六种三唑类杀菌剂对番茄叶霉病菌的毒力及其安全性和田间防效评价

The toxicity of six triazole fungicides to Cladosporium fulvum and their safety and field efficacy in the control of tomato leaf mold

为筛选出有效防治番茄叶霉病的药剂,采用生长速率法及平板涂布法测定6种三唑类杀菌剂对番茄叶霉病菌菌丝生长及分生孢子萌发和芽管伸长的毒力,评价其对番茄植株的安全性和对叶霉病的田间防效。结果表明,己唑醇、苯醚甲环唑、戊唑醇和氟硅唑对番茄叶霉病菌菌丝生长的毒力均较高,EC_(50)分别为0.50、0.55、0.80、2.42 mg/L,其次为腈菌唑和四氟醚唑,EC50分别为6.92、15.08 mg/L。6种杀菌剂抑制病菌分生孢子萌发及芽管伸长的作用均较弱,对芽管伸长的抑制活性高于对孢子萌发的抑制活性;戊唑醇和四氟醚唑抑制孢子萌发的作用相对较强,100 mg/L处理的抑制率为60%~70%,戊唑醇、四氟醚唑和己唑醇抑制芽管伸长的作用相对较强,100 mg/L处理的抑制率均在70%以上。己唑醇和戊唑醇200 mg/L处理番茄植株,显著抑制其株高,苯醚甲环唑和腈菌唑对其影响相对较小,这4种杀菌剂对番茄植株的叶色及形态均无明显影响;且这4种杀菌剂对番茄叶霉病的田间预防效果均高于治疗效果,其中150 mg/L己唑醇的预防效果和治疗效果均最高,分别为90.67%和85.58%;苯醚甲环唑的最低,300 mg/L时预防效果为80.16%,治疗效果为71.68%。

In order to screen the effective fungicides to control tomato leaf mold caused by Cladosporiumfulvum, the toxieities of six triazole fungicides against mycelial growth, spore germination and germ tube elongation of C. fulvum were measured, the effects of triazole fungicides to the growth of tomato plants and their field efficacy trials were also evaluated. The result showed that hexaconazole, difencon- azole, tebuconazole, flusilazole had a high activity inhibiting the mycelia growth with ECs0 value of 0.50, 0.55, 0.80, 2.42 mg/L, followed by myclobutanil and tetraconazole, of which ECs0 values were 6.92, 15.08 mg/L. The inhibitory effects of six triazole fungicides on spore germination and germ tube elongation was weak and the inhibitory activity on germ tube elongation were higher than that on spore germination. Tebuconazole and tetraconazole had relatively higher inhibition with 60%-70% at 100 mg/L on spore germination than other fungicides. And tebuconazole, tetraconazole and hexaconazole had higher inhibition over 70% at 100 mg/L on germ tube elongation than other fungicides. When tomato plants were treated by hexaconazole and tebuconazole at 200 mg/L, the height of plants was significantly inhibited. Difenconazole and myclobutanil had of tomato plants. And there were no effect on the relatively little effect on the height and stem diameter morphology and leaf color of tomato plants. The pro- tective effects of triazole fungicides on tomato leaf mold in field were higher than that of curative effect. At the concentration of 150 mg/L, hexaeonazole provided the highest control effect against leaf mold, with protective effect was 90.67% and curative effect was 85.58%. Difenconazole had the lowest control effect, with protective effect was 80.16% and the curative effect was only 71.68% at the rate of 300 mg/L.