Related Research Articles
Fusarium patch is a disease in turf grass settings also called pink snow mold or Microdochium patch. In many cool season grass species in North America, it is caused by the fungus Microdochium nivale. The white-pink mycelium on infected leaf blades is a distinguishing characteristic of the Microdochium nivale pathogen. Fusarium patch is considered economically important in the turf grass industry because of its tendency to cause significant injury to golf greens, thereby decreasing putting surface quality. Dissimilar from other snow molds, such as gray snow mold, Microdochium nivale does not need snow cover to cause widespread infection.
Poa pratensis, commonly known as Kentucky bluegrass, smooth meadow-grass, or common meadow-grass, is a perennial species of grass native to practically all of Europe, North Asia and the mountains of Algeria and Morocco. Although the species is spread over all of the cool, humid parts of the United States, it is not native to North America. The Spanish Empire brought the seeds of Kentucky bluegrass to the New World in mixtures with other grasses. In its native range, Poa pratensis forms a valuable pasture plant, characteristic of well-drained, fertile soil. It is also used for making lawns in parks and gardens and has established itself as a common invasive weed across cool moist temperate climates like the Pacific Northwest and the Northeastern United States. When found on native grasslands in Canada, for example, it is considered an unwelcome exotic plant, and is indicative of a disturbed and degraded landscape.
Sod, also known as turf, is the upper layer of soil with the grass growing on it that is often harvested into rolls.
Typhula incarnata is a fungal plant pathogen in the family Typhulaceae.
Ascochyta is a genus of ascomycete fungi, containing several species that are pathogenic to plants, particularly cereal crops. The taxonomy of this genus is still incomplete. The genus was first described in 1830 by Marie-Anne Libert, who regarded the spores as minute asci and the cell contents as spherical spores. Numerous revisions to the members of the genus and its description were made for the next several years. Species that are plant pathogenic on cereals include, A. hordei, A. graminea, A. sorghi, A. tritici. Symptoms are usually elliptical spots that are initially chlorotic and later become a necrotic brown. Management includes fungicide applications and sanitation of diseased plant tissue debris.
Cercospora beticola is a fungal plant pathogen which typically infects plants of the genus Beta, within the family of Chenopodiaceae. It is the cause of Cercospora leaf spot disease in sugar beets, spinach and swiss chard. Of these hosts, Cercospora leaf spot is the most economically impactful in sugar beets. Cercospora beticola is a deuteromycete fungus that reproduces using conidia. There is no teleomorph stage. C. beticola is a necrotrophic fungus that uses phytotoxins specifically Cercospora beticola toxin (CBT) to kill infected plants. CBT causes the leaf spot symptom and prevents root formation. Yield losses from Cercospora leaf spot are around 20 percent.
Magnaporthe salvinii is a fungus known to attack a variety of grass and rice species, including Oryza sativa and Zizania aquatica. Symptoms of fungal infection in plants include small, black, lesions on the leaves that develop into more widespread leaf rot, which then spreads to the stem and causes breakage. As part of its life cycle, the fungus produces sclerotia that persist in dead plant tissue and the soil. Management of the fungus may be effected by tilling the soil, reducing its nitrogen content, or by open field burning, all of which reduce the number of sclerotia, or by the application of a fungicide.
Sand-based athletic fields are sports turf playing fields constructed on top of sand surfaces. It is important that turf managers select the most suitable type of sand when constructing these fields, as sands with different shapes offer varied pros and cons. Regular maintenance of sand-based athletic fields is just as important as the initial construction of the field. As water and other aqueous solutions are added, a layer of thatch may accumulate on the surface of the turf. There are different ways to manage this level of thatch, however the most common are aeration and vertical mowing.
Colletotrichum cereale is a plant disease (fungus) that has been found to cause crown rot anthracnose of turf grass most commonly occurring on golf courses. Anthracnose can occur as both a foliar blight and basal rot. This disease attacks the crowns of plants, which is different than other anthracnose diseases. Anthracnose of turfgrass can be a foliar disease or in this case a basal rot of the lower portion of the plant. It attacks different species of turfgrass throughout the world most commonly annual bluegrass and creeping bentgrass.
Magnaporthe poae is an ascomycete fungus which causes the turfgrass disease commonly known as summer patch, or Poa patch. The disease occurs mostly on Kentucky bluegrass (Poa pratensis), Fescues (Festuca sp.), and on Annual bluegrass (Poa annua). Bentgrass may also become infected but shows very few symptoms and quickly recovers. Summer Patch will usually become noticeable between June and September, although small signs can appear at any time but are not noticeable because the turfgrass can recover quickly.
Brown patch is a common turfgrass fungal disease that is caused by species in the genus Rhizoctonia, usually Rhizoctonia solani. Brown patch can be found in all of the cool season turfgrasses found in the United States. Brown patch is most devastating to: Bentgrass, ryegrass, Annual bluegrass, and Tall fescue. Brown patch is also found in Kentucky bluegrass and Fine fescue but this is rare or does minimal damage. Brown patch is known as a foliar disease, so it does not have any effect on the crown or roots of the turf plant.
