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

studies, there are some areas that could be investigated to determine if their efficacy canbe improved. The timing of application of biofungicides for management of clubrootneeds to be evaluated. The critical time for the application of biofungicide appears to lieimmediately after seed germination, when the biofungicide must be present at high levelsto colonize the root. Also, it is only after seed germination that root exudates stimulateresting spore germination. A second application of biofungicide within 2 weeks ofsowing might increase the population of the biofungicide agent in the rhizosphere zoneand increase colonization. For the second application, the same biofungicideconcentration with a high volume of water sufficient to drench the roots of 2-week-oldseedlings should be examined. For growth room trials, 25 mL could be applied at 2weeks after the first inoculation to reduce infection success of secondary zoospores.Also, additional research with a wider range of concentrations of biofungicides isrequired.Further work to demonstrate the impact of soil compaction and to assesstreatments to reduce compaction is required. Experiment 1 and 2 may be repeated withcompacted soil and light watering. Investigation on the role of soil moisture on clubrootdevelopment under field and controlled environmental conditions is required.The current study demonstrated that the interaction of pH and temperature affectsinfection success by P. brassicae and subsequent clubroot levels in canola. Biofungicidesdid not to reduce clubroot levels under field conditions. The interaction of host, growthmedia and pathotype affects the efficacy of biofungicides against clubroot under growthroom conditions. Growers can select the field plots based on soil pH levels and plantingdates can be manipulated to reduce the effect of high temperature. The efficacy of114