Abstract:In order to make clear the relationship between the canopy-air temperature difference under different soil moisture and rice yield and quality of different drought resistance varieties, and establish reasonable irrigation index, a field trial was performed using five controlling water treatments to illustrate the response of canopy-air temperature difference to soil water stress and the relationship between canopy-air temperature difference and rice yield and quality at the jointing-booting stage. Results showed that soil water stress significantly impacted on canopy-air temperature difference and the more water stress the lower absolute value of canopy-air temperature difference. The daily variation canopy-air temperature difference was closely related to air temperature and humidity under different water stress treatment. Under the same conditions, the absolute value of canopy-air temperature difference of drought susceptive variety (Liaojing 294) was lower than drought resistance (Kaijing 1). There were significant positive correlations between absolute value of canopy-air temperature difference and filled grain number per panicle, 1000-grain weight, seed setting rate, rice yield, percentage of brown rice, percentage of milled rice, percentage of head rice, broken rice rate and taste value. But it was significant negative correlation between blighted grain number and canopy-air temperature difference. Comprehensive analysis showed that canopy-air temperature difference could be used as a rice water-saving threshold at the jointing-booting stage when the average canopy-air temperature in Liaojing 294 and Kaijing 1 were 0.2℃ (soil water potential treatment S1: -0.008~-0.015MP) and 0.7℃(soil water potential treatment S2:-0.02~-0.03MP) respectively. Under this condition no significant influence was observed on rice yield. This study establish water\|saving irrigation index for rice plating, in order to realize accurate quantitative rice irrigation, and provide theoretical basis.