Effect of plastic films on growth and leaf physiological characteristics of grapevine

Abstract：The effects of plastic filming under different covering layers on the growth, photosynthesis and related enzvmes of granevine were studied to Drovide guidance for earlv maturing cultivation in the Southern China. The experiments investigated the influences of no plastic cover （control）, single plastic film （treatment Ⅰ）, double plastic films （treatment Ⅱ）, and triple plastic films （treatment Ⅲ） on the growth and physiological characteristics of Summer Black and Zuijinxiang. The significant differences in average stem height, rhizome diameter and leaf size were observed between the treatment Ⅱ/Ⅲ and the control,and the treatment III had the strongest effect, while the differences between treatment I and the control were not obvious. The increase in the layers of plastic film resulted in the decrease of net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentrations and water use efficiency.The level of chlorophyll a and chlorophyll b increased in respond to the additional layers, with a decline of the ratio of chlorophyll a and chlorophyll b. The concentration of MDA also increased. In addition, plastic filming influenced the concentration of reduced glutathione as well as the activities of superoxide dismutase, peroxidase and catalase of grapevine leaves. The intensity of these impacts was higher in treatment Ⅰ,followed by treatment Ⅱ, the control group and treatment Ⅲ in decreasing order. Summer Black also showed higher tolerance to weak light compared to Zuijinxiang. In conclusion, normal growth and development of Summer Black and Zuijinxiang could be achieved under single layer plastic filming, while twolayer plastic filming may result in certain degree of the impact. Plastic filming with three layers can severely influence the growth of the two cultivars.