Effect of Low Temperature and Freezing Injury on Whole Growth Period of Sweet Waxy Corn in Wuzhai County of Shanxi Province and Defensive Measures

Freezing injury is one of main meteorological disasters affecting growth and development of Wuzhai sweet waxy corn．The most economical and effective measure to prevent freezing injury is to understand characteristics of Wuzhai low-temperature freezing injury, select the best sowing and harvesting time, and avoid risk of freezing injury．Based on meteorological data of 65 years temperature, 10 cm ground temperature and frost day in Wuzhai county and data of freezing injury in recent 10 years, effects of low temperature freezing injury on whole growth period of sweet waxy corn in Wuzhai county were analyzed and studied by using methods of mathematical statistics, probability statistics and excel analysis．Results showed that during growth period of sweet waxy corn in Wuzhai County, risk of freezing injury was higher in spring and lower in autumn．From seedling stage to three leaf stage of sweet waxy maize, period with the highest risk of freezing injury was from April 25 to May 15．In harvest period of sweet waxy corn, risk of freezing injury was the highest in late September．According to research results, corresponding defense countermeasures were put forward in order to provide technical support for scientific and rational planting of sweet and waxy corn．