陕西小麦黄矮病演变与厄尔尼诺现象

The Relationship of Wheat Yellow Dwarf Disease in Shaanxi and El Nino Appearance

据资料分析，陕西小麦黄矮病历年发生和流行周期为2～7a，这与厄尔尼诺现象的复出周期有吻合趋势，即厄尔尼诺年的翌年是小麦黄矮病发生流行年。以蒲城县为例，在厄尔尼诺现象发生年中，与历年平均值相比，月降水量减少而月均气温增高；厄尔尼诺现象出现后前述气候现象持续时间一般较长，不仅影响当年，还可延续至次年，往往造成秋、冬、春连旱，为小麦黄矮病发生提供了有利的气候条件。

Wheat yellow dwarf discase data has been carefully studied and the result shows that thewheat yellow dwarf disease in Shaanxi has a epidemic frequency of 2～7 years which is almost like the ElNino appearance frequency. Therefore, it seems that the wheat yellow dwarf disease may likely take placein the following year immediatcly after El Nino appcarance. The further ananysis of the El Nino effect onthe climate factors in Pucheng County, Shaanxi Province reveals that El Nino might easily creat afavourable climate condition for the wheat yellow dwarf disease in Shaanxi.