EFFECT OF COBALT, CADMIUM, AND NICKEL AS INHIBITORS OF ETHYLENE BIOSYNTHESIS ON FLORAL MALFORMATION, YIELD, AND FRUIT-QUALITY OF MANGO

Among the treatments of exogenous foliar spray application of sulphate s of cobalt (Co) and cadmium (Cd) at 0, 250, 500, 1000, and 1500 ppm, and nickel (Ni) at 0, 100, 200, and 400 ppm prior to flower bud differ entiation in the first week of October, cobalt sulphate (1000 ppm) or cadmium sulphate (1500 ppm) significantly (P=0.05) reduced floral malf ormation of mango (Mangifera indica L) cv. Langra by 65 to 71% and inc reased the fruit yield by 35 to 37%. The physical characteristics of t he fruit were not affected significantly at the lower concentrations b ut higher concentrations of Co and Cd caused reduction. Total and non- reducing sugars in the fruit were adversely affected by the higher rat es of Co and Ni applied, but exhibited no effect on total soluble soli ds percentage (TSS%) or reducing sugars. The foliar spray application of the sulphates of Co, Ni, and Cd increased their respective concentr ations in the leaf tissue without any phytotoxic symptoms. Most of the desirable effects were achieved with the 1000 ppm cobalt sulphate tre atment applied in the first week of October prior to flower bud differ entiation.