RESUMO Determinar o acúmulo e a exportação de nitrogênio (N) pelo feijoeiro em função da palhada e do seu parcelamento é importante visando o manejo e a sustentabilidade dos sistemas agrícolas. O objetivo com esse trabalho foi determinar o acúmulo e a exportação de N pelo feijoeiro cultivado sob palhada de milho ( Zea mays) e braquiária (Urochloa ruziziensis) exclusivos ou em consórcio e em função do parcelamento da adubação nitrogenada em cobertura. O experimento foi conduzido em Jaboticabal-SP-Brasil, durante a safra 2012/13, num Latossolo Vermelho eutrófico típico, sob área irrigada no sistema plantio direto. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas com quatro repetições, totalizando 120 subparcelas dimensionadas em 25m2 cada. As parcelas foram constituídas pelos sistemas de cultivo antecessores ao feijoeiro: milho, milho consorciado com braquiária e braquiária. As subparcelas foram compostas por dez parcelamentos da adubação nitrogenada de cobertura (PN) estádios fenológicos V 3, V4 e R5 em diferentes combinações. A produtividade de grãos do feijoeiro difere entre os sistemas de cultivo e em função do parcelamento do N em cobertura. O cultivo exclusivo de braquiária proporciona maiores acúmulos de N na parte aérea do feijoeiro comparado ao milho e seu consórcio com braquiária. Independentemente do sistema de cultivo, a aplicação de N em cobertura em dose única de 90 kg ha-1 em V4 (terceiro trifólio) proporciona acúmulos e exportações semelhantes àqueles na ausência da adubação nitrogenada. Os parcelamentos com aplicação de N em cobertura no estádio R5 (pré-florescimento) incrementa as exportações desse nutriente no feijoeiro em sucessão ao milho e seu consórcio com braquiária. | ABSTRACT Determining nitrogen (N) accumulation and export by common bean as a function of straw and of the splitting of this nutrient is very important, aiming at the management and sustainability of agricultural systems. This study aimed to determine the N accumulation and export by common bean as a function of Zea mays and Urochloa ruziziensis grass straw (maize, maize/U. ruziziensis intercropping and U. ruziziensis) and splitting of top-dressing N fertilization. The experiment was conducted in Jaboticabal-SP-Brazil, during the 2012/13 crop season, in a Red Eutrophic Oxisol (Eutrudox) in no-tillage under irrigation. The experimental design was a randomized block with split plots with four replicates, totaling 120 subplots sized in 25m2 each. The plots consisted of the cropping systems prior to common bean: maize, maize/ U. ruziziensis intercropping and U. ruziziensis. The subplots were composed of ten top-dressing N fertilization splitting schemes (NS) at the phenological stages V3, V4 and R5 in different combinations. Common bean grain yield differs among cropping systems and as a function of top-dressed N split application. U. ruziziensis grass as single crop promotes greater N accumulation in common bean shoots compared to maize and its intercropping with U. ruziziensis grass. Regardless the cropping system, top-dressing N application in a single dose (90 kg ha-1) at V4 leads to similar accumulations and exports to those found in the absence of N fertilization. Splitting schemes with N application at the R5 stage increase the exports of this nutrient by common bean in succession to maize and its intercropping with U. ruziziensis grass.

