Indicação de cultivares de feijão-caupi para produção de grãos secos no estado do Ceará

Abstract

The Northeast region is the largest producer of cowpea in Brazil. Among the northeastern states, Ceará stands out for having the largest planted area and the second largest production in the country, registering, however, one of the lowest yields. In this sense, cowpea breeding programs have been focusing their efforts on launching more productive cultivars that are well adapted to the specific conditions of each state and/or growing region. However, this process of recommending cultivars is hampered by the occurrence of the interaction between genotypes and environments, which consists of the differentiated response of the genotypes according to environmental variations. The aim of this work was to evaluate the interaction between genotypes and environments, as well as to indicate, for the state of Ceará, superior cowpea cultivars in terms of adaptability, stability and productivity of dry grains. The experiments were conducted in four different municipalities in the state of Ceará (Crateús, Madalena, Bela Cruz and Limoeiro do Norte), with two tests carried out in Crateús, totaling five assessment environments. The experimental design used in each assay was randomized blocks with 12 genotypes and four replications. The following agronomic traits were evaluated: number of days for flowering, lodging, architecture, cultivation value, number of pods per plant, pod length, number of grains per pod, mass of one hundred grains, grain index and productivity. Analysis of variance (individual and joint) and path analysis were performed, and the means of quantitative characters were grouped by the Scott-Knott test. After detecting the significance of the genotype x environment interaction, the adaptability and phenotypic stability of the genotypes were analyzed using the GGE biplot methodology. The number of pods per plant had the greatest direct effect on grain yield. The municipality of Crateús, in the irrigated system, was discriminative and representative, and can be considered ideal for genotype evaluation. The cultivars BRS Pajeú and BRS Potengi can be recommended for cultivation in the state of Ceará due to their high productivity of dry grains, adaptability and stability, and for having excelled in most of the production components.