直播早稻适宜播种温度分析

为满足近年来直播稻种植的气象服务需求，开展直播早稻适宜播种温度研究。以南昌地区的常规种植早稻‘湘早籼45’为研究对象，设置3月26日、3月29日、4月2日、4月5日以及4月10日共5个播期，研究分析不同播期下直播早稻的出苗率、农艺性状以及产量的特征。结果表明，成苗率与出苗期间平均气温和平均最低气温呈显著正相关关系；适时早播有利于提高直播早稻有效穗数、每穗粒数和结实率；气温对苗高和叶龄变化有明显影响。连续3~5日平均温度达18℃，日最低气温在15℃以上时，有利早稻直播。

Suitable Sowing Temperature for Direct Seeding Early Rice

In order to meet the meteorological service demand of direct seeding early rice in recent years, suitable sowing temperature of direct seeding early rice was studied. A conventional early rice variety ‘Xiangzaoxian 45’ of Nanchang area was used as the research material, five sowing dates were set, which were March 26, March 29, April 2, April 5 and April 10. The seedling emergence rate, agronomic traits and yield of direct seeding early rice under different sowing dates were analyzed. The results showed that there were significantly positive correlations between the seedling rate and the average temperature and minimum temperature during seedling emergence. Timely and early sowing was beneficial to increase effective panicle number, grain number per panicle and seed setting rate of direct seeding early rice. Temperature had obvious effect on the change of seedling height and leaf age. When the average temperature reached 18℃ and the daily minimum temperature was above 15℃ for 3-5 days, it was favorable for direct seeding of early rice.