Efficiency of two Systemic Insecticides on Seed Treatment of Three Wheat Cultivars in Management of Some Viral Diseases with Natural Vectors in Shahrekord

Viral diseases are among the most important diseases of wheat in Chahar Mahal Va Bakhtiari province. During 2005-2008 growing seasons, the efficacy of seed treatment with imidacloprid and thiamethoxam on three cultivars of wheat were tested for the control of viral diseases, including: Barley yellow dwarf virus (BYDV-PAV and BYDV-MAV serotypes), Cereal yellow dwarf virus (CYDV-RPV serotype), Wheat dwarf virus (WDV), Iranian maize mosaic virus (MIMV), Barley yellow striate mosaic virus (BYSMV) and Wheat streak mosaic virus (WSMV), with natural vectors under field condition in Shahrekord. The experimental design was a split plots arrangement of a randomized complete block with four replications. Disease incidence was determined based on the percentage of plants exhibiting symptoms and ELISA test. At harvest, data was collected on yield and yield components. Results showed that seed treatment insecticides increased grain yield and yield components, with significant reduction occur BYDV-PAV, BYDV-MAV, CYDV-RPV, WDV, IMMV and BYSMV in wheat plants compare with untreated control, while occur WSMV was not affected. “Shahriar” wheat cultivar treated with imidacloprid was the most effective treatment for control of viral diseases. The effect of seed treatment with imidacloprid was higher than thiamethoxam. Occurrence virus diseases on Alvand cultivar was more than other cultivars. The amounts of infection to WSMV, BYDV-PAV, CYDV-RPV, WDV, BYSMV, BYDV-MAV and MIMV in seed treatment plots were from highest to lowest (in descending order).