This study evaluated the physical and physiological attributes of saved cowpea seeds (Vigna unguiculata L. Walp.) used in the Brazilian semi-arid area and compared them with certified seed varieties. The study tested 37 saved seed samples from the state of Rio Grande do Norte and two varieties of certified seeds (“BRS Guariba” and “BRS Pujante”) from the production field of Embrapa Products and Market, Petrolina, PE, Brazil. The seeds were tested for moisture, hectoliter weight, weight of 1,000 seeds, and physical purity to evaluate the physical quality. Germination, first germination count, field emergence, emergence rate index, shoot dry mass, and accelerated aging were tested for physiological quality. The saved cowpea seeds showed great differences, suggesting the influence of genetic variability and different growing environments. The use of saved cowpea seeds by small farmers in the semi-arid areas of Northeastern Brazil is impractical, because these seeds have inferior physical and physiological qualities compared to certified cowpea seeds.

This study evaluated the physical and physiological attributes of saved cowpea seeds (Vigna unguiculata L. Walp.) used in the Brazilian semi-arid area and compared them with certified seed varieties. The study tested 37 saved seed samples from the state of Rio Grande do Norte and two varieties of certified seeds (“BRS Guariba” and “BRS Pujante”) from the production field of Embrapa Products and Market, Petrolina, PE, Brazil. The seeds were tested for moisture, hectoliter weight, weight of 1,000 seeds, and physical purity to evaluate the physical quality. Germination, first germination count, field emergence, emergence rate index, shoot dry mass, and accelerated aging were tested for physiological quality. The saved cowpea seeds showed great differences, suggesting the influence of genetic variability and different growing environments. The use of saved cowpea seeds by small farmers in the semi-arid areas of Northeastern Brazil is impractical, because these seeds have inferior physical and physiological qualities compared to certified cowpea seeds. | Objetivou-se avaliar a qualidade física e fisiológica de sementes salvas de feijão-caupi (Vigna unguiculata L. Walp.) utilizadas no semiárido brasileiro e compará-las com as variedades de sementes certificadas. Foram testadas 37 amostras de sementes salvas oriundas de diferentes municípios do Rio Grande do Norte e duas variedades de sementes certificadas (BRS Guariba e BRS Pujante), provenientes do campo de produção da Embrapa Produtos e Mercado, Petrolina, PE. Para avaliação da qualidade física, as sementes foram submetidas aos testes de grau de umidade, peso hectolítrico, peso de mil sementes e pureza física. Na avaliação da qualidade fisiológica testou-se a germinação, primeira contagem de germinação, emergência em campo, índice de velocidade de emergência, matéria seca de parte aérea e envelhecimento acelerado. As sementes salvas de feijão-caupi apresentaram grandes diferenças, sugerindo tanto a influência da variabilidade genética como dos diferentes ambientes de cultivo. A utilização de sementes salvas de feijão-caupi pelos pequenos produtores das áreas semiáridas do nordeste do Brasil se constitui em prática inviável por se tratar de sementes de qualidades física e fisiológica inferiores às sementes de origem certificadas.

The objective of this work was to evaluate the effects of different storage conditions on the physiological and sanitary quality and oil content of castor bean (Ricinus communis) seeds. Seeds of castor bean plants of the Guarani, and IAC-80 cultivars were stored in two environments (cold room, and room conditions), using three package types (multifoliate Kraft paper bag, and polyethylene bag, and polyethylene bag with vacuum at 1 atm). In addition, another storage condition was evaluated: cryopreservation (-196 °C) in foil paper bags. Seed quality was evaluated before storage and at 4, 8, and 12 months after storage by testing their 7-day and 14-day germination, emergence, health, water content, and oil content. The experiment was conducted in a completely randomized design, with 7×4 factorial arrangement consisting of seven storage conditions and four evaluation times. Cryopreservation is the ideal condition for maintaining the seed physiological quality of the Ricinus communis cultivars used throughout storage. The oil content of the R. communis seeds decreases, and the incidence of Aspergillus spp. and Fusarium spp. fungi increases throughout storage, regardless of the storage conditions.

