Effects of Different Light Intensity on Photosynthetic Characteristic and Yield Characters of Kidney Bean

The photosynthetic characteristic,yield characters and yield were studied under four different light intensity treatments(100%,75.7%,50.3% and 24.5% sun-shading) of kidney bean.The results indicated that the chlorophyll content of leaves was increased in a short time after shading,but decreased under long shading and was significantly lower than that of the controls.The chlorophyll content,photosynthetic rate,stomatal conduatance and transpiration rate of leaves were increased with increasing light intensity in a certain range of light intensity,but intercellular CO2 concentration was decreased.The numbers of flowers of kidney bean were reduced under shading,especially the numbers of pods per plant,seeds per plant and seeds weight were significantly or very significantly decreased,and high shading level increased influence degree.The photosynthetic productions of different organs were significantly decreased after shading,especially the growth of pod.The economic yield per plant of 75.7%,50.3% and 24.5% sun-shading were decreased 43.2%,80.8% and 91.8% respectively.It seemed that kidney bean requires high light intensity.