Desempenho do feijão de corda Vigna unguiculata (L.)Walp.1832 sob estresse químico: implicações para o cultivo no sul do Piauí

Abstract

Cowpea (Vigna unguiculata) plays a key socioeconomic role in Northeastern Brazil, but its productivity can be affected by poor-quality irrigation water, especially in regions with limited sanitation. This study evaluated the effects of chemical stress caused by irrigation with a neutral detergent solution (5% v/v) on the growth, development, and yield of cowpea plants in southern Piauí. The experiment was conducted in open field conditions with two treatments: a control group irrigated with potable water and a chemically stressed group irrigated with the detergent solution. Morphological and productive parameters—including plant height, stem length, pod length and width, number of locules, weight of 100 grains, and total grain weight—were analyzed using Shapiro–Wilk, Levene, ANOVA, and Mann–Whitney tests. Chemical stress significantly reduced plant height and the number of locules, indicating negative effects on vegetative growth and reproductive capacity. Other variables showed no significant differences, possibly due to plant mortality in the stressed treatment and the need for estimated values. The results demonstrate that irrigation with detergent-contaminated water compromises cowpea development, highlighting the importance of monitoring water quality in family farming systems in regions with inadequate sanitation