In wheat crops, it is often observed that the number of plants per area is lower than that of viable seeds used, which may be related to both environmental conditions and seed vigor. The aim of this study was to assess the effect of seed vigor level at different sowing densities on growth, development, and grain yield in wheat cultivars. The experiments were conducted in Londrina and Ponta Grossa, PR, Brazil, under a randomized block design in a 2 × 2 × 3 factorial scheme, with four replications. Two seed vigor levels (high and low), two sowing densities (200 and 400 viable seeds per m2), and three wheat cultivars (BRS Sabiá, BRS Gaivota, and BRS Gralha Azul) were assessed. In order to assess growth and development, plant samples were collected at the phenological stages of seedling growth, stem elongation, booting, and ear emergence. We assessed the emergence of seedlings, height and dry matter of plant shoot, and grain yield. The sowing density of 200 seeds per m2 led to a higher shoot dry matter production per plant at the stages booting and ear emergence. The cultivar BRS Sabiá presented the highest grain yield in Londrina, while BRS Sabiá and BRS Gralha Azul presented the highest grain yield in Ponta Grossa. High vigor seeds favor stand establishment, growth and development of plants at early phenological stages, and grain yield of wheat.

ABSTRACT In wheat crops, it is often observed that the number of plants per area is lower than that of viable seeds used, which may be related to both environmental conditions and seed vigor. The aim of this study was to assess the effect of seed vigor level at different sowing densities on growth, development, and grain yield in wheat cultivars. The experiments were conducted in Londrina and Ponta Grossa, PR, Brazil, under a randomized block design in a 2 × 2 × 3 factorial scheme, with four replications. Two seed vigor levels (high and low), two sowing densities (200 and 400 viable seeds per m2), and three wheat cultivars (BRS Sabiá, BRS Gaivota, and BRS Gralha Azul) were assessed. In order to assess growth and development, plant samples were collected at the phenological stages of seedling growth, stem elongation, booting, and ear emergence. We assessed the emergence of seedlings, height and dry matter of plant shoot, and grain yield. The sowing density of 200 seeds per m2 led to a higher shoot dry matter production per plant at the stages booting and ear emergence. The cultivar BRS Sabiá presented the highest grain yield in Londrina, while BRS Sabiá and BRS Gralha Azul presented the highest grain yield in Ponta Grossa. High vigor seeds favor stand establishment, growth and development of plants at early phenological stages, and grain yield of wheat. | RESUMO Na cultura do trigo, frequentemente, observa-se que o estabelecimento do número de plantas por área é inferior ao de sementes viáveis utilizadas, o que pode estar relacionado tanto a condições do ambiente quanto ao vigor de sementes. O objetivo foi avaliar o efeito do nível de vigor de sementes, em diferentes densidades de semeadura, sobre o crescimento, o desenvolvimento e o rendimento de grãos em cultivares de trigo. Os experimentos foram conduzidos em Londrina e Ponta Grossa, PR, Brasil, sob o delineamento experimental de blocos casualizados, em esquema fatorial 2 x 2 x 3, com quatro repetições. Foram avaliados dois níveis de vigor de sementes (alto e baixo), duas densidades de semeadura (200 e 400 sementes viáveis por m2) e três cultivares de trigo (BRS Sabiá, BRS Gaivota e BRS Gralha Azul). Para avaliação do crescimento e desenvolvimento foram realizadas coletas de plantas nos estádios fenológicos de desenvolvimento da plântula, alongamento do colmo, emborrachamento e emergência da inflorescência. As avaliações efetuadas foram: emergência de plântulas, altura e massa seca da parte aérea de plantas e produtividade de grãos. A densidade de semeadura de 200 sementes por m2 acarreta maior produção de massa seca da parte aérea por planta nos estádios de emborrachamento e emergência da inflorescência. Em Londrina, a cultivar BRS Sabiá e, em Ponta Grossa, a BRS Sabiá e a BRS Gralha Azul apresentam maiores produtividades de grãos. Sementes de alto vigor favorecem o estabelecimento do estande, o crescimento e o desenvolvimento das plantas nos estádios fenológicos iniciais e a produtividade de grãos de trigo.

Título em português: Crescimento e rendimento de trigo em resposta ao vigor de sementes e densidades de semeadura.

