Optimizing Drought-Resistant Cowpea Cultivar Selection Mediated by Silicon Supplementation using TOPSIS tool

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) is an essential food in many arid regions of developing countries. However, its cultivation is threatened by climate change. Silicon (Si) fertilization has been used to reduce environmental stress impact. However, it is necessary to investigate how various plant cultivars treated with Si perform under drought stress conditions. Here, we develop and evaluate a computational model for selecting cowpea cultivars that are more tolerant to water deficit across different Si concentrations. This computational model integrates two mathematical methodologies: the Manhattan distance and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to analyze cowpea cultivar performance across various conditions, aiding in identifying the best-suited cultivars for different climates. Data from a factorial experiment (3 × 3 × 4) were evaluated, covering three cowpea cultivars (BRS Novaera, BRS Tumucumaque, and BRS Xiquexique), three water regimes (well-irrigated control at 75% of field capacity (FC), moderate drought at 60% FC, and severe drought at 45% FC), and four Si concentrations (0.0, 1.0, 2.0, and 4.0 mM). Si application had beneficial effects across the cowpea cultivars, mitigating drought stress impact. The most successful cultivars at Si concentrations of 0.0, 2.0, and 4.0 mM were BRS Xiquexique, BRS Tumucumaque, and BRS Novaera, respectively. However, the combined model results revealed that BRS Novaera cultivar displayed better performance under water stress when treated with Si. Our findings also highlight the sensitivity of cultivar selection to Si application compared to water stress. This methodology can benefit farmers by enabling precise adjustments of applied Si level, selecting tolerant cultivars, and considering the climatic conditions of the growing region.