Botryosphaeria stem blight lesions on blueberry. Figure 4. Look for leaves that turn brown or red and a rapid wilting of the plant. Blueberry stem blight is a fungal disease caused by Botryosphaeria dothidea. Those that have a history of stem blight problems include Bluechip, Duke and Misty. The disease has very obvious symptoms for which to watch. Birds relish the fruit, so cover shrubs with netting as the fruit ripens. This disease is caused by the bacterium Pseudomonas syringae pv. Algal stem blotch has become a significant disease on southern highbush blueberries (SHB) in Florida. Cross-section of blueberry stem, showing brown discoloration caused by the fungus Botryosphaeria dothidea. Epidemiology and chemical control of phomopsis canker of highbush blueberry. The fungus enters the flower buds and eventually moves into the stem. Blueberries with stem blight experience cane death, which can result in the fatality of the plant if it is widespread. Shortly after green tip, symptoms become visible. Finally, use caution when mowing or using other equipment around the blueberry bush. With good crop management, most blueberry diseases can be avoided. New infections can be observed throughout the summer months. ... Botrytis blossom blight (Gray mold) Botrytis cinerea. The disease is especially severe on 1- and 2-year-old plantings of susceptible cultivars. The fungus overwinters in infected stems and infection occurs through wounds caused by pruning, mechanical injury or other stem disease sites. Mummy berry is a fungal disease that causes the berries to shrivel and drop. Check the cut end and if you see brown tissue, make another cut further down the stem until you no longer find brown tissue. A stem blight-infected stem will have a uniform, light brown discoloration in the wood extending down the infected side of the stem. Blueberry stem blight is caused by a fungus called Botryospheria dothidia. 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. The infection can also develop in wounds at the base (crown) of the bush in susceptible cultivars, resulting in rapid plant death without the typical flagging symptom associated with infections on individual stems. Cooperative Extension center. Botrytis blight or gray mold – Cool, wet weather causes gray mold (Botrytis cinerea) to grow on blueberry bushes. On soils with a high organic content (>5%), new plantings can be established without the use of fertilizer. Several cultural practices help prevent stem blight in blueberries. … 2017. Infected stems will wilt and die, and young twigs will die back from elongated cankers produced by the fungus. — Read our Infected prunings should be removed well away from the field and burned or shredded. A wide range of other pathogen types can also cause economic loss, ranging from the virus-like blueberry stunt phytoplasma to dodder (Cuscuta sp. and blueberry stem blight than are most rabbiteye varieties. 4). Site selection appears to play a part in the severity of stem blight. Even the smallest of wounds, such as those caused by pests, creates an opening for the fungal pathogen. Botryosphaeria dothidea and other spp. Some cultivars, such as Bluechip (Vaccinium corymbosum “Bluechip”) and Bounty (Vaccinium corymbosum “Bounty”) are more susceptible to the disease than others. Remove a stem that contains both dead and green leaves and split it lengthwise. Most recently-released blueberry cultivars have some resistance to stem blight. 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. Potential but infrequent disease problems include stem blight, root rot, anthracnose, cane cankers, mildew and botrytis. Fusicoccum Canker or Godronia Canker (Godronia cassandrae): Fusicoccum canker is caused by a fungus that infects blueberry stems causing dieback and plant decline. The fungus enters the plant through wounds and causes rapid death of individual canes and entire bushes. Further diagnosis can be accomplished by removing a wilting stem that has both dead and healthy portions and splitting it longitudinally. Stem blight is the most common disease that kills our blueberry bushes in Florida. 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. While most losses are due to root rot, or to stem and twig canker diseases, fruit rots and nutritional problems can also reduce yields. Botryosphaeria Stem Blight. Bird damage has been quite severe on some farms in some years. Lowbush cultivars were the most resistant including ‘Chignecto and ‘Blomidon’. Once established (3-4 year), these cultivars tend to survive fairly well, unlike Bluechip and Bounty. The blight overwinters on dead or decomposing plants that are covering the soil. Pruning can be done anytime infected stems are observed, but care should be taken to cut well below the infected area. Aside from bearing fruit, the shrubs can be used in hedges, borders and even grown in containers on the patio. Cooperative Extension prohibits discrimination and harassment regardless of age, color, disability, family and marital status, gender identity, national origin, political beliefs, race, religion, sex (including pregnancy), sexual orientation and veteran status. (fungi) Botryosphae- ria stem blight, commonly referred to as dieback, is a prevalent and destructive disease of blue- berries in the southeastern United States. Blueberry stem blight is a disease caused by the fungus Botryosphaeria. Blueberry is a crown forming, woody, perennial shrub in the family Ericaceae grown for its fruits, or berries, of the same name. 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. ), a parasitic higher plant. New infections occur following rains when tender new tissue is present … Receive Email Notifications for New Publications. Botryosphaeria stem blight of southern blueberries: effect of fertilization, temperature, and Botryosphaeriaceae species on lesion - (Peer Reviewed Journal) Effect of nitrogen fertilization and fungicides on Botryosphaeria stem blight lesion development on detached stems - (Peer Reviewed Journal) Smith, B.J., Miller Butler, M.A. In addition to twig blight and canker, the fungus causes a fruit rot. When cutting into the infected stem, brown discoloration inside the stem will be visible. These spores are released year-round with the exception of a few weeks in winter; however, the greatest numbers of infections occur in early summer. Resistance of blueberry cultivars to botryosphaeria stem blight and phomopsis twig blight. 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. ), native to North America, thrive in acidic soil and can be cared for like rhododendrons. Infected stems quickly wilt and die. Find more information at the following NC State Extension websites: N.C. On stems, Phomopsis twig blight symptoms may be confused with symptoms of Fusicoccum canker (figure 2). 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. It can cause stunted growth and leaf yellowing (Figure 1), as well as increased susceptibility to Botryosphaeria, in some cases leading to plant death. Both highbush and rabbiteye cultivars are susceptible to this disease. Phomopsis twig blight lesions ranged from 18 mm to 98 mm (Fig. The disease also occurs on many other wild and cultivated plant species (including alder, holly, wax myrtle, blackberry and willow) which contributes to the survival and spread of the disease. Spores are disseminated by rainwater. In this study, eight fungal isolates were obtained from twenty stem blight lesions of blueberry collected in Nanping, Fujian province, China.
2020 blueberry stem blight