The objective of this work was to evaluate the effects of different storage conditions on the physiological and sanitary quality and oil content of castor bean (Ricinus communis) seeds. Seeds of castor bean plants of the Guarani, and IAC-80 cultivars were stored in two environments (cold room, and room conditions), using three package types (multifoliate Kraft paper bag, and polyethylene bag, and polyethylene bag with vacuum at 1 atm). In addition, another storage condition was evaluated: cryopreservation (-196 °C) in foil paper bags. Seed quality was evaluated before storage and at 4, 8, and 12 months after storage by testing their 7-day and 14-day germination, emergence, health, water content, and oil content. The experiment was conducted in a completely randomized design, with 7×4 factorial arrangement consisting of seven storage conditions and four evaluation times. Cryopreservation is the ideal condition for maintaining the seed physiological quality of the Ricinus communis cultivars used throughout storage. The oil content of the R. communis seeds decreases, and the incidence of Aspergillus spp. and Fusarium spp. fungi increases throughout storage, regardless of the storage conditions. | Para investigar se diferentes condições de armazenamento interferem no potencial fisiológico, sanitário e no teor de óleo de sementes de mamona (Ricinus communis) foram utilizadas sementes de duas cultivares, Guarani e IAC-80, armazenadas em dois ambientes (câmara fria e armazém convencional) em duas embalagens (saco de papel Kraft multifoliado e saco plástico - com e sem acondicionamento a vácuo a 1 atm). Testou-se ainda outro tipo de acondicionamento, utilizando-se papel aluminizado para criopreservação das sementes (-196 °C). A qualidade das sementes foi avaliada antes do armazenamento e após 4, 8 e 12 meses por meio dos testes de geminação (contagem aos 7 e 14 dias), emergência, sanidade, teor de água e teor de óleo. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 7x4, sendo sete condições de armazenamento e quatro épocas. A criopreservação (-196 °C) é a condição ideal para manutenção do potencial fisiológico de sementes de Ricinus communis, cultivares IAC-80 e Guarani, ao longo do armazenamento. Independente das condições de armazenamento de sementes de R. communis, o teor de óleo decresce e a incidência dos fungos Aspergillus spp. e Fusarium spp. aumenta ao longo do armazenamento.

The efficiency of biological products combined with biological fertilization for controlling Pratylenchus brachyurus in soybean crops, and effects of these treatments on soybean crops were evaluate. A greenhouse experiment was conducted at the Mato Grosso State University, in Brazil, using a randomized block design with a 10×2 factorial arrangement, and four replications. The treatments consisted of Trichoderma asperellum, B. subtilis, Purpureocillium lilacinum, B. subtilis + T. asperellum, B. subtilis + P. lilacinum, T. asperellum + P. lilacinum, B. subtilis + T. asperellum + P. lilacinum and abamectin, and Controls with, and without nematodes. Nematode population, plant height, stem base diameter, and soil microbiological characteristics (at 60 and 120 days after sowing - DAS), shoot dry weight (60 DAS), and number of pods per plant, and grain yield (120 DAS) were evaluated. The treatments were efficient for the control of phytonematodes at 60 DAS; the efficiency of treatments with biological products increased when combined with biological fertilization. The biological products were more efficient for controlling the nematodes than abamectin at 120 DAS; and the percentage of control were higher when they were combined with biological fertilization, in both growing periods. The biological treatments resulted in better agronomic characteristics, and higher number of pods per plant, and grain yield, affecting the plants in the first growing period, and significant interaction with the biological fertilizer for these variables in the second growing period. The interaction between treatments and biological fertilization was significant for soil microbiological characteristics in the second growing period.

