Effects of Varieties and Micronutrients Fertilization on the Production of Quality Bean in Selected Areas of Southern Ethiopia

Abstract

Zinc and Iron are essential trace elements for plants, animals, and humans, and their deficiencies cause a health risk and can slow physiological processes associated with illness and death in the developing world. Experiments were conducted in Taba, Halaba, and Butajira in a quadruple factorial design on farmers’ fields to evaluate the response of haricot bean varieties to different Zn and Fe levels. The two factors for zinc experiment were the concentration of zinc fertilizer (0, 0.5, 1, or 1.5%) and the haricot bean variety (Nasir, Ibado, Hawassa Dume, or Sari-1), and the factors for iron experiment include haricot bean varieties (Nasir, Ibado, Hawassa Dume, and Sari-1) and Fe fertilizer (0, 1, 2, and 3% solution). Zinc sulfate (ZnSO₄∙7H₂O) and Iron sulfate (FeSO₄.7H₂O) were sprayed on the leaves, and nitrogen (N) and phosphorus (P) were applied to the soil equally for all treatments just before planting, using urea and triple super phosphate (TSP), respectively. Haricot beans were planted in rows with a spacing of 10 cm between plants and 40 cm between rows. Plant height, number of pods per plant, number of seeds per pot, 1000 seed weight, and biomass and grain yields were determined. Leaves and seeds from each treatment plot were analyzed for their Zn and Fe contents. The results indicated that haricot bean production varied significantly among varieties both in yield parameters and tissue Zn and Fe concentrations, with the highest grain yield being produced by Nasir and Hawassa Dume. Nasir also produced the highest seed Zn and Fe; therefore, it was found to be the best variety both in quantity and quality. Haricot bean production also varied significantly among locations, with the highest grain yield at Butajira. The application of increasing levels of Zn and Fe fertilizers significantly increased tissue Zn and Fe concentrations. The growing seasons also significantly affected haricot bean production in terms of yield parameters and tissue Zn and Fe concentrations. In conclusion, Zn and Fe concentrations varied among haricot bean varieties, and Zn and Fe fertilization enriches haricot bean with the elements and hence improves its quality.

Keywords: Concentration, Leaf Zn and Fe, Seed Zn and Fe, Zn and Fe fertilization, Tissue Zn and Fe, Haricot bean varieties