Salicylic acid and antitranspirant polymer mitigate the effects of water stress on the growth and yield of cowpea

Water stress can limit the growth and production of cowpea (Vigna unguiculata (L.) Walp.), necessitating the use of strategies that induce plant tolerance to mitigate its effects on the crop. This includes the application of salicylic acid (SA) and antitranspirant polymer (AP). The objective of this study was to evaluate the effect of SA and AP applications on the growth and production of cowpeas subjected to water stress. The experiment was conducted in field conditions at Sítio Boqueirão, Catolé do Rocha, Paraíba, Brazil. The experimental design used was randomized blocks, comprising 10 treatments with four replications. The evaluated treatments included nine combinations generated according to the Central Composite Design experimental matrix, involving five doses of SA and five doses of AP applied to plants under water stress, along with an additional treatment (without water stress and application of SA and AP). The assessed variables included morphological parameters and yield. The data were subjected to canonical correspondence analysis and confidence ellipses. The application of SA and AP increased growth (summer and spring) and productivity (summer). However, in spring, there was a decrease in productivity and an increase in the number of days until the initiation of pod harvesting in cowpeas under water stress.