For an accessible format of this publication, visit It can affect leaves, flowers, and fruit. Leaf spot is caused by the fungus Mycosphaerella fragariae and manifests as dark purple to reddish-purple spots on multiple parts of the strawberry plant. To be sure, check the roots for rusty-red or brown discoloration in spring, before the plant is due to fruit. The fungus infects the plant and produces more spores in spots on the upper and lower leaf surface that spread the disease during early summer. The fungus overwinters on infected leaves. 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 common leaf disease of strawberry is white spot. Symptoms. F. A. Wolf teleomorph; Marssonina fragariae (Lib.) The following junebearing varieties are reported to be resistant to both leaf spot and leaf scorch: Allstar, Canoga, Cardinal, Delite, Earliglow, Honeoye, Jewell, Lester, Midway and Redchief. A large number of viruses infect strawberries, either singly or in combination.Often, symptoms are worse with multiple infections. See: Strawberry Cultivar Susceptibility. Fruit caps and fruit may also be infected. Accessibility Accommodation. Disease Prevention. Red stele, black root rot, powdery mildew, botrytis fruit rot, leaf spot, and leaf scorch are the most important strawberry diseases in Colorado. OUTER LEAVES OF STRAWBERRY PLANTS ARE BROWN AND WILTED This can be caused by the disease Verticillium Wilt. Resistant varieties are available for this disease. 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. Chapter 9 in Strawberry Production Guide for the Northeast, Midwest, and Eastern Canada. Leaf blight is most destructive to older leaves in the late summer. Leaf blight is caused by the fungus, Phomopsis obscurans. Remove as much leaf debris from fields as possible at the time of renovation. By: Pamela S. Mercure, IPM Program Assistant, University of Connecticut, Updated by: Mary Concklin, UConn IPM. Angular Leaf Spot: Anthracnose: Black Root Rot: Botrytis: Leaf Blight: Leaf Scorch It is systemic within plants, and cannot be eradicated. However, the emphasis on control of leaf diseases should be placed on the use of resistant varieties. All are favored by warm, moist weather. Leaf spot. There are several strands of this disease, but all can be treated in the same manner. Plant in light, well-drained soil in a location exposed to all-day sun and good air circulation. Note that in these two leaves, there is some of each disease present on each leaf. Within each perithecium, asci (30-40 … Strawberries (Fragaria spp) are the only hosts of the pathogens causing these diseases. If you have a disability and experience difficulty accessing this content request accommodation here. Look for stunted leaves and loss of luster. In severe cases, stolons, fruit trusses and petioles may become infected which may girdle and kill the stem. On fruit, superficial black spots may form under moist weather conditions. Tiny black dots appear in the spots. This bacterium infects only strawberries. If outbreaks of these leaf diseases become significant, the plants will become weakened resulting in increased susceptibility to root diseases and winter injury. Virus infection can result in a wide range of symptoms, including mottling, leaf crinkling, yellow spotting, vein banding (lighter areas surrounding the veins), plant distortion and stunting. Angular Leaf Spot is a bacterial disease caused by Xanthomonas fragariae. Cause Ramularia grevilleana (sexual: Mycosphaerella fragariae), a fungus that overwinters on old infected leaves and as sclerotia.Conidia are produced abundantly in lesions on infected leaves. Columbus, Ohio 43210 Angular leaf spot, caused by the bacterium Xanthomonas fragariae, has spots that appear angular and reddish-brown on the upper leaf surface and water-soaked on the lower leaf surface. Common Strawberry Diseases in Florida 1 Michelle S. Oliveira and Natalia A. Peres 2 This new two-page publication of the UF/IFAS Plant Pathology Department describes symptoms of most common strawberry diseases in Florida and summarizes the efficacy of fungicides labeled for management of such diseases. There are three fungal leaf spots of strawberry, Leaf Spot, Leaf Blight, and Leaf Scorch. Plant narrow rows with well-spaced plants to keep the canopy dry. Leaf Scorch (Diplocarpon earlianum (Ellis and Everh.) It occurs worldwide, wherever strawberries are grown. A distinct reddish-purple to rusty brown border surrounds the spot. Removing infected leaves after harvest (during renovation) is helpful in reducing