| Autor: |
Gao MW; State Key Laboratory of Crop Biology/National Research Center of Apple Engineering and Technology/College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, Shandong, China., Nie PX; Shandong Institute of Pomology, Tai'an 271000, Shandong, China., Sun Y; State Key Laboratory of Crop Biology/National Research Center of Apple Engineering and Technology/College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, Shandong, China.; College of Science and Information, Qingdao Agricultural University, Qingdao 266109, Shandong, China., Jiang YM; State Key Laboratory of Crop Biology/National Research Center of Apple Engineering and Technology/College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, Shandong, China., Zhang JC; State Key Laboratory of Crop Biology/National Research Center of Apple Engineering and Technology/College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, Shandong, China., Zhang JX; State Key Laboratory of Crop Biology/National Research Center of Apple Engineering and Technology/College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, Shandong, China. |
| Abstrakt: |
The main tree water status indicators which sensitively responded to drought stress and related to tree water balance were investigated in treatment of progressive decrease of soil water potential under shelter from rain. The results showed that stem maximum daily shrinkage (MDS) and midday stem water potential (Ψ stem ) were most sensitive to drought stress among all the water status indicators. MDS not only significantly responded to reference crop evapotranspiration (ET 0 ), but also was sensitive to soil drought stress. MDS was significantly positively related to ET 0 , and the correlation between relative stem daily maximum shrinkage (MDS r ) and relative soil water potential (Ψ r soil ) was highly significant. Moreover, the stems could be measured in succession and recorded automatically. Midday Ψ stem was also sensitive to soil drought stress, and significantly negatively related to ET 0 . The correlation between relative midday stem potential (Ψ r stem ) and Ψ r soil was significant. But so far, it is difficult to automatically measure either leaf or stem water potential. Predawn leaf water potential (Ψ pd ), daily stem growth (DG) or stomatal conductance (g s ) also responded to drought stress to some extent under moderate or heavy drought stress, but they were not sensitive. |
