Agronomic performance, bioactive profile, and nutritional quality of cowpea [Vigna unguiculata (L.) Walp] under aluminum edaphic stress conditions in the Peruvian Amazon

Abstract

Cowpea [Vigna unguiculata (L.) Walp] is a strategic legume for food security in the Peruvian Amazon owing to its resilience in marginal soils. The aim of this study was to evaluate the agronomic performance, bioactive profile, and nutritional quality of eight cowpea accessions grown under high aluminum saturation (69.01%) and extreme acidity (pH 3.50) in Zungarococha (Loreto, Peru). Phenological and yield traits were assessed under a randomized complete block design, together with total phenolic content and antioxidant capacity (DPPH and ABTS), and the proximate and mineral composition of the grain. Analysis of variance revealed highly significant differences among accessions. Accession PER1005852 was identified as a dual-purpose ideotype, combining the highest grain yield (1.42 t ha⁻¹) with a strong antioxidant profile. Protein content ranged from 21.87% to 24.97% (highest in PER1005851), with a high phosphorus content (616.70 mg/100 g in CP0112) and an iron content consistent with the range reported for the species (7.60 mg/100 g in CP0063). Multivariate analysis confirmed that dark seed-coat pigmentation is a phenotypic indicator of greater nutraceutical potential. It is concluded that Amazonian cowpea is a functional food with a dense nutritional profile, of interest for breeding and biofortification programs in the face of climate change.