Biofortification of cowpea beans with iron: iron´s influence on mineral content and yield

Abstract

Iron (Fe) deficiency is the most prevalent nutrient deficiency worldwide. Agronomic biofortification is an agricultural strategy for improving the micronutrient concentrations in staple food plants. At present, fertilization is a major vehicle for changing plant mineral contents and food quality. A greenhouse study was conducted to assess the effects of iron chelate and ferrous sulfate applications on the biofortification of Fe and its impacts on the mineral content and yield of cowpea beans. Four application rates of both forms were tested (0, 25, 50, and 100 µM L-1) for 40 d. The amount and type of Fe application affected the mineral seed content, yield and yield components. Applying of Fe in the form of ferrous sulfate at 25 µM L-1 was found to be the optimal rate for biofortifying the cowpea bean plant, because it favored the seed yield and increased the bioavailable Fe content in the seeds over that of the control. The best iron chelate rate was 100 µM·L-1. Thus, it was considered feasible to implement an Fe fertilization program to improve the nutritional quality of cowpea bean crops by increasing the Fe concentrates in the seeds.