The efficiency of biological products combined with biological fertilization for controlling Pratylenchus brachyurus in soybean crops, and effects of these treatments on soybean crops were evaluate. A greenhouse experiment was conducted at the Mato Grosso State University, in Brazil, using a randomized block design with a 10×2 factorial arrangement, and four replications. The treatments consisted of Trichoderma asperellum, B. subtilis, Purpureocillium lilacinum, B. subtilis + T. asperellum, B. subtilis + P. lilacinum, T. asperellum + P. lilacinum, B. subtilis + T. asperellum + P. lilacinum and abamectin, and Controls with, and without nematodes. Nematode population, plant height, stem base diameter, and soil microbiological characteristics (at 60 and 120 days after sowing - DAS), shoot dry weight (60 DAS), and number of pods per plant, and grain yield (120 DAS) were evaluated. The treatments were efficient for the control of phytonematodes at 60 DAS; the efficiency of treatments with biological products increased when combined with biological fertilization. The biological products were more efficient for controlling the nematodes than abamectin at 120 DAS; and the percentage of control were higher when they were combined with biological fertilization, in both growing periods. The biological treatments resulted in better agronomic characteristics, and higher number of pods per plant, and grain yield, affecting the plants in the first growing period, and significant interaction with the biological fertilizer for these variables in the second growing period. The interaction between treatments and biological fertilization was significant for soil microbiological characteristics in the second growing period. | Objetivou-se avaliar a eficiência de produtos biológicos associados à adubação biológica no biocontrole de Pratylenchus brachyurus na cultura da soja, além do impacto destestratamentos sobre o desenvolvimento da cultura. O experimento foi conduzido em casa de vegetação, na UNEMAT, Campus de Tangará da Serra, com delineamento experimental em blocos casualizados, esquema fatorial 10X2, com quatro repetições. Foram avaliados: testemunha com e sem nematoides, Trichoderma asperellum, Bacillus subtilis, Purpureocillium lilacinum, B. subtilis+ T. asperellum, B. subtilis+ P. lilacinum, T. asperellum+ P. lilacinum, B. subtilis+ T. asperellum+ P. lilacinum e abamectina. Avaliou-se o nível populacional de P. brachyurus, altura, diâmetro do colo das plantas e características microbiológicas do solo aos 60 e 120 DAS; massa seca da parte aérea aos 60 DAS; número de vagens/planta e produtividade aos 120 DAS. Observou-se que aos 60 DAS os tratamentos promoveram eficiência no controle do fitonematoides, quando associados a adubação biológica somente os tratamentos biológicos melhoraram sua eficiência. Aos 120 DAS os produtos biológicos apresentaram maior eficiência no controle de P. brachyurus que a abamectina, aumentando sua eficiência quando adicionada a adubação biológica (nas duas épocas de semeadura). As características agronômicas, número de vagens/planta e produtividade submetidas aos tratamentos biológicos apresentaram melhor desempenho, havendo interação significativa entre tais tratamentos na primeira época de semeadura e interação com à aplicação do adubo biológico para estas variedades nas segunda época de semeadura. Com relação ás características microbiológicas do solo, houve interação entre os tratamentos somente com a aplicação da adubação biológica na segunda época de semeadura.

Vegetable production is an impactful activity, characterized by intensive land use, high input demand, and it requires strategic management adoption, especially in sustainable production systems, where the pillars of sustainability (environmental, social and economic) must be respected. In this sense, the objective of this work was to evaluate economic indicators of lettuce production using Caatinga spontaneous species (Calotropis procera: rooster tree) as fertilizer and cultivated in two seasons (spring and fall-winter) in the municipality of Serra Talhada, PE. The experimental design was in randomized blocks, arranged in a 4 x 4 factorial scheme, with three replications. The first factor was the biomass amounts of green manure (5.4, 8.8, 12.2 and 15.6 t ha-1 on a dry basis); and the second was their incorporation times in the soil (0, 10, 20 and 30 days before lettuce transplanting). The green mass yield, production costs, rate of return, and net profit margin were determined. The amount 15.6 t ha-1 of C. procera allowed higher profitability to the organic production of lettuce, and it is considered ideal to incorporate the green manure 11 (spring) and 15 (fall-winter) days before transplanting the vegetable. The spring crop promoted a superior economic return to the fall-winter planting, demonstrating economic viability even in the smallest amount of C. procera.

