Symptoms begin to appear just prior to bloom and can continue to develop during bloom. Annemiek Schilder and Mark Longstroth, Michigan State University Extension, Department of Plant Pathology -
This article was published by Michigan State University Extension.  Growers are instructed to watch for a rapid blight of flowers at bloom that is not caused by a spring freeze. The plant usually retains the scorched blossoms into the fall. Some cultivars (e.g., Stanley) also show marginal leaf chlorosis. The virus also infects several wild Vaccinium species, some of which show symptoms similar to highbush blueberries. Previously unreported in New England, blueberry plants from fields in Connecticut and Massachusetts have recently tested positive for blueberry scorch virus. In New Jersey, it is also known as Sheep Pen Hill disease, which is caused by a different strain of the same virus. The blueberry shock virus originated in the Pacific Northwest, which means the environment must be cool and somewhat moist.  Growers need to buy only virus-tested planting material. Blueberries are the only known host of blueberry shock virus, however, recent research papers show cranberries may also be susceptible to the virus. Infected bushes often exhibit symptoms for one to four years and then become symptomless. Follow the Sampling Guidelines for Blueberry Scorch Virus (pdf) for testing plant samples. The virus has been detected across Europe and it is likely to spread over large distances and enter new areas with the movement of plants. Different strains of the virus exist with the greatest virus diversity identified in British Columbia. On the other hand, Bluecrop, Duke, and Blu-ray varieties of blueberry have a limited rate of spreading.  However, the two can be differentiated based on the patchiness of the healthy and infected bushes and a second flourish of leaves later in the season associated with blueberry shock virus.  The rate of spread within a field varies by cultivar; the spread is very rapid in Berkeley, Bluegold, Bluetta, Earliblue, Liberty, and Pemberton, and slow in Bluecrop, Duke, and Blu-ray. Since blueberry shock virus is transmitted by pollen and readily dispersed by bees and other pollinators, it is difficult to control. In some cultivars, sudden and complete death of leaves and flowers can occur. Begin scouting for development of scorch at this time and flag all suspect bushes. Recently, two new blueberry viruses were found in Michigan. Scorch is a serious disease of blueberries (Vaccinium corymbosum) caused by blueberry scorch virus.  In addition, blueberry shock virus can be differentiated by its second flush of leaves later in the season. Blueberry scorch virus is transmitted by infected cuttings and aphids. Research has shown that yields are not significantly affected in recovered bushes. World distribution of Blueberry scorch virus (BLSCV0) Continent Country State Status; America: Canada: Present, restricted distribution Blueberry scorch virus ATCC ® PV-691™ Designation: Application: Plant research.  Flowers are the avenues of the infection and pollinators are involved in the form of inoculation. July 14, 2009. BLUEBERRY SCORCH VIRUS Robert Martin 1, Gene Milbrath 2, Jan Hedberg 2. A strain of blueberry scorch virus benign to varieties commonly grown in the Pacific Northwest has been historically present in Washington. It is known to be present in western NY and northern Pennsylvania, and was first detected in New York 2008.  The environmental conditions directly contribute to the spreading of the blueberry shock virus.  In 2009, the disease was found in a western Michigan field, and may be preset in Pennsylvania as of 2011. To ATCC Valued Customers, ATCC stands ready to support our customers’ needs during the coronavirus pandemic. Virions are flexuous rods ca.  Blueberry shock virus is differentiated and diagnosed from these other diseases based on the following characteristics:, These features and symptoms of blueberry shock virus differentiate them for other diseases with similar symptoms. It is important to be able to recognize the symptoms for monitoring and in case of future outbreaks.  If plants are suspected to have the virus, based on symptoms, growers are instructed to send in the symptomatic branches to a diagnostic lab for virus testing.  Honey bees are one of the main pollinators of blueberries. Blueberry scorch virus (BIScV) Symptoms of BIScV vary largely according to virus strains and host type. It is particularly important not to import planting material from areas where shock and scorch virus are known to occur, unless it has been virus tested. Symptoms are very similar to those of scorch, i.e., sudden, complete flower and leaf necrosis during the bloom period. If you experience any issues with your products or services, please contact ATCC Customer Service at firstname.lastname@example.org.  