Research On Occurrence Rules And Control Of Wheat Leaf Blotch In Changli Area

Wheat leaf blotch was infected by various pathogens.However,the research about wheat leaf blotch has not investigated in details.The occurrence rules,epidemic factors,pathogens identification of wheat leaf blotch were investigated in this paper.Moreover,the indoor toxicity and field efficacy against to blotch were evaluated.The results showed as follows:1.According to the field investigation,in late April,the incidence rate and disease index of wheat leaf blotch were 3.5% and 0.04,respectively,which meant wheat leaf blotch entered the starting period.Wheat leaf blotch developed rapidly in early May,and reached the peak period in early and middle June and the incidence rate might be up to 92.3% in June 14 th,2014.2.According to the results of investigation and analysis,meteorological factors,wheat variety,growth periods and cultivation conditions affected the occurrence of wheat leaf blotch.Temperature and relative humidity affected the incidence of wheat leaf blotch.The resistance of jingdong 8 was stronger than that of fengkang 8 to wheat leaf blotch.Wheat leaf blotch started from the jointing stage,but developed slowly from the booting to heading stage.Whereas it developed rapidly at the filling stage,and reached the peak at the milk stage.3.The results of isolation and identification of wheat leaf blotch showed that Alternaria triticina and Bipolaris sorokiniana were two main species which usually mixed infected in the field in Changli area.4.The antifungal activity of four kinds of fungicides against wheat leaf blotch was evaluated.The results showed that the tuzet wettable powder had the superior antifungal activity toward Alternaria triticina and Bipolaris sorokiniana,the EC50 of tuzet wettable powder toward Alternaria triticina and Bipolaris sorokiniana were13.02 mg/L and 8.44 mg/L,respectively.Compared with other three fungicide,the antifungal activity of inprodione wettable powder toward Alternaria triticina and Bipolaris sorokiniana was the lowest,the EC50 were 251.19 mg/L and 139.84 mg/L,respectively,toward to Bipolaris sorokiniana and Alternaria triticina.5.The results of field efficacy showed that the control efficiency of tuzet wettable powder was 66.1%,and the production of wheat increased 18.1%.The best period for wheat leaf blotch controlling was from the flowering to filling stage.Therefore,the yield and quality of the wheat will be greatly improved if it is sprayed at the appropriate period.