Effect of Shading and Rain-Shelter on Plantlet Growth and Antioxidant Systems in Strawberry (Fragaria x ananassa)

In the present experiment, cultivar 'Benihoppe' was employed to study the effect of shading and rain-shelter on plantlet growth and antioxidant systems. The main results were as follows. (1) During the shading treatment the temperature (1: 00 pm) inside the greenhouse was reduced compared to the control. The plastic houses covered with 60 and 70% shading nets decreased temperatures by less than 1 degrees C compared with the CK, while 80 and 90% shading nets decreased it by 1.2 and 1.3 degrees C, respectively. Even in the cloudy dawn and early drawn, shading of 80% maintained a light intensity of more than 10,000 lux and plantlets still grew. (2) The plantlets under shade grew much higher than in the control. In the four shading treatments plantlets were significantly higher than those in the open field. The plantlets under 90% shade were the highest among the treatments, which was 14.35% higher than in the control. (3) Under shading conditions, the anthracnose incidence and disease index were reduced, while the average plantlet numbers per square meter increased. The maximum numbers were those of 80 and 90% shade treatments. And the smallest disease incidence was in the 80% shading treatment. (4) The results showed that with increasing shade, the content of Chl and MDA and the activities of SOD and POD, changed regularly and significantly in order to adapt to the low light environment. (5) The most suitable shading measure is a sunshade net with shading of about 80%.