霜脲氰和代森锰锌对马铃薯晚疫病菌的离体活性及混合增效作用

测定霜脲氰、代森锰锌对马铃薯晚疫病菌不同生长发育阶段的毒力,发现霜脲氰抑制马铃薯晚疫病菌菌丝生长的活性明显高于代森锰锌,抑制孢子囊和游动孢子萌发及孢子囊释放游动孢子的活性明显低于代森锰锌;两药抑制游动孢子游动的活性很低。以1∶7、1∶8混配对游动孢子萌发及菌丝生长的抑制表现增效,以1∶1~1∶10混配对抑制孢子囊萌发的增效系数为1.55~5.39,其中1∶5的增效系数高达5.39。

Activity of Cymoxanil and Mancozeb and Synergism of Their Mixtures against Phytophthora infestans

The inhibitory activity of cymoxanil, mancozeb and their mixtures on Phytophthora infestans tested at different stage, in vitro, showed that cymoxanil was stronger in inhibiting the mycelium growth of the pathogen than mancozeb, but it was less effective in inhibiting the germination of sporangia and zoospores. Meanwhile these two fungicides were less effective in inhibiting mobility of zoospores. The mixtures of cymoxanil with mancozeb at the ratio of 1∶7 and 1∶8 were synergistic in inhibiting the germination of zoospores and mycelium growth, and synergistic ratio(SR) of the mixtures of the two compounds at the ratio of 1∶1~1∶10 was 1.55~5.39, and SR of the mixture of 1∶5 was as high as 5.39.