关键词: 早稻, 直播, 倒春寒, 烂种, 烂秧

Abstract: In 2020, early rice was affected by cold in late spring, and large areas of serious rotten seedlings appeared in Zhejiang. Several investigation sites found that direct seeding rice is particularly serious, and the part of machine transplanting seedlings also died of seedlings due to low temperature and cold injury. Meteorological data analysis showed that, the average temperature in each ten-day of March 2020 was higher than that of previous years, and the temperature in early April was lower than that of previous years. The main reason for the phenomenon of large-scale rotten seed and dead seedlings, first, the late spring coldness temperatures on the 28-31 of late March are low and the daily temperature difference is small. The second, the temperature is high in the early March, mid-March and early late-March, low in the late period, and the temperature changes in the early and late periods are large. Early rice direct seeding prematurely, and the risk of temperature is high. Some early rice seedlings are not properly managed for seeding and seedlings, and the quality of substrates for mechanical transplanting seedlings and insulation equipment are not in place. In view of the existing problems and causes, the countermeasures of early rice to prevent dead seedlings from falling into the cold and rotten in the spring are proposed.

Key words: early rice, direct seeding, cold in late spring, rotten seed, dead seedling