Selection of superior cowpea lines for multi-traits and adaptabilities to the Piauí semi-arid using genotype by yield*trait biplot analysis.

Cowpea is a great socioeconomically important leguminous plant worldwide. The crop is an excellent source of proteins and minerals, mainly for the poorest populations. It is cultivated in some states of Brazil. The Piauí semi-arid is the most yielding zone in the state. Thus, the selection of superior cowpea genotypes for multi-traits and adaptabilities to this growing area is very important for the small-scale and medium-scale farmers in Piauí. The objective of this study was to select the superior cowpea lines for their multitraits and adaptabilities to the Piauí semi-arid zone based on the genotype by the yield*trait (GYT) Biplot approach. Seventeen elite lines and three cultivars were evaluated in a randomized complete block design with four replications under the rainfed growing condition at three different locations away from the Piauí semi-arid zone