Cynthia Ash Kanner and Michelle Grabowski, Extension educator. Make a second application 3 to 4 weeks later. In addition, white and Norway spruce can also be severely affected, while on occasion, other landscape spruces (e.g. Maintain a 3 to 4 inch deep, even layer of wood chip mulch around your tree to prevent weed growth. Date modified: 2015-08-04. Infected trees have few needles near the trunk and look thin, or see-through. You can have your tree looking lush and beautiful again within a few years by following a program of needle cast … It mostly occurs on spruces that are not being grown in their native habitat. Trees can be protected from Rhizosphaera needle cast with properly timed fungicide applications. However, it is not uncommon to see disease develop in patches higher in the tree. A common problem encountered on spruce trees is browning of the needles. Spruce needle cast (Lophodermium piceae) Information on host(s) Main host(s) Balsam fir, black spruce, Colorado spruce, Sitka spruce, subalpine fir, white spruce. Do not plant Colorado blue spruce (Picea pungens) or other spruce that are not well adapted to the environmental conditions in your area. This damage can be caused by a variety of problems including needle cast diseases, branch cankers, insect pests, mites, or environmental conditions. Needle Cast of Spruce Description. Needle cast is a broad group of fungal diseases that cause conifers to shed needles. And there are a number of needlecast diseases based on the particular tree/fungus combination. Needles progressively turn bright yellow, purplish-pink and finally brown. Needle cast diseases can be effectively controlled with fungicides containing chlorothalonil. Feedback on this page. All rights reserved. White spruce is moderately resistant and Norway mostly resistant. See other fact sheets on pine, Douglas-fir, and spruce diseases for details on controlling needlecasts on those trees. Remove the bottom most branches from the trunk to help increase circulation around the tree canopy. There are a number of possible causes, but one that is frequently a problem in Manitoba is needle disease. Rhizosphaera needle cast (caused by the fungus Rhizosphaera kalkhoffii) primarily infects Colorado blue spruce, while Stigmina needle cast (caused by the fungus Stigmina lautii) affects both blue spruce and Black Hills spruce. It is most common in trees growing outside of their native range. Again, if you apply fungicides for needle cast disease, we ask you to make one of those applications one month after your first application. 1 Response. This shedding of needles can be more serious to conifers than losing leaves is to deciduous The problem is made more likely and presents sooner when specimens are improperly located AND by failure to apply a fungicide, which should be done even before the decline occurs as the affected portion will not recover. Hello, There are several fungal issues and diseases that Colorado blue spruce trees can develop over time that will result with needle loss and dead branches, Rhizospera needle cast is just one of them. However, spruce trees, like all plants, are also susceptible to attack by pathogens and arthropods, and they can suffer from environmental stress and other ‘non-contagious’ factors. Trees can be protected from Rhizosphaera needle cast with properly timed fungicide applications. The fungus Rhizosphaera kalkhoffii causes needle cast of spruce. It starts on the inner and lower growth and progresses upward through the tree. While visually unappealing, these diseases rarely lead to tree mortality on their own. One common needle disease in … Index; General classification; Diet and feeding behaviour; Diseases. Similarities and differences between the two diseases exist. 1 Response. The timing of the two applications is the same for the second and third year. Timing of treatment for Stigmina needle cast is similar, except preliminary data suggest that the trees should be treated indefinitely, with at least two properly timed fungicide applications per year. Spruce needle rust, also known as Weir's cushion rust, is caused by the fungus Chrysomyxa weirii. Within a few years after treatment, an infested spruce tree can look beautiful again. Plant Norway (P. abies) or white spruce (P. glauca) as they are more resistant to Rhizosphaera needle cast. But the new, protected needles will be free of symptoms next year and will remain on the tree. Section menu. Norway spruce (P. abies) is relatively resistant but can become infected when grown under stressful conditions. Rhizosphaera needle cast is a fungal disease, caused by Rhizosphaera kalkhoffii that attacks the needles of Colorado blue spruce in the spring, as new needles emerge. Date modified: 2015-08-04. Plant spruce trees on sites with acidic, moist, well drained soils and full sun. Trees stressed from drought, poor planting practices or other factors are more likely to suffer from Rhizosphaera needle cast. Needle Cast Disease of Blue Spruce Rhizosphaeria needle cast. Infection usually begins on lower branches. What fungicide? The first application should occur when the new needles are half elongated (50% elongation relative to previous years’ needle length). What is the best product to use on conifer trees for needle cast? Some cultivars of Colorado Blue spruce might be more resistant than others to needlecast. Rhizosphaera needle cast is a fungal disease of spruce trees that causes needles to turn brown and fall off. Spruce trees