玉米病害发生现状与推广品种抗性对未来病害发展的影响

 随着全球气候变化、耕作方式改变和新品种推广,我国玉米病害的发生也有所改变。在春玉米区,丝黑穗病仍然持续严重为害,大斑病呈加重趋势;在夏玉米区,局部地区小斑病发生较重,而矮花叶病普遍发生较轻;以往的次要病害已成为重要病害:如,南方锈病在夏玉米区南部严重发生,瘤黑粉病成为生产中的突出问题,土传病害日益加重,细菌性病害发生渐多。对玉米主要推广品种、近年国家和主产省份审定品种的抗病性分析表明,在北方春玉米区,由于品种抗性水平降低、个别感病品种的推广及病原菌致病力变异,大斑病在近年仍将呈现较重发生趋势;丝黑穗病的发生则由于推广抗病品种和种子包衣技术而有所减轻,但局部地区仍会严重发生;由于缺乏抗病品种,灰斑病和弯孢菌叶斑病的发生将主要取决于气候因素。在北方夏玉米区,小斑病暴发的可能性较小,但已有强致病力菌株出现;由于推广品种普遍对茎腐病抗性水平较低并受耕作制度的影响,茎腐病和苗枯病将成为主要病害;多数品种对南方锈病缺乏抗性,南方锈病发生面积将继续扩大,发病程度也将增加。

The status of maize diseases and the possible effect of variety resistance on disease occurrence in the future

With the changes of the global climate,cultivation methods and release of new varieties, the maize diseases have changed in recent years in China. In spring maize zone the head smut has been continually severe and the northern corn leaf blight has become severe again. In summer maize zone the southern corn leaf blight has been a problem in some areas and maize dwarf mosaic is slight. Some diseases which used to be unimportant have become main diseases now, e. g. southern corn rust in the south areas of summer maize zone, common corn smut and soil-borne diseases in all of growing areas, bacterial leaf diseases in some fields. On the basis of the result of analysis on resistance of varieties released, which were verified by national and provincial crop committees, it can be predicted that in the north spring maize zone the northern corn leaf blight will be severe because of the low level of resistance in varieties and new virulent race in the pathogen. As release of resistant varieties and use of seed-dressing technique the head smut will be controlled effectively, but in some areas it will be severe continuously. The occurrence of gray leaf spot and curvularia leaf spot will be affected by the weather. In north summer maize zone the southern corn leaf blight will be not severe. Stalk rot and seedling blight will be main problems because most of the varieties possess low level of resistance and new cultivation methods have been developed. Southern corn rust will be severe and heavily.