持续高温与棉花黄萎病发生的关系及对棉花产量和品质的影响

The relationship between continuous high temperature and the occurrence of cotton Verticillium wilt and its effect on yield and quality of cotton

7、8月份是棉花产量形成的关键期。本研究依据石河子地区2015年7、8月份持续高温年份和2014年比较正常年份的气象资料,采用常规病原培养、病圃鉴定和分级调查的方法,研究了7、8月份持续高温对棉花黄萎病菌生长及其发病的影响;并采用常规考种、实收产量和品质检测的方法,确定供试品种在7、8月份持续高温年份和一般年份间的产量和品质。结果表明:高温对棉花黄萎病菌的生长有明显的抑制作用,7、8月份持续高温不仅会使田间黄萎病的发生明显减轻,同时会明显减少单株结铃数,增加蕾铃脱落率、并使马克隆值升高,从而对产量和棉纤维的品质影响较大。2015年7、8月份持续高温天气是导致新疆棉区黄萎病明显减轻、产量降低、品质下降的主要原因之一。

July to August was the crucial period for cotton yield formation in Xinjiang.In our study,according to Shihezi＇s climatological data of continuous high temperature weather from July to August in 2015 and normal year in 2014,the effects of cultural characteristics of Verticillium dahliae,severity of disease,production and quality of cotton in field were evaluated,by the methods of observing isolates in petri dish and investigating incidence in disease nursery and classification survey in field.Results showed that high temperature significantly inhibited the growth of V.dahliae; the continuous extremely hot weather in July to August had not only contribut to reducing severity of disease,but significantly reduced boll numbers per plant,square and boll abscission rates increased,and micronaire value of fibre increased,and thus affecting cotton production and quality greatly.Therefore,continuous extremely hot weather in July to August were one of the main cause of reducing severity Verticillium wilt,yield of cotton and quality of fibre in Xinjiang.