The aim of this study is to document the heretofore unrecorded natural occurrence of the larval parasitoid Digonogastra sp. on Diatraea flavipennella Box, 1931 (Lepidoptera: Crambidae) in sugarcane fields. The collections were made in the Usina Santa Clotilde area, in Rio Largo municipality, Alagoas State, Brazil. This is the first record of Digonogastra sp. parasitizing caterpillar of D. flavipennella in Brazil. The parasitism rate was found to be 14.06%. The occurrence of this parasitoid indicates potential for natural regulation of that pest in sugarcane crop.

ABSTRACT The aim of this study is to document the heretofore unrecorded natural occurrence of the larval parasitoid Digonogastra sp. on Diatraea flavipennella Box, 1931 (Lepidoptera: Crambidae) in sugarcane fields. The collections were made in the Usina Santa Clotilde area, in Rio Largo municipality, Alagoas State, Brazil. This is the first record of Digonogastra sp. parasitizing caterpillar of D. flavipennella in Brazil. The parasitism rate was found to be 14.06%. The occurrence of this parasitoid indicates potential for natural regulation of that pest in sugarcane crop. | RESUMO O objetivo deste estudo foi registrar a ocorrência natural do parasitoide larval Digonogastra sp. em Diatraea flavipennella Box, 1931 (Lepidoptera: Crambidae) em cana-de-açúcar. As coletas foram realizadas na Usina Santa Clotilde (9º25’S, 35º49’W, 127m de altitude), no município de Rio Largo, Estado de Alagoas, Brasil. Este é o primeiro registro do gênero Digonogastra parasitando lagartas de D. flavipennella no Brasil. A taxa de parasitismo verificada foi de 14,06%. A ocorrência deste parasitoide indica um potencial de regulação natural da referida praga em cana-de-açúcar.

RESUMO O objetivo do trabalho foi avaliar o desempenho de linhagens elite de feijão-caupi de porte ereto e semiereto em ambientes de Mato Grosso e Minas Gerais. Os ensaios foram conduzidos em Jaíba, Janaúba e Sete Lagoas em Minas Gerais, e em Primavera do Leste e Nova Ubiratã em Mato Grosso. Foram avaliados 20 genótipos de feijão-caupi. Utilizou-se o delineamento de blocos casualizados, com quatro repetições. Os dados obtidos foram submetidos a análises de variância individuais e conjunta e as médias agrupadas pelo teste de Scott-Knott (P<0,05). Foram avaliados os caracteres porte da planta, acamamento, valor de cultivo, comprimento de vagem e rendimento de grãos. Nos ambientes do Mato Grosso, destacaram-se as linhagens MNC04-768F-21 e MNC04F-795F-168 como as mais produtivas e com características de porte da planta, acamamento e valor de cultivo semelhantes às da cultivar BRS Guariba. Nos ambientes de Minas Gerais, especialmente na região Norte do Estado, representada pelos ambientes de Jaíba e Janaúba, destacaram-se como mais produtivas as linhagens MNC04-769F-30, MNC05-795F-154, MNC04-769F-49 e a cultivar BRS Tumucumaque. Entretanto, as cultivares BRS Guariba, BRS Tumucumaque, BRS Novaera, BRS Itaim e BRS Cauamé, e as linhagens MNC04-792F-143 e MNC04-792F-144 apresentam produtividades satisfatórias e boas características de porte, acamamento e valor de cultivo, representando boas alternativas para recomendação de cultivo nesta região. | ABSTRACT The objective of this work was to evaluate the agronomic performance of erect and semi-erect cowpea elite lines grown in the States of Minas Gerais and Mato Grosso, Brazil. The experiments were conducted in Jaíba, Janaúba, Sete Lagoas (Minas Gerais), Primavera do Leste and Nova Ubiratã (Mato Grosso), with 20 genotypes of cowpea, arranged in a randomized block design with four replications. The data were subjected to individual and joint analyses of variance and means grouped by the Scott-Knott test (p<0.05). The plant growth habit, lodging, cultivation value, pod length and bean yield were evaluated. The lines MNC04-768F-21 and MNC04F-795F-168 had the highest bean yield in the experiments conducted in Mato Grosso, and their growth habit, lodging and cultivation value were similar to those of the cultivar BRS-Guariba. The lines MNC04-769F-30, MNC05-795F-154 and MNC04-769F-49 and the cultivar BRS-Tumucumaque had the highest bean yield in the experiments conducted in Minas Gerais. However, the cultivars BRS-Guariba, BRS-Tumucumaque, BRS-Novaera, BRS-Itaim and BRS-Cauamé and the lines MNC04-792F-143 and MNC04-792F-144 showed satisfactory bean yield and good growth habit, plant lodging and cultivation value in the State of Minas Gerais, especially in the northern region of the state (Jaíba and Janaúba), representing good alternatives for the genotypes recommended for this region.

