Preliminary Study On Technological Measure For Chemical Reduction In Wheat In Inner Mongolia

In China,chemical control is still the main method for wheat disease and weeds.In response to the green control strategy advocated by the Ministry of Agriculture of China.In this paper,the chemical control with fungicides and herbicides reduction for wheat disease and weeds、utilization rate of fungicide deposition with different sprayers,fungal diversity in rotation plots of wheat fields in Inner Mongolia were studied.The efficacy of 12 frequently-used fungicides for control of Gibberella zeae of wheat was tested by the methods of growth rate and spore germination.Three commonly used sprayers were chosen to test fungicide utilization rate,and the droplet density,fungicide deposition and fungicide utilization rate of each sprayer were determined.For weeding,the field and greenhouse experiments were carried out with herbicide reduction and the addition of adjuvant to verify the effects of adjuvants such as Jintou,Jijian and HPP on reducing amount and enhancing effect of herbicide in wheat field.Soil samples of wheat rotation plots(potato,rape,milk thistle,sugar beet and wheat)were collected for ITS2 high-throughput sequencing,and the diversity of fungal community and species richness of soil in wheat rotation plots were analyzed,mainly for G.zeae and Bipolaris sorokiniana,and the crops field suitable for wheat rotation were identified.A set of measures for reducing fungicides,herbicides and increasing efficiency of wheat production were put forward.1.12 fungicides were tested.The results of the growth rate of mycelia showed that the EC50 of 25%difenoconazole was the lowest and the inhibitory effect was the best,followed by 430g/L tebuconazole and 17%fluazinam.The results of spore germination method showed that the EC50 of 25%difenoconazole was the lowest,which had the best inhibitory effect on spore germination and germ tube elongation,followed by 430g/L tebuconazole,250g/L azoxystrobin and 17%fluazinam.Therefore,difenoconazole,tebuconazole and fluazinam are recommended for prevention of wheat scab.2.The results of fungicide utilization showed that the droplet deposition density,deposition amount and fungicide utilization rate of Deer 4630 sprayer on wheat were higher than that of Deer 654 knapsack sprayer and knapsack electric sprayer,the droplet deposition density was 5.8833～25.0944 deposition/cm2,and the deposition amount was 0.4581～1.4880μg/cm2,and the fungicide utilization rate was 75.92%.3.The results of field and greenhouse experiments on the herbicide reduction with adjuvant showed that the Jijian had the best effect.In field trial,the stem control efficiency was 91.66%and the fresh weight control efficiency was 97.53%when the Jijian was added and herbicide reduced by 30%in 15d.The greenhouse test results showed that the stem control efficiency was 90.01%and the fresh weight control efficiency was 86.87%when the Jijian was added and herbicide reduced by 30%.4.Through high-throughput sequencing technology and statistical analysis,it was found that the community structure and species richness of the five soil samples were significantly different,B.sorokiniana was not found in five soil samples.And the content of G.zeae as the lowest(0.008%)in the plots of rape soil samples,which was more suitable for rotation with wheat.