1999年黑龙江省北部讷河、嫩江、依安、富裕等市、县部分大豆地块发生了历史罕见的严重花荚脱落甚至达到不实的情况。仅讷河绝产和几乎绝产面积就高达641万亩,直接经济损失3500多万元。因此引起各级政府及广大农技人员、干部和群众的关注和重视,急切地想探明原因,制定有效地防 In 1999, in northern part of Heilongjiang Province, such as Nehe, Nenjiang, Yi’an and Wealthy, serious rare flower pods broke off even in some soybean plots in cities and counties of the Heilongjiang Province. Nehe River alone almost absolutely no shortage of area and an area of ​​up to 6.41 million mu, the direct economic loss of more than 3500 million. Therefore, it has aroused the concern and attention of all levels of government and the vast numbers of agricultural technicians, cadres and the masses, eager to find out the reason and formulate effective prevention