Effect of preharvest spray of growth regulators on fruit retention and quality of mandarins (Citrus Reticulata Balanco)

摘要

Furit drop in mandarin is one of the problems faced by the growers in many parts of India hills. Once pre-harvest fruit drop is due to the imbalance in hormone level (3). Spraying of growth regulators play an important role in controlling fruit drop (4). The present study was conducted to observe the effect of 2,4- D, GA_3, and their combination in controlling fruit drop and their impact on the quality of fruits. The experiment was carried out at Horticultural Research Station, Yercaud during 1997-98. The growth regulators 2,4- D (10,15 & 20ppm) ,GA3 (10,15 & 20ppm) and their combinations were sprayed when the fruits were in green mature stage. Unsprayed plants were used as control. trees were selected for each treatment three and the treatments were replicated thrice in a randomized block design. Data on fruit drop was recorded at 10 days interval starting from the day of spraying and the fruit retention percentage was worked out after the harvest. On visual observations the pathological fruit drop was separated. The total soluble solid was estimated by hand refractrometer. The estimation of sugar and the started methods.