Seed-borne Pathogens on Wheat (Particularly Smuts) in Turkey1

The important seed-borne diseases of wheat in Turkey are common bunt ( Tilletia caries and T. foetida ), loose smut ( Ustilago nuda tritici ), dwarf bunt ( T. contraversa ) and flag smut ( Urocystis tritici ). Seed treatment against common bunt is widely used in Turkey. The damage is about 10–15 %, sometimes 90 % in some fields where seeds are sown without treatment. About 10 % of wheat fields were infected with bunt during 1972–1974. Seed treatment with carboxin (Vitavax) is recommended against loose smut of wheat in Turkey, but has not yet been used. Some wheat varieties, especially Siirak (1593/51) wheat, are highly susceptible to loose smut. The proportion of smut-infected heads reached 30–40 % in this variety and about 32 % of wheat fields were infected with loose smut during 1972–1974. The damage was about 6 % in infected fields. Yield losses were at least 35,000 tons. Dwarf bunt is distributed at high altitude (1300–2000 m) in eastern Turkey; 2500 ha of wheat fields are infected with dwarf bunt. The disease causes 1–80 % losses in some fields. The wheat variety Yayla 305 is recommended for infected areas. Flag smut is present in some areas of Turkey, but yield losses are not important. Seed treatment is effective against seed-borne spores.