出版社：Polish Society of Ecological Engineering (PTIE)
摘要：Water stress is an indicator that plant are suffering from drought.For optimization of the crop production is necessary to indicate physiological changes, those can be represented by stem expansion or shrinkage and sap flow rate.We used the Dynagage SGA5-WS (Dynamax) sensors for the sap flow monitoring and the sensors Diameter Dendrometer Small (Ecomatik) for measuring branches diameter changes in our research.The research was realized during two seasons, in the summer (from 31st July to 14th August 2018) and in the spring (from 27th March to 14th April 2019).The subject in our research were walnut trees (Juglans regia) situated in the private orchard in Nové Zámky area in Slovak Republic.The sap flow values in summer were on average range of 90 g.h-1, with maximum measured values above 160 g.h-1 measured after the precipitation events.After increasing of soil moisture on 1st and 2nd August 2018, it was detected the branches diameter expansion up to 0,05 mm.However, the other spring values were much lower.The sap flow reached less than 35 g.h-1 what was one third values in summer 2018.This phenomenon is a result of the low transpiration intensity of transpiration or a leafless state of trees.Although the changes in diameter were not significant in the early vegetation stage, there were monitored some fluctuation causing the diameter was shrinked by 0,2 mm due to a negative average air temperature.
