THE NEED OF GRAIN LEGUMES FOR IRON, MANGANESE, AND ZINC FERTILIZATION UNDER EGYPTIAN SOIL-CONDITIONS - EFFECT AND UPTAKE OF METALOSATES

A pot experiment was conducted over two successive seasons using pea and cowpea grown in Mitscherlich pots filled with a loamy soil characterized by high pH, low organic matter content and adequate contents of almost all the micronutrients. Liquid metalosates of iron (Fe), manganese (Mn), and zinc (Zn) (amino-acid-chelated) compounds were foliar applied at a concentration of 100 ppm of the element, either individually or in combinations. Results showed that plant growth in terms of height, internode length, number of branches, and dry weight of the plant were sinificantly increased in response to the foliar applications of Fe or its combinations with the other micronutrients, Mn and Zn. Number of pods, and plant and seed yields were increased with foliar applications of Fe and Mn, or their combinations. Meanwhile, seed weight was increased only in pea by the application of Fe, Mn, and Zn as an individual element or in combination as both plants were not capable of efficient uptake of the micronutrients, particularly Fe and Mn from soil to meet their yield nutritive requirements. An increase in seed yield was the result of better plant performance by the improvement of the nutritive status, the result better growth as well as pod production.