Abstract: The study with two grapevine varieties Manicure Finger and Fujiminori grown in a rain-shelter plastic greenhouse in the Yangtze River Delta region showed that in the greenhouse, the photon flux density (PFD) decreased greatly, while air temperature (T_a), vapor pressure (V_p) and transpiration rate (T_r) had little changes, no matter in sunny or cloudy days. The leaf thickness and fresh weight per cm² of the two varieties decreased by 28.6% and 18.4%, and 13.1% and 11.6%, respectively, total chlorophyll content and apparent quantum yield (AQY) had a slight increase, but chlorophyll a and b contents and chlorophyll a/b ratio had no obvious difference with the open-air cultivation (CK). In sunny days, the diurnal mean value of net photosynthetic rate P_n, diurnal integral value of P_n, and water use efficiency (WUE) of Manicure Finger and Fujiminori decreased by 18.7% and 13.1%, 17.2% and 11.9%, and 26.0% and 36.9%, but stomatal conductance (G_s) increased by 76.8% and 100.8%, respectively, while in cloudy days, the corresponding values of abovementioned parameters were decreased by 48.7% and 33.5%, 34.0% and 29.8%, and 69.2% and 67.7%, and increased by 178.0% and 85.1%, respectively. The variation extents of the parameters were larger for Manicure Finger than for Fujiminori, especially in cloudy days, indicating the great differences of ecological adaptability between these two grapevine varieties.

Key words: Dredged sludge, Agricultural application, Environmental impact