EFFECT OF ROOT TEMPERATURE AT NIGHT ON GROWTH AND DEVELOPMENT OF STRAWBERRY IN THE GREENHOUSE

Planting strawberries in the greenhouse is the main cultural mode in China. But the temperature at night is very low especially in the hanging shelf culture and these had a bad effect on the growth of strawberry. In this study, strawberries (Fragaria × ananassa ‘Benihoppe’) were planted with different root temperatures at night with different heating controls in different greenhouses. The temperature was 13°C in the treatment group and 10°C in the control group. The different temperatures conditions were evaluated on vegetative growth of plants, yield and fruit quality. The results showed that the root temperatures of strawberry had an effect on vegetative growth of plant. The plant heights, leaf area, crown diameter and another vegetative growth indexes of the strawberry grown at the high root temperature were higher than that at the low root temperatures. But, the impact on the physiological indexes of leaves such as sugar content and chlorophyll content was not big. And yield per plant increased as root temperature increased. High temperatures also improved the yield of strawberry. The yield of the control group was 52.61% of yields in the high temperature treatment group. The rate of high quality fruit and the number of fruits in the treatment group was also higher than the control group. On fruit quality, there was no significant difference between different temperatures. The soluble solid content and the firmness of strawberry grown in this study did not have significant differences. In a word, increasing the temperature in a range can improved the yield of strawberry that matured early without adversely affecting fruit quality.