; ethephon + glyphosate; glyphosate and compounds of organic carboxylic radicals + glyphosate. The sub-subplots were composed of evaluation times: 0; 15 and 30 days after applying the products. Samples from each plot were collected manually and sent to the laboratory for the determination of soluble Brix solids (% broth); Sucrose content in the broth - Pol (% broth); Reducing sugars (RS%); Total reducing sugars (TRS%); Fiber (%); Purity (%); Humidity (%) and Total recoverable sugar TRS (kg t-1). The plots were fully harvested and the stems were taken for weighing and for characteristics determination: Yield per hectare (TCH) and Yield of sugar per hectare (TAH). The SP803280 variety was more responsive to the use of mixtures of chemical ripeners. For the technological characteristics, sulfometurom methyl (0.02 kg ha-1) + glyphosate (0.15 L ha-1) presented the best results from 15 days after application. Mixtures of chemical ripeners did not increase the yields of stalks and sugar per area. | RESUMO O objetivo deste trabalho foi avaliar a aplicação das misturas de maturadores químicos na qualidade tecnológica e produtividade agrícola da cana-de-açúcar . Foi utilizado o delineamento experimental em blocos casualizados arranjados em parcelas sub-subdivididas com 4 blocos, sendo as parcelas principais constituídas pelas variedades de cana-de-açúcar: SP803280 e SP801842. As subparcelas consistiram da aplicação dos seguintes produtos com suas respectivas misturas: controle - ausência de maturador; sulfometurom metil + glifosato; etefon + glifosato; glifosato e compostos de radicais carboxílicos orgânicos + glifosato. As sub-subparcelas foram constituídas de épocas de avaliação: 0; 15 e 30 dias após as aplicações dos produtos. As amostras de cada parcela foram colhidas manualmente e encaminhadas ao laboratório para determinação dos sólidos solúveis Brix (% caldo); teor de sacarose no caldo - Pol (% caldo); Açúcares redutores (AR%); Açúcares redutores totais (ART%); Fibra (%); Pureza (%); Umidade (%) e Açúcar total recuperável ATR (kg t-1). As parcelas foram totalmente colhidas e os colmos despontados para pesagem e para a determinação das características: Rendimento de colmos por hectare (TCH) e Rendimento de açúcar por hectare (TAH). A variedade SP803280 destacou-se como mais responsiva ao uso das misturas de maturadores químicos. Para as características tecnológicas, a mistura sulfometurom metil (0,02 kg ha-1) + glifosato (0,15 L ha-1) apresentou os melhores resultados a partir dos 15 dias após a sua aplicação. As misturas de maturadores químicos não proporcionaram aumentos de produtividade de colmos e açúcar por área.

The objective of this work was to evaluate the effect of applying mixtures of chemical ripeners on the technological quality and agricultural productivity of sugarcane. The experimental design consisted of randomized blocks arranged in split- split-plots with four blocks, the main plots being constituted by sugarcane varieties SP803280 and SP801842. The subplots consisted of the application of the following products with their respective mixtures: control - absence of ripener; Sulfometrom methyl + glyphosate; ethephon + glyphosate; glyphosate and compounds of organic carboxylic radicals + glyphosate. The sub-subplots were composed of evaluation times: 0; 15 and 30 days after applying the products. Samples from each plot were collected manually and sent to the laboratory for the determination of soluble Brix solids (% broth); Sucrose content in the broth - Pol (% broth); Reducing sugars (RS%); Total reducing sugars (TRS%); Fiber (%); Purity (%); Humidity (%) and Total recoverable sugar TRS (kg t-1). The plots were fully harvested and the stems were taken for weighing and for characteristics determination: Yield per hectare (TCH) and Yield of sugar per hectare (TAH). The SP803280 variety was more responsive to the use of mixtures of chemical ripeners. For the technological characteristics, sulfometurom methyl (0.02 kg ha-1) + glyphosate (0.15 L ha-1) presented the best results from 15 days after application. Mixtures of chemical ripeners did not increase the yields of stalks and sugar per area.

ABSTRACT 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. | RESUMO 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.

