Interação intergenotípica no consorciamento milho x feijão

Abstract

The objective of this work was to study the intergenotypic interaction in a maize and beans intercropping system; to study the application of techniques used in the assessment of genotype x environment interactions to the study of genotype x genotype interactions; to verify the possibility of using a autogamous species (beans) as an environmental indicator for an alogamous species (maize) for use in the genetically stratified selection method; and to study the relationship of experimental errors in order to verify whether the environmental effect in the two species has the same nature. Four genotypes of maize and four genotypes of beans were used. The maize genotypes were the hybrids C-125, C-606, C-525 and C-701. The bean cultivars were Corado, Carioquinha, Milionário 1732 and IAC-Bico de Ouro. The experimental design was random blocks with 3 repetitions. The treatments were maize hybrids in association with bean cultivars, using a 4 x 4 factorial. The characteristics observed in the maize were: stand; the height of the plant, measured to the base of the tassel; the height of insertion of 1st spike; the length of the spike; the weight of the spike; the number of rows of grains of the spike; the grain weight per plant and, the ramifications number of the tassel. In the beans the following characteristics were observed: stand; the internodes length; the number of pods; the number of seeds per plant; the weight of seeds per plant; and the weight of 100 seeds. Analysis were conducted using methods considered for the study of genotype x environment interactions, in order to study the genotype x genotype interactions. The intergenotypic interaction in maize and beans was not significant for all the characteristics studied, except for the weight of 100 seeds in the beans. The techniques of study of the genotype x environment interaction can be applied to the study of the genotype x genotype interactions, enhancing the understanding of the relations between the genotypes. According to the results, the beans genotype 1 (Corado) was responsible for the presence of significant interaction in the weight of 100 seeds, having a differentiated response in relation to the different genotypes of maize. The bean cultivars cannot be used as indicator plant for the maize. The variation due to the experimental error in maize was, in general, not correlated with the variation due to the experimental error in beans, except for the number of grains per plant, which had highly significant residual correlation with other characteristics of the maize plant.