1. 在防控马铃薯早疫病的百菌清、丙环•嘧菌酯、嘧菌酯、嘧菌•百菌清、春雷•王铜、丙环唑和戊唑醇等7种药剂的筛选试验中，使用丙环•嘧菌酯、嘧菌酯、嘧菌•百菌清的处理区与对照相比，最终防效为98.90%、98.40%和97.64%，在产量方面增产效果明显，亩增产分别为357.34kg、282.68kg和298.68 kg，增产率分别为13.56%、10.53%和11.34%。
2. 从3套早疫病化学防控方案中，筛选出了1套最佳的施药方案。该方案整个生长季喷施五次药剂，在成株期病害发生前进行初次施药（6月23日），施药间隔10-20d，用药顺序为进富（代森锰锌）、易保（噁唑菌酮）、青岚（嘧菌酯）、扑海因（异菌脲）、和拿敌稳（肟菌•戊唑醇），该方案亩产量为3085.4 kg，亩增产量为346.8kg，大薯增产率为12.67%，每亩增加经济效益最高为252.2元，最后一次施药后7天防效为93.62%。
Potato early blight and late blight, two general occurrences are an endangering serious disease in potato production which is causing enormous losses in potato stocks. At present, strictly regulated chemical control is the most effective and directly employed method used, under the premise of lack of resistant varieties and agricultural measures cannot control the disease significantly enough. In this study, on the basis of former indoor drug screening conducted on the potato, early blight and late blight and the comprehensive prevention and control technology of chemicals are used in order to obtain effective agents of early and late blight and establish the comprehensive system of control techniques and providing technical services and guidance for local farmers to minimize the loss of potato production by these two major diseases. In addition, we also conducted the sensitivity of antiseptic to 30 Phytophthora infestans collected from Inner Mongolia and measured these strains resistance of Metalaxyl. The main results of the study are as follows:
1. Firstly, in the screening tests of seven kinds of antiseptic named Chlorothalonil, Propiconazole and Azoxystrobin, Azoxystrobin, Azoxystrobin and Chlorothalonil, Kasugamycin and Copperoxychloride, Propiconazole, Tebucoazole etc. It was found that for potato early blight, the last control efficiency of treatment area was 98.90%, 98.40% and 97.64% and the efficiency of yield increase was significantly higher. The potatoes which are treated by Azoxystrobin, Propiconazole and Azoxystrobin and Azoxystrobin and Chlorothalonil when compared with the previous it was found their increasing yield was 357.34kg/667m2,282.68kg/667m2 and 298.68 kg/667m2, respectively. Also the increasing percentages of yield were 13.56%, 10.53% and 11.34%.
2. Next, the study screened out the best set of a spraying program from three sets of chemical prevention programs of early blight. They were sprayed five times in the growing season; the first time of spraying in the adult stage (June23), the interval of spraying was 10-20d. The order is Jinfu (Mancozeb), Famoxate (Famoxadone), Qinglan (Azoxystrobin), Rovral (Iprodione), Nativo (Trifloxystrobin • tebuconazole). It was found that the yield of this program was 3085.4kg, the increasing yield was 346.8kg and the increase in the commodity of the potato was 12.67% compared with CK, the increase in economic benefits was 252.2 Yuan and the last control efficiency was 93.62%.
3. In addition, the results of potato early blight occurring when it is treated by different gradient of nitrogen suggested that a certain scope use of nitrogen could actually suppress the occurrence of early blight and that there was no significant difference in the ultimate yield.
4. Furthermore, in the screening tests of five kinds of antiseptic named Cyazofamid, Matrine, Dimethomorph and Initium, Yl-ethyl and metiram and Eugenol etc. It was held that for potato late blight, the last control efficiency of Dimethomorph and Initium and Cyazofamid were 94.54% and 94.18% compared with the others and the increasing yields were 407.1kg/667m2 and 479.8 kg/667m2, respectively. The increasing percentages of yield were 17.41% and 20.42%, the increasing percentages were significantly higher than compared with other treatments.
5. Also, one integrated effective spraying program we selected from three sets of programs, with spraying taking place five times during the growing season, according to potato late blight forecasts, spraying when the centre strain was found in the field. The order is Shandesheng (Mancozeb), Equation pro (Famoxadone•Cymoxanil), Infinito (Fluopicolide•propamocab hydrochloride), Revus (Mandipropamid) and Baitai (Yl-ethyl and metiram). The increasing yield of this program was 687.6kg, the increase in the commodity of the potato was 37.33% compared with CK and the increase of economic benefits was 872.8 Yuan and the last control efficiency was 90.95%.
6. Finally, the average EC50 value of 50% Dimethomorph was (0.1022±0.0053)μg/mL and the EC50 value 68.75%Fludioxonil & Propamocarb was (2.8573±0.1041)μg/mL to the tested 30 strains of late blight, all of strains were found to have sufficent resistance to Metalaxyl.