Abstract
Bitertanol and thiabendazole seed treatment (1.5 g a.i./kg) and PCNB soil treatment (2.67 kg a.i./ha) were compared for control of dwarf bunt [Tilletia controversa] in Nugaines and Wanser winter wheat [Triticum aestivum] seeded on four dates. PCNB applied to the soil surface in late fall was the most effective treatment and reduced dwarf bunt incidence 88-96% in both cultivars seeded on all four dates. Seed treatment with bitertanol was about twice as effective as thiabendazole and reduced dwarf bunt to less than 5% in both cultivars seeded on 27 September and 11 October. Thiabendazole seed treatment provided control only in wheat seeded on 11 October. Both seed treatments reduced wheat yields. Dwarf bunt reduced yields by about 0.83% for each percentage of disease incidence.