The objective of this work was to evaluate the agronomic performance of erect and semi-erect cowpea elite lines grown in the States of Minas Gerais and Mato Grosso, Brazil. The experiments were conducted in Jaíba, Janaúba, Sete Lagoas (Minas Gerais), Primavera do Leste and Nova Ubiratã (Mato Grosso), with 20 genotypes of cowpea, arranged in a randomized block design with four replications. The data were subjected to individual and joint analyses of variance and means grouped by the Scott-Knott test (p<0.05). The plant growth habit, lodging, cultivation value, pod length and bean yield were evaluated. The lines MNC04-768F-21 and MNC04F-795F-168 had the highest bean yield in the experiments conducted in Mato Grosso, and their growth habit, lodging and cultivation value were similar to those of the cultivar BRS-Guariba. The lines MNC04-769F-30, MNC05-795F-154 and MNC04-769F-49 and the cultivar BRS-Tumucumaque had the highest bean yield in the experiments conducted in Minas Gerais. However, the cultivars BRS-Guariba, BRS-Tumucumaque, BRS-Novaera, BRS-Itaim and BRS-Cauamé and the lines MNC04-792F-143 and MNC04-792F-144 showed satisfactory bean yield and good growth habit, plant lodging and cultivation value in the State of Minas Gerais, especially in the northern region of the state (Jaíba and Janaúba), representing good alternatives for the genotypes recommended for this region.

ABSTRACT This study was conducted to evaluate the use of Curcuma longa (Linnaeus) extract in the in vitro control of Bipolaris oryzae (Breda de Haan) and to characterize the effect of this extract on rice seed germination. A completely randomized arranged in a factorial experimental design was used: three isolates of B. oryzae from rice seed from different rice-growing regions of Rio Grande do Sul (Fronteira Oeste, Campanha, and Sul) were tested with three concentrations (20, 40, and 80 mg/mL) of C. longa plus a control treatment (0 mg/mL). Each reaction was repeated in quadruplicate. The effect of the extract upon the disease development was evaluated based on mycelial growth (PMG) and spore production; rice seed germination was evaluated using a germination test (Germitest®). The PMG results demonstrate that the treatments were effective in reducing PMG, with a stronger response observed as the concentration of the extract increased. An average inhibition of 84% of sporulation was observed for the tested strains compared with the control treatment. There were, however, no significant differences in terms of seed germination test with the different C. longa concentrations. Therefore, treatment of rice seeds with C. longa extract does not affect seed germination but positively inhibits mycelial growth and sporulation, affecting the in vitro sporulation of the different isolates of B. oryzae. | RESUMO Objetivou-se avaliar o uso do extrato de Curcuma longa (Linnaeus) no controle de Bipolaris oryzae (Breda de Haan) in vitro, bem como conhecer o seu efeito sobre a germinação de sementes de arroz. O delineamento experimental foi inteiramente casualizado arranjado em um sistema fatorial: três isolados de B. oryzae de sementes de arroz, oriundas de três regiões orizícolas do Rio Grande do Sul (fronteira oeste; campanha e sul) x três concentrações (20; 40 e 80 mg/mL) de C. longa, mais um tratamento controle (0 mg/mL), com quatro repetições. O efeito do extrato sobre o desenvolvimento do patógeno foi avaliado a partir do crescimento micelial (CMC) e produção de esporos, para a germinação das sementes de arroz foi avaliado através do teste de germinação em papel toalha (Germitest®). Os resultados para o CMC demonstram que os tratamentos foram efetivos, reduzindo o CMC conforme aumentava-se as concentrações do extrato. Em relação a esporulação, ocorreu a inibição média de 84% para os isolados testados, quando comparado ao tratamento controle. Já para o teste de germinação de sementes, não houve diferença significativa entre as diferentes concentrações. Dessa forma, conclui-se que o extrato de C. longa quando em contato com a semente de arroz, não interfere na sua germinação e que age positivamente inibindo o crescimento micelial e afetando a esporulação dos diferentes isolados de B. oryzae in vitro.

