武汉地区金森女贞炭疽病的发生及病原暹罗炭疽菌对不同药剂的敏感性

Occurrence of Anthracnose on Ligustrum japonicum and Fungicides Susceptibility on Colletotrichum siamense in Wuhan

近年来,金森女贞炭疽病普遍发生,为明确其在武汉地区的发生规律,以筛选出较好的防控药剂,文章对全市多地金森女贞发病情况开展调查,并采用菌丝生长速率抑制法测定了金森女贞炭疽病病原暹罗炭疽菌(Colletotrichum siamense)对4种杀菌剂的敏感性。结果表明:该病具有潜伏侵染的特点,初期症状不明显,10月危害加重,至11月底发病率达60%~90%。4种杀菌剂对C.siamense的菌丝生长均有抑制作用,其中50%多菌灵可湿性粉剂和10%苯醚甲环唑水分散粒剂抑制作用最强,EC_(50)值分别为0.035 mg/mL和0.145 mg/mL;25%三唑酮可湿性粉剂的抑制效果最差,EC_(50)值达39.396 mg/mL。多菌灵可湿性粉剂和苯醚甲环唑水分散粒剂可考虑用于园林绿化养护中金森女贞炭疽病的防治。

To identify the occurrence of anthracnose on Ligustrum japonicum in Wuhan and screen out effective fungicides for control of Colletotrichum siamense,the infection was investigated and fungicides susceptibility on C.siamense tested.It demonstrated that latent infection occurred in the anthracnose on L.Japonicum.The early symptoms were not obvious.The damage was aggravating in October,and the incidence reached up to 60~90%at the end of November.The effect of 50%Carbendazim WP and 10%Difenoconazole WG was better than other fungicides,and the value of EC50 of those two fungicides was 0.035 mg/mL and 0.145 mg/mL,respectively.The effect of 25%Triadimefon WP was the worst in those four fungicides;its EC50 value reached 39.396 mg/mL.From the above,Carbendazim and Difenoconazole were the recommended fungicides for preventing anthracnose on L.Japonicum.