Hosts, Signs, and Symptoms
A wide variety of rose species are susceptible to powdery mildew. In light of this it is more practical to discuss the rose varieties that are resistant as opposed to those that are susceptible. Two varieties that have been found to show resistance to rose powdery mildew are "Paul's Pink" rose variety and the "Magic" rose variety. Other research has shown that many chestnut rose (Rosa roxburghii) varieties are also resistant to powdery mildew. R. sterilis, R. kweichonensis, R. laevigata, R. lucidissima, and R. chinensis have all been shown to be resistant to powdery mildew. R. multiflora var. multiflora and R. multiflora var. cathayensis have all been shown to be susceptible to rose powdery mildew. Symptoms caused by the rose powdery mildew can be a dwarfing of the growth of the plant ,or the twisting and deforming of leaves, but more noticeable is a sign of the disease, which is the white condia, the “powder” that appears on the plant surfaces, such as leaves, shoots, flowers, and buds. The fungus may grow on both new and old leaves, but is generally more concentrated on the underside of the leaf
Read more about this topic: Podosphaera Pannosa
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