IMPROVING SEED YIELD OF BLACK GRAM (VIGNA MUNGO L. VAR. DPU-88-31) THROUGH FOLIAR FERTILIZATION OF ZINC DURING THE REPRODUCTIVE PHASE

The response of zinc (Zn) deficiency on reproductive yield and recovery through foliar application of Zn was determined in black gram, an important edible legume in India. Results revealed that foliar spray of Zn [0.01 and 0.5% zinc sulfate (ZnSO₄)] improved not only the flowering, pollen producing capacity, pollen viability, stigma-receptivity and pollen-stigma interaction but also the yield parameters like number, size and weight of pods and seeds. Zinc deficiency induced changes in pollen grain structure, activity of esterase and poor stigmatic exudation leading to improper pollen-stigma interaction, which seem to be the main cause of poor fertility and decreased seed yield. Foliar application of 0.5% ZnSO₄ after bud formation was most beneficial not only for reproductive yield but also seed Zn content.