The Development Of A Safe And Efficient Rice Seed Coating Agent

Pyricularia oryae CaV?fusarium moniliforme sheld?Pythium aphanidermatum aphanidermatum are three pathogens causing Fusarium moniliforme sheld,they can lead to seedling death,poor growth,germination rate decline and other issues.The seed coating agent can reduce the usage amount of the pesticide,at the same time,the purpose of increasing seed germination rate,increasing seedling growth,reducing seed use,increasing yield and product quality was achieved.In order to develop an efficient and safe rice seed coating agent,in this paper,the toxicity test,selection of compound formulation,safety and pot experiment in laboratory were studied in four aspects:toxicity test in laboratory,selection of compound formulation,preparation of dosage form,safety of medicament and pot experiment.1.The determination of pyrazolyl ether ester,Pyraclostrobin Fludioxnil Boscalid Thifluzamide Pyrazole Phenamacril Fenoxanil Benthiavalicarb-isopropyl Spiroxamine Fenhexamid Prothioconazole and Azoxystrobin,The indoor virulence of 12 bactericidal agents,such as spironisamine and cycloacylamine,to 3 major diseases of rice seedling,blast grisea and Fusarium curcuma were studied.In this study,pyrazole etheric acid a broad-spectrum fungicided of methyl methoxyacrylate was used as the main agent,the screening agents were Pyraclostrobin Fludioxnil Boscalid Thifluzamide Pyrazole Phenamacril Fenoxanil Benthiavalicarb-isopropyl Spiroxamine Fenhexamid Prothioconazole and Azoxystrobin.The results of indoor virulence test showed that:the Pyricularia oryae Cav.t fungus was most sensitive to Pyraclostrobin and its EC50 was 0.022 mg/L,the others were Azoxystrobin(0.198 mg/L)and Pyrazole(0.383 mg/L);The Pyrazole intravital inhibition of Pyricularia oryae Cav.t fungus was the most obvious and its EC5owas0.015mg/L,Phenamacril(0.139mg/L)and Pyraclostrobin(2.834mg/L)had a better inhibitory effect;fluke nitrile had a significant effect on the inhibition of mycelium mycelium,the Fludioxnil with EC50 lower than that of lmg/L were Pyrazole ether ester(0.207mg/L),Phenamacril(0.231 mg/L)and Pyrazole(0.647mg/L).Therefore,the effect and safety of comprehensive medicament in field experiment were discussed in this paper,three kinds of diseases(Pyricularia oryae Ca-v.t,root rot and bad seedling disease)of rice were mixed with pyrazolyl ester and pyracycline at seedling stage,and the results showed that pyrazole and pyronidazole could be used as control agents for rice seedling stage.2.The synergistic effect of the combination of Pyraclostrobin and Fludioxonil was analyzed and evaluated by the Horsfall method.The results were as follows:the synergetic value C of the combination of pyrazole etheric ester and pyrolenil against Pyricularia oryae Cav.was 1 or more;the maximum ratio was 1.28 at a volume ratio of 7:3,which was parabolic linear.The synergistic effect of the compounding agent on rice seedling pathogen showed that,the C value was greater than 1.2 in the interval of 7:3?4:6,and the synergistic value of the other volume ratio was above 1,showing obvious synergistic effect.For Pythium aphanidermatum spp.,the synergistic value of each compound volume showed an increasing trend.The C value at 6:4 reached a maximum of 1.27,and the C value was above 1.2 in the range of 7:3?5:5.Therefore,this study determined that the volume ratio of the compounding agent was in the range of 7:3?5:5,which was a synergistic effect on the three rice seedlings.3.After fully considering the field control effect,safety and economic benefits,Pyraclostrobin and Fludioxonil were selected in a volume ratio of 7:3(mass ratio of 1:1).The preparation concentration of Pyraclostrobin and Fludioxonil were tentatively determined to be 20%in consideration of the ratio between the medicaments,the amount of the field,and the usual dose of the seed coating agent.Through orthogonal test,the ratio of surfactants,thickeners,film formers,dispersants,pigments and other additives were optimized and the formulation of the seed coating agent was finally determined:the thickener is 0.15%xanthan gum,silicic acid Magnesium aluminum 1.5%,dispersant wood sodium 1.5%,surfactant 3%AR?812,film former 4%,pigment 6%.4.Refer to the indoor indoor safety test guidelines,and carry out an indoor safety test on the 20%Pyraclostrobin of the Pyraclostrobin aqueous suspension.The results show that the 20%Pyraclostrobin has a 20%Pyraclostrobin The germination rate,root length,seedling length,fresh weight,dry weight,germination potential and vigor index of 6 rice cultivars with 4 kinds of rice cultivars treated with nitrile water suspension were 1:100.The physiological index value is higher or closer to the CK group and has higher safety.