Evaluating the Effect of Fertilizers on Physiological Growth, Chemical, Bioactive Components and Secondary Metabolites in Vigna Unguiculata (L.)

Vigna unguiculatata (L.) (Cowpea) is an African indigenous protein-dense crop that most sub-Saharan Africans rely on for food and nutrition security.

The current study assessed the effect of different levels of poultry manure fertilizer (10, 30, 60 and 90 kg F/ha) and nitrogen fertilizer (30, 45, 60 and 90 kg N/ha) on the growth, yield, mineral composition, bioactive compounds and secondary metabolites in the legume crop Vigna unguiculata (L.). At the end of 15 weeks, 90 kg F/ha and 45 kg N/ha enhanced the growth, yield, mineral composition, production of ascorbic acid, total phenolic and FRAP assay, this informed our decision for the selection of this treatments (45kgN/ha, 90kgF/ha and 0kg/ha control) for further analyses of secondary metabolites.

Poultry manure and nitrogen fertilizer improved the mineral compositions of cowpea leaves, and different accumulation trends were noted depending on different application levels, with poultry manure responding well.

Thus, the application of organic poultry manure at 90 kg F/ha for cowpea cultivation should potentially be recommended in the Mpumalanga Province.