OPTIMIZING TIME OF MICRONUTRIENT APPLICATION TO WHEAT PLANTS GROWN ON SANDY SOILS

A 2-year field study was carried out at Ismailia Agricultural Re­search Station during the two growing winter seasons of 1997/1998 and 1998/1999 to evaluate the optimum physiological stage of wheat plants for micronutrients Fe, Zn and Mn application. Mixture of Fe-chelate (6 % Fe), Zn-chelate (12 % Zn) and Mn-chelate (13 % Mn) at the ratio of 3:2:2 respectively was foliar applied (1 g mixture/L of water) at dif­ferent physiological growth stages, i.e. tillering, elongation, booting and heading. The wheat plants received a single spray at each of these stag­es or two sprays at each pair of these stages alternatively. The obtained results revealed that foliar applications of the stud­ied micronutrients at booting stage only or along with either tillering or elongation stage had the most significant effect on increasing wheat grain and straw yields along with the investigated yield attributes as well as grain protein content. This may suggest that booting stage is the most suitable stage to apply micronutrients for wheat plants. another spray at tittering or elongation stage being favorable. Grain contents of P, Fe, Zn and Mn were not significantly affected by the time of micronu­trient application whereas grain K content did.