This study was conducted to evaluate the use of Curcuma longa (Linnaeus) extract in the in vitro control of Bipolaris oryzae (Breda de Haan) and to characterize the effect of this extract on rice seed germination. A completely randomized arranged in a factorial experimental design was used: three isolates of B. oryzae from rice seed from different rice-growing regions of Rio Grande do Sul (Fronteira Oeste, Campanha, and Sul) were tested with three concentrations (20, 40, and 80 mg/mL) of C. longa plus a control treatment (0 mg/mL). Each reaction was repeated in quadruplicate. The effect of the extract upon the disease development was evaluated based on mycelial growth (PMG) and spore production; rice seed germination was evaluated using a germination test (Germitest®). The PMG results demonstrate that the treatments were effective in reducing PMG, with a stronger response observed as the concentration of the extract increased. An average inhibition of 84% of sporulation was observed for the tested strains compared with the control treatment. There were, however, no significant differences in terms of seed germination test with the different C. longa concentrations. Therefore, treatment of rice seeds with C. longa extract does not affect seed germination but positively inhibits mycelial growth and sporulation, affecting the in vitro sporulation of the different isolates of B. oryzae.

ABSTRACT Rice is one of the world’s most consumed cereals, however, its production is affected by fungal diseases. Thus, the objective of this work was to evaluate the severity of diseases and grain yield potential of upland rice with silicon fertilization combined with seed microbiolization with Bacillus methylotrophicus isolates. Two experiments were conducted, one in Igarapé do Meio, Maranhão (MA), Brazil, with rice seeds of the variety Palha-Murcha and one in São Bento MA with rice seeds of the variety BRS-Primavera. A randomized block experimental design in a split-plot arrangement with five replications were used in both experiments, with agro-silicon rates (0.0, 1.0, 2.0, 4.0 and 6.0 Mg ha-1) in the plots and microbiolized and non-microbiolized rice seeds with B. Methylotrophicus at concentration of 108 CFU ml-1 in the subplots. The seedling emergence, grain yield, number of panicles, plant height, plant dry weight and severity of brown leafspot, leaf scald and grain spot were evaluated. Soil fertilization with agro-silicon affected positively the plant height of the variety Palha-Murcha and the number of panicles, plant dry weight and grain yield of the variety BRS-Primavera, and negatively the germination of the variety BRS-Primavera. Leaf scald severity in the variety BRS-Primavera reduced with microbiolized seeds with B. methylotropicus. Microbiolization with B. methylotropicus had no effect on severity of brown leafspot and grain spot in the varieties evaluated. | RESUMO O arroz é um dos cereais mais consumidos em todo o mundo e sua produção é afetada por doenças fúngicas. Neste sentido objetivou-se avaliar a severidade de doenças e o potencial produtivo do arroz de terras altas em função da aplicação de silício e sementes microbiolizadas com isolados de Bacillus methylotrophicus. Foram realizados dois experimentos, em dois munícipios do estado do Maranhão, Brasil: um em Igarapé do Meio, com sementes de arroz da variedade Palha Murcha e outro em São Bento, com a variedade Primavera. Os experimentos foram instalados no delineamento em blocos casualizados, com cinco repetições, em parcelas subdivididas. As parcelas foram constituídas por cinco doses de agrosilício (0,0; 1,0; 2,0; 4,0 e 6,0 t ha-1) e as subparcelas foram constituídas por sementes de arroz microbiolizadas e não microbiolizadas com B. methylotrophicus, na concentração de 108 UFC ml-1. Os parâmetros avaliados foram emergência de plântulas, produtividade de grãos, número de panícula, altura de planta, massa de planta seca e severidade de mancha parda, escaldadura e mancha de grãos. As doses de agrosilício aplicadas no solo afetaram positivamente a altura de plantas, para a variedade Palha Murcha. Na variedade Primavera, as doses de agrosilício influenciaram de forma positiva o número de panículas, massa de planta seca e a produtividade de grãos e de forma negativa a germinação. Para esta variedade, a severidade da escaldadura foi reduzida quando as sementes foram microbiolizadas com B. methylotropicus. A microbiolização com B. methylotropicus não influenciou a severidade da mancha parda e a severidade da mancha de grãos, para as duas variedades de arroz.