Pythiumdisease, also known as "Pythiumblight," "cottony blight," or "grease spot," is a highly destructive turfgrass disease caused by several different Pythium species. All naturally cultivated cool-season turfgrasses are susceptible to Pythium and if conditions are favorable to Pythium it can destroy a whole turfgrass stand in a few days or less. Pythium favors hot and very humid weather and will usually develop in low areas or swales in the turfgrass.
Dollar spot is a fungal disease of turfgrass caused by the four species in the genus Clarireedia, in the family Rutstroemiaceae. The pathogen blights leaf tissues but does not affect turf grass roots or crowns. There is evidence that a fungal mycotoxin produced by the pathogen may cause root damage, including necrosis of the apical meristem in creeping bentgrass. However, the importance of this toxin is unknown and its effects are not considered a direct symptom of dollar spot. The disease is a common concern on golf courses on intensely managed putting greens, fairways and bowling greens. It is also common on less rigorously maintained lawns and recreational fields. Disease symptoms commonly result in poor turf quality and appearance. The disease occurs from late spring through late fall, but is most active under conditions of high humidity and warm daytime temperatures 59–86 °F (15–30 °C) and cool nights in the spring, early summer and fall. The disease infects by producing a mycelium, which can be spread mechanically from one area to another.
Typhula blight is most commonly known as a turf disease, but can also be a problem with wheat. Typhula blight is caused by a Typhula fungus, either Typhula incarnata or T. ishikariensis. Typhula incarnata is the causal agent for gray snow mold and T. ishikariensis causes speckled snow mold. Snow molds are caused by cold tolerant fungi that require snow cover or prolonged periods of cold, wet conditions. Typhula blight is most notably found in the turf industry, affecting a wide range of turfgrasses. Upon the snow melt, gray circular patches of mycelium are found. These mycelia produce a survival structure called a sclerotia that survives the warm summer months. Typhula blight is commonly controlled with fungicide applications in the late fall and by other cultural practices. If unchecked, snow molds can cause severe turf loss.
Snow mold is a type of fungus and a turf disease that damages or kills grass after snow melts, typically in late winter. Its damage is usually concentrated in circles three to twelve inches in diameter, although yards may have many of these circles, sometimes to the point at which it becomes hard to differentiate between different circles. Snow mold comes in two varieties: pink or gray. While it can affect all types of grasses, Kentucky bluegrass and fescue lawns are least affected by snow mold.
Turf melting out is caused by the fungal pathogen Dreschlera poae, in the family Pleosporaceae. It is a common problem on turfgrass and affects many different species. The disease infects all parts of the plant most commonly on golf course roughs, sports fields, and home lawns. There are two stages of the disease: the leaf blade infection and the crown and root infection Melting out occurs during the cool weather of April and May and is encouraged by high nitrogen fertility. The disease is spread by wind-blown or water splashed spores and survive in thatch.
Brown ring patch is a recently described Rhizoctonia-like disease of turf grass caused by the fungus Waitea circinata var. circinata. The disease primarily affects putting greens and causes yellow or brown rings up to 1 metre (3.3 ft) in diameter. Brown ring patch was first observed in Japan and has since spread to the United States and China (2011).
Necrotic ring spot is a common disease of turf caused by soil borne fungi that mainly infects roots (4). It is an important disease as it destroys the appearance of turfgrasses on park, playing fields and golf courses. Necrotic Ring Spot is caused by a fungal pathogen that is an ascomycete that produces ascospores in an ascocarp (6). They survive over winter, or any unfavorable condition as sclerotia. Most infection occurs in spring and fall when the temperature is about 13 to 28°C (5). The primary hosts of this disease are cool-season grasses such as Kentucky bluegrass and annual bluegrass (6). Once turf is infected with O. korrae, it kills turf roots and crowns. Symptoms of the disease are quite noticeable since they appear as large yellow ring-shaped patches of dead turf. Management of the disease is often uneasy and requires application of multiple controls. The disease can be controlled by many different kind of controls including chemicals and cultural.
Gray leaf spot (GLS) is a foliar fungal disease that affects grasses. In grasses other than maize it is caused by Pyricularia grisea, which only infects perennial ryegrass, tall fescue, and St. Augustine grass in places with warm and rainy climates.
Drechslera leaf spot is a fungal disease of turfgrass caused by several species of Drechslera.
References
- ↑ Buczacki, S. and Harris, K., Pests, Diseases and Disorders of Garden Plants, HarperCollins, 1998, p484
- ↑ "Turfgrass Diseases: Red Thread (Causal Fungus: Laetisaria fuciformis)".
- ↑ Smiley, Richard (1981). "Nontarget Effects of Pesticides on Turfgrasses". Plant Disease . American Phytopathological Society (APS). 65 (17): 17. doi:10.1094/PD-65-17. Cornell University, Ithaca, NY.