EFFECT OF ABSCISIC ACID ON SEXUAL TENDENCY AND PRODUCTIVITY OF MONOECIOUS CUCUMBER IN HYDROPONICS

摘要

It has been reported that exogenous abscisic acid (ABA) can alter sex expression of the cucumber. Our purpose was to study the effect of exogenous ABA on sex expression and yield of a monoecious cucumber (Cucumis sativus L. cv. Hokyoku No.2), under the condition of hydroponics. The cucumber seeds were germinated and grown in conglomeratic stones filled 13 cm baskets which were soaked in modified balanced nutrient solution, in a green house. ABA and other regulator (GA3, AOA, Ethrel or AgNO3) treatments were done foliaryly, once time, by spraying until run-off at the fully expanded 2nd true leaf stage. The experiments were carried out in 10 replicates. Daily flowering observations and harvesting fruits on each node were conducted on the main stem (3rd - 17th node) and the side stem (1st node) of the plant. Shoots above the 17th node of the main stem and the 1st node of the side one were excised. When cucumber fruits grew to about 17 - 18 cm length, they were harvested.