10种杀菌剂对番茄晚疫病菌的室内毒力测定

Toxicity Test of Ten Fungicides to Phytophthora infestans in Laboratory

采用菌丝生长抑制法测定了烯酰吗啉、嘧霉胺等10种杀菌剂对番茄晚疫病菌(Phytophthora infestans)的室内活性。结果表明:50%烯酰吗啉可湿性粉剂防效最高,EC50和EC90值分别为1.81μg/ml和10.63μg/ml,回归方程为Y=4.57272+1.66462X;其次是250 g/L嘧菌酯悬浮剂和75%百菌清可湿性粉剂,EC50和EC90值分别为2.70、2.54μg/ml和1.08×107、10708.95μg/ml,但两种药剂随着浓度的增加防效增加不显著,EC90的值都较高;58%甲霜.锰锌可湿性粉剂和70%代森联水分散粒剂的防效相对较高,EC50低于10μg/ml,分别为6.09、8.75μg/ml,EC90分别为69.98、60.19μg/ml,回归方程分别为Y=4.05225+1.20831X和Y=3.55894+1.52997X。25%多菌灵可湿性粉剂对病原菌菌丝也有抑制作用,各个处理菌丝扩展面积大,但菌丝生长稀薄,长势弱。

The toxicity of 10 fungicides against Phytophthora infestans was detected by the method of mycelium growth inhibition. The results showed that 50% dimethomorph WP had the best control effect with ECso and ECgo as 1.81 μg/ml and 10.63 p.g/ml respectively, and the regression equation was Y =4.57272 ＋ 1. 66462X. The followed fungicides were 250 g/L azoxystrobin SC and 75% chlorothalonil WP with the ECso as 2.70μg/ml and 2.54μg/ml, and the ECgo as 1.08 x 107μg/ml and 10 708.95 μg/ml respectively. But with the increase of dosage, the control effects of the two fungicides did not increase significantly, and their ECgo value were higher. The control effects of 58% metalaxyl mancozeb WP and 70% metiram WDP were relatively higher with the EC50 value as 6.09 μg/ml and 8.75μg/ml, and the ECgo as 69.98μg/ml and 60.19μg/ml respectively. Their regression equations were Y = 4. 05225 ＋ 1. 20831X and Y = 3. 55894 ＋ 1.52997X respectively. 25% carbendazim WP also could inhibit Phytophthora infestans. Although the extended area of hypha was great, the hypha grew weak and thin.