Vegetable production is an impactful activity, characterized by intensive land use, high input demand, and it requires strategic management adoption, especially in sustainable production systems, where the pillars of sustainability (environmental, social and economic) must be respected. In this sense, the objective of this work was to evaluate economic indicators of lettuce production using Caatinga spontaneous species (Calotropis procera: rooster tree) as fertilizer and cultivated in two seasons (spring and fall–winter) in the municipality of Serra Talhada, PE. The experimental design was in randomized blocks, arranged in a 4 x 4 factorial scheme, with three replications. The first factor was the biomass amounts of green manure (5.4, 8.8, 12.2 and 15.6 t ha-1 on a dry basis); and the second was their incorporation times in the soil (0, 10, 20 and 30 days before lettuce transplanting). The green mass yield, production costs, rate of return, and net profit margin were determined. The amount 15.6 t ha-1 of C. procera allowed higher profitability to the organic production of lettuce, and it is considered ideal to incorporate the green manure 11 (spring) and 15 (fall–winter) days before transplanting the vegetable. The spring crop promoted a superior economic return to the fall–winter planting, demonstrating economic viability even in the smallest amount of C. procera. | A produção de hortaliças é uma atividade impactante, que se caracteriza pelo uso intensivo do solo, alta demanda de insumos e requer adoção estratégica de manejo, sobretudo em sistemas de produção sustentável, em que os pilares da sustentabilidade (ambiental, social e econômico) devem ser respeitados. Neste sentido, o objetivo desse trabalho foi avaliar indicadores econômicos da produção de alface adubada com espécie espontânea da Caatinga (Calotropis procera: Flor-de-seda) e cultivada em duas épocas (primavera e outono-inverno), no município de Serra Talhada-PE. O delineamento experimental foi em blocos casualizados, com os tratamentos arranjados em esquema fatorial 4 x 4, com três repetições, sendo o primeiro fator: as quantidades de biomassa do adubo verde (5,4; 8,8; 12,2 e 15,6 t ha-1 em base seca); e o segundo: seus tempos de incorporação ao solo (0, 10, 20 e 30 dias antes do transplantio da alface). Além do rendimento de massa verde e dos custos de produção, foram determinadas as rendas bruta e líquida, taxa de retorno e índice de lucratividade. A quantidade de 15,6 t ha-1 de C. procera possibilitou maior rentabilidade à produção orgânica de alface, sendo considerado ideal incorporar o adubo verde 11 (primavera) e 15 (outono-inverno) dias antes do transplantio da hortaliça. O cultivo de primavera promoveu retorno econômico superior ao plantio de outono-inverno, demonstrando viabilidade econômica mesmo na menor quantidade de C. procera.

Many watermelon (Citrullus lanatus) diseases are caused by soilborne pathogens in Brazil and worldwide. The goal of this study was to identify and quantify the frequency of phytopathogenic fungi associated with watermelon root rot and vine decline that were also present in the roots of weeds in the major watermelon production regions in the state of Rio Grande do Norte, Brazil. We collected root samples from 10 of the most prevalent weed species in 16 watermelon producing areas. The plants were identified and their frequencies in the fields were calculated. The fungi found in the weed roots were isolated and the main genera associated with watermelon vine decline were identified. We identified 13 weed species belonging to nine botanical families. The weed species with the highest frequencies found in the field were Amaranthus spinosus (25.0%), Trianthema portulacastrum (18.8%), Commelina sp. (18.8%), and Boerhavia diffusa (12.5%). The fungi Macrophomina, Rhizoctonia, and Monosporascus were isolated from the roots of the weed plants. While Macrophomina was isolated from 12 different types of plants, Rhizoctonia and Monosporascus were isolated from four and two different plant species, respectively.

Muitas são as doenças causadas por patógenos habitantes do solo em melancia (Citrullus lanatus) no Brasil e no mundo. O objetivo do presente trabalho foi identificar e quantificar a frequência de fungos fitopatógenos associados ao “declínio” de ramas em melancia, presentes nas raízes de plantas daninhas nas principais áreas produtoras no estado do Rio Grande do Norte. Foram coletadas 10 amostras de raízes de espécies de plantas daninhas de maior prevalência em 16 áreas produtoras de melancia. As plantas foram identificadas e, calculada a respectiva frequência em campo. Foi realizado o isolamento fúngico das raízes, sendo posteriormente identificados os principais fungos associados ao declínio de ramas. Foram identificadas 13 espécies de plantas daninhas, pertencentes a nove famílias botânicas. As espécies de plantas daninhas que apresentaram as maiores frequências em campo foram Amaranthus spinosus (25,0%), Trianthema portulacastrum (18,8%), Commelina sp. (18,8%) e Boerhavia diffusa (12,5%). Das raízes das plantas daninhas que apresentaram maior frequência foram isolados os gêneros Macrophomina, Rhizoctonia e Monosporascus. O primeiro foi isolado de 12 espécies de plantas, o segundo de quatro espécies e o terceiro de duas espécies.

