Powdery mildew
resistant to water so rain often limits the epidemics and spore dispersal by rain is negligible, since spores explode when in contact with water for no more [...] it harder for the fungi to enter the leaves To reduce chances of powdery mildew in greenhouses, it is advised to first ventilate by only opening the windows [...] apple, pear, outdoor grown rose and other Rosaceae , the fungus causing powdery mildew is extremely sensitive to water and ‘hides’ on the underside of the