小麦重大病虫害发生流行的气候影响评价

 为分析评价气候变化对小麦重大病虫害发生流行的影响,揭示全球变暖趋势下异常气候条件对病虫害时空演替和发生规律的作用机制,通过收集整合20个中国冬小麦主产省(区、市)经规范连续、广泛系统的测报调查所获得的病虫害发生数据,对应2009-2010冬小麦生育期间气候特点和极端气候事件,与历史常规年份的病虫害发生状况和气候条件进行比较.结果表明,在该生长季,由于初冬强降温、春季持续低温以及西南麦区秋冬春三季连旱等异常天气气候条件的影响,小麦重大病虫害发生时期推迟,其中条锈病扩展流行范围小、发生轻,纹枯病和白粉病扩展流行范围广、发生中等,麦蜘蛛等前期虫害发生较轻,赤霉病、蚜虫等穗期病虫害发生严重.从而得出,影响不同种类病虫害发生流行的关键时期、关键气象因子有所不同,这为病虫害预测预报分类指导和关注重点提供了依据;为做好预测预报、评估气象灾害对病虫害发生的影响,应做到“大小兼顾、长短结合,分类关注、抓住关键”.

An Assessment of the Impact of Climatics Condition on Wheat Pests Outbreak and Diseases Spread

This paper gives a comprehensive analysis and assessment of the impact of climatic conditions on wheat pest outbreak and disease spread, to find out the mechanism how abnormal weather and climate affects the pest and disease occurrence. Reliable data were collected via continuous field monitoring and observation in 20 main wheat-planting provinces, and are related to the climatic traits and meteorologic disasters in the whole development stage of winter wheat during 2009-2010. These year's data are compared with those of past normal years. It is indicated that the unusural meteorologic events, such as the sudden and sharp drop of temperature at the beginning of winter and the long-lasting abnormal low temperature in spring in northern and eastern wheat zones, and historically rare drought through autumn, winter and spring in south-western wheat zones, would postpone the stage of wheat pests and diseases with remarkable diversification of each kind. Wheat stripe rust is restricted to a smaller range and in less serious grade. Wheat sharp spot and wheat powdery mildew occur in a massive area and on a medium grade. Wheat scab and aphids break out seriously at the heading stage; nevertheless wheat mites are lighter than a mid-size one at the former stage. It is concluded that the key stage and the weather elements are different for different pests and diseases, as the bases for classification and focus for forecast. In order to improve the forecast and assessment, it is important to pay attention to weather conditions in both broad and particular areas and for both long and short periods, using the "classification" and "focus" methods.