Powdery mildews are the main causes of plant deterioration and reduction in quality of rose flowers. Two surveys were carried out on disease incidence, severity in different cultivars of rose and its existing management practices during autumn season and winter season on rose flowers in the two different greenhouses at MaiSirwa. Disease assessment was made by randomized block design. Result of the surveys clearly indicated that rose flower at all stages of growth was susceptible to powdery mildew infection. Disease incidence and severity was higher during the autumn season in the both greenhouses than winter season. Disease incidence and severity rate among the cultivars in each greenhouse was found different in both of the periods. Disease incidence and severity in the autumn season was 81.94 to 100% and 25.83to 86.81% in greenhouse-I respectively, while, in greenhouse-II it was 23.33 to 78.70% and 25.11to 4.66% recorded respectively. During winter season disease incidence was between 29.44 to7.77 % and severity was 5.88 to 1.55 % in greenhouse-I, in green house-II it was observed that 34.72 to 10 % and 8.11 to 2% respectively. Though some available fungicides were used for the controlling of powdery mildews, which were more effective during the winter season but not in the autumn period in both the greenhouses.
