杀菌剂对桉树焦枯病菌的毒力测定及林地防病效果

Fungicidal activity of several fungicides in controlling Cylindrocladium quinqueweptatum Figueredo and efficacy in field

选用12.5%戊唑醇可湿性粉剂、80%代森锰锌可湿性粉剂、75%百菌清可湿性粉剂、22.7%二氢蒽醌悬浮剂、70%甲基托布津可湿性粉剂和25%丙环唑乳油6种杀菌剂对桉树焦枯病菌进行毒力测定试验,并用80%代森锰锌可湿性粉剂、75%百菌清可湿性粉剂和25%丙环唑乳油进行林地病害防治试验。结果表明,6种杀菌剂对桉树焦枯病菌菌丝生长均有抑制作用。戊唑醇的毒力最高,其EC50值为4.123 7 mg/L,其次是丙环唑,EC50值为68.052 8 mg/L,毒力最弱的是甲基托布津,EC50值为16 390.51 mg/L。代森锰锌、百菌清和丙环唑在浓度为1、5 mg/mL时,均可以完全抑制焦枯病菌产孢。施用代森锰锌、百菌清和丙环唑防治后,桉树林地病情指数分别比防治前下降了7.22%、15.53%、33.33%,对照区病情指数比防治前升高了28.33%。在病害发生之前施用代森锰锌或百菌清,可有效预防病害的发生,一旦桉树苗圃或幼林发生病害,立即施用丙环唑,可起到有效防治作用。

Six fungicides Tebuconazole 12.5% WP、Mancozeb 80% WP、Chlorothalonil 75% WP、Dithianon 22.7% SC、Thiophanate-methyl 70% WP and Propiconazole 25% EC were tested on fungicidal activity in controlling Cylindrocladium quinqueweptatum Figueredo and 3 fungicides’ efficacy in field.The results showed that 6 fungicides had fungicidal activity in inhibiting the growth of hypha.The most fungicidal activity among 6 fungicides was that of Tebuconazole 12.5% WP,the next was Propiconazole 25% EC.The fungicidal activity of Thiophanate-methyl 70% WP was the worst.EC50 were 4.1 237 mg/L、68.052 8mg/L and 16 390.51 mg/L,respectively.The conidia were not detected when the concentrations of Mancozeb 80% WP、Chlorothalonil 75% WP and Propiconazole 25% EC were 1 mg/mL and 5 mg/mL.The DI（Disease Index）of eucalypts plantation after spraying 800 Mancozeb 80% WP,600 Chlorothalonil 75% WP and 1 000 Propiconazole 25% EC was decreased 7.22%、15.53% and 33.33%,respectively,compared with that before spraying.In the control block,the DI was increased 28.33% than that before spraying.