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.
Sod, also known as turf, is the upper layer of soil with the grass growing on it that is often harvested into rolls.
Rhizoctonia solani is a species of fungus in the order Cantharellales. Basidiocarps are thin, effused, and web-like, but the fungus is more typically encountered in its anamorphic state, as hyphae and sclerotia. The name Rhizoctonia solani is currently applied to a complex of related species that await further research. In its wide sense, Rhizoctonia solani is a facultative plant pathogen with a wide host range and worldwide distribution. It causes various plant diseases such as root rot, damping off, and wire stem. It can also form mycorrhizal associations with orchids.
Pythium volutum is a plant pathogen infecting wheat, barley, and turfgrass. It is known to be sensitive to some of the compounds typically present in selective media commonly used for isolating Pythium spp., so isolation may require alternative methods.
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.
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.
Ophiosphaerella is a genus of fungi in the family Phaeosphaeriaceae. The genus was described by Italian-Argentinian botanist and mycologist Carlos Luigi Spegazzini in 1909.
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.
Red thread disease is a fungal infection found on lawns and other turfed areas. It is caused by the corticioid fungus Laetisaria fuciformis and has two separate stages. The stage that gives the infection its name is characterised by very thin, red, needle-like strands extending from the grass blade. These are stromata, which can remain viable in soil for two years. After germinating, the stromata infect grass leaf blades through their stomata. The other stage is visible as small, pink, cotton wool-like mycelium, found where the blades meet. It is common when both warmth and humidity are high.
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.
Stromatinia cepivora is a fungus in the division Ascomycota. It is the teleomorph of Sclerotium cepivorum, the cause of white rot in onions, garlic, and leeks. The infective sclerotia remain viable in the soil for many years and are stimulated to germinate by the presence of a susceptible crop.
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).
Bacterial wilt of turfgrass is the only known bacterial disease of turf. The causal agent is the Gram negative bacterium Xanthomonas campestris pv. graminis. The first case of bacterial wilt of turf was reported in a cultivar of creeping bentgrass known as Toronto or C-15, which is found throughout the midwestern United States. Until the causal agent was identified in 1984, the disease was referred to simply as C-15 decline. This disease is almost exclusively found on putting greens at golf courses where extensive mowing creates wounds in the grass which the pathogen uses in order to enter the host and cause disease.
Melon necrotic spot virus (MNSV) is a virus that belongs to the genus Gammacarmovirus of the family Tombusviridae. It has been observed in several countries of the Americas, Africa, Asia, and Europe. It is considered to be an endemic virus in greenhouses and field productions of Cucurbitaceae crops, including melon, cucumber, and watermelon. MNSV is mainly spread through infected soil, seedlings, insects, and by the root-inhabiting fungus vector Olpidium bornovanus. Symptoms vary between Curbitaceae crops, but generally consist of chlorosis, brown necrotic lesions, leaf wilt, fruit decay, and plant death. Management of the disease consists of preventing infection by rotating fields and crops, steam sterilization, and disposal of infected plants. Also, treated seeds with heat or chemicals are efficient in preventing infection. MNSV is important in melon plants as it causes vast economical damage worldwide reducing significant yields.
