Effects of Iron Fertilization on Yield and Tissue Micronutrients Concentrations of Different Haricot Bean (Phaseolus Vulgaris L.) Varieties in Southern Ethiopia

Abstract

Although required in smaller quantity, micronutrients are as essential as macronutrients for optimum growth and yield for beans. This study was conducted under field conditions at Halaba, Butajira and Taba, and under greenhouse conditions with soils collected from the aforementioned locations to evaluate the effect of Fe fertilization on tissue micronutrients (Zn, Fe, Cu and Mn) contents of different haricot bean varieties. The treatments include two factors, haricot bean varieties (Nasir, Ibado, Hawassa Dume, and Sari-1) and levels of foliar-applied iron (Fe) fertilizer (0, 1, 2, and 3% solution). Both the pot and field experiments indicated that yield and tissue micronutrients (Zn, Fe, Cu and Mn) concentrations of haricot bean varied significantly across soils (locations) and among varieties.  The highest seed Fe concentration (59.04 mg kg^-1) was recorded in Taba soil, whereas the lowest value, 35.63 mg kg^-1, was observed in Halaba soil. Hawassa Dume and Nasir produced the highest and equal grain yield, whereas Nasir produced the highest seed Fe concentration (59.02 mg kg^-1). The highest leaf Fe concentration (290.19 mg kg^-1), was observed with Ibado. Foliar application of FeSO₄.7H₂O did not significantly influence tissue Zn concentration and leaf Cu concentration, but seed Cu, tissue Mn and tissue Fe were significantly affected by Fe fertilization. The application of different levels of Fe fertilizer did not significantly influence yield of haricot bean varieties, but it significantly increased both leaf and seed Fe concentrations.  Consequently, Nasir and 3% FeSO₄.7H₂O were found to be the best variety and rate, respectively, for quality production of haricot bean.

Keywords: Manganese, Iron, Copper, Zinc, Concentration and Haricot bean