摘要：As a p otential petro-diesel substitute, low number of fruit productionbecomesthe main constrain to develop J. cu rcasas a second plant oil source after palm oil in Malaysia. Utilization of plant growth regulators has been scientificall y proven to increase plant growth under certain concen trations. This study was conducted to investigate the effect of different concentrations of ethephon on leaves, flowering, fruit size and number of fruit seed of J. curca s. Different concentration of ethephon (0 mg L-1, 1 50 mg L-1, 300 mg L-1and 600 mg L-1) was sprayed once on foliar. Application of ethep hon induced leaves discoloration and necrosis 24 hours after treatment. Number of leaves on plant extremely reduced in 72 hours. All ethephon treated plant fastened flower buds production, app roximately 15 days in average after shoot emergence. Highest concentration (6 00 mg L-1) reduced 26.95% flower stalk comp ared to control. 150 mg L-1and 300 mg L-1promoted female flower up to 8.4 compared to control. 300 mg L-1o f ethephon reduced 32 .6% number of fruit and 20.54% number of seed, while 150 mg L-1slightl y increase 8.4 % of fruit size compared to control. Ethep hon has potential in promoting flower buds and increasing number o f female flowers in J. curcasbut not an effective growth regulator in increasing number of fruits
