Apple Powdery Mildew
Apple Powdery Mildew  Damage from apple powdery mildew attack results in stunted growth. The foliage becomes distorted and twig growth is reduced. Also, the fruit surface may become russetted or discolored, and dwarfed. Heavily mildewed trees are weakened, and are more susceptible to other pests and winter injury.Susceptible Plants- Apple, pear, peach, and quince Symptoms- Apple powdery mildew may be found on buds, blossoms, leaves, twigs, and fruit. Symptoms first appear in the spring on the lower surface of leaves, usually at the ends of branches. Small, whitish felt-like patches of fungal growth appear and quickly cover the entire leaf. Diseased leaves become narrow, crinkled, stunted and brittle. By mid-summer, tiny, black round specks show up on the lower leaf surface, but more commonly on the twigs. These are fungal fruiting bodies, but their importance in the disease cycle is probably minimal.  The fungus spreads rapidly to twigs, which stop growing and become stunted. In some cases the twigs may be killed back. Leaves and blossoms from infected buds will be diseased when they open the next spring. Infected blossoms shrivel and produce no fruit. Fruit symptoms are not usually seen unless the disease has built up to high levels on susceptible cultivars. Diseased fruit has a fine network type surface blemish called russetting. Prevention and Control- Apple varieties vary greatly in their susceptibility to apple powdery mildew. Jonathan, Granny Smith, Mutsu (Crispin), Rome, Cortland, Baldwin, Monroe and Idared are very susceptible and should be avoided if powdery mildew is a problem. Most other varieties may also be infected if inoculum is present and conditions are favorable for infection. Plant trees in sunny locations with good air drainage. This reduces the humidity around trees and reduces the chances of disease. Mulch under trees to stop soil from drying out. Water trees in dry weather. In winter cut out infected shoots. In spring remove infected leaves and shoots, spray with seaweed extract to promote strong growth. Fungicide Spray- BI-CARB Old Fashioned Fungicide.for control of apple powdery mildew.
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