Situdies On Controlling Sharp Eye Spot Of Wheat By Seed Coaing Of Pyraclostrobin

Wheat is one of the most important food crops in the world.It is of good adaptability,wide distribution and multi-purpose.Wheat is second only to rice of the total grain ration in our country.It is very important to ensure the high quality and high yield of wheat for food security in china.In this paper,Rhizoctonia cerealis and wheat Tainong 18 bred by Ruifeng Crop Breeding Research Institute was used as experimental material,pyraclostrobin was used as test reagent.We studied the indoor toxicity of pyraclostrobin to Rhizoctonia cerealis,the drug resistance risk of Rhizoctonia cerealis to pyraclostrobin after Rhizoctonia cerealis was selected continuously by agents,the effects of pyraclostrobin seed dressing on wheat seed germination and seedling growth under indoor and field conditions and the effects of pyraclostrobin seed dressing on yield and on the control of wheat sharp eyespot under field conditions.The results show that pyraclostrobin dressing can effectively control the wheat sharp eyespot,promote wheat seed germination and growth,increase the yield of wheat.1.The indoor toxicity test of Rhizoctonia cerealisWith the pyraclostrobin as test agents,tebuconazole as control agent,we used mycelium growth rate method to test their toxicity on wheat Rhizoctonia cerealis.The result indicate that the EC₅₀ and EC₉₀ of pyraclostrobin on Rhizoctonia cerealis are 0.3671 mg·L^-1 and 3.9362 mg·L^-1,the EC₅₀ and EC₉₀ of tebuconazole on Rhizoctonia cerealis are 0.1873 mg·L^-1和 6.3668 mg·L^-1.2.The drug resistance of Rhizoctonia cerealis after continuous selection agents by pyraclostrobinAfter 30 generations of Rhizoctonia cerealis on the drug-added medium,the EC₅₀ of pyraclostrobin on Rhizoctonia cerealis increased from 0.3671 mg·L^-1 to 5.7148 mg·L^-1,the drug resistance of Rhizoctonia cerealis after continuous selection agents increased to 15.6 times of the previous resistance.3.The effects of pyraclostrobin seed dressing on wheat seed germination and seedling growthWe studied the effects of wheat germination and seedling growth by seed coating with 20% pyraclostrobin FS under indoor and field conditions.Results of the test showed that it can increase the emergence of wheat in advance,improve the uniformity,germination rate and growth rate dressing seed with 0.4/10000-0.8/10000 active ingredient.Compared with blank control,the germination potential,germination percentage,germination index and vigor index of wheat seed dressed with 0.4/10000 were increased by 16.7%,5.8%,3.60 and 2.57,respectively.Meanwhile,it can increase the amylase activity during wheat germination,accelerate the transformation rate of endosperm,and provide more nutrition for wheat germination.The amylase activity increased fourth days after germination for up to 74.5%.We also found that pyraclostrobin seed can make the chlorophyll content,root activity and antioxidant substances increased,enhanced resistance in this study.Compared with blank control,the seedling height,leaf age,tiller number,plant weight and secondary root number were significantly improved with the growth of seedlings after coating seed with 0.6/10000-0.8/10000 pyraclostrobin.4.The effects of pyraclostrobin seed dressing on yield and on the control of wheat sharp eyespot under field conditionsThe field test plot was randomly divided into groups.Plot area was 30 m².Each treatment had 4 replicates.Dressing seed by other components without pyraclostrobin was served as blank control.Field efficacy trials indicated that the test agent of pyraclostrobin and the control agent of tebuconazole possessed very good control effect on wheat sharp eyespot both,the control effect of withered white spike was more than 85%.The yield increasing effect of treatment with 0.8/10000 pyraclostrobin was best,it was up to 11.8%.