A Microtiter Assay Shows Effectiveness of Fungicides for Control of Colletotrichum spp. from Strawberry

The anthracnose pathogens, Colletotrichum acutatum, C. gloeosporioides, and C. fragariae, have developed resistance to several fungicides. We used a microtiter assay to test in vitro the activity of 16 agrochemicals against 10 isolates of Colletotrichum spp. using a dose-response format. At a concentration of 30 μM, captan, thiram, cyprodinil, chlorothalonil, azoxystrobin, and kelthane provided nearly 100% inhibition of the growth of all 10 Colletotrichum isolates. Iprodione, vinclozolin, metalaxyl, and fosetyl-Al did not inhibit growth of any isolate. Benomyl and thiobendazole inhibited growth of the C. fragariae and C. gloeosporioides isolates, but did not inhibit growth of the six C. acutatum isolates. This article not subject to US copyright law. Patrick Page is currently affiliated with the School of Pharmacy, University of Southern Mississippi.