Epidemiology and Management of Powdery Mildew of Red Rose Caused by Sphaerotheca Pannosa Var. Rosae

Maximum powdery mildew was observed in the cool and humid months of January and February, Multiple linear regression analysis indicated that an increase in 1°C maximum temperature, disease will be increased by 1.75% and l°C decrease in minimum temperature disease will be increased by 2.75%. An increase in 1% maximum and minimum RH will give 0.26 and 0.29% increase in disease. Four weather factors had 56% influence on disease development, In field trial, all treatments as two foliar sprays at 10 days interval were able to reduce disease and enhanced rose flower yield over untreated control. Minimum disease and maximum flower yields were obtained in triflumizole 480 SC (0.08, 0.06, 0.04 and 0.02%) followed by 15 EC arid 30 WP. Hexaconazole 5 EC and triadermefon 25 WP were at par followed by azadirectin 15.