Water consumption of wine grape under different weather conditions in desert oasis

Variation of vine-tree sap flow is critical for optimizing irrigation schedule and improving water use efficiency in the vineyard. A Dynamax sap flow measuring system was used to measure the vine-tree sap flow for a whole growing season in 2010 at Huangtai vineyard, Wuwei Experimental Station of Crop Water Use, Ministry of Agriculture in China. Results indicated that the vine-tree sap flow was mainly controlled by the leaf area index at initial growth stage, while by radiation, air temperature and humidity and soil moisture at the mid and later growth stage. But the response patterns of vine-tree sap flow to these environmental factors were notably different under different weather conditions. The agreement between sap flow and such meteorological factors, such as radiation, air temperature and humidity in the cloudy days was significantly higher than that in the clear days, while the agreement between sap flow and soil moisture in cloudy days was notably lower than that clear days. In addition, the sap flow was predominantly affected by radiation in clear days, while by air humidity in the cloudy days. This study revealed the mechanism of water consumption under different weather conditions in desert oasis.