降水变化对中国农作物病虫害的影响

Impacts of Precipitation Variations on Crop Diseases and Pests in China

基于已有研究成果,采用农作物病虫害发生危害时空变化对降水时空变化响应事实检测的方法,系统分析降水变化对农作物病虫害影响的已有观测事实及其变化规律性,提出其影响的最新认知,并对今后的发展方向进行了展望。已有影响事实检测表明:一定区域、时段的降水偏少、高温干旱有利于部分害虫的繁殖加快、种群数量增长,降水、雨日偏多有利于部分病害发生程度和害虫迁入数量的明显增加,病虫危害损失加重;暴雨洪涝可使部分病害发生突增,危害显著加重;暴雨可使部分迁入成虫数量突增、田间幼虫数量锐减;降水强度大,可使部分田间害虫的死亡率明显增加、虫口密度显著降低。高温干旱年可使部分病虫害大发生、飞蝗可比常年多发生1代,持续多雨年可使部分病虫害发生界限北移。梅雨期长且梅雨量多的年份有利于江淮地区稻飞虱、稻纵卷叶螟的迁入危害,稻纵卷叶螟迁入早的年份可比常年多繁殖1代。西太平洋副热带高压偏强年份有利于害虫迁入始见期提早、数量增加、范围扩大、危害加重。台风暴雨可使部分病害突发流行、田间虫口密度显著降低,台风多雨有利于害虫的迁入危害。厄尔尼诺年的当年、次年易暴发农作物病虫害。降水变化对农作物病虫害影响的时空变化及其规律性、发生与灾变的影响预估、风险评估及适应对策将是未来需要重点解决的关键问题。

Based on the previous research,the existing observations of the impacts of precipitation variations on crop diseases and pests and the regularities were systematically analyzed by detecting the facts of the temporal-spatial variation of crop diseases and pests in response to the precipitation variations,and the updated understanding of the precipitation variations on crop diseases and pests were put forward.Additionally,directions for future research were suggested.Existing facts indicated that,for a certain area in a certain period,less rainfall,high temperature and drought accelerated the breeding speed and population growth of some pests.More rainfall and rainy days could be good for the distinct aggravation of some diseases,the sharp increase in immigration of pests and the aggravation of damage caused by crop diseases and pests.Rainstorms and floods could lead to the sudden increase of some diseases and significantly aggravated damage.The rainstorms could lead to sudden increases in immigration of some adults,dramatic decreases of larvae in fields.Intensive rainfall could increase the mortality of some pests in fields sharply and reduce the population density distinctly.In the high temperature and drought years,there might be outbreak of some crop diseases and pests,locusts could breed one more generation than normal.In the continuous rainy years,the occurrence boundary of some crop diseases and pests could move northward.The year with longer Meiyu period and more Meiyu rainfall was advantageous to the immigrations of rice planthoppers and Cnaphalocrocis medinalis Guenee in Jianghuai region and one more generation of Cnaphalocrocis medinalis Guenee would occur in the year with the earlier immigration.The year with stronger western Pacific subtropical high was helpful for the earlier occurrence of first immigration of pests,increasing the quantity,expanding the range and aggravating the damage.The typhoon rainstorms could contribute to the outbreak and prevalence of some diseases and sharp decreases of population density of pests in fields,while a great amount of typhoon rainfall was beneficial to pest immigration.In the El Nino year and the next year,crop diseases and pests might break out readily.The temporal-spatial variation and regularities of the impacts of precipitation variations on crop diseases and pests,impacts projection of occurrence and catastrophe,risk assessment and adaptive strategies are the key issues needed to be resolved in the future.