Studies on intervarietal differences in the resistance of the tea plant to cold. I. The resistance of young tea buds to cold in a warm winter spell.
Harada, S.; Watanabe, A.; Kano, T.
Chagyo Kenkyu Hokoku/Tea Res. J 29(4): 1-5
The resistance to cold of the buds of 11 Japanese varieties was tested during January, 1953, when a spell of mild weather had caused the buds to swell. Resistance was tested by transfer to a refrigerator at 5 degrees C. for 1-5 hr. Varietal differences in resistance to cold were noted, the most resistant varieties being the diploid Yamatomidori and the triploid U-21. The degree of resistance was positively correlated with the refractive index of the cell sap.