ANTHRACNOSE May infect leaves, twigs, buds, shoots, and even the fruit of various landscape trees Raking and removing infected leaves will remove the main source of spores that could infect the tree next spring Anthracnose may cause defoliation on most maple, oak, elm, walnut, birch, sycamore, and hickory trees. Occasionally, it can affect ash and linden trees.

Apple Scab Most severe during spring and early summer when the humidity is high and the temperature is moderate Most obvious symptoms occur on leaves and fruit in the spring and summer, and look like small velvety brown-olive green spots that enlarge and darken to become more or less circular

Black spot Roundish black spots with fringed margins that can be up to ½’’ in diameter Spots form on the upper sides of leaves The disease is caused by a fungus called Diplocarpon rose To control black spots, rake fallen leaves and remove infected canes Avoid wetting leaves when watering and maintain air circulation around within the plants to promote drying

Botrytis MANAGEMENT Commonly called gray mold Remove dead or dying tissue from the plants and from the soil surface Heat and ventilate greenhouses to prevent high humidity conditions Avoid injuring plants in any way Found virtually everywhere plants are grown Can attack many different types of plants Signs of Botrytis: Fading flowers Leaves on which fading infected flowers have fallen Broken stems or injured leaves Commonly called gray mold

Canker Symptoms Management Brown/reddish lesions on the bark of trunks or branches, or as injured areas on smaller twigs New leaves appear smaller than normal, often curled or sparse, and pale green/yellow/brown in color. Common, widespread, and destructive to a wide range of trees and shrubs Management Keep plants healthy through proper planting, mulching, watering, soil management, pruning, and winter protection practices Do not prune when bark is wet Avoid all unnecessary bark wounds

Cedar-apple rust Control Fungicides Using resistant varieties Can defoliate trees and blemish fruit making them unmarketable Before an apple can be infected, adequate moisture must be present in a temperature range from 46-75F to allow for formation of basidiospores on cedar galls Leaves are most susceptible to infection when 4-8 days of age Fruit are susceptible from tight cluster through bloom

Crown Gall Management Avoid wounding plants near the soil line Can infect a wide range of herbaceous and woody plants Usually restricted to the roots, lower stems, and lower branches of infected plants Caused by the soil-borne bacterium Agrobacterium tumefaciens Management Avoid wounding plants near the soil line Prune infected plants (Disinfect cutting tools between each cut)

Fireblight Symptoms Dead branches Water-soaked blossoms Management A bacterial disease that can kill branches and whole plants of many members of the rose family, including apple, pear, quince, and crabapple Can be spread by insects, splashing rain or contaminated pruning tools Symptoms Dead branches Water-soaked blossoms Light brown/blackened leaves Discolored bark Black “shepherd’s crook” twigs Dried fruit Management Pruning (Sterilize all tools after each cut) Chemical Sprays

Powdery mildew Management Avoid overhead watering Remove and destroy all infected plants Prune overcrowded material Looks like powdery splotches of white or gray, on the leaves or stems of plants Different powdery mildew fungi infect different plants Causes Dampness High humidity Crowded plantings Poor air circulation Lilacs, crab apples, phlox, monarda, roses, grapes, squash and cucumbers are all likely targets for powdery mildew

Root rot Symptoms Appear overwatered or droopy Brown, slimy, smelly roots Plant leaves start turning yellow Plants drink much less water than usual Plants affected by root rot will start losing their leaves, yellowing, drooping, and look like they’re dying Affected plants will drink less water Management Keep growing area clean Add beneficial bacteria to the water Try to get as much oxygen as possible dissolved in the water