Arbuscular mycorrhizal fungi (AMF) and growth promoting bacteria in plants (PGPBs) benefit the survival and development of plantlets; such benefits are attributed to the increased absorption of nutrients, increased photosynthetic rate and tolerance to abiotic stress. The aim of this study was to evaluate if the co-inoculation PGPBs and the AMF, Glomus clarum, improves the growth of micropropagated Manihot esculenta Crantz. The experiment was conducted in the greenhouse. The PGPBs used were Azospirillum amazonense (BR 11140), Herbaspirillum seropedicae (BR 11175), Gluconacetobacter diazotrophicus (BR 11284) and Streptomyces sp. (S 30) and mixtures with double inoculation (Streptomyces sp + A. amazonense, Streptomyces sp + H. seropedicae, Streptomyces sp + G. diazotrophicus, A. amazonense + H. seropedicae, A. amazonense + G. diazotrophicus, and H. seropedicae + G. diazotrophicus). Strains of PGPBs inoculated in cassava cv. "BRA Pretinha III" influenced mycorrhizal colonization and the number of glomerospores, and synergistic effects occurred between Glomus clarum and PGPBs. The crude protein content revealed the contribution of PGPBs to nitrogen nutrition in cassava where the inoculated plants assimilated N in equal proportion with those that received mineral nitrogen. The combined inoculation of PGPBs in the presence of Glomus clarum was significant in cassava and fostered better performance in plant growth over time, similar to all the variables studied. Co-inoculation of PGPBs and AMF can meet the N need of cassava, with implications for the reduced use of N fertilizer.

Arbuscular mycorrhizal fungi (AMF) and growth promoting bacteria in plants (PGPBs) benefit the survival and development of plantlets; such benefits are attributed to the increased absorption of nutrients, increased photosynthetic rate and tolerance to abiotic stress. The aim of this study was to evaluate if the co-inoculation PGPBs and the AMF, Glomus clarum, improves the growth of micropropagated Manihot esculenta Crantz. The experiment was conducted in the greenhouse. The PGPBs used were Azospirillum amazonense (BR 11140), Herbaspirillum seropedicae (BR 11175), Gluconacetobacter diazotrophicus (BR 11284) and Streptomyces sp. (S 30) and mixtures with double inoculation (Streptomyces sp + A. amazonense, Streptomyces sp + H. seropedicae, Streptomyces sp + G. diazotrophicus, A. amazonense + H. seropedicae, A. amazonense + G. diazotrophicus, and H. seropedicae + G. diazotrophicus). Strains of PGPBs inoculated in cassava cv. "BRA Pretinha III" influenced mycorrhizal colonization and the number of glomerospores, and synergistic effects occurred between Glomus clarum and PGPBs. The crude protein content revealed the contribution of PGPBs to nitrogen nutrition in cassava where the inoculated plants assimilated N in equal proportion with those that received mineral nitrogen. The combined inoculation of PGPBs in the presence of Glomus clarum was significant in cassava and fostered better performance in plant growth over time, similar to all the variables studied. Co-inoculation of PGPBs and AMF can meet the N need of cassava, with implications for the reduced use of N fertilizer. | Os fungos micorrízicos arbusculares (FMA) e com as bactérias promotoras de crescimento (BPCPs) beneficiam a sobrevivência e o desenvolvimento de plântulas; tais benefícios são atribuídos ao aumento da absorção de nutrientes, aumento da taxa fotossintética, e aumento da tolerância a estresse abiótico. O objetivo deste estudo foi o de avaliar se a co-inoculação de BPCPs e do FMA, Glomus clarum, melhora o crescimento de Manihot esculenta Crantz micropropagada. As BPCPs utilizadas foram Azospirillum amazonense (BR 11140), Herbaspirillum seropedicae (BR 11175), Gluconacetobacter diazotrophicus (BR 11284) e Streptomyces sp. (S 30), isoladas e em mistura com dupla inoculação (Streptomyces sp. + A. amazonense), (Streptomyces sp. + H. seropedicae), (Streptomyces sp. + G. diazotrophicus), (A. amazonense + H. seropedicae), (A. amazonense + G. diazotrophicus), (H. seropedicae + G. diazotrophicus). As estirpes de BPCPs inoculadas na mandioca cv. "BRA Pretinha III" influenciaram a colonização micorrízica e o número de glomerosporos. Nessas  condições ocorreram efeitos sinérgicos de Glomus clarum com essas BPCPs. O teor de proteína bruta revelou a contribuição de BPCPs na nutrição nitrogenada de mandioca em que  as plantas inoculadas assimilaram N em proporção igual àquelas que receberam nitrogênio mineral. A inoculação combinada de BPCPs na presença de Glomus clarum foi significativa na mandioca e melhorou o crescimento da planta ao longo do tempo, como em todas as variáveis estudadas. A co-inoculação de BPCPs e FMA pode atender a necessidade de N para mandioca, implicando redução no uso de fertilizante nitrogenado.

