Abstract
This experiment was conducted to clarify the effects of the low temperature (vernalization, particularly) on the shortening of growth period of Italian ryegrass and to know the optimum temperature and days of this treatment. The treatments were combination of a) temperature 0°C and 5°C, b) days 10, 20, 30, 40 days. It was found that 10 days treatments at 0°C and 5°C were little effective, while 20, 30 and 40 days treatments at both temperatures were more effective. The effects were recognized more clearly in the case of 30 and 40 days treatments at both temperatures and the date of initiation of internode elongation was advanced by 7∼11 days. But it has been found that buds and roots in 20 days onward treatments at 5°C grew too long to handle them in the sowing practice. Thus, the good result can be expected, according to this test, from the vernalization of Italian ryegrass for 30, 40 days at 0°C.
