These contain the spores (conidia) of the causal fungus. Tar spot is a fungal disease that manifests itself as black spots on the leaves of infected trees. The variety of sour cherries that is the most susceptible are the English morello cherries.This is considered a serious disease in the Midwest, New England states, and Canada. Cherry leaf spot is a fungal disease that develops on the defoliated leaves that rest around the cherry tree. These fungal spores lie dormant on the ground throughout the winter months. Black Spot disease appears on the leaves of trees and shrubs as small black circular spots that range in size from about ¼ inch to 1 inch in diameter. This cherry tree disease (leaf spot) forms reddish purple spots on the leaves’ upper surfaces before the leaves turn brown. Cherry tree losing leaves, yellowing leaves with black spots and holes Asked August 19, 2016, 4:14 PM EDT Dear Sir/Madam, I thought our mature cherry tree was just losing leaves because of the extreme heat in the last few weeks, but am now concerned that it may have some sort of blight/disease. Cherry Leaf Spot. By then, spots show brown on the undersides of leaves, and during wet periods tiny, whitish, feltlike patches appear in their centers. They normally appear on the upper surface of the leaf, starting in the early to mid-spring. As the disease progresses, the leaf tissue around the black spot often yellows and premature leaf drop often occurs. Cherry leaf spot is a fungal disease which infects cherries and plums. As the disease progresses, whole leaves turn yellow and drop from the tree. Cherry blackfly overwinters on the tree as eggs, from which wingless aphids hatch in spring as the foliage develops; Winged forms appear in June-July, and these migrate to wild flowers known as bedstraws, Galium species Infestations on cherries gradually die out during July, but damaged leaves remain visible for the rest of the summer Symptoms. During the wet spring months, the rain assists these spores in traveling up into the cherry tree, infecting its newly developing foliage. caused by the pathogenic fungi Apiognomonia erythrostoma and Blumeriella jaapii. Black leaf spot, or shot-hole disease, Xanthomonas pruni, is a bacterial disease causing irregular shaped spots of purple, brown, or black color on the leaves. The leaves either shrivel, turn brown and remain hanging on the tree throughout winter in the case of leaf scorch, or become yellowed, mottled and drop prematurely in the case of leaf spot. Some spots may drop out, leaving a shotholed appearance. The leaves can become chlorotic due to leaf spot if there are lesions present, and the cherries can fail to develop if the cherry tree disease leaf spot progresses to severe levels. On sweet cherry leaves the spots tend to be somewhat larger. Cherry leaf scorch and leaf spot are diseases of Prunus spp. Sweet, sour, and ornamental cherries are susceptible to the disease, being most prevalent in sour cherries. Leaf scorch: Leaves become blotchy and brown in … Biology. Early symptoms of the disease include yellow spots on the foliage in spring that turn black as the disease develops.