Rendimento de grãos secos e componentes de produção de genótipos de feijão-caupi em cultivo irrigado e de sequeiro

Abstract

Resumo: Estudos realizados com feijão-caupi, Vigna unguiculata (L.) Walp., têm mostrado que é possível obter genótipos estáveis com adaptação ampla e bons níveis de produtividade, principalmente com o uso de irrigação. Neste trabalho, objetivou-se avaliar o desempenho de genótipos de feijão-caupi em cultivo irrigado e de sequeiro. O delineamento experimental foi em blocos casualizados, com 20 tratamentos e quatro repetições, sendo cada unidade experimental constituída por uma parcela de quatro linhas de 5 m espaçadas de 0,80 m. Avaliou-se comprimento, largura e número de grãos por vagem, massa de cem grãos e produtividade de grãos secos. Nos sistemas de cultivo irrigado e de sequeiro, as cultivares e linhagens apresentaram respostas diferenciadas com relação à produtividade de grãos secos. As linhagens MNC02-701F-2 e MNC02-676F-1 foram as mais produtivas no sistema de cultivo irrigado, e as linhagens MNC03-736F-2 e MNC02-675F-9-5 no sistema de sequeiro. As linhagens MNC02-675F-9-5 e MNC03-736F-2 e as cultivares BRS Xiquexique e BRS Gurguéia apresentaram produtividades semelhantes quando cultivadas em regime irrigado e de sequeiro. A interação no desempenho de genótipo de feijão-caupi em sistemas distintos (irrigado e sequeiro) sugere forte influência de fatores ambientais sobre os componentes de produção avaliados, tornando-os dependentes de variações ambientais e de manejo. Palavras-chave: Produtividade de grãos. Interação. Vigna unguiculata (L.) Walp.Abstract: Studies with the cowpea, Vigna unguiculata (L.) Walp., have shown that it is possible to obtain stable genotypes of wide adaptation and with good levels of productivity, mainly through the use of irrigation. The aim of this study was to evaluate the performance of cowpea genotypes under irrigated and rainfed cultivation. The experimental design was of randomised blocks with 20 treatments and four replications, each experimental unit comprising a plot of four 5 m rows spaced 0.80 m apart. The length, width and number of grains per pod, 100-grain weight and dry grain yield were evaluated. In the irrigated and rainfed systems, the cultivars and strains showed different responses in relation to dry grain yield. The MNC02-701F-2 and MNC02-676F-1 strains were the most productive under the irrigated system, and the MNC03-736F-2 and MNC02-675F-9-5 strains under the rainfed system. The strains MNC02-675F-9-5 and MNC03-736F-2 and the cultivars BRS Xiquexique and BRS Gurguéia had similar yields when grown under the irrigated and rainfed regimes. The interaction on genotype performance in the cowpea under different systems (irrigated and rainfed) suggests the strong influence of environmental factors on the production components under evaluation, making them dependent on environmental variation and management.

Root Nodule Preparation as a Low-Cost Inoculant for Cowpea

“…BRS Guariba had higher values for this variable in both locations, ranging from 13.5 to 15.4 seeds in Crato (Table 3) and from 13.9 to 15.1 seeds in Madalena (Table 4). Such values agree with Silva et al (2016), who obtained values in the range of 13.13 to 15.83 seeds in evaluating 20 genotypes in Roraima. This difference, especially between Sempre Verde and BRS Guariba, can be found when we observe 100SW, in which the cv.…”

“…The mean yields were at levels lower than the values generally obtained under experimental conditions because the population adopted was approximately 41,600 plants, similar to that adopted by small farmers. In contrast, some studies, such as Silva et al (2016) and Souza et al (2017), adopt more than 100,000 plants ha -1 , achieving yields of 1,200 and 1,400 kg ha -1 , respectively. In addition, the two experiments were set up on dryland that, together with low rainfall indices, compromise production.…”

Effect of water regimes and plant densities on cowpea production1

“…In the no-tillage system, the highest pod length was 16.34 cm, when a density of 21 plants m -2 was used with 285 mm of water depth, which is lower, when compared to the one used in the conventional growing system. Silva et al (2016) evaluated the dry grain yield and cowpea production components under an irrigated system and observed increases in the pod length values (16-22 cm) with higher water depths (360 mm) than the ones tested in this study. Freitas et al (2013) observed that the no-tillage and conventional systems may influence the following cowpea production components: pod length, number of grains per pod, number of grains per plant and grain yield.…”

“…Souza et al (2011) evaluated cowpea under a conventional production system and observed a grain yield of 1,376.9 kg ha -1 , with 449 mm of water depth, being 29 % higher than the one used in this study. Silva et al (2016), evaluating the dry grain yield and cowpea production, observed increases of 30.4 %, with values ranging 886.72-1,274.06 kg ha -1 , with irrigation of 360 mm depth, under the conventional production system.…”

“…When the irrigation is well conducted, it increases both cowpea yield and grain quality (Oliveira et al 2011, Silva et al 2013and 2016, Locatelli et al 2014. Silva et al (2016) evaluated 20 genotypes under irrigation and observed an average grain yield 27 % higher than the same genotypes under no irrigation. These differences may be doubled or tripled in areas with severe water deficiency.…”