Improvement of Manuring Method for Prevention of Bark Splitting Injury caused by Autumn Frost in young Tea Plants

Abstract

The influence of manuring method on the cold resistance of young tea plants during the occurrence period of the bark splitting injury was investigatad.
The young tea plants fertilized with one third of the current doses of nitrogenous fertili-zer and with no nitrogenous fertilizer in autumn, Sept. to early Oct., obtained the cold hardiness more early than the normally fertilized one did.
However, normal usage of autumn fertilizer in due time after summer fertilization was omitted and the normal doses of nitrogen if their application was made very early, such as in early Aug. or suspended untill such late as, Nov. accelerated a cessation of autumn growth and the hardening of the young tea plants.
The growth of the young tea plants well-fed with basal manure plus summer dressing was not affected by the time of autumn manuring.
The potassium effect on cold resistance of the tea plants was not detected, although there has been many reports on it.
These results suggest that the later manuring in autumn is better choice for prevention or reduction of bark splitting injury in dangerous region.