ABSTRACT The objective of this work was to evaluate the agronomic performance of elite-strains of cowpea cultivars under the conditions of the north of Minas Gerais (MG), Brazil. Fifteen elite-strains and five erect and semi-erect cultivars of cowpea were evaluated in the 2014 and 2015 summer-fall crop seasons in Janaúba MG. A randomized block experimental design was used with four replications. Plant size, lodging and value of cultivation, pod length and grain yield were evaluated. The data of the two crops were subjected to individual and joint analysis of variance. The genotype-crop interactions significantly affected all studied variables. The strains MNC04-792F-146 and MNC04-792F-144 stood out as the most productive genotypes in both crops. The cultivars BRS Itaim and BRS Novaera presented adequate size and lodging characteristics for cultivation, and values of cultivation that meet commercial standards, thus representing good alternatives for the genotypes cultivated in the north of Minas Gerais. | RESUMO Objetivou-se com este trabalho avaliar a performance agronômica de linhagens-elite e cultivares de feijão-caupi, nas condições de cultivo do Norte de Minas Gerais. Foram avaliadas 15 linhagens-elite e cinco cultivares de feijão-caupi de portes ereto e semiereto, nas safras de verão-outono de 2014 e 2015, em Janaúba, MG. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Foram avaliados o porte da planta, o grau de acamamento e o valor de cultivo, o comprimento da vagem e o rendimento de grãos. Os dados obtidos foram submetidos a análises de variância individuais e conjunta, envolvendo as duas safras de cultivo. Verificou-se efeito significativo para a interação entre genótipos e safras para todas as variáveis estudadas. As linhagens MNC04-792F-146 e MNC04-792F-144 destacaram-se por estarem entre os genótipos mais produtivos nas duas safras avaliadas. As cultivares BRS Itaim e BRS Novaera apresentaram simultaneamente características de porte e acamamento adequadas para o cultivo, além de obterem valor de cultivo compatível com o padrão comercial, representando boas alternativas de cultivo no Norte de Minas Gerais.

The objective of this work was to evaluate the agronomic performance of elite-strains of cowpea cultivars under the conditions of the north of Minas Gerais (MG), Brazil. Fifteen elite-strains and five erect and semi-erect cultivars of cowpea were evaluated in the 2014 and 2015 summer-fall crop seasons in Janaúba MG. A randomized block experimental design was used with four replications. Plant size, lodging and value of cultivation, pod length and grain yield were evaluated. The data of the two crops were subjected to individual and joint analysis of variance. The genotype-crop interactions significantly affected all studied variables. The strains MNC04-792F-146 and MNC04-792F-144 stood out as the most productive genotypes in both crops. The cultivars BRS Itaim and BRS Novaera presented adequate size and lodging characteristics for cultivation, and values of cultivation that meet commercial standards, thus representing good alternatives for the genotypes cultivated in the north of Minas Gerais.

ABSTRACT The restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) mixed model method has been used to study the effects of genotype by environment interaction (G x E) in various crops including cowpea. This work aimed to analyze the G x E interaction via mixed models to identify cowpea genotypes that meet high adaptability, stability and productivity of pods and green grains when grown under Mossoró, Rio Grande do Norte State conditions. Crop value and use were evaluated in two growing seasons, using randomized complete blocks design with 23 genotypes and four replications. The genetic parameters were estimated by the REML/BLUP procedure and selection was based on the harmonic mean of the relative performance of genetic values (HMRPGV). Agreement between the HMGV, relative performance of genotypic values (RPGV) and HMRPGV statistics, provided genotype discrimination. Furthermore, the HMRPGV results enabled the simultaneous selection of superior genotypes for productivity, adaptability and stability. For the productivities of pods and green grains, the most notable genotypes were the cultivars BRS Xiquexique and BRS Aracê, and the line MNC05-835B-15, which showed a high productivity of grains, adaptability and stability, and could be grown in the two growing seasons considered in the study. | RESUMO A metodologia de modelos mistos REML/BLUP tem sido empregada para estudar os efeitos da interação genótipos x ambientes (G x E) em várias culturas, inclusive em feijão-caupi. O objetivo deste trabalho foi analisar a interação genótipos por ambientes em feijão-caupi via modelos mistos e identificar genótipos que reúnam alta adaptabilidade, estabilidade e produtividade de vagens e grãos verdes nas condições de Mossoró, RN. Os genótipos foram avaliados em ensaios de valor de cultivo e uso conduzidos em duas épocas de cultivo, sob delineamento experimental de blocos completos casualizados, com 23 genótipos e quatro repetições. Os parâmetros genéticos foram estimados via procedimento REML/BLUP, e a seleção baseou -se no método da média harmônica do desempenho relativo dos valores genéticos (MHPRVG). Houve concordância entre as estatísticas MHVG, PRVG e MHPRVG na discriminação dos genótipos, sendo que esta última possibilitou a seleção simultânea de genótipos superiores em produtividade, adaptabilidade e estabilidade. Para as produtividades de vagens e grãos verdes os genótipos de maior destaque foram as cultivares BRS Xiquexique, BRS Aracê e a linhagem MNC05-835B-15 que reuniram alta produtividade de grãos, adaptabilidade e estabilidade, podendo ser cultivados nas duas épocas de cultivo consideradas no estudo.

The restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) mixed model method has been used to study the effects of genotype by environment interaction (G x E) in various crops including cowpea. This work aimed to analyze the G x E interaction via mixed models to identify cowpea genotypes that meet high adaptability, stability and productivity of pods and green grains when grown under Mossoró, Rio Grande do Norte State conditions. Crop value and use were evaluated in two growing seasons, using randomized complete blocks design with 23 genotypes and four replications. The genetic parameters were estimated by the REML/BLUP procedure and selection was based on the harmonic mean of the relative performance of genetic values (HMRPGV). Agreement between the HMGV, relative performance of genotypic values (RPGV) and HMRPGV statistics, provided genotype discrimination. Furthermore, the HMRPGV results enabled the simultaneous selection of superior genotypes for productivity, adaptability and stability. For the productivities of pods and green grains, the most notable genotypes were the cultivars BRS Xiquexique and BRS Aracê, and the line MNC05-835B-15, which showed a high productivity of grains, adaptability and stability, and could be grown in the two growing seasons considered in the study.

ABSTRACT 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. | RESUMO 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.

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.

ABSTRACT In flood plains, cover crops are able to alter soil properties and significantly affect rice nutrition and yield. The aims of this study were to determine soil properties, plant nutrition, and yield of tropical rice cultivated on flood plains after cover crop cultivation with conventional tillage (CT) and no-tillage system (NTS) at low and high nitrogen (N) fertilization levels. The experimental design was a randomized block in a split-split-plot scheme with four replications. In the main plots were cover crops [sunhemp (Crotalaria juncea and C. spectabilis), velvet bean (Mucuna aterrima), jackbean (Canavalia ensiformis), pigeon pea (Cajanus cajan), Japanese radish (Raphanus sativus), cowpea (Vigna unguiculata)] and a fallow field. In the subplots were the tillage systems (CT or NTS). The nitrogen fertilization levels in the sub-subplots were (10 kg N ha-1 and 45 kg N ha-1). All cover crops except Japanese radish significantly increased mineral soil nitrogen and nitrate concentrations. Sunhemp, velvet bean, and cowpea significantly increased soil ammonium content. The NTS provides higher mineral nitrogen and ammonium content than that by CT. Overall, cover crops provided higher levels of nutrients to rice plants in NTS than in CT. Cover crops provide greater yield than fallow treatments. Rice yield was higher in NTS than in CT, and greater at a higher rather than lower nitrogen fertilization level. | RESUMO O uso de plantas de cobertura pode alterar atributos do solo e afetar significativamente a nutrição das plantas e produtividade do arroz cultivado em planícies inundáveis. Este trabalho teve como objetivo determinar atributos do solo, nutrição de plantas e produtividade do arroz irrigado tropical em planícies irrigáveis por inundação após o cultivo de plantas de cobertura, no preparo convencional do solo (PC) ou sistema plantio direto (SPD) em baixa e alta adubação com N. O delineamento experimental foi em blocos casualizados, no esquema de parcelas sub-subdivdidas, com quatro repetições. Nas parcelas estavam as coberturas vegetais [Crotalaria juncea, C. spectabilis, mucuna preta (Mucuna aterrina), feijão de porco (Canavalia ensiformis), feijão guandu (Cajanus cajan), nabo forrageiro (Raphanus sativus), feijão caupi (Vigna unguiculata) e pousio], nas subparcelas o sistema de preparo do solo (PC ou SPD) e nas sub-subparcelas a adubação nitrogenada (10 e 45 kg ha-1 N). As plantas de cobertura, com exceção do nabo forrageiro, proporcionam incrementos nos teores de N total e nitrato no solo. C. juncea, C. spectabilis, mucuna preta e feijão caupi proporcionam incrementos nos teores de amônio no solo. O SPD proporciona maiores teores de N total e amônio do que o PC. No âmbito geral, as plantas de cobertura proporcionaram maiores teores de nutrientes nas plantas de arroz no SPD do que no PC. As plantas de cobertura também proporcionaram maior produtividade do arroz em relação ao tratamento pousio. O rendimento do arroz é maior em SPD do que PC, e superior com alto nível de adubação nitrogenada.

