玄参斑枯病的药剂防治研究

为了筛选防治玄参斑枯病的有效药剂，测定了10％苯醚甲环唑（世高）ME等5种杀菌剂对玄参斑枯病菌的室内毒力，并进行了田间防治试验。结果表明，5种杀菌剂对玄参斑枯病菌的Ec。值大小顺序为：咪鲜胺〈苯醚甲环唑〈三唑酮〈代森锰锌〈多菌灵，其中以咪鲜胺对玄参斑枯病菌的菌丝生长抑制作用最强，EC50为3．45mg／L；苯醚甲环唑、三唑酮、代森锰锌依次减弱，多菌灵的抑制作用最小。EC卯为72．91mg／L。5种药荆对玄参斑枯病的防治效果以10％苯醚甲环唑ME1200倍稀释液最好（96．03％），25％咪鲜胺（使百克）EC1200倍稀释液稍次（91．65％），再次为15％三唑酮WP800倍稀释液和50％多菌灵WP800倍稀释液，防效分别为84．23％和81．74％；70％代森锰锌WP800倍稀释液最差（61．94％）。试验结果还表明，供试药剂持效期可达10d以上，对玄参无药害。

Study on Chemical Control of Figwort Spot Caused by Septoria scrophulariae West

The toxicity of five fungicides to Septoria scrophulariae West causing figwort spot was tested by the means of mycelial growth method under the condition of laboratory respectively and the field control experiment against the disease was carried out to screen the effectual chemicals for the control of the disease. The toxicity test results showed that the order of EC50 values of five fungicides was： pmchloraz 〈 difenoconazole 〈 triadimefon 〈 carbendazin 〈 mancozeb. Among those tested fungicides, the inhibition effect of prochloraz against S. scrophulariae was the most significant, with EC50 value of 3.45mg/L, the inhibition of dffenoconazole, triadimefon and carbendazin were gradually weakened, and the inhibition of mancozeb was the lowest, with EC50 value of 72.91 mg/ L. The feld control experiment results showed that the control effectiveness of 10% difenoconazole ME at 1 ： 1200 concentration against figwort spot was the highest （96.03%）, next were 25% prochloraz EC, 15% triadimefon WP and 50% carbendazin WP in turn, and 70% mancozeb WP was the lowest. In addition, the experiment also indicated that the tested fungicides had duration over 10 days and no damage to figwort.