草坪褐斑病病原菌鉴定、流行规律及其综合控制技术的研究

Study on Causal Agent, Epidemic Law and Integrated Control Techniques of Turfgrass Brown Patch Disease.

通过 1996～ 1999年的调查研究表明 ,引起北京市草坪褐斑病的病原主要为立枯丝核菌 ,该菌以菌核在土壤中越冬 ,气温在 17℃以上时菌核开始萌发 ,萌发的最适温度为 30℃ ,土壤温度在 2 0℃以上时菌丝开始侵染 ;病害的流行可分为 4个时期 :菌核萌发期、侵染发病初期、发病盛期和病害稳定期 ,前两个时期是病害防治的关键时期 ;扑海因、甲基托布津和万霉灵对病菌的毒力强 ,可以作为病害防治的化学药剂 ,生防菌制剂特立克和X8也有一定的防治效果。在综合研究的基础上 ,依据病害的田间流行规律及发生特点配制了 3种药剂。田间防治试验表明 ,综合利用这

Isolations from 93 turf samples with brown pacth symptoms and pathogenicity tests indicated that Rhizoctonia solani Kuhn is the most important pathogen causing brown patch of turfgrass. R. solani survives winter for growth in the form of bulbils, germinates at air temperature ≥17℃, optimum 30℃. At soil temperature ≥20℃, fungal hyphae begin infecting leaves. Disease epidemic includes 4 periods: bulbils germinating phase (Ⅰ), infecting and diseasing primary phase (Ⅱ), disease explosive phase (Ⅲ) and stabilizing phase (Ⅳ), Ⅰ and Ⅱ are key phase of controlling disease. Toxicity and bioassay tests indicated that fungicides Rovral, Jiameiling and Topsin-M are strongly toxic to R. solani, that biological agents Telike and X8 can inhibit growth of R. solani. On the basis of laboratory test and disease characteristics, 3 kinds of chemical reagents were made up, named C-1, C-2 and C-3, field tests proved that brown patch disease can be controlled effectively by integrated using C-1, C-2 and C-3.