两湖平原罕见早稻结实障碍调查

2009年6月我国长江中游两湖平原部分地区发生了罕见的早稻结实障碍.为查清受害程度和原因.对该地区典型田块、典型品种的受害状况和气象条件进行了调查.结果表明,该地区早稻受害严重,不同田块的结实率为20%-70%.以40%-60%居多.估计全域早稻受害面积达13万hm~2,产量损失达30.1万t.对灾害发生期间的气象资料调查表明,两湖平原典型地区在5月23-29日均出现了日平均气温低于18℃的连续低温阴雨过程的所谓"五月寒"天气,而这一过程与受害早稻品种的花粉母细胞减数分裂期基本重叠.结合田间受害分布和穗部植物学特征,综合判定此次早稻结实障碍.系该地区5月下旬发生的"五月寒"天气对早稻花粉母细胞减数分裂期形成的冷害所致.

Field Survey to an Exceptionally Serious Mal-seeding Disaster in Early Rice at Jianghan Plain and Dongting Lake Plain Areas

In June 2009, an exceptionally serious mal-seeding in early rice occurred in Jianghan Plain and Dongting Lake Plain areas located in the middle reaches of Yangtze River of China. A survey was made to the rice fields and the weather conditions to find out the possible causes underlining the damage. The result showed that the early rice was injured seriously in this area. Their seed-setting rates of different fields were between 20% and 70%, with most of them being between 40% and 60%, comparing to the normal seed-setting rate of 90%. The whole area involved was estimated to be up to 1.3×10~5 hm~2, and the production losses up to 3.01 xlO5 t in rice grains. Weather conditions survey indicated that during the period May 23-29~(th), the two plains experienced a consecutive 7 days "Cold May" weather, which was characterized by a morethan 3 days continuous chilling and raining weather process, during which the average temperature was down to less than 18℃.Synchronically, the damaged rice was experiencing its meiosis stage in reproductive growth at this period. By further examining the victim distribution of the fields and the botanical characteristics of the panicles, it was concluded that the mal-seeding disaster was from the chilling on early rice in late May at its meiosis stage.