RESUMO A fruticultura irrigada no Vale do São Francisco vem se destacando na região Nordeste do Brasil e o manejo incorreto da adubação tem proporcionado problemas de degradação física e/ou química do solo. O trabalho teve como objetivo avaliar a variabilidade espacial dos atributos químicos de um Latossolo Vermelho -Amarelo cultivado com banana (Musa spp). O estudo foi realizado no perímetro irrigado de Nupeba em Riachão das Neves/BA. Em uma área cultivada por 18 anos com banana prata fertirrigada por microaspersão. Em abril de 2017 coletou-se amostras simples de solo nas profundidades de 0-0,20 m e de 0,20-0,40 m, a partir de uma malha experimental constituída de 40 pontos georreferenciados e distanciados a cada 10 metros. Nas amostras de solo foram determinados: pH (H2O); Carbono orgânico; Fósforo (P); Potássio (K+); Cálcio (Ca2+); Magnésio (Mg2+) e Acidez potencial (H+Al) e calculados a soma de bases (SB), capacidade de troca catiônica (CTC) e saturação por bases (V%). Os resultados das análises foram avaliados por meio da estatística descritiva e a técnica da geoestatistica. A análise descritiva identificou a normalidade dos dados. A variabilidade espacial foi confirmada, permitindo a confecção de mapas. A área analisada possui baixa fertilidade (V<55%) e o manejo inadequado de correção e adubação do solo podem reduzir a disponibilidade dos nutrientes para a cultura implantada, tornando o solo passível de degradação com o uso da irrigação. Os mapas de distribuição permitem a visualização da área, possibilitando a aplicação de insumos com taxa variada, visando à homogeneização da fertilidade do solo. | ABSTRACT Irrigated fruit growing in the São Francisco Valley has been standing out in the Northeast region of Brazil and the incorrect management of fertilization has caused problems of physical and / or chemical degradation of the soil. The work aimed to evaluate the spatial variability of the chemical attributes of a Latossolo Vermelho-Amarelo (Oxisol) grown with banana (Musa spp). The study was carried out in the irrigated perimeter of Nupeba in Riachão das Neves / BA. In an area cultivated for 18 years with silver banana fertigated by micro sprinkling. In April 2017 simple soil samples were collected at depths of 0 -0.20 m and 0.20 -0.40 m, from an experimental grid consisting of 40 georeferenced points and spaced every 10 meters. The soil samples determined: pH (H2O); Organic carbon; Phosphorus (P); Potassium (K+); Calcium (Ca2+); Magnesium (Mg2+) and Potential acidity (H + Al) and the sum of bases (BS), cation exchange capacity (CEC) and base saturation (V%) were calculated. The results of the analyses were evaluated using descriptive statistics and the geostatistics technique. The descriptive analysis identified the normality of the data. The spatial variability was confirmed, allowing the making of maps. The analyzed area has low fertility (V <55%) and the inadequate management of soil correction and fertilization can reduce the availability of nutrients for the implanted crop, making the soil susceptible to degradation with the use of irrigation. The distribution maps allow the visualization of the area, allowing the application of inputs with varying rates, aiming at homogenizing the soil fertility.

ABSTRACT The Brazilian Northeast region suffers from some abiotic stresses that are responsible for the loss of agricultural production, such as long drought periods and high evapotranspiration, associated with the quality of the water, which induces the use of saline water as an alternative for the expansion of irrigated areas, and silicate fertilization contributes to reduce the effects of salinity under the Northeastern semi -arid conditions. The objective of this study was to evaluate the osmotic potential and physiological indices of yellow passion fruit seedlings under irrigation water salinity and silicate fertilization. The experiment was carried out under greenhouse conditions at the Federal University of Campina Grande, Pombal -PB, Brazil, in a randomized block design in a 5 x 5 factorial scheme, relative to five levels of electrical conductivity of irrigation water - ECw (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five doses of silicate fertilization (0; 25; 50; 75 and 100 g silicon per plant) in four replicates and two plants per plot. The application of 50, 75 and 100 g silicon per plant reduced the osmotic potential in the leaf tissues of ‘Gigante Amarelo’ passion fruit plants. Water salinity lower than 1.3 dS m-1 resulted in an increase in chlorophyll b content; increase in carotenoid content was observed in plants subjected to silicon doses of 25 and 100 g per plant. Salinity levels above 1.1 dS m-1 compromised the performance of photosystem II of passion fruit plants when subjected to silicon doses. | RESUMO O Nordeste brasileiro sofre com alguns estresses abióticos que são responsáveis pela perda de produção agrícola, como os longos períodos de estiagem e elevada evapotranspiração, associado à qualidade das águas que induz ao uso de águas salinas como alternativa para expansão das áreas irrigadas, com isto a adubação silicatada contribui para redução dos efeitos da salinidade nas condições de semiárido nordestino. Objetivou-se avaliar o potencial osmótico e os índices fisiológicos de mudas de maracujazeiro amarelo sob salinidade da água de irrigação e adubação silicatada. O experimento foi desenvolvido em condições de casa de vegetação na Universidade Federal de Campina Grande, Pombal-PB, em delineamento de blocos ao acaso em esquema fatorial 5 x 5, relativo a cinco níveis de condutividade elétrica da água de irrigação - CEa (0,3; 1,0; 1,7; 2,4 e 3,1 dS m-1) e cinco doses de adubação silicatada (0; 25; 50; 75 e 100 g de silício por planta) em quatro repetições e duas plantas por parcela. A aplicação de 50, 75 e 100 g por planta de silício reduziu o potencial osmótico nos tecidos foliares das plantas de maracujazeiro ‘Gigante Amarelo’. A salinidade da água menor que 1,3 dS m-1 resultou em incremento no conteúdo de clorofila b; aumento nos teores de carotenoides foi verificado nas plantas submetidas as doses de 25 e 100 g de silício. Níveis salinos acima de 1,1 dS m-1 comprometeram o desempenho do fotossistema II das plantas de maracujazeiro quando submetidas as doses de silício.

