Fungicide resistance of Fusarium spp. on potato in the new Bundeslaender

At 6 potato stores (4 for seed potatoes, 2 for ware potatoes) in the new Bundeslaender, the percentage of carbendazim-resistant Fusarium strains among the Fusarium population was determined during the storing periods 1987/88...1989/90. 829 isolates were identified as Fusarium sulphureum and 385 isolates as Fusarium coeruleum and tested in vitro for resistance to carbendazim. More than 90 % of the isolates of F. sulphureum from the seed potato stores Oehna and Daberkow were resistant. At the ware potato stores Wolgast and Wittbrietzen, percentage of carbendazim-resistant Fusarium isolates within the F. sulphureum population varied between 60 % and 74 %. F. coeruleum did not show carbendazim resistance. It is suggested to renounce the use of benzimidazole products for seed dressing in areas where these products have been used for a longer time