Rice is one of the world’s most consumed cereals, however, its production is affected by fungal diseases. Thus, the objective of this work was to evaluate the severity of diseases and grain yield potential of upland rice with silicon fertilization combined with seed microbiolization with Bacillus methylotrophicus isolates. Two experiments were conducted, one in Igarapé do Meio, Maranhão (MA), Brazil, with rice seeds of the variety Palha-Murcha and one in São Bento MA with rice seeds of the variety BRS-Primavera. A randomized block experimental design in a split-plot arrangement with five replications were used in both experiments, with agro-silicon rates (0.0, 1.0, 2.0, 4.0 and 6.0 Mg ha-1) in the plots and microbiolized and non-microbiolized rice seeds with B. Methylotrophicus at concentration of 108 CFU ml-1 in the subplots. The seedling emergence, grain yield, number of panicles, plant height, plant dry weight and severity of brown leafspot, leaf scald and grain spot were evaluated. Soil fertilization with agro-silicon affected positively the plant height of the variety Palha-Murcha and the number of panicles, plant dry weight and grain yield of the variety BRS-Primavera, and negatively the germination of the variety BRS-Primavera. Leaf scald severity in the variety BRS-Primavera reduced with microbiolized seeds with B. methylotropicus. Microbiolization with B. methylotropicus had no effect on severity of brown leafspot and grain spot in the varieties evaluated.

RESUMO Objetivou-se avaliar o desempenho produtivo-econômico da consorciação palma forrageira e sorgo em relação ao sistema de plantio exclusivo da palma forrageira sob diferentes lâminas de irrigação com água salina. A pesquisa foi conduzida em Serra Talhada, PE, com delineamento em blocos ao acaso, arranjo fatorial com parcelas subdivididas (5×2), quatro repetições, sendo considerada como parcelas as lâminas de irrigação complementar com base na evapotranspiração de referência (0; 8,75; 17,5; 26,25 e 35% ETo), e as subparcelas, os sistemas de plantio: palma exclusiva e consórcio palma-sorgo. O experimento foi conduzido por um ano, sendo um ciclo de palma e dois ciclos do sorgo. Ao final foram obtidas as produtividades de matéria fresca e seca. A rentabilidade econômica foi analisada por meio da receita líquida (RL) e da relação benefício/custo (B/C) da palma destinada à venda tanto para forragem como “semente” para o plantio, e do sorgo para produção de forragem. Simulações de RL e B/C foram feitas ao longo da vida útil de oito anos do sistema de irrigação. As lâminas de água aumentaram a produtividade de matéria seca do consórcio, devido ao benefício gerado ao sorgo. Com base na RL e B/C, verificou-se que a palma e o sorgo destinados à venda como forragem mostraram mais vantagem quando consorciadas e maior rentabilidade a partir do 2º ano de implantação do sistema de irrigação. Conclui-se que, o consórcio palma forrageira e sorgo irrigado com água salina deve ser recomendado para a produção de forragem no Semiárido brasileiro. | ABSTRACT The objective of this study was to evaluate the productive and economic performance of a forage cactus and sorghum intercropping system in relation to a forage cactus single cropping system under different irrigation blades with saline water. The study was conducted in Serra Talhada, State of Pernambuco, in a randomized block design, consisting of a factorial arrangement with split-plot parcels (5×2) and four replications. The five plots were the irrigation depths based on the reference evapotranspiration (ETo) (0, 8.75, 17.5, 26.25, and 35% ETo) and the two cropping systems were single forage cactus cropping and cactus intercropped with sorghum. The experiment was conducted for one year, with one forage cactus cycle and two cycles of sorghum. Yields were obtained at the end of the cycles. Economic profitability was analyzed by means of net revenue (NR) and the benefit/cost ratio (B/C), with cactus forage sold as forage or as "seed" and sorghum as forage. Net revenue and B/C simulations were carried out over an eight-year useful life span of the irrigation system. Increasing irrigation depth increased the dry matter yield of the intercropping system because of higher sorghum yield. Based on the NR and B/C ratio values, forage cactus and sorghum produced as forage produced higher economic outcomes in the intercropping system and showed a higher profitability from the 2nd year of implementation of the irrigation system. Forage cactus and sorghum intercropping irrigated with saline water is therefore recommended for forage production in the Brazilian semi-arid region.

The objective of this study was to evaluate the productive and economic performance of a forage cactus and sorghum intercropping system in relation to a forage cactus single cropping system under different irrigation blades with saline water. The study was conducted in Serra Talhada, State of Pernambuco, in a randomized block design, consisting of a factorial arrangement with split-plot parcels (5×2) and four replications. The five plots were the irrigation depths based on the reference evapotranspiration (ETo) (0, 8.75, 17.5, 26.25, and 35% ETo) and the two cropping systems were single forage cactus cropping and cactus intercropped with sorghum. The experiment was conducted for one year, with one forage cactus cycle and two cycles of sorghum. Yields were obtained at the end of the cycles. Economic profitability was analyzed by means of net revenue (NR) and the benefit/cost ratio (B/C), with cactus forage sold as forage or as "seed" and sorghum as forage. Net revenue and B/C simulations were carried out over an eight-year useful life span of the irrigation system. Increasing irrigation depth increased the dry matter yield of the intercropping system because of higher sorghum yield. Based on the NR and B/C ratio values, forage cactus and sorghum produced as forage produced higher economic outcomes in the intercropping system and showed a higher profitability from the 2nd year of implementation of the irrigation system. Forage cactus and sorghum intercropping irrigated with saline water is therefore recommended for forage production in the Brazilian semi-arid region.

