بررسی کارآیی برخی از سموم قارچکش در ممانعت از رشد عامل پژمردگی فوزاریومی سیب‌زمینی

Fusarium wilt caused by Fusarium oxysporum f.sp. tuberosi (Fot) is one of the most important soil-borne and tuber -borne diseases of potato. Applying pesticides is one of the conventional ways of controlling Fusarium wilt, then it is necessary to evaluate the effect new fungicides on controlling this infection. The effect of five chemical compounds Alto Combi (Cyproconazole+ Carbendazim) SC 42%, Thiophanate Methyl (Topsin M) WP 70%, Ortiva Top (Azoxystrobin+ Difenoconazole) EC 5.32%, Falcon (Tebuconazole + Triadimenol +Spiroxamine) EC 46%, Rovral-TS (Iprodione +Carbendazim) WP 52.5 % with three different doses were studied in vitro, as a complete randomized design with four replications. There were 16 different treatments including five different fungicides in three different levels and control treatment. A 0.5cm-ring of the medium containing pathogen mycelium was placed on the center of a plate containing PDA and fungicide were cultured and incubated at 25 ̊C. The fungal radial growth of Fot was recorded seven days after the beginning of experiment. Results showed that Fot mycelial growth significantly inhibited by all fungicides whereas various fungicides showed different inhibitory percent on pathogen. Different concentrations of fungicides showed different effects on pathogen growth, too. Mycelial growth completely suppressed using Rovral-TS WP 52.5 % at the lowest dose (10 ppm). Pathogen growth inhibited by Alto Combi SC 42%, Falcon EC 46%, Topspin M WP 70% and Ortiva Top at 12.5, 20, 100 and 160 ppm respectively. The present study showed that there was no significant difference between conventional Rovral-TS and Alto Comboi and Falcon in respect of preventing Fot mycelial growth.