四种杀菌剂对烟草灰霉病菌的毒力及对烟草灰霉病的抑制作用

Toxicity of four fungicides against fungus Botrytis cinerea in tobacco and their inhibition effects against tobacco gray mold

为筛选防治烟草灰霉病的有效药剂,采用菌丝生长速率法和孢子萌发法测定氟啶胺、咪鲜胺、苯醚甲环唑及代森锰锌4种杀菌剂对烟草灰霉病菌Botrytis cinerea的毒力,同时通过离体叶片评价这4种杀菌剂对烟草灰霉病的保护和治疗作用。结果表明,氟啶胺和咪鲜胺对菌丝生长活性抑制最强,有效抑制中浓度ECjs50平均值分别为0.02、0.03 mg/L,苯醚甲环唑次之,代森锰锌最弱,EC_(js50)平均值分别为0.39、7.86 mg/L;氟啶胺对孢子萌发活性抑制最强,代森锰锌次之,有效抑制中浓度EC_(mf50)平均值分别为0.06、0.16 mg/L,咪鲜胺和苯醚甲环唑最弱,ECmf50平均值均大于25.00 mg/L。离体试验表明,氟啶胺对烟草灰霉病保护作用最强,浓度为50 mg/L时,防治效果为100.00%,咪鲜胺和苯醚甲环唑次之,防治效果分别为88.62%和76.46%,代森锰锌最弱,浓度为1 000 mg/L时防治效果仅为75.81%;氟啶胺对烟草灰霉病治疗作用最强,浓度为100 mg/L时的防治效果为85.75%,咪鲜胺和苯醚甲环唑次之,浓度为200 mg/L时的防治效果分别为85.47%和76.48%,代森锰锌最弱,浓度为1 000 mg/L时防治效果为70.24%。表明氟啶胺和咪鲜胺更适合烟草灰霉病的防治。

In order to screen effective fungicides for the control of tobacco gray mold, the toxicity of four fungicides, fluazinam, prochloraz, difenoconazole and mancozeb, against fungus Botrytis cinerea from tobacco were tested in vitro using both mycelial growth and conidial germination methods, and the protective and curative effects of these fungicides against tobacco gray mold were also detected in vivo on detached tobacco leaves. The results showed that fluazinam and prochloraz exhibited the highest inhibition against mycelial growth of B. cinerea, with average ECjs50(median effect concentration) values of 0.02 and 0.03 mg/L, respectively, followed by difenoconazole(0.39 mg/L);mancozeb showed poor inhibition(7.86 mg/L). Fluazinam exhibited highest inhibition against conidial germination of the pathogen, with an average ECmf50 value of 0.06 mg/L, followed by mancozeb(0.16 mg/L), while prochloraz and difenoconazole showed the poorest inhibition(both>25.00 mg/L). The strongest protective activity was observed in fluazinam(100.00% at 50 mg/L), followed by prochloraz(88.62%) and difenoconazole(76.46%), while the lowest activity was detected in mancozeb(75.81% at 1 000 mg/L). The strongest curative activity was detected in fluazinam(85.75% at 100 mg/L), followed by prochloraz(85.47% at 200 mg/L) and difenoconazole(76.48% at 200 mg/L), while the lowest activity was observed in mancozeb(70.24% at 1 000 mg/L). The results showed that fluazinam and prochloraz were more suitable for the control of tobacco gray mold.