Investigation On The Occurrence And Prevention Of Head Blight Of Wheat In The Huanghai Farm In Jiangsu Province

The wheat planting area is very large in Jiangsu farm.Head blight of wheat(Fusarium graminearum)has become very important restricting factor of the wheat quality.Meantime the disease has leaded to the decline of wheat output in this area.In this paper some studies had been done including the disease seriously investigation and varieties resistance investigation,some datum had been collected,such as temperature,relative humidity,sunshine hours of everyday and rainfall,the main factor of making the disease severity was analyzed.The all datum were get together from 2016 to 2017.Some experiments had been achieved,for instance,the control disease effect of various chemical germicides,various times and the times of spray germicide.The effect of different nitrogenous fertilizer amount on the disease had been obtained.The purpose of this paper was that analyzing head blight of wheat characteristics in Huanghai farm,main factor of effect the disease.Above those are favorable for the control head blight of wheat.The results showed that the obvious resistant difference were existent between various varieties.The resistance of huaimai 19 and huaimai 28 to the disease were stronger than that of other varieties,the incidence of these two varieties were 0.1%,0.4%and disease indices were 0.1 and 0.2 respectively while the incidence of huaimai 33,huaimai 23,mingmai 1 and yannong 5158 were more than 1.0%and disease indices were 0.5,0.6,0.5 and 0.6 respectively.Above results presented that must be careful to plant varieties because the resistance of those varieties,huaimai 33,huaimai 23 ect.,were weak.The average incidence of head blight of wheat in 2016 and 2017 were 1.0%,0.8%respectively and the disease index were 0.4 and 0.3 respectively.The disease severity in 2017 was lighter than the disease severity in 2016.The disease severity was obvious different in different planting areas in the farm.The disease was the most serious in three planting areas with incidence 1.1%,1.0%and 1.0%respectively,while the most light disease occurred in other three planting areas with the incidence 0.4%,0.6 and 0.6%.Some factors could effect the disease severity and epidemic such as relative humidity,temperature,sunshine hours of everyday and rainfall.The results of Grey Relational Analysis revealed that the relative degree between relative humidity,rainfall,sunshine hours of everyday,temperature and disease severity were 0.89,0.7,0.7 and 0.6.The main factor of effect disease severity was relative humidity next rainfall.In Huanghai farm,26 April to 3 May was the date of heading and flowering of wheat.Therefore,the relative humidity and rainfall in the stage were the most important factor to the disease.Some chemical germicides exhibited control effect.The control effect of 25%Phenamacril was the strongest among the experiment germicides and the control effect reached above 60%.Next,the compound of Tebuconazole and Thiram exhibited some control effect.The control effect of the chemical germicides was the strongest when spray germicide at 30%flowering rate than that of 80%flowering rate.The experiment with different nitrogen application showed that the incidence and disease index were climbing with the increase of nitrogen fertilizer application.The disease incidence was the lowest in 360 kg·hm-2 nitrogen fertilizer which incidence was 2.4%.However,the incidence increased and reached 7.8%when 720 kg·hm-2 nitrogen fertilizer.