Experimentation of Transpiration Rate and Influence Factors of Late Rice

Based on the experimentation of controlled irrigation on late rice, the national 863 special project on water-saving irrigation, performed at Jiangxi province, diurnal change and variation in the whole growing season of transpiration rate were analyzed in this paper. In addition, relationships between transpiration and meteorological factors, stoma conductance, soil water moisture were studied. Results showed that the maximum of diurnal transpiration would be delayed when soil water moisture decreased. Transpiration rates in traditional irrigation usually were higher than that in controlled irrigation, but sometimes were lower or equal in the afternoon. Air temperature, leaf temperature, vapor pressure deficit and stoma conductance were the key factors affecting transpiration, and the effects would be different in different growing stages. Correlation existed between stoma conductance and transpiration rate. The transpiration rate were also affected by soil water moisture and rebound after recovering water, but such effects would be lagged in different degrees.