Management of Powdery Mildew in Rose Under Polyhouse Condition

Powdery mildew of rose caused by Sphaerotheca pannosa var rosae (Wallr) Lev. is one of the important diseases which causes enormous losses both in terms of quality and quantity of rose under protected condition. A field trial under protected condition was conducted at NARP, Pune, during 2000–2001 to 2002–2003, to find out the effective fungicidal application for its management. The crop was sprayed with eight different fungicides starting the first spray from the first appearance of disease. Five sprays were given at an eight day interval. The effect of each treatment on disease intensity and yield was recorded. The disease index was significantly reduced in treated plots when compared with untreated control. Analysis of data for three years showed that powdery mildew in rose can be significantly reduced (89.17% PDC) by spraying Difenoconazole 0.05% at an eight day interval and there by increased number of “A” grade flowers (0.791akh flowers/500 m²), net income (Rs. 86290/500 m²) with higher benefit cost ratio (1:1.45). It was followed by dinocap 0.05% and tridemorph 0.05% with 1:1.25 B:C ratio. Hence, it is recommended to give five sprays of Difenoconazole @ 0.05% at an eight day interval for better management of powdery mildew in rose under protected condition.