Hema Kasinathan Thesis May 1 2012.pdf - Atrium - University of ...

another study, the biofungicides Serenade and Prestop were as effective as fungicides inreducing clubroot severity in canola (up to 91% reduction) under growth room conditions(Peng et al. 2011). However, under high disease pressure, the biofungicides wereineffective for the suppression of clubroot on canola and Shanghai pak choy. In fieldtrials on mineral soil, Serenade and Prestop were not effective on canola. However,Actinovate and Serenade were as effective as Allegro in suppressing clubroot on napacabbage field trials on muck soil, reducing clubroot severity by approximately 50% (Penget al. 2011).1.5.3 FungicidesVarious classes of fungicides have been assessed for efficacy against P. brassicaesince the early 1950’s, where none of the treatments provided complete control(Campbell 1954). In a glasshouse study, benomyl and trichlamide reduced root hairinfection and symptom development, but quintozene was not effective (Naiki and Dixon1987). In another study, application of quintozene as a soil treatment or in-rowapplication reduced clubroot severity compared to the nontreated control, but the yieldwas not affected (Hwang et al. 2011b). However, quintozene is currently recommendedfor clubroot management in Canada (OMAFRA 2011b). Perlka is a nitrogenous fertilizerand a source of calcium for plants. Application of Perlka (10% calcium cyanamide, 50%calcium oxide, 19.8% nitrogen, 1.5% magnesium oxide), a soil amendment withfungicidal activity, at the rate of 1.0 T/ha at 7 days before sowing, reduced clubrootincidence to 16% from 43% in the nontreated control (McDonald et al. 2004).27