Red clover as a model plant for studying the effects of fungicide andbiological treatments to control Calonectria diseases

Abstract: The efficacy of 12 fungicides, applied alone and in mixtures at different rates, and 8biological control agents (BCAs) were evaluated in 9 assays to test their ability to reduceinfections caused by Calonectria morganii and C. pauciramosa on the host-model plantTrifolium pratense. Overall, good results were obtained with prochloraz + cyproconazole,thiophanate-methyl, Cu hydroxide and Trichoderma spp. against collar and root rot caused byboth pathogens. In detail, propamocarb + fosetyl-Al, azoxystrobin, cyproconazole, K phosphiteand fosetyl-Al were the most effective fungicides for reducing C. morganii infections. Of theBCAs, Clonostachys roseae and Penicillium oxalicum were effective for controlling C. morganiiinfections, while Bacillus subtilis QST713 and Streptomyces griseoviridis K61 were noteffective.