Signs & Symptoms of Diseased Fruit Trees

Stone Fruit Diseases

• Trees with fruit that contain hard pits or stones are classified as stone fruit trees and include the almond, peach, apricot, nectarine, cherry and plum trees. They are afflicted by fungal problems like brown rot, a disease that first appears on the fruit as a small brown spot, then expands to encompass the entire fruit and eventually completely rots it. It remains on the tree hanging in mummified form. Another fungal disease, peach leaf curl, causes the leaves of peaches and nectarines to turn yellow then brown before curling and falling from the tree.

Stone Scab and Rot

• Scab is a fungal disorder that afflicts peaches, cherries, plum, and apricot causing scab-like lesions on the fruit and often resulting in rot. Scab also attacks leaves and twigs but does the most damage on fruit. Clitocybe Root Rot and Armillaria Root Rot are soil-borne fungi that result in the development of yellow leaves as the roots of the tree rot away and are unable to absorb and distribute water and nutrition to the foliage. Fruiting bodies of the fungi that resemble mushrooms will grow at or near the base of infected trees.

Citrus Diseases

• Fungal diseases like Phytophthora foot rot infect citrus trees producing a slimy, water-logged, reddish-brown bark. Sooty canker or limb wilt kills the sapwood of a citrus tree with limbs developing cankers -- open wounds -- and leaves wilting, turning brown and prematurely defoliating. Dry root rot slowly eats away at the roots of a citrus tree, with leaves turning yellow and dieing. A number of other bacterial and viral diseases attack various parts of the citrus tree.

Apple Diseases

• The fungal disease powdery mildew dusts the leaves of an apple tree with a white, fungal powder that can reduce the growing vigor of the tree. Phytophthora crown, collar, and root rots produce an overall stunting of growth, while the foliage becomes bare and yellow and falls from the tree prematurely. The growth of the fruit is also stunted and it may take on color too early. Additionally, apple trees are susceptible to fire blight, a bacterial disease that darkens the leaves making them appear scorched.