Performance of cowpea progenitor and hybrids in varying concentration levels of phosphorus in hydroponic setup

Among the abiotic factors limiting cowpea productivity, phosphorus (P) is a crucial element. However, in Zambia, no study has determined optimal soil P concentrations for the available cowpea germplasm. The objectives of this study were (i) to identify cowpea genotype that performs better in different concentration levels of phosphorus in hydroponic setups, and ii) to determine the phenotypic response of agronomic variables in different concentration levels of phosphorus. The experiment was set up as 4 x 10 completely randomized design (CRD) replicated 3 times, with 4 doses of P, thus, 0mg/L, 4.7mg/L, 9.3mg/L and 13.95mg/L in nutrient medium and ten genotypes (G). Genotype LT BT1h was identified as a better performer across P concentration. Further exploration of G x P interaction main effects revealed that genotype LT BT1 h performed better than the progenitor in all doses of P concentration except in a medium with 9.3mg/L and 13.95mg/L. Overall, the results showed that applying a concentration above 9.3mg/L P impeded seedling productivity. Significantly better performances were obtained with shoot biomass, plant biomass, and shoot length of the measured variables, implying that the identified variables, at varying levels of P concentration, can initially be used to aid in selecting high-performing genotypes. The identified novel and best-performing cowpea hybrids for economic traits are recommended for further evaluation and consideration.