ABSTRACT Pulse irrigation may be more advantageous for peanut crops than continuous irrigation, when using brackish water. However, studies on pulse irrigation with brackish water considering the environmental conditions of the Northeast region of Brazil using are incipient. Therefore, the objective of this study was to evaluate the effect of using brackish water for pulse and continuous dripping irrigations on the grain yield and production characteristics of peanut (Arachis hypogaea L.) crops. A completely randomized block design with four repetitions was used, in a 6*2 factorial arrangement consisted of six electrical conductivities of the irrigation water (EC; 0.2, 1.6, 2.8, 4.0, 5.2, and 6.4 dS m-1) set by adding NaCl to the irrigation water, which originally had 0.2 dS m-1, until reaching the respective EC; and two irrigation methods (pulse and continuous). The evaluated variables were fresh and dry weights of shoot, 10 grains, pods, grains, and production; number of pods and grains; and percentages of empty pods (EP%) and perfect grains (PG%). The addition of salt to the irrigation water negatively affected all variables studied, except for EP% and PG%. The lowest EP% were found for the pulse irrigation, which increased the pod and grain yields, regardless of the EC of the irrigation water. Under the conditions of the present study, the use of brackish waters with electrical conductivities of up to 2.98 dS m-1 is viable for peanut production. | RESUMO A irrigação por pulsos pode proporcionar maiores rendimentos para a cultura do amendoim em comparação a irrigação contínua com a utilização de águas salobras, contudo, estudos para as condições do Nordeste brasileiro utilizando esta técnica de manejo da irrigação associada ao uso de águas salobras são incipientes. Diante disso, objetivou-se com o trabalho avaliar o efeito do uso de águas salobras e da irrigação por gotejamento pulsado e contínuo sobre a produção de grãos e características produtivas do amendoim (Arachis hypogaea L.). O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial de 6 x 2, composto por seis condutividades elétricas da água de irrigação (CEa: 0,2; 1,6; 2,8; 4,0; 5,2 e 6,4 dS m-1), na qual foi adicionada NaCl a água de abastecimento (CEa: 0,2 dS m-1) até atingir as respectivas CEa, e duas formas de aplicação da irrigação por gotejamento (com pulsos e contínua), com quatro repetições. As variáveis analisadas foram: a massa fresca e seca da parte aérea de 10 grãos, das vagens, dos grãos e da produção, além do número de vagens, do número de grãos, da percentagem de vagens chochas (PerVC) e da percentagem de grãos perfeitos (PerGP). A salinidade influenciou negativamente todas as variáveis estudadas, com exceção do PerVC e da PerGP. As menores percentagens de vagens chochas foram obtidas com a irrigação pulsada que por sua vez demonstrou a maior produção de vagens e de grãos independentemente dos níveis de condutividade elétrica da água avaliados. Nas condições desta pesquisa, é viável produzir amendoim utilizando águas salobras com condutividade elétrica de até 2,98 dS m-1.