ABSTRACT The aim of this study was to assess the productive performance of cowpea cultivars with different growth habits as a function of population density in the MATOPIBA region, Brazil. The experiments were carried out in Magalhães de Almeida, MA in the agricultural season 2014/2015. The cultivars BRS Itaim, BRS Tumucumaque, and BRS Pajeú, which present an erect, semi-erect, and semi-prostrate growth habits, respectively, were assessed. For the erect and semi-erect cultivars, a total of 8, 12, 16, 20, 24, and 28 plants m−2 were used whereas for the semi-prostrate cultivar, a total of 2, 6, 10, 14, 18, and 22 plants m−2 were used. The experimental design was a randomized block design with four replications and treatments composed of plant densities. Grain yield and number of pods per area presented a quadratic response to the increased plant density whereas a decreasing linear response was observed for the number of pods per plant. The maximum grain yield of erect, semi-erect, and semi-prostrate cultivars were 1,076 kg ha−1 (19.5 plants m−2), 1,252 kg ha−1 (18.7 plants m−2), and 755 kg ha−1 (14.5 plants m−2), respectively. The number of pods per area was the character that most correlated (P<0.01) with grain yield, regardless of the plant growth habit. | RESUMO O objetivo deste trabalho foi avaliar o desempenho produtivo de cultivares de feijão-caupi de diferentes tipos de porte da planta, em função da densidade populacional, na região do MATOPIBA. Os experimentos foram conduzidos no município de Magalhães de Almeida, MA, ano agrícola 2014/2015. Foram avaliadas as cultivares BRS Itaim, de porte ereto, BRS Tumucumaque, de porte semiereto e BRS Pajeú, de porte semiprostrado. Para as cultivares de portes ereto e semiereto utilizaram-se 8; 12; 16; 20; 24 e 28 plantas m-2 e para a cultivar de porte semiprostado de 2; 6; 10; 14; 18 e 22 plantas m-2. O delineamento experimental foi o de blocos casualizados com quatro repetições e os tratamentos constituídos pelas densidades de plantas. Os rendimentos de grãos e o número de vagens por área responderam quadraticamente ao aumento da densidade de plantas, enquanto resposta linear decrescente foi observada para o número de vagens por planta. Os rendimentos de grãos máximos das cultivares de portes ereto e semiereto foram, respectivamente, de 1.076 kg ha-1 (19,5 plantas m-2) e 1.252 kg ha-1 (18,7 plantas m-2) e para a cultivar de porte semiprostrado foi de 755 kg ha-1 (14,5 plantas m-2). O número de vagens por área foi o caráter mais correlacionado (P<0,01) com o rendimento de grãos, independentemente do tipo de porte da planta.

The aim of this study was to assess the productive performance of cowpea cultivars with different growth habits as a function of population density in the MATOPIBA region, Brazil. The experiments were carried out in Magalhães de Almeida, MA in the agricultural season 2014/2015. The cultivars BRS Itaim, BRS Tumucumaque, and BRS Pajeú, which present an erect, semi-erect, and semi-prostrate growth habits, respectively, were assessed. For the erect and semi-erect cultivars, a total of 8, 12, 16, 20, 24, and 28 plants m−2 were used whereas for the semi-prostrate cultivar, a total of 2, 6, 10, 14, 18, and 22 plants m−2 were used. The experimental design was a randomized block design with four replications and treatments composed of plant densities. Grain yield and number of pods per area presented a quadratic response to the increased plant density whereas a decreasing linear response was observed for the number of pods per plant. The maximum grain yield of erect, semi-erect, and semi-prostrate cultivars were 1,076 kg ha−1 (19.5 plants m−2), 1,252 kg ha−1 (18.7 plants m−2), and 755 kg ha−1 (14.5 plants m−2), respectively. The number of pods per area was the character that most correlated (P<0.01) with grain yield, regardless of the plant growth habit.