inoculum and controlling all the leaf diseases. Leaves will drop off. It is mostly a leaf disease, but can attack both leaf and fruit stalks and also fruit. However, some fruits may be more severely infected. Tiny black dots may be seen in the center of the spots. In the presence of free water, these spores can germinate and infect the plant within 24 hours. Diplocarpon earlianum is a fungus that causes leaf scorch, one of the most common leaf diseases of strawberry. It is favored by warm (68° to 86° F), wet weather. The whole leaflet may turn brown. Angular leaf spot on strawberry leaves. Strawberry diseases can affect fruit, flowers, leaves, roots, and crowns of strawberry plants, and sometimes cause the collapse of the whole plant. If your strawberry plants have leaves with slow, stunted growth and metallic, blue-green dull coloration, they are probably suffering from red stele root rot. If the fields are mown at the end of the season, the mowings must be either removed from the field or plowed under. Spots can also develop on fruit (causing 'black seed disease'), stems, petioles, caps, and runners in favorable years. It is found worldwide, and occurs sporadically in New England. The centers become brownish. Mycosphaerella fragariae is an ascomycetous plant pathogenic fungus that causes one of the most common diseases of strawberry.M. Take care in spacing runner plants in matted-row culture. Leaf spot is a fungal disease that is also called strawberry rust. There are three leaf diseases that affect strawberry plants in North America. What does common leaf spot look like? There are subtle differences among these diseases, but they also have a few things in common. These spots enlarge and the centers turn grayish to white on older leaves and light brown on young leaves. No strawberry varieties have resistance to angular leaf spot. Yield is not usually affected. It is a fungal leaf spot disease that usually occurs in late spring to early summer. CFAES Diversity  |  Nondiscrimination notice  |  Site Map. STRAWBERRY LEAF DISEASES Three major leaf diseases can cause serious damage to strawberry plants in Illinois: leaf spot, leaf scorch, and leaf blight. 1998. It is caused by a fungus in the soil. Leaf Diseases of Strawberry . Figure 2. Common spot of strawberry is one of the most common and widespread diseases of strawberry.Common spot of strawberry is caused by the fungus Mycosphaerella fragariae (imperfect stage is Ramularia tulasnei).Symptoms of this disease first appear as circular, dark purple spots on the leaf … The conidia are produced in large numbers on clusters of short stalks (conidiophores) that form over the entire underleaf surface. When viewed normally, they are dark green. | Columbus, Ohio 43210. Fungal Leaf Spots. When the entire leaflet is covered, it appears purplish to reddish to brown. These cultural practices should help reduce infection: If leaf diseases are a problem in the planting, fungicides will aid in control. All three fungal leaf spots are similar in life cycle. These larger spots often follow veins. What are strawberry viruses? Plant disease-free plants where there is good air circulation and in well-drained soil. The fungus overwinters as mycelium or fruiting structures on the old leaves that remain attached to the plant. This fungus will spread until all the leaves are contaminated. In wet weather, a thick fluid can appear on the undersides of the infected leaves, which will dry to a shiny brown varnish-like film. Gradually, the specks merge into a large spot, the middle of which brightens, and as a result is perforated - … One to six round reddish-purple spots appear on the leaflet, usually on older leaflets in the later part of the season. Secondly, conidi… The primary damage from leaf diseases is a loss of vigor through reduced leaf area. This fluid and film is diagnostic for this disease. On highly susceptible varieties, these diseases can cause significant economic damage. Strawberry Leaf Diseases– Identification and Management Cathy Heidenreich, Berry Extension Support Specialist, Cornell Department of Horticulture First published in New York Berry News, Vol. See current recommendations for chemical control measures. These spores are spread by splashing rain. Yield is not usually affected. Symptoms. Cercospora is a very common disease of vegetables, ornamentals and other plants. Strawberry pathogens can attack all plant parts and affect yield and quality. Initially, these spots develop on the upper leaf surface and are deep purple to red in color.