Cane spot (Elsinoë veneta) in red raspberry: infection periods and fungicidal control

Abstract

Dichlofluanid controlled cane spot ( Elsinoë veneta ) of raspberry cv. Mailing Jewel when applied before harvest in a four‐spray programme, but carbendazim, vinclozolin and iprodione were ineffective. Lesions predominated in the fruit‐bearing region of canes in a zone 46‐120 cm above soil level. Bait plants exposed for periods of 2 weeks in two infected plantations in north‐east Scotland developed lesions, after incubation for 4‐6 weeks, only on internodes which were the youngest at the time of exposure. Infection occurred in all periods from mid‐April to late July. The infection of bait plants was related to the distribution of lesions on canes in the spray trial. An isolate of E. veneta obtained from a plantation sprayed with carbendazim and vinclozolin was resistant when tested in vitro to carbendazim, benomyl and thiophanate‐methyl. This isolate and another MBC‐sensitive strain were both relatively insensitive to the dicarboximide fungicides iprodione and vinclozolin.