Studies On The Combined Toxicity Against Phytophthora Infestans And Field Application Research Of Flumorph And Cyazofamid

As the fourth main grain,the potato occupies an important position in the grain system of our country.It has strong adaptability to the environment,is relatively resistant to drought and barren,has high utilization rate of water,high economic benefit,the planting area and the area are enlarged.The occurrence of various diseases and pests reduced the quality and yield of potato,especially late blight.Flumorph is famous for its good therapeutic effect and long lasting period,and cyazofamid is widely used for its excellent protective effect.The combination of flumorph with therapeutic effect and cyazofamid with protective effect can achieve the double effect of protection and treatment,which is more advantageous to improve the effect of prevention and control of oomycetes disease.Therefore,the combined virulence of flumorph and cyazofamid against Phytophthora infestans was studied,and a reasonable proportion with synergistic effect was selected,and then the field experiment was conducted to determine the field control effect of flumorph and cyazofamid.The results show that:1.The results of laboratory combined virulence test showed flumorph and cyazofamid had obvious inhibiting effects on Phytophthora infestans,and five different combinations had more obvious inhibiting effect on Phytophthora infestans.The experimental results showed that the synergism of 20%flumorph and 10%cyazofamid was the most significant.The regression equation of virulence was:Y=0.9008X+5.6490,R²=0.9924,EC₅₀=0.19?g/mL,and SR=1.95.The other four combinations also had different degrees of additive synergism.2.According to the results of laboratory combined virulence test,the best synergistic combination of 20%flumorph+10%cyazofamid was selected for processing.With 20%flumorph,10%cyazofamid,2.5%naphthalene formaldehyde condensate of methyl naphthalene sulfonate,3%farm milk 1601,0.4%silicone,4%glycerol,0.5%sodium alginate,0.5%xanthan gum,water make up 100%of the formula processing,made 30%flumorph cyazofamid suspension.,The performance indexes are in conformity with the standard.3.Safety test and field efficacy test of 30%flumorph cyazofamid suspension concentrate on Potato showed that the 30%flumorph cyazofamid suspension was safe for potato growth when the dosage was 150 g/ha,300 g/ha,600g/ha?1,2,4 times of the concentration set in the field efficacy test?.There is no adverse effect.Before the onset of the disease,the dosage was90¹50g/ha,the control effect of after the last dose 10 d was 73%⁸6%,which was higher than that of the control agents.In the early stage of disease occurrence,the dosage of 90¹50g/ha had a control effect of 71%⁸1%in after the last dose 10 d,which was higher than that of the control single dose.But it is lower than the control effect of 687.5 g/L fluopicolide propamocarb hydrochloride suspension.The results showed that this test agent could be used both as protective and therapeutic agents in the stage of disease onset,which had both protective and therapeutic effects.4.The control effect of 30%flumorph cyazofamid suspension was tested.When the dosage was 120¹80 g/ha,the control effect on tomato late blight reached 77%⁸3%10 d after the last dose,and at a dosage of 90¹50 g/ha,The control effect on pepper blight was71⁸1%15 d after the last dose,was 64⁷7%30 d after the last dose.In addition,no adverse effects were found in the course of tomato late blight and pepper blight.The control effect and dosage of other diseases need further test and research.