There is no known cure for blueberry shock virus, so extra precaution should be taken when buying and handling suckers and plant material.  Recovered plants are often the source of inoculum that will infect healthy plants, as no symptoms are shown. in 2000, and now it is widespread in all blueberry growing areas of the province. This makes viral testing important for blueberry producers to stop the spread. , Blueberry shock virus infects a variety of different blueberry cultivars.  Additionally, the virus is not transmitted via direct contact between plants and is unlikely to occur via pruning shears.. Some of the blueberry shock virus hosts include: Berkeley, Bluecrop, Bluegold, Bluetta, Blu-ray, Duke, Earliblue, Liberty, and Pemberton. However, all highbush blueberry varieties appear to be susceptible. Photo courtesy of University of Ga. CES.  Blueberry shock virus causes shock of blueberries in Oregon, Washington, and British Columbia. MDA quarantine regulations stipulate that no plants, buds, vegetative cuttings or any other blueberry planting material should be brought into Michigan from regulated areas (BC, WA, OR, NJ, MA, CT) unless it has been certified to be virus-free by a virus-free certification program recognized by MDA. This virus is spread by pollen moved by wind or bees.  The virus within pollen grains can survive in the beehive for one to two weeks, which can contribute to the spread of the virus.  Plants should be monitored for symptoms during bloom and suspicious plants should be marked. The virus spreads readily to neighboring fields but usually not more than 1 km (0.6 miles). To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464). Blueberry scorch virus(BlScV) was first found in British Colombia (B.C.) Scorched blossoms are often retained throughout the summer and may resemble spring frost injury, Phomopsis or Botrytis blight. Recently, two new blueberry viruses were found in Michigan. Blueberry scorch virus is a problematic virus for blueberry growers in New Jersey, Oregon, Washington, and British Columbia. In Sheep Pen Hill disease, leaves may show a red line pattern in the fall.  The main issue is leaf and foliage necrosis, which slows and neglects photosynthesis and therefore reduces blueberry (yield) quality.  The plant may recover and look like it goes back to normal, even though the plant is now a virus reservoir. Symptoms are easily seen during bloom and you should be aware that this disease is present on your farm. The aphids spread blueberry scorch virus. Previously unreported in New England, blueberry plants from fields in Connecticut and Massachusetts have recently tested positive for blueberry scorch virus. The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.  A virus test is used to ensure that a nursery stock does not get infected. Blueberry shock virus symptoms may resemble other diseases such as blueberry scorch virus, mummy berry shoot strikes, Phomopsis twig blight, and Botrytis blossom blight. The diseases they cause are not new since they are present in other growing regions such as the Pacific Northwest, but they are new to Michigan.  The Bromoviridae family contains single-stranded, positive-sense RNA viruses. Blueberry scorch virus (BlSV) is a serious disease of blueberries. Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Symptoms of blueberry shock and blueberry scorch can be quite dramatic but are also easy to confuse with Phomopsis or mummy berry. The blueberry shock virus spreads by pollination; therefore, spreading only occurs in spring when pollinators are active. This information is for educational purposes only. In addition, the fruit production is observed to be abnormal after inoculation and shock.  Virus particles are icosahedral and 30 nm in diameter. Blueberry Scorch Virus. Blueberry shock-symptoms resemble those of the Blueberry Scorch Virus but may not reappear in spring growth in years following initial infection, although plants remain infected. In addition, there are quarantine laws in some states, like Michigan, that prohibit importing blueberry plant material that have not been tested for the virus. Suckers and plant material should be tested for the virus before introduction into a nursery or field. BIShV was first discovered in a blueberry field containing highbush blueberry (Vaccinium corymbosum L.) in Washington in 1991.
2020 blueberry scorch virus