often thrive in North Dakota under the right conditions. The other spruces fall somewhere in between susceptible and resistant. Rhizosphaeria symptoms on blue spruce. Other pests and environmental problems can cause browning and death of older needles, including normal needle death that occurs simply as a function of needle age or shading. Student Focused. University of Minnesota Extension discovers science-based solutions, delivers practical education, and engages Minnesotans to build a better future. The second application should occur three to four weeks after the first application. Before spraying fungicide, send a lab sample to the UMN plant disease clinic to confirm that Rhizosphaera is responsible for the damage. Regents of the University of Minnesota. Proper timing of the fungicide application is critical for effective control. Branches that are severely infected often died. Asked March 14, 2013, 12:03 PM EDT. Needle Cast of Spruce Description. The other spruces fall somewhere in between susceptible and resistant. Blue spruce decline from needle cast is an obvious and long-known problem that could and should be avoided. The recent pattern of milder than usual winters and cool spring temperatures combined with wet conditions in the northeast have favored development of a fungal disease known as "needle cast". The following spring the spots appear more pronounced and the needles turn yellow, brown and then drop mid-season. This genus also infects several conifer species including; fir, cedar, spruce, and pine. White spruce is intermediately susceptible. Spruce and coniferous trees are susceptible to environmental, insect and disease problems that can cause the trees to discolor, lose needles and possibly die. The disease can also affect other conifers including black, Engelmann, Serbian, Sitka, and white (e.g., Black Hills) spruce; Austrian, mugo and eastern white pine; Douglas fir and western … Is there a product that treats needle cast & scale on Spruce trees? Spruce needle cast (Lophodermium piceae) Information on host(s) Main host(s) Balsam fir, black spruce, Colorado spruce, Sitka spruce, subalpine fir, white spruce. The disease typically starts in lower portions of the tree where humidity and temperatures are higher. Chlorothalonil based fungicides may discolor spruce needles. Blue spruce decline from needle cast is an obvious and long-known problem that could and should be avoided. In the case of Swiss needle cast of Douglas fir and Rhizosphaeria of spruce, randomly select 20 or more trees scattered around the plantation, and remove three sample branches from each tree. Another key characteristic of needle cast is the microscopic rows of small black dots (fungal fruiting bodies) that displace the normally white stomata along the length of the underside of needles. Needle Cast in Spruce Trees Many spruce trees across Minnesota have brown or missing needles along with dead branches. It starts on the inner and lower growth and progresses upward through the tree. To avoid Needle Cast in Colorado Blue Spruce, provide ample space for the mature size of the tree at planting. It can make Colorado blue spruce unsightly and unusable in many landscape settings. Needle Cast in Spruce Trees Many spruce trees across Minnesota have brown or missing needles along with dead branches. Asked March 14, 2013, 12:03 PM EDT. In many cases, the problem is needle cast disease. The typical needle cast problem on a blue spruce is rhizophora, which is typically treated by spray in May. If there is a known problem this year, perhaps you could recommend a spray. This needle-cast disease is caused by a fungus that thrives in dark and moist conditions. What is the best treatment for my Blue Spruce which has developed Rhizosphaera Needle Cast? Hosts Most spruce (Picea) species are susceptible to the disease but Colorado blue spruce (P. pungens) is particularly susceptible. Several other fungi result in symptoms very similar to Rhizosphaera. A lab test is the only way to determine the difference between the two different needle cast diseases but treatment for both is similar. Needlecast Disease of Spruce: One Possible Explanation for Browning Spruce Needles. Rhizosphaera needle cast primarily infects Colorado blue spruce, while Stigmina needle cast affects both blue spruce and Black Hills spruce. Like other evergreens, spruce will not replace fallen needles; therefore infected trees often have holes of bare branches in their canopies. The problem is made more likely and presents sooner when specimens are improperly located AND by failure to apply a fungicide, which should be done even before the decline occurs as the affected portion will not recover. It is most common in trees growing outside of their native range. Dead needles show rows of black fruiting bodies. This shedding of needles can be more serious to conifers than losing leaves is to deciduous Symptoms, the visible indications that the needle is diseased, do not appear until the late winter, spring, and early summer of the next year. Rhizosphaeara needle cast is one of the most common fungal diseases of Colorado blue spruce. Whenever possible plant spruce trees grown from local seed sources. Rhizosphaera needle cast disease is caused by the fungus Rhizosphaera kalkhoffii Bubak. This spruce originates from the Rocky Mountain regions of the west and is Coloardo’s state tree. If unsure whether a spruce has a needle cast disease, consider consulting with your local county agent. There