In flood plains, cover crops are able to alter soil properties and significantly affect rice nutrition and yield. The aims of this study were to determine soil properties, plant nutrition, and yield of tropical rice cultivated on flood plains after cover crop cultivation with conventional tillage (CT) and no-tillage system (NTS) at low and high nitrogen (N) fertilization levels. The experimental design was a randomized block in a split-split-plot scheme with four replications. In the main plots were cover crops sunhemp (Crotalaria juncea and C. spectabilis), velvet bean (Mucuna aterrima), jackbean (Canavalia ensiformis), pigeon pea (Cajanus cajan), Japanese radish (Raphanus sativus), cowpea (Vigna unguiculata) and a fallow field. In the subplots were the tillage systems (CT or NTS). The nitrogen fertilization levels in the sub-subplots were (10 kg N ha-1 and 45 kg N ha-1). All cover crops except Japanese radish significantly increased mineral soil nitrogen and nitrate concentrations. Sunhemp, velvet bean, and cowpea significantly increased soil ammonium content. The NTS provides higher mineral nitrogen and ammonium content than that by CT. Overall, cover crops provided higher levels of nutrients to rice plants in NTS than in CT. Cover crops provide greater yield than fallow treatments. Rice yield was higher in NTS than in CT, and greater at a higher rather than lower nitrogen fertilization level.

RESUMO Objetivou-se, com esse trabalho, a avaliação técnica e econômica da produtividade do tomateiro cultivado com diferentes frequências de irrigação no litoral cearense. O experimento foi conduzido em campo na área experimental da Universidade Federal do Ceará, Fortaleza, Ceará, durante o período de agosto a dezembro nos anos de 2011 e de 2012. O delineamento experimental utilizado nos dois ciclos de avaliações foi de blocos ao acaso, composto de seis tratamentos equivalentes às frequências de irrigação: F2 (dois dias); F3 (três dias); F4 (quatro dias), F5 (cinco dias), F6 (seis dias) e F7 (sete dias), com quatro repetições. Aos vinte dias após o transplantio (DAT), quando as plantas já estavam aclimatizadas no campo, foram diferenciados os tratamentos. A colheita se iniciou aos setenta DAT e foi concluída aos noventa DAT. Foram analisadas as seguintes variáveis: comprimento, diâmetro e massa do fruto, número de frutos por planta e a produtividade, sendo também realizada a análise econômica do cultivo. Os produtores da região litorânea do estado do Ceará, que visem um maior rendimento econômico quanto a receita liquida devem adotar uma Frequência de irrigação de dois dias (F2). | ABSTRACT The objective of this work was to technically and economically evaluate the productivity of tomato grown under different irrigation frequencies in the coast of Ceará, Brazil. The experiment was conducted in the experimental area of the Federal University of Ceará, Fortaleza, State of Ceará, Brazil, from August to December of 2011 and 2012. A randomized block experimental design was used in the two crop cycles, with six irrigation frequencies, consisted of 2 (F2), 3 (F3), 4 (F4), 5 (F5), 6 (F6) and 7 (F7) days of interval between irrigations, and four replications. The treatments were evaluated at twenty days after transplanting (DAT), when the plants were fully acclimated to the field. The harvesting began at seventy DAT and ended at ninety DAT. The variables analyzed were fruit length, diameter and weight, number of fruits per plant and fruit yield. The economic performance of the crop was also evaluated. Tomato producers of the coastal region of the State of Ceará, who aim to increase economic return, i.e., net income, must adopt a two- day irrigation frequency (F2).

The objective of this work was to technically and economically evaluate the productivity of tomato grown under different irrigation frequencies in the coast of Ceará, Brazil. The experiment was conducted in the experimental area of the Federal University of Ceará, Fortaleza, State of Ceará, Brazil, from August to December of 2011 and 2012. A randomized block experimental design was used in the two crop cycles, with six irrigation frequencies, consisted of 2 (F2), 3 (F3), 4 (F4), 5 (F5), 6 (F6) and 7 (F7) days of interval between irrigations, and four replications. The treatments were evaluated at twenty days after transplanting (DAT), when the plants were fully acclimated to the field. The harvesting began at seventy DAT and ended at ninety DAT. The variables analyzed were fruit length, diameter and weight, number of fruits per plant and fruit yield. The economic performance of the crop was also evaluated. Tomato producers of the coastal region of the State of Ceará, who aim to increase economic return, i.e., net income, must adopt a two- day irrigation frequency (F2).