2019 Volume 2019 Issue 127 Pages 1-10
Covering cultivation is a critically important method for high quality powdered green tea production. The covering period, once a year previously, becomes twice a year with drastically increasing demand for powdered green tea since around 2000. Therefore, there is a fear of some damage to the tea tree by decreased growth due to insufficient photosynthesis. This research was conducted for five years to examine the effect of covering periods in a year on the growth of tea shoots and the canopy surface temperature based on thermal images. As prolongation of covering period in a year, decreased growth, and higher temperature on the canopy surface in midsummer were observed, since the 2nd year of direct covering cultivation, and since the 3rd year of ceiling-shelf covering cultivation, indicating that the difference in the covering methods has influences on the growth of tea tree over several years. Our results suggested possibility of detecting accumulative damage to the tea tree caused by excessive covering period, based on thermal images of the canopy surface.
