EFFECT OF PRE AND POST-BLOOM SPRAYS OF UREA AND BORIC ACID ON GROWTH, FRUIT SET, YIELD AND FRUIT QUALITY OF APPLE CV. STARRING DELICIOUS

摘要

The experiment was carried out to study the effect of pre and post bloom sprays of urea and boric acid on growth, fruit set, yield, and quality of apple cv. Starking Delicious grafted on M7 rootstock planted at 4.5 x 4.5m apart. The prebloom sprays included urea at 0.25%, 0.5% and 1%, urea 0.25%+boric acid 0.1%, urea 0.5%+boric acid 0.1% and urea 1%+boric acid 0.1%, boric acid at 0.05%, 0.1% and 0.2%, the post bloom sprays were urea at 0.5%, 1% and 2% and pre+post bloom sprays were urea at 0.25%, 0.5% and 1%. The highest growth in terms of shoot length was observed with pre+post bloom sprays of urea at 1% and the highest fruit set and yield were recorded with urea 1% + boric acid 0.1% followed by urea 0.5% +boric acid 0.1%. The lowest growth, fruitset and yield were observed with control. Pre + post bloom sprays of urea resulted in the highest fruit length, breadth and weight. The highest total soluble solids were recorded with boric acid 0.2% and the reducing and total sugars were the highest with control. The lowest total soluble solids, reducing and total sugars were recorded with pre+post bloom sprays of urea 1%.