Efeito da desfoliação no rendimento e conteúdo protéico do feijão nhemba -vigna unguiculata (l) walp

Abstract

The leaves and grains of cowpea (Vigna unguiculata (L) Walp) are of great importance for human consumption. The consumption of leaves consists of defoliations throughout the life cycle of the plant, so this study aimed to evaluate the effect of defoliation on cowpea production. The trial was set up at the Umbelúzi Agricultural Station, located in the Boane district, Maputo Province, in Mozambique. For which the experimental design of Randomized Complete Blocks was used, in a split-plot arrangement, which included varieties and defoliation, which were applied to the main plot and subplot, respectively. The trial consisted of 3 repetitions (blocks), each block had 2 main treatments (varieties: INIA36B and INIA76B) and these in turn had 5 subtreatments [defoliation levels: 1- do not defoliate (Do), 2- remove 2 leaves ( D|), 3- take 4 leaves (D2), 4- take 6 leaves (D3) and 5- harvest all the leaves (D4)], totaling 10 treatments per block (see attached diagram). Two defoliations were manually performed on each branch of the plant, starting from the softest leaves. The first defoliation was carried out in the vegetative phase and the second in the beginning of the reproductive phase. For the statistical analysis, the GL'M procedure from SAS (1985) was used to perform the analysis of variance (ANOVA) and the contrast test. Defoliation was found to affect grain yield and leaf protein content. The grain yield decreased as defoliation intensified, while the protein content of the leaves increased regardless of the level of defoliation. The monetary conversion of grain and leaves showed that the grain yield that is lost as a result of defoliation is overcompensated by the monetary value of the leaves.