RESPONSE OF FABA BEAN TO FOLIAR APPLICATION OF COPPER AND MOLYBDENUM UNDER PHOSPHORUS FERTILIZATION LEVELS

Response of faba bean (Vicia faba, L.) variety Giza 184 to foliar application of copper and molybdenum was studied as possible factors to improve its yield and quality under phosphorus fertilization levels. Two field experiments were carried out at Sakha Agricultural Research Station Farm, Kafr El-Sheikh Governorate, during the two successive winter seasons of 2003/2004 and 2004/2005. Split plot design with four replicates was used. The main plots were assigned to three phosphorus application levels of 0(P₀), 15 (P₁) and 30 (P₂) kg P₂O₅ fed^-1 as superphosphate 15.5% P₂O₅. The sub plots were allotted for seven micronutrients foliar spray treatments of 0, 50 ppm copper (Cu₁), 100 ppm copper (Cu₂), 30 ppm molybdenum (Mo₁), 60 ppm molybdenum (Mo₂), Cu₁ + Mo₁ and Cu₂ +  Mo₂. The results can be summarized as follows:
                The effect of microelements application on seeds, straw and biological yields were highly significant. The highest mean values were recorded with Cu₂ spraying, while the lowest values were obtained with P fertilizer only. The interaction between P levels and microelements spraying high significantly affected faba bean seed and straw, yields were obtained with P₀Cu₂ treatments. Phosphorus treatments affected the response of copper treatment, the least effect was under P₂ treatment. The sequence effect of P treatments only can be arranged as follows: P₁ > P₀ > P₂ in both seasons. Phosphorus heavy additions adversely affected faba bean yield. Increasing P fertilizers from 15 to 30 kg P₂O₅ fed^-1 led to decrease the net return of faba bean compared to the control. The highest net return values of 825, 5 and 748 L.E., fed^-1 were obtained under P₀ Cu₂ treatment in the first and second seasons, respectively. Increasing P fertilizer led to decrease the net return from faba bean treated with the copper fertilizer. The treatment of Cu₂ had the highest nitrogen and protein contents  in both seasons. Available N and P in the soil increased with increasing P fertilizer level.