FRUIT ROT CONTROL IN LONGKONG (AGLAIA DOOKKOO GRIFF.) WITH CHEMICAL AND HOT WATER TREATMENT

Preharvest spray with 1,500 ppm carbendazim, 1, 500 ppm mancozeb, 200 ppm citric acid, and 5,000 ppm sodium hypochlorite at 40 days after fruit set for 3 times at 2 weeks interval reduced fruit rot by 96.4, 56.3, 45.4 and 44.7% and fruit drop by 80.7, 63.6, 65.1 and 9.5% after harvest, respectively compared with unsprayed control. Among postharvest hot water treatment (HWT), dipping in 47ºC water for 3 min was the most promising, reducing fruit rot by 57.8%. Good postharvest fruit rot control was also provided by 3 min-dipping in 750 ppm prochloraz solution compared to imazalil, prochloraz, hydrogen peroxide or sodium hypochlorite treatment. Prochloraz also gave the highest fruit drop reduction of about 83.9%. Combined hot water and prochloraz treatment further reduced fruit rot by more than 90%.