APPLICATION OF PLANT GROWTH REGULATOR AND POTASSIUM NITRATE TO IMPROVE THE QUALITY AND YIELD IN WASHINGTON NAVEL ORANGES (CITRUS SINENSIS)

Fruit yields of traditional navels like Washington Navels are lower as compared to other sweet oranges due to low fruit set and quality problems like creasing. Effect of plant growth regulator and Potassium (GA3 and KNO3) alone and in combination were tested in Sargodha, Punjab conditions at full bloom stage of Washington navel oranges. Impact of these treatments was tested on fruit yield, quality and to reduce the physiological disorder; incidence of creasing. Fruit set and yields were increased over non-treated trees, while combine treatment of GA3 and KNO3 (GA3 25% and KNO3 2%) had best results in fruit yields and quality i.e. fruit weight, size, TSS, acidity and other qualitative characteristics of the fruit. Creasing was effectively minimized by spraying plant in combination of GA3 and KNO3, thus reducing the quantitative and qualitative post-harvest fruit losses.