RESUMO Geometridae é uma das famílias mais diversificadas de Lepidoptera e o conhecimento sobre a distribuição e biologia básica de suas espécies é muito limitado, restringindo-se em muitos casos à localidade-tipo. Não há nenhum inventário das espécies ocorrentes no semiárido do Nordeste do Brasil e das suas plantas hospedeiras. Neste trabalho é registrada a ocorrência da espécie Numia terebintharia Guenée em uma área de caatinga dessa região, avaliada a importância desse registro no quadro do conhecimento da distribuição das espécies do gênero e documentada a planta hospedeira de suas lagartas e as injúrias às suas folhas. Algumas árvores de Ziziphus joazeiro Mart. apresentavam cerca de 90% de suas folhas com injúrias. Esse é o primeiro registro da N. terebintharia para o Brasil e o primeiro de sua planta hospedeira. | ABSTRACT Geometridae is one of the most diverse Lepidoptera families; however, little information about Geometridae species is found, even regarding their distribution and basic biology, which are in general restricted to type locality. Lists of species and their host plants are not found for the Semiarid region of the Northeast of Brazil. The present note reports the occurrence of caterpillars of the species Numia terebintharia Guenée consuming leaves of evergreen trees of Ziziphus joazeiro Mart. in a site with xerophilous deciduous Caatinga vegetation in that region. Some trees had approximately 90% of their leaves with injuries. This is the first record of N. terebintharia caterpillars occurring in Brazil and the first record of Z. joazeiro as their host plant.

ABSTRACT The common bean exhibits wide genetic variability for technological quality traits, mineral concentrations, and bioactive compounds. For this reason, investigating the correlations between those traits in common bean lines of different gene pools contributes to the progress of biofortification programs. In the present study, two recombinant inbred line populations of Mesoamerican and Andean common bean were evaluated at the F5:7 generation. Technological quality was evaluated based on mass of 100 grains and seed coat color, which was determined using a colorimeter that analyzed the L* (white to black), a* (green to red) and b* (blue to yellow) values. The concentration of six minerals and bioactive compounds (phytates and phenolic compounds) was evaluated and used to characterize the nutritional composition of the lines. The evaluated common bean lines differed (p ≤ 0.05) for all technological quality traits, mineral concentrations, and bioactive compounds, except for the zinc concentration in Andean beans. Seed coat color (L*, a*, and b* values) was highly correlated with most of the evaluated minerals and with the phytates in Mesoamerican beans. In Andean beans, seed coat color (L*, a*, and b* values) was correlated with the concentrations of potassium, magnesium, iron, and phenolic compounds. The nutritional composition of common bean lines of different classes is variable: black beans have higher concentrations of potassium, phosphorus, calcium, zinc, and phytates; carioca beans stand out with high magnesium concentration; and cranberry beans have higher concentrations of potassium, magnesium, and iron.

ABSTRACT The success of the integrated crop-livestock system depends on the correct pasture management, particularly regarding nitrogen fertilization and grazing intensity. The objective of this study was to evaluate the total production of forage and the proportion of the botanical and structural components of black oat and annual ryegrass mixture. The experimental design was randomized blocks with three replicates and the treatments were arranged in a three-factorial scheme: seed inoculation (with and without Azospirillum brasilense inoculation), grazing management (conventional grazing, where the animals were kept in pasture with no control of pasture height; 30, 20 and 10 cm at the end of grazing, and a control without grazing), and nitrogen fertilization (0, 50 and 100 kg nitrogen ha-1). In treatments with pasture heights where grazing ended at 30, 20 and 10 cm, the height was monitored and biomass was collected when the animals entered and exited the plots. Manual separation of the components was used to determine the dry mass of green leaves, stems, senescent material and inflorescence. Total dry mass production was obtained based on the initial forage mass plus the daily accumulation rates. The proportion of structural components varied according to the different grazing managements, nitrogen doses and inoculation with Azospirillum brasilense. Biomass production of black oat and ryegrass mixture was increased by nitrogen application and Azospirillum brasilense inoculation.

