五种杀菌剂对马铃薯晚疫病菌孢子萌发的抑制作用

Inhibition Effect of Five Fungicides on Spore Germination of Phytophthora infestans

测定河北双吉75%代森锰锌水分散粒剂、河北双吉80%代森锰锌可湿性粉剂、美国陶氏80%代森锰锌可湿性粉剂、25%双炔酰菌胺悬浮剂和68.75%氟菌·霜霉威悬浮剂5种杀菌剂对马铃薯晚疫病菌[Phytophthora infestans(Mont.)de Bary]孢子囊直接萌发、间接萌发(释放游动孢子)及游动孢子萌发的抑制作用。结果表明,5种杀菌剂对孢子囊直接萌发的抑制效果均比较好,而对孢子囊间接萌发和游动孢子萌发的抑制效果各不相同。其中,河北双吉75%代森锰锌水分散粒剂和河北双吉80%代森锰锌可湿性粉剂对孢子囊直接和间接萌发的抑制效果最显著,浓度在5μg/m L以上时抑制率均为100%。美国陶氏80%代森锰锌可湿性粉剂和25%双炔酰菌胺悬浮剂,浓度在20μg/m L时几乎能完全抑制孢子囊的直接萌发或间接萌发,68.75%氟菌·霜霉威悬浮剂对孢子囊间接萌发的抑制作用相对较差。游动孢子的萌发对5种药剂较为敏感,1μg/m L的药剂浓度就能使游动孢子萌发得到显著抑制。

Inhibition effect of five fungicides including Hebei shuangji 75% manocozeb WG, Hebei shuangji 80% manocozeb WP, Dow 80% manocozeb WP, 25% mandipropamid SC, 68.75% fluopicolide.propamocarb SC on direct germination of sporangia, indirect germination of sporangia （zoospore release） and germination of cystospores of Phytophthora infestans were studied. The results showed that all five fungicides exhibited efficient inhibition activity to direct germination of sporangia, with different inhibition effect on indirect germination of sporangia or germination of cystospores. Hebei shuangji 75% manocozeb WG and Hebei shuangji 80% manocozeb WP had best inhibition activity against sporangia direct or indirect germination and the concentration of 5 μg/mL was sufficient to suppress sporangia germination at 100% inhibition rate. The inhibition effect was followed by 25% mandipropamid SC and Dow 80% manocozeb WP, which almost completely inhibited direct or indirect germination of sporangia respectively at 20 μg/mL concentration. 68.75% fluopicolide.propamocarb SC had relatively poor inhibition effects on sporangia indirect germination. Germination of cystospores were sensitive to five fungicides, which was suppressed completely by as low as 1 μg/mL fungicides.