Evaluation of fungicides for control of Cercospora zebrina on subterranean clover

Abstract

In field trials conducted in Western Australia during 1982-84, fungicides were screened for their efficacy in controlling cercospora disease (caused by Cercospora zebrina) in subterranean clover (Trifolium subterraneum). Benomyl and carbendazim gave the best disease control. Smaller disease reductions were obtained with bitertanol, chlorothalonil, propiconazol and thiophanate methyl, while captafol, prochloraz and triadimefon were ineffective. Rates as low as 150 g (a.i.)/ha of benomyl or carbendazim were effective sprayed either in August or in September. Spraying both in August and September gave a better result in only 1 trial, and there was little additional disease control from increasing rate of application of either of the fungicides to 275 g (a.i.)/ha. Disease control from fungicides resulted in seed yield increases up to 68%.