Effects of Different Training Methods on Growth and Yield in Passion Fruit

Abstract

In this study, we investigated the effects of different training methods (TM) on growth, yield and fruit quality of ‘Ruby Star’ passion fruit under plastic house cultivation. In the TM-upward, the bearing shoot was extended upward, and in the TM-downward, it was extended downward. The average daily air temperature ranged from 15 to 23 ℃ during the flowering period and 20 to 28 ℃ thereafter. The illuminance between rows was lower in the TM-upward than in the TM-downward. The vegetative growth was vigorous in the TM-upward, such as the internode length and individual leaf area being larger than those in the TM-downward. The incidence of flower with upright style was lower and the fruit set percentage was higher in the TM-upward than in the TM-downward. The fruit yield was 1.5 times higher in the TM-upward than in the TM-downward. In the TM-upward, the percentage of fruits with good coloring was lower and the sugar content was lower than in the TM-downward. In conclusion, it was clarified that the TM-upward promotes the vegetative growth and the crop yield, whereas the less-sweet fruit might be resulted by low light intensity, suggesting better light irradiance should be altered in the future.