Thiabendazole vs difenoconazole in chemical control of seed-borne toxigenic fungi affecting wheat quality

Abstract

Two common fungicides: Vial TrasT (60 g/l tebuconazole and 80 g/l thiabendazole) and Oplot (90 g/l difenoconazole and 45 g/l tebuconazole) were tested for effectiveness against seed-borne toxigenic fungi Fusarium spp. and Alternaria spp. using naturally infected wheat (Triricum aestivum L., cultivar Novosibirskaya-14) seeds collected from the field located near Krasnoyarsk, Russia. Treatment with Oplot statistically significantly reduced Fusarium infection by 10 percentage points (from 31.4% to 21.4%) and statistically significantly reduced Alternaria infection by 25.8 percentage points (from 42.9% to 17.1%). Treatment with Vial TrasT demonstrated no statistically significant effect in reducing infection both for Fusarium and Alternaria. The results demonstrates that populations of Fusarium spp. and Alternaria spp. in Middle Siberia have developed resistance to tebuconazole and thiabendazole, but not to difenoconazole.