are a number of possible causes, but one that is frequently a problem in Manitoba is needle disease. Do not overcrowd plants. This site is supported in part by the Crop Protection and Pest Management Program [grant no. When setting out sprinklers, direct the water away from needles. Rhizosphaera needle cast primarily infects Colorado blue spruce, while Stigmina needle cast affects both blue spruce and Black Hills spruce. These other causes can be easily confused with a needle cast disease. Spruce in both urban and rural landscapes can be affected. Norway spruce has been shown to be highly resistant while White spruce and its variant, Black Hills spruce are intermediately resistant. Needle cast diseases are the main reason for the casting of last year’s needles. Rhizosphaera needle cast is caused by the fungus Rhizosphaera kalkhoffii. Identifying the fungal fruiting bodies in the stomata is crucial before a needle cast disease can be diagnosed and before fungicide treatments are applied. The trees are about 20 to 25 years old and have always been beautiful. The University of Minnesota is an equal opportunity educator and employer. The disease can also affect other conifers including black, Engelmann, Serbian, Sitka, and white (e.g., Black Hills) spruce; Austrian, mugo and eastern white pine; Douglas fir and western hemlock. Rhizosphaera needle cast is a fungal disease of spruce trees that causes needles to turn brown and fall off. It can take up to 15 months for the needles to show visible symptoms after the initial infection. Growth of the fungal pathogen from the spots on the needle will cause the death of the entire needle. The longer you let it go on, the more needles your tree will lose. Examine the white rows of stomata on 2-year-old needles and if half of the branches have dark fruiting bodies on more than 10 percent of the needles, consider treating the entire plantation. The symptoms of needle cast first appear on needles as light green to yellow spots, which eventually turn red or brown. Rhizosphaera Needle Cast . Needle cast is a common name for rhizosphaera, a type of fungus that targets spruce trees. Some spruce trees, such as Colorado Blue Spruce may be susceptible to environmental stress. A common problem encountered on spruce trees is browning of the needles. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Oriental and Serbian) also suffer from the disease. The fungicide Chlorthalonil is registered for controlling this needle cast … Repeated needle loss can result in branch death after 3 to 4 years and, in rare cases, eventually cause tree death. Although we have seen needle cast diseases as far west as Minot, we expect it to occur rarely, if at all, west of U.S. Highway 83. Discolored needles fall off in late summer to fall. Leave at least a 2 inch space between the mulch and the trunk to allow for air movement. The Colorado Blue Spruce often loses its rigid needles after wet seasons. Another key characteristic of needl… The Colorado blue spruce is the most susceptible spruce to this disease. Rhizosphaera Needle Cast. Needle cast is a broad group of fungal diseases that cause conifers to shed needles. Needles are most commonly infected when they are young and still growing. Aaron Bergdahl - Forest Health Specialist. Needles progressively turn bright yellow, purplish-pink and finally brown. Colorado and Engelmann spruce are very susceptible, but Norway and white spruce are somewhat resistant. How should I treat infected adult trees? Dead needles show rows of black fruiting bodies. Rhizosphaera needle cast disease, caused by a fungal pathogen, can severely impact spruce, killing needles and causing them to drop prematurely. can make Colorado blue spruce It unsightly and unusable in many landscape settings. Older needles can become infected if environmental conditions are highly favorable for disease. The disease occurs statewide, but is more common in the northern part of the state. These "fruiting structures" may be black, orange-red, or tan, depending upon the fungus. However, infected needles often don’t show symptoms right away, and may take one to three years to develop. Several other fungi cause symptoms very similar to Rhizosphaera and correct identification is important. Two needle cast diseases occur in North Dakota: Rhizosphaera needle cast and Stigmina needle cast. Rhizosphaera needle cast is the most common disease on spruce trees that is received in the Plant and Insect Diagnostic Clinic. Infection usually begins on lower branches. Please read information in the links provided below. Index; General classification; Diet and feeding behaviour; Diseases. Stigmina needle cast is often mistaken for Rhizosphaera needle cast. In the case of Swiss needle cast of Douglas fir and Rhizosphaeria of spruce, randomly select 20 or more trees scattered around the plantation, and remove three sample branches from each tree. © Ed Zaworski with the Plant and Insect Diagnostic Clinic at Iowa State University shows how one can properly identify Rhizosphaera Needle Cast. Remember, the label is the law. Rhizosphaera needle cast disease is caused by the fungus Rhizosphaera kalkhoffii Bubak. Wet years such as 2017 are great for the fungus, but bad for trees. The fruiting bodies of Rhizosphaera kalkhoffii are spherical (Figure 2) while those of Stigmina lautii have what look like microscopic hairy projections emerging from a the fruiting body (Figure 3) . 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