Occurrence Dynamics And Chemical Control Of Fusarium Head Blight In Wheat In Hexian County

The Fusarium head blight(FHB)is one of the most important plant diseases that harm wheat production.Frequent occurrence of FHB on wheat was observed in Hexian county,Anhui Province,and this disease reached the level of pandemic in 2003,2010,2012 and 2016.In the prevention and control of FHB,the common methods are to cultivate disease-resistant wheat varieties and chemical control based on the understanding of the regularity of disease occurrence.However,in the Hexian county area,there has been no systematic investigation of the occurrence of FHB;the control effect of commonly used fungicides on FHB are also scarce.In additon,the tolerance of local wheat cultivars on wheat head blight have not yet been reported.Therefore,it is urgently needed to study these above mentioned issues.The results will be of great significance to effectively control the occurrence and damage of FHB.In this paper,the occurrence of FHB in the past six years(2012-2018)was systematically investigated and analyzed statistically.Next,the control effect of conventional fungicides on FHB was preliminarily identified through field trials.Finally,the tolerance of wheat varieties to FHB was studied.The main results are as follows:1.In the past six years(2012-2018),FHB on wheat in five of the six years was more and more popular,the exception is 2013.In these years,the occurrence of seedling rot and stalk rot in the early stage of wheat growth was also more than that of the previous years.The possible causes are related to the changes of the cultivation system,as well as the "straw returning" measurements implemented in recent years.2.30% tebuconazole/thiram WP,25% cyanenyl ester SC,and a combination of 90% carbendazim WG and 430 g/L oftebuconazole SC can effectively control FHB.In the year that FHB will be moderately heavy,first times can be applied in the period of wheat flush to early flowering and second times after 7 days.Meanwhile,it is suggested that the alternately rotated use of these chemicals can effectively prevent the epidemic of FHB.3.From the point of view of disease tolerance,Ningmai 13 is the most suitable wheat cultivar in the Hexian county area,followed by the Shengxuan 6 and Sumai 9.However,regardless of the disease tolerance of wheat,it is very necessary to prevent FHB by fungicide application.