Lesions can have various shades and are visible on the upper and lower side of the leaf (Figure SS-2). All three fungal leaf spots are similar in life cycle. Strawberry diseases can affect fruit, flowers, leaves, roots, and crowns of strawberry plants, and sometimes cause the collapse of the whole plant. Angular Leaf Spot is a bacterial disease caused by Xanthomonas fragariae. Purplish or reddish blotches are sometimes seen on the undersides of leaves. 1984. What are strawberry viruses? It is found worldwide, and occurs sporadically in New England. It is favored by warm (68° to 86° F), wet weather. Scales and thrips attack the leaves of strawberry leaves, sucking out plant juices. Avoid working in the fields when the plants are wet. CFAES COVID-19 Resources: Safe and Healthy Buckeyes | COVID-19 Hub | CFAES Calendar. Identification of Leaf Diseases Leaf Spot (caused by the fungus Mycosphaerella fragariae) Within each perithecium, asci (30-40 … Symptoms of leaf spot first appear as circular, deep purple spots on the upper leaf surface. APS Press, St. Paul, MN. Control of this disease is only to prevent high levels of disease and fruit infection the following season. On highly susceptible varieties, these diseases can cause significant economic damage. Strawberries in this region are commonly affected by three fungal leaf diseases--leaf spot, leaf scorch, and leaf blight. Fungal diseases of the leaf may occur as soon as the first leaves unfold in early spring and continue until dormancy in the late fall. It is identified by small reddish to purple spots, 3 to 5 mm in diameter, with light grey centre which appears on the top side of leaves (Figure 2). The three major leaf diseases that are caused by fungi have a similar disease cycle and are controlled in a similar manner. The centers of the blotches become brownish. The leaf spot fungus produces microscopic spores from three different sources that infect new leaves in the spring. Leaf Scorch, the third of the fungal leaf spots, is caused by Diplocarpon earliana. Leaf blight is caused by the fungus, Phomopsis obscurans. In general, using the best quality transplants is a good way to prevent the introduction of diseases and pests into your strawberry fields. Leaf scorch is a fungal disease that infects the green areas of strawberry plants in the same manner as leaf spot. Scouting should begin in fields that have a history of the disease as soon as buds extend from the crown, and should continue until bloom. The primary damage from leaf diseases is a loss of vigor through reduced leaf area. Most problems with strawberry leaves are caused by fungal infections. Get some tips on recognizing this strawberry leaf spot disease and how to prevent its occurrence. There are several strands of this disease, but all can be treated in the same manner. Strawberries (Fragaria spp) are the only hosts of the pathogens causing these diseases. Removing infected leaves after harvest (during renovation) is helpful in reducing inoculum and controlling all the leaf diseases. They do not generally cause severe damage, but may weaken plants enough to cause overwintering problems. These spots enlarge and the centers turn grayish to white on older leaves and light brown on young leaves. Kleb.) No resistant varieties are available for Leaf Blight; see current recommendations for chemical control measures. The University of Connecticut, Cooperative Extension System, College of Agriculture and Natural Resources is an equal opportunity program provider and employer. The round spots are usually between 1/8 and 1/4 inches in diameter and most easily seen on the leaves of an infected strawberry plant. A large number of viruses infect strawberries, either singly or in combination.Often, symptoms are worse with multiple infections. They do not generally cause severe damage, but may weaken plants enough to cause overwintering problems. Firstly, older infected leaves that remain alive during the winter give rise to conidia that are splashed by water, or by handling wet infected plants, to the new foliage. Lesions also develop on stems, petioles and runners. The conidia are produced in large numbers on clusters of short stalks (conidiophores) that form over the entire underleaf surface. Copyright © 2016, The Ohio State University, Michael A. Ellis, Department of Plant Pathology, © 2020 The Ohio State University, College of Food, Agricultural, and Environmental Sciences, College of Food, Agricultural, and Environmental Sciences, Ohio Agricultural Research and Development Center, 2120 Fyffe Road | Room 3 Ag Admin Bldg.  X Research source University of Massachusetts Cooperative Extension System. Oddly enough, the first signs are not white spots, but small round dots of a reddish-brown hue that appear on the entire leaf area. Leaf blight is most destructive to older leaves in the late summer. What does common leaf spot look like? Disease Prevention. Infection by one pathogen often leads to infection by others, compounding the problem. OUTER LEAVES OF STRAWBERRY PLANTS ARE BROWN AND WILTED This can be caused by the disease Verticillium Wilt. It is a fungal leaf spot disease that usually occurs in late spring to early summer.