The Preliminary Investigation Of Synergistic Effect Of Several Synergists On Fusarium Head Blight Chemical Control Agents

Fusarium head blight(FHB)is a typical climatic disease,one of most damaging fungal disease in wheat production caused by several species of Fusarium graminearum Schw.Will seriously affect the yield and quality of wheat,the main means of prevention and control is spraying fungicides in the flowering period,but if the flowering period encounters continuous rainfall or continuous cloudy conditions,it will aggravate the occurrence and prevalence of diseases,rainy weather cause unable to spray apply fungicides normally or cause a large amount of fungicides to be lost from the plant,often used more times or more quantity to ensure effectiveness,drifting loss of most active ingredients into the environment,not only reduces the utilization rate of fungicides,affecting the effectiveness of prevention and control,resulting in fungicide waste,but also causes environmental pollution problems.Addition synergists to fungicides can reduce the surface tension coefficient of the liquid,facilitate the spread and adhesion of the liquid on the leaf surface and resist the rain,reduce the loss of active ingredients,improve the control effect and reduce the amount of fungicides.In this test,phenamacril and tebuconazole were used as test agents to investigate the effect of three synergists: jijian,organic silicon and anrongle on the surface tension coefficient of phenamacril and tebuconazole solution,contact angle and spreading area on wheat leaves;the effect of different synergists and concentrations on the deposition of the two solutions on wheat plants was measured by pesticide residue detection method,and the effect of the synergist jijian on the ability of the fungicide tebuconazole to withstand rainwater washing;the synergistic effect of the fungicides on the growth of mycelium of the F.graminearum;the best synergist concentration in the deposition test was selected to investigate the effect of the synergist on the control effect of the fungicide in the field.The results show that.1.All synergists can reduce the surface tension coefficient and contact angle of phenamacril and tebuconazole solution on wheat leaves,increase the spreading area on wheat leaves,can significantly increase the amount of sedimentation on the wheat plant,reduce the drift of the fungicides,increase the amount of target sedimentation,can reduce the amount of fungicides application by 30%,the synergistics effect of organic silicon >anrongle > jijian,rainfall washout resistance test shows that jijian can enhance the ability of tebuconazole to withstand rainfall washout.2.The F.graminearum mycelium inhibition test results show that: the jijian and anrongle use alone have no inhibitory effect on the growth of mycelium,when mixed with phenamacril,jijianacrilibi 1.1313 and anrongleand bition test rshowed a synergistic effect on phenamacril;when mixed with tebuconazole,the SR was less than 1,didn thshow a synergistic effect on tebuconazole.3.The field prevention test found that: these synergists can enhance the control effect of wheat blight while reducing the amount of phenamacril and tebuconazole,increase wheat yield,but do not increase the amount of fungicide residues in wheat seed grain,among which the most effective effect is jijian,0.36 mL/L jijian and fungicides mixed ues can reduce the amount of medicine 30%～50%,0.7 mL/L organic silicon and 0.2 mL/L anrongle mixed with fungicides can reduce the dosage by 30%.