Control Effect of Several Agrochemicals on Wheat Yellow Dwarf

The efficacy trial was conducted in the field with wheat variety Shanken 9740,inoculating strain GAV of barley yellow dwarf virus(BYDV) with Schizaphis graminum were conducted at wheat setting up stage.Agrochemicals combination of pesticide 2.5% imidacloprid wettable power at a dilution of 2000 and plant virus inhibitors(20% Virus A wettable power at a dilution of 500,3.95% Bilken virucide wettable power at a dilution of 500,5% Junduqing aqueous solution at a dilution of 500 and 2% Ningnanmycin aqueous solution at a dilution of 300) were sprayed,incidence and disease index of wheat yellow dwarf as well as the number of yellowing leaf were investigated at flowering stage,the results showed that all combinations have preventive and control effect on accidence and development of wheat yellow dwarf,and the preventive effect is superior to the control effect.Among the above combinations,the effect of the combination of Bilken viruaside and imidacloprid was the best,and the average preventive and control effect were 58.08% and 53.03%,respectively.Then,chlorophyll in wheat leaves,extracted by mixed soak with analytically pure acetone and analytically pure ethanol(2∶1),were measured to test which wheat yellow dwarf was controlled by 3.95% Bilken virucide wettable power at a dilution of 500 in laboratory,the result indicated that Bilken viruaside could inhibit BYDV from the harm of chlorophyll to relieve the damage.