Study of Flower Induction Time in Kiwifruit Actinidia deleciosa cvs Hayward and Tomuri

Understanding of flower induction and its related physiological events are very important in regulating of the kiwifruit fruiting. In this research, kiwifruit flower induction was investigated using defoliation without girdling and with girdling on current shoots, 4-6 months after bud swollen, in eight treatments for two years. Based on the results, the year alone was not statistically significant for measuring traits, but its interaction with the variety and treatment affected significantly some of the measured traits. Defoliation without girdling of female Hayward and male Tomuri cultivars current shoots did not have a significant effect on the percentage of budbreak and percentage of fertile shoots, but the number of flowers per cane and means flower per new shoots of Tomuri cultivar was significantly greater than those of Hayward. The effects of defoliation with girdling treatment on the budbreak percent, fertile shoot percent, the number of flowers per cane and the mean flowers per new shoot were 32.92%, 4.00%, 4.00 and 1.29 flowers for Hayward and 47.08%, 52.5%%, 53.53 and 11.72 flowers for Tomuri respectively. Flower induction in Tomuri cultivar started two weeks earlier than Hayward about five months from bud swelling and peaked in mid-September. Flower induction in the Hayward cultivar began about five and a half months from bud swelling and lasted until the end of it’s when about 88% of the broken buds were fruitful.