Study on Diurnal Variations of WUE and Relevant Parameters for Different Cultivars of Apple Trees
Qu Guimin, Shen Xiang, Wang Hongxia, and She Huairui (Department of Horticulture, Shandong Agricultural University, Taian 271018 )
10-year-old apple trees were used as materials in the experiment. The diurnal variations of WUE and relevant parameters for different cultivars were preliminarily studied. The main results were as follows: 1. The leaf WUE was in the order of Starkrimson Fuji Starking under the adequate soil water content, and Fuji Starking Starkrimson in drought soil; 2. When in case of drought the Pn and Pn/Ci of Fuji were higher, but the Tr was lower, so Fuji was not sensitive to the soil water content;3. It had to be at the cost of high transpiration rate for Starkrimson to get a high photosynthetic rate; 4. No matter whether the water is supplied adequately or not, the Gs of Fuji is always less than that of Starkrimson and Starking; so it is beneficial for Fuji to use the soil water.