Research On The Chemical Control Technique Of Potato Early And Late Blight In Hebei Province

Potato is a vegetable and food crops with the potentially of high yield, and it has beenbecoming more and more prominent in Hebei province and even in China’s modernagriculture, especially, on the road to get rich in the poor area. Potato early and late blightwidespread occurred in potato, and could cause huge economic losses to potato growerevery year. The chemical control is the most effective method for potato early and lateblight on the present, and even for a long period of time because it was lack for resistancevarieties and the agriculture measures could not remarkably control the two diseases. Inthis study, we aimed to obtain fungicides and chemical programs on controlling potatoearly and late blight and establish demonstrative areas to provide for the local farmersthrough chemical fungicides and programs screening in the field. In addition, we alsotested the mating types and resistance to metalaxyl of60isolates collected from Weichangcounty Hebei province in2012. The main results were as follows.1. Azoxystrobin and DYP-1620·Tebuconazole could control potato early blight in thefield and the effect of Azoxystrobin on controlling potato early blight was significantlyhigher than that of DYP-1620·Tebuconazole.The control efficiency of Azoxystrobin andDYP-1620·Tebuconazole were92.86%and85.94%, respectively, and their increasing yieldpercentages were44.37%,39.80%, respectively. The increasing percentages of large potatoare58.49%and41.62%, respectively.2. Fluopicolide·propamocab hydrochloride, Eugenol and Flumorph-fosetyl couldcontrol potato late blight in the field. Fluopicolide·propamocab hydrochloride had the bestperformance against the potato late blight, the control efficiency was between82.15%~93.07%. The increasing of yield and commodity potato were respectively59.90%,74.74%. Eugenol and Flumorph-fosetyl comes second, the control efficiency wererespectively76.67%,75.93%, the increasing of yield were respectively44.95%,23.92%.The increasing of commodity potato were respectively50.65%,28.44%.3. One integrated effective spraying program we selected from three sets of program,six times spraying in the growing season, the first time of spraying in the adult stage, therewas no disease in the field(July10), the interval of spraying was7~10d. The order isMancozeb80%WP, Mandipropamid25%SC, Curzate-M872%WP, Equationpro 52.5%WDG, Curzate-M872%WP, Fluopicolide·propamocab hydrochloride68.75%SC.The increasing of commodity potato was46.61%compared with CK, the increasing ofeconomic benefits was494.1yuan.4. The demonstrative experiment of controlling potato early and late blight had a greatpromotional value. The control efficiency for potato early and late blight were respectively90.75%,83.28%. The yield of is3347.97kg/667m2, the increasing of commodity potatowas75.43%compared with CK. the increasing of economic benefits was916.1yuan.5. All the60tested isolates for Phytophthora infestans were A1mating type of60isolates,58were highly resistant to metalaxyl, accounting for96.67%and2were sensitiveto metalaxyl, accounting for3.33%. The metalaxy-resistant isolates still dominated in thepopulation of P. infestans from Weichang county of Hebei province.