Leaf rust is one of the main diseases affecting wheat. The damages vary according to the area cultivated with susceptible cultivar, the pathogen physiological races and the climate conditions. The best control strategy for susceptible cultivars has been the use of fungicide applied to seeds as treatment. The aim of this study was to verify the efficiency of this technology after 29 years of use in Brazil. The field experiment was conducted with two wheat cultivars, Pampeano and Ônix, with natural rust infection in 2009 growing season. For seed treatment, the fungicide triadimenol (15% SC) was used at three levels of the commercial formulation (135, 270, 540 mL/100 Kg seeds). Rust infection was natural and the leaf rust incidence was weekly assessed. Data were subjected to analysis of variance and regression analysis, and the area under the disease incidence progress curve was calculated. There were no significant differences among fungicide levels and disease intensity in the control treatment; however, there was difference for rust intensity between cultivars.
Chemical control; triadimenol Triticum aestivum; Puccinia triticina