Swine wastewater can be used as a biofertilizer and promote significant improvements in soil physical-chemical attributes and yield. The objective of this study was to evaluate the effects of swine wastewater application on soil and maize yield. The experiment was conducted at the Agricultural Sciences Center of the Federal University of Piauí, in Teresina, Piauí, Brazil, from August to November 2015. The experimental design used completely randomized blocks in split-plot scheme, with five doses of swine wastewater (0, 25, 50, 75 and 100 m3 ha-1) in the plots and two soil depths (0.20 and 0.40 m) in the subplots, with four replications. Exchangeable contents of calcium, magnesium, phosphorus, potassium and sodium, electrical conductivity, pH, sum of bases, base saturation, potential acidity and cation exchange capacity, and crop yield were evaluated. Results showed calcium, magnesium, sum of bases and cation exchange capacity increased with elevated levels of swine wastewater. Potassium and sodium contents however decreased with doses of 51.58 and 52.28 m3 ha-1, respectively. Except for potassium and potential acidity, variables showed higher values at the 0-0.20 m depth.

Swine wastewater can be used as a biofertilizer and promote significant improvements in soil physical-chemical attributes and yield. The objective of this study was to evaluate the effects of swine wastewater application on soil and maize yield. The experiment was conducted at the Agricultural Sciences Center of the Federal University of Piauí, in Teresina, Piauí, Brazil, from August to November 2015. The experimental design used completely randomized blocks in split-plot scheme, with five doses of swine wastewater (0, 25, 50, 75 and 100 m³ ha-1) in the plots and two soil depths (0.20 and 0.40 m) in the subplots, with four replications. Exchangeable contents of calcium, magnesium, phosphorus, potassium and sodium, electrical conductivity, pH, sum of bases, base saturation, potential acidity and cation exchange capacity, and crop yield were evaluated. Results showed calcium, magnesium, sum of bases and cation exchange capacity increased with elevated levels of swine wastewater. Potassium and sodium contents however decreased with doses of 51.58 and 52.28 m3 ha-1, respectively. Except for potassium and potential acidity, variables showed higher values at the 0-0.20 m depth. | A água residuária da suinocultura pode ser usada como biofertilizante e promover melhorias significativas nos atributos físico-químicos do solo e na produtividade. Objetivou-se avaliar os efeitos da aplicação da água residuária da suinocultura no solo e na produtividade do milho-verde. O experimento foi conduzido no Centro de Ciências Agrárias da Universidade Federal do Piauí, em Teresina, Piauí, no período de agosto a novembro de 2015. O delineamento experimental adotado foi em blocos casualizados em esquema de parcela subdividida, com 4 repetições, sendo os tratamentos constituídos por cinco doses de água residuária da suinocultura (0, 25, 50, 75,100 m³ ha-1) nas parcelas e duas profundidades do solo (0,20 e 0,40 m) nas subparcelas. Foram avaliados os teores trocáveis de cálcio, magnésio, fósforo, potássio e sódio, condutividade elétrica, pH, soma de bases, saturação por base, acidez potencial e capacidade de troca de cátions, e a produtividade da cultura. Os resultados demonstraram que os teores de cálcio, magnésio, soma de base e capacidade de troca de cátions aumentaram com a elevação dos níveis de água residuária da suinocultura, no entanto os teores de potássio e sódio reduziram a partir das doses de 51,58 e 52,28 m3 ha-1, respectivamente. Com exceção do potássio e acidez potencial, as demais variáveis apresentaram maiores valores na profundidade de 0-0.20 m.

