The stem blight fungus causes a rapid wilt with browning or reddening of leaves on individual branches, often followed by death of the entire plant as the fungus spreads downward through vascular tissue to the base of the plant. The most resistant highbush cultivars, Bluechip and Rubel averaged lesion lengths of 26 mm. Phytopathology 67:1481-1484. The disease is especially severe on 1- and 2-year-old plantings of susceptible cultivars. 2017. Mummy berry is a fungal disease that causes the berries to shrivel and drop. Initial symptoms of blueberry stem blight typically occur in early summer and are followed soon after by the death of the plant. Otherwise, the disease will remain in the stem and continue on down to the crown, possibly killing the plant. In this study, we examined the causal agent of blueberry stem blight at commercial greenhouse farms in the suburban area of Beijing, China. Both highbush and rabbiteye cultivars are susceptible to this disease, which enters the plant through wounds and causes rapid death of individual canes and entire bushes. Blueberry blight. "Flagging," a symptom of stem blight of blueberry, caused by the fungus Botryosphaeria dothidea. The blight overwinters on dead or decomposing plants that are covering the soil. Finally, use caution when mowing or using other equipment around the blueberry bush. Bird damage has been quite severe on some farms in some years. Botryosphaeria stem blight lesions on blueberry. New infections can be observed throughout the summer months. N.C. Blueberry is a crown forming, woody, perennial shrub in the family Ericaceae grown for its fruits, or berries, of the same name. Infected stems will wilt and die, and young twigs will die back from elongated cankers produced by the fungus. With good crop management, most blueberry diseases can be avoided. Her articles have appeared at Trulia.com, SFGate.com, GardenGuides.com, RE/MAX.com, MarketLeader.com, RealEstate.com, USAToday.com and in "Chicago Agent" magazine, to name a few. Unfortunately, fungicides don’t offer protection against blueberry stem blight. … Kentucky blueberry growers sometimes experience plant and crop losses due to diseases. Botrytis blight is a fungus that also attacks the shoots, but it also infects the blossoms and causes them to turn brown or become covered with gray, fuzzy mold. A stem blight-infected stem will have a uniform, light brown discoloration in the wood extending down the infected side of the stem. ), a parasitic higher plant. Control of this disease depends on cultural methods; fungicidal chemicals do not provide adequate protection. This publication printed on: Dec. 02, 2020, NC A&T State University, in all 100 counties and with the Eastern Band of Cherokee A necrotic, brown lesion forms on the twig around the blighted bud, and the sunken necrotic area spreads as the disease progresses (figure 1). In some years and locations, twig blight can be severe, with over 100 blighted twigs per bush. The pathogen spores float on the wind and in rain and enter the plant through wounds. This can be avoided by thorough field preparation prior to planting. Diagnose the fungal disease twig or stem blight by inspecting your blueberry plant for infected, dead twigs that rapidly die back up to 6 inches from the tip. Infections are usually associated with a wound caused by mechanical damage or insect damage, or can be related to late-season cold injury on succulent shoots that occurred during the previous growing season. © Copyright 2020 Hearst Communications, Inc. Indians. Birds relish the fruit, so cover shrubs with netting as the fruit ripens. The fungus overwinters in infected stems and infection occurs through wounds caused by pruning, mechanical injury or other stem disease sites. Later in the growing se… Receive Email Notifications for New Publications. Fertilizer management is neccessary to prevent formation of succulent shoots late in the growing season. In this study, eight fungal isolates were obtained from twenty stem blight lesions of blueberry collected in Nanping, Fujian province, China. When stem blight starts showing up in a production field, first check for all of the above discussed stressors, diseases, and pests. A) Brown blighted shoots on blueberry plant affected by Botryosphaeria stem blight disease. NC State University and NC The worst cases of stem blight in commercial fields occur on soils which are extremely sandy, resulting in poor growth, or on the black, heavy muck soils that promote excessive growth. Bacterial canker can be particularly severe on young plants in new plantings because a high proportion of the wood is succulent and susceptible to disease. The fungus enters the flower buds and eventually moves into the stem. Blueberry stem blight has become one of the most severe diseases influencing blueberry productivity and quality in China. On soils with a high organic content (>5%), new plantings can be established without the use of fertilizer. It results in blossom blight, fruit rot and dying green branches. syringaeand is a problem in production areas west of the Cascade Mountains. Spores are disseminated by rainwater. Blueberry stem blight is a fungal disease caused by Botryosphaeria dothidea. In most cases, stem blight finishes the job, but other stresses play a lead or contributory role. In this study, eight fungal isolates were obtained from twenty stem blight lesions of blueberry collected in Nanping, Fujian province, China. Resistance of blueberry cultivars to botryosphaeria stem blight and phomopsis twig blight. Never prune blueberries in their first or second years, except to remove infected stems. Stem blight of blueberry is especially dangerous on 1- to 2-year plants, but it affects mature bushes as well. Blueberries (Vaccinium spp.) Editor’s Note: The Jan. 3, 2013 issue of the “Small Fruit Update”, published by Peerbolt Crop Management in Portland, OR, featured an in-depth look at bacterial blight in blueberries. If you find a light brown line down one side of the inside of the stem, suspect stem blight. Some cultivars, such as Bluechip (Vaccinium corymbosum “Bluechip”) and Bounty (Vaccinium corymbosum “Bounty”) are more susceptible to the disease than others. Another wounding phenomenon which occurs in new fields is caused by termites. The fungus enters the plant through wounds and causes rapid death of individual canes and entire bushes. Blueberries (Vaccinium spp. Based in the American Southwest, Bridget Kelly has been writing about gardening and real estate since 2005. If any brown areas are visible in this cross-section, the cut must be made again further down the stem until all infected tissue is removed. Infected prunings should be removed well away from the field and burned or shredded. Spores are carried by wind and rain from infected stems to wounds on healthy plants. Blueberry stem blight is caused by a fungus called Botryospheria dothidia. Algal stem blotch has become a significant disease on southern highbush blueberries (SHB) in Florida. Find more information at the following NC State Extension websites: N.C. Site selection appears to play a part in the severity of stem blight. Twig BlighTs, sTem Cankers, and sTem BlighTs In the field, the most obvious symptom is called 'flagging'; stems recently killed by the fungus do not drop their leaves, resulting in a brown-leafed 'flag' which stands out against the green healthy portions of the bush. Look for leaves that turn brown or red and a rapid wilting of the plant. Site selection when establishing new plantings appears to play a part in the severity of stem blight. Infected buds become brown and die. On stems, Phomopsis twig blight symptoms may be confused with symptoms of Fusicoccum canker (figure 2). These plants are frequently damaged by … Diseases caused by fungi (stem canker, stem blight, leaf spots and fruit rots) are of primary concern. Cultivars which are known to be very susceptible to stem blight should be avoided in areas where stem blight has been a problem. Pruning serves two control functions: 1) It removes infections from bushes, preventing eventual death of the individual stem or plant, and 2) it reduces the number of spores released in the field by removing dead, spore-bearing stems. A wide range of other pathogen types can also cause economic loss, ranging from the virus-like blueberry stunt phytoplasma to dodder (Cuscuta sp. These spores germinate and invade the vascular tissue of the host, causing a pecan-brown discoloration which extends up and down the stem from the infection point, eventually killing the stem. This disease is caused by the bacterium Pseudomonas syringae pv. While most blueberry cultivars are highly disease and pest resistant, some are susceptible to a deadly disease known as stem blight. Botrytis blight or gray mold – Cool, wet weather causes gray mold (Botrytis cinerea) to grow on blueberry bushes. 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