Study on effect of the 2 new fungicides Bellis and Collis in chemical control of Peach and Nectarine powdery mildew

Powdery mildew of peach, caused by sphaerotheca pannosa (Wallr) Lev. is one of the most important diseases of peach in Iran. The disease is caused considerable damage and reduces the quantity and quality of crop. Recently, the low rate use of new and harmless fungicides,compatible with environmental conditions has been considered to control of plant diseases. In this study, effectiveness of new fungicides, Collis and Bellis with Current poisons were tested in a compeletly randomized block design with 10 treatments and 3 replications in two areas (Qazvin and Sarri) during 2009 year. Fungicides were including: Bellis 0.4, 0.7 and 1 gr/lit; Collis 0.2, 0.5 and 0.8 ml/lit; Stroby 0.2 gr/lit, Flint 0.2 gr/lit and controls with water spraying and no spraying. The disease severity was evaluated with a scale of 0-7 and 0-3 for leaves and fruits, respectively with randomly sampling after occurring of disease symptoms. The means of disease severity were compared using Duncan's multiple rang test and results showed a significant difference between all used fungicides and controls. From aspect effectiveness, Collis 0.8 and 0.5 ml/lit and Bellis 1 gr/lit were the most effective on disease control in two areas, Qazvin and Sari and were ranked in first group. But in Qazvin area Stroby 0.2 gr/lit and Bellis 0.7 gr/lit also were in first group, Flint 0.2 gr/lit was in second group and the other fungicides were in third group. In Sari area, Bellis 0.7 gr/lit Stroby 0.2 gr/lit and Flint 0.2 gr/lit were ranked in second group and the other fungicids were in third group.