Nitrogen fertilization is a limiting factor for grapevine production; its excess or deficiency can cause changes in fruit quantity and quality. Thus, the objective of this work was to evaluate productive parameters of grapevines of the Isabel-Precoce cultivar subjected to nitrogen and organic fertilization in the western semiarid region of the state of Rio Grande do Norte (RN), Brazil. The experiment was conducted at the Experimental Farm of the Federal Rural University of the Semi-Arid Region, in Mossoró, RN, Brazil, during two production cycles. The soil of the area used was classified as dystrophic Red Argissolo (Udult) of sandy texture. The experiment was conducted in a randomized block design with six replications, using a 5×2 factorial arrangement, with 5 nitrogen fertilizer rates (0, 30, 60, 90, and 120 kg ha-1) and two organic fertilizer rates (0, and 20 m3 ha-1 of bovine manure). The production components number of bunches per plant, grape production per plant, grape yield, weight, length and width of bunches, number of berries per bunch, and ten-berry weight were evaluated. The nitrogen rates and organic fertilizer rates used were significant (p=0.05) for all evaluated components. The N rate of 60 kg ha-1 combined with the organic fertilization generated the best results for the analyzed variables. N rates from 60 to 120 kg ha-1, applied singly or combined with organic fertilizer, hindered the production components of the Isabel-Precoce grapevines.

Nitrogen fertilization is a limiting factor for grapevine production; its excess or deficiency can cause changes in fruit quantity and quality. Thus, the objective of this work was to evaluate productive parameters of grapevines of the Isabel-Precoce cultivar subjected to nitrogen and organic fertilization in the western semiarid region of the state of Rio Grande do Norte (RN), Brazil. The experiment was conducted at the Experimental Farm of the Federal Rural University of the Semi-Arid Region, in Mossoró, RN, Brazil, during two production cycles. The soil of the area used was classified as dystrophic Red Argissolo (Udult) of sandy texture. The experiment was conducted in a randomized block design with six replications, using a 5×2 factorial arrangement, with 5 nitrogen fertilizer rates (0, 30, 60, 90, and 120 kg ha-1) and two organic fertilizer rates (0, and 20 m3 ha-1 of bovine manure). The production components number of bunches per plant, grape production per plant, grape yield, weight, length and width of bunches, number of berries per bunch, and ten-berry weight were evaluated. The nitrogen rates and organic fertilizer rates used were significant (p≤0.05) for all evaluated components. The N rate of 60 kg ha-1 combined with the organic fertilization generated the best results for the analyzed variables. N rates from 60 to 120 kg ha-1, applied singly or combined with organic fertilizer, hindered the production components of the Isabel-Precoce grapevines. | A adubação nitrogenada na videira apresenta-se como um fator limitante na produção, visto que seu excesso ou deficiência são capazes de propiciar alterações na quantidade e qualidade final dos frutos. Assim, o objetivo deste trabalho foi avaliar os parâmetros produtivos da videira ‘Isabel Precoce’ submetida a adubação nitrogenada e orgânica na região semiárida do Oeste Potiguar. O experimento foi implantado na Fazenda Experimental da UFERSA, em Mossoró, RN, cujo clima é semiárido. O solo da área é um Argissolo Vermelho Distrófico de textura arenosa. A pesquisa foi realizada em dois ciclos de produção. O delineamento experimental utilizado foi blocos casualizados com seis repetições, em esquema fatorial 5 x 2, que corresponderam a 5 doses de fertilizante nitrogenado (0, 30, 60, 90 e 120 kg ha-1), na ausência e presença de adubação orgânica (0 e 20 m3 ha-1 esterco bovino). Foram avaliados número de cachos por planta, produção por planta e produtividade, bem como peso, comprimento e largura dos cachos, número de bagas por cacho e peso de dez bagas. A aplicação das doses de nitrogênio (N), bem como o uso ou não de adubo orgânico (AO) no solo, conferiram efeito significativo (p≤0,05) para todos os componentes avaliados. A dose de 60 kg ha-1 de N na presença do AO foi a que proporcionou os melhores resultados nas variáveis analisadas. A elevação dos níveis de N, a partir da dose de 60 até 120 kg ha-1 combinadas ou não a fonte orgânica, inibiram os componentes produtivos da videira ´Isabel Precoce´.