ABSTRACT Commercial exploitation of the coffee crop is one of the most important activities in the world’s agricultural sector. One of the main phytosanitary problems affecting the crop is the presence of Meloidogyne incognita. Several measures have been tested for the management of this pathogen, albeit with low efficiency. The objective of this work was to quantify the damage and losses and to manage M. incognita race 1 with Pochonia chlamydosporia and Trichoderma harzianum biological nematicides, comparing them to a chemical nematicide. The experiment was carried out in a commercial area naturally infested by the nematode and cultivated with the conilon coffee variety ‘Vitória INCAPER 8142’, clone V02. The treatments were tested with Carbofuran nematicide and with biological nematicides composed of P. chlamydosporia Pc-10 and T. harzianum ESALQ 1306. The biological products were applied alone or in combination. The lowest NPF (final nematode population) occurred in plants treated with P. chlamydosporia and Carbofuran. P. chlamydosporia was the most effective biological agent in the management of M. incognita. There was a reduction in production with an increase in the nematode population. The highest application costs of management methods for M. incognita race 1 per hectare were for three and two applications of Carbofuran and three applications of P. chlamydosporia + T. harzianum. The treatments with lowest application costs were one application of T. harzianum and one application of P. chlamydosporia. It was concluded that all treatments were efficient for the management of M. incognita race 1, causing a decrease in the roots and soil population.

ABSTRACT Sourgrass (Digitaria insularis) is one of the main species causing significant losses in Brazilian soybean production systems. Thus, this paper aimed to evaluate sourgrass interference on soybeans grown under Cerrado conditions. Three field experiments were conducted, of which the first two (E1 and E2) simulated sourgrass after pre-sowing burndown, using plants already emerged by the time soybeans were sown; whereas the third (E3) simulated both sourgrass and soybeans emerged simultaneously. Both E1 and E2 were conducted in a randomized complete block design (RCBD) with five treatments based on sourgrass infestation densities (0, 2, 4, 6, and 8 plants m-2) and four replications. In turn, E3 was also carried out in an RCBD but with treatments arranged in a 2 x 5 factorial and four replications. The first factor comprised two soybean cultivars, while the second was sourgrass density levels, just as in E1 and E2. The results showed that increasing sourgrass densities reduced soybean yield regardless of the plant growth stage when the crop was sown. Yield losses were higher when sourgrass plants were already established by the time soybean was sown. Soybean yield losses reached up to 80% under higher sourgrass infestation levels.

ABSTRACT Cowpeas (Vigna unguiculata L. Walp) are an economically and socially important legume in northern and north-eastern Brazil and can establish effective symbiosis with nitrogen-fixing bacteria. We evaluated the symbiotic compatibility and efficiency of rhizobial strains from Pernambuco semi-arid soils and determined their symbiotic stability on the IPA-206, BR 17-Gurguéia, and BRS Novaera cultivars, selected for different environments. The experiment was conducted in a greenhouse to evaluate a 3 × 28 factorial arrangement (cultivars selected for different environments × inoculation with the currently recommended strain, uninoculated plants with or without mineral nitrogen, and 25 rhizobial strains from semi-arid soils) in a randomized block design with four replicates. We determined nodule number, shoot and root dry matter, nodule dry matter by nodule number, nitrogen accumulated in the shoot by nodule dry matter, nitrogen content and accumulation in the shoot, relative efficiency of the recommended strain based on nitrogen accumulation, and shoot dry matter. Overall, the cultivars responded differently to different strains and cultivar biological nitrogen fixation potential. Strains G7.85 and BR 3262 showed potential for biological nitrogen fixation. BR 3262 was confirmed to be adequate for inoculation of different cowpea cultivars.