in a Japanese blueberry field. Anthracnose and Septoria are the two main causes of leaf spotting. Preharvest fruit losses of 10 to 20 percent and postharvest losses of up to 100 percent have been reported. Less frequently, blueberry leaves may develop a reddish-purplish hue in spring if the weather is cold. It commonly infects the developing shoots and leaves. Anthracnose is most common on young shoots and fruit but can be found on any succulent plant part. This coloration disappears with the arrival of warmer weather. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. Development of lesions results primarily from infection through hydathodes at the margins of the leaf, and to a lesser extent through wounds. It is characterized by appearing spotting on blueberry leaves. In severe cases it may also cause sunken lesions and cankers on twigs and stems. Later, a gray-green mass of fungal mycelium and dark green spores may be seen on the surface of the berry (figure … This disease can appear on fruit before harvest (ripe rot) but more often appears as a … Fig. Numerous fungal diseases cause leaf spotting including gloeosporium leaf spot (also called anthracnose), septoria leaf spot, rust and powdery mildew. Alternaria is another common leaf spot fungus which attacks many types of plants. Blueberries infected with anthracnose fruit rot. 2015-41595-24254 from the USDA National Institute of Food and Agriculture. Gloeosporium leaf spot can cause severe defoliation and reduction in yield of blueberry crops. Found mainly in the eastern United States, the disease causes “dark, water soaked lesions on stems, leaves or fruit,” according to Colletotrichum fructicola was the predominant species with strong aggressiveness. Suggestions for Establishing a Blueberry Planting in Western North Carolina, North Carolina State University Plant Disease and Insect Clinic. On vegetables, it can affect any part of the plant. Anthracnose affects many deciduous and evergreen trees and shrubs and can also infect vegetables, flowers, fruit, and turfgrass in some regions in California. Colletotrichum gloeosporioidesmay also be found on blueberries in the southern United States. Gloeocercospora leaf spot is also prevalent on blueberry crops but causes little major damage. Fruit rot caused by Alternaria first results in sunken lesions on berries. Anthracnose or ripe rot is a common pre- and post-harvest fruit rot of highbush blueberry in British Columbia (B.C.). Small reddish flecks on young leaves and stems of succulent shoots. Fruit also ma… Each is a fungal organism that overwinters in soil or plant debris and spreads primarily through rain splashing. Introduction. Some samples came from the same blueberry growing areas, but from different orchards; approximately 20 samples were collected in a 1 hectare orchard. It is caused primarily by the fungus Colletotrichum acutatum. As the lesions enlarge (up to 1/4 inch), the center will become increasingly sunken and turn gray. NCSU Cooperative Extension Service. I have pruned out the dried and yellowed leaves, but upon turning a few of the leaves over and found some orange spore-like developments on the leaves. Bright yellow-orange pustules of spores visible on the underside of leaves, small (roughly 1/4 to 3/8 inch [6–10 mm]), somewhat angular dark brown lesions surrounded by red or yellow on upper leaf surfaces. The spots are often so close together on black and purple raspberries that they form large irregular areas (cankers). Blueberry (Vaccinium spp.) Valdensinia is a relatively new … Symptoms develop on leaves, twigs, canes and fruits (figs1-4). 2012). Anthracnose is caused by the fungus Elsinoe necator (formerly E. veneta). I am investigating alternative control methods using novel information on the pathogens life cycle discovered during my MS research on this disease. This fungus causes the berries to “leak” and have a shrunken appearance, especially near the blossom end of the fruit. On fruits, it produces small, dark, sunken spots, which may spread. Stem lesions first appear on current season’s growth as dark red circular to elliptical lesions around leaf scars. It reduces yield and post-harvest fruit quality in blueberry industries world-wide. Anthracnose occurs in all blueberry producing areas in B.C. From 2016 to 2018, a total of 85 samples of blueberry leaves (n = 48) and stems (n = 37) showing typical symptoms of anthracnose on three blueberry cultivars were collected from six blueberry growing areas in Sichuan Province, China . This disease is typically caused by Colletotrichum acutatum. Anthracnose is a fungal disease that affects plants by forming dead areas on leaves and fruit. Anthracnose diseases occur in both northern and southern US blueberry production regions, but are most problematic in tropical and subtropical regions of the eastern United States (Cannon et al. Photo courtesy of. Alternaria Leaf Spot (Alternaria tenuissima) occurs primarily in the spring during prolonged periods of cool wet weather, when spores are produced in abundance. I attributed it to the excess rain that we had last week. The anthracnose fungus Colletotrichum acutatum was detected in symptomless blueberry bushes (Vaccinium spp.) Anthracnose is a general name given to diseases caused by a group of fungal pathogens in the genus Colletotrichum. Colletotrichum can also cause anthracnose on leaves. Phosphorus deficiency causes purple coloration in blueberry leaves, but this is rarely observed in the field. On leaves, the centers of the lesions can fall out, producing a “shot-hole” appearance. Blueberry (Vaccinium spp.) This work is supported by New Technologies for Agriculture Extension grant no. The main two fruit rot diseases in Michigan blueberries are anthracnose and alternaria fruit … These pathogens affect a wide range of plants, including fruit crops, trees, turfgrass, and vegetable crops. On highly susceptible cultivars such as Jersey, the disease results in severe dieback, measuring up to 20 inches. Anthracnose first appears in the spring on the young shoots as small, purplish, slightly raised or sunken spots.