Plant Disease Management Handbook

Cause Puccinia coronata, a fungus that overwinters on infected plants. Tall fescue, perennial ryegrass, bluegrass, and orchardgrass are all susceptible. The alternate host is buckthorn (Rhamnus spp.). Its importance varies considerably with its proximity to the grass host. Primary inoculum is urediniospores; secondary inoculum (urediniospores) is produced in initial pustules and disseminated by wind. Teliospores are two-celled and are produced in late summer.

See:

Wheat (Triticum aestivum) - Common Bunt (Stinking Smut)

See also:

Grass for Seed - Endophyte

See:

Grass for Seed - Barley Yellow Dwarf

Cause Cercosporidium graminis (teleomorph: Mycosphaerella recutita), a fungus that overwinters as mycelial stromata in affected leaves and debris and infects all cool season turf and forage grasses including: orchardgrass, fescue, ryegrass, bluegrass, and bentgrass. Conidia develop from overwintering mycelium and are splashed, blown, or otherwise disseminated to healthy leaves. The brown stripe fungus sporulates during cool, moist weather in spring and autumn.

Cause Puccinia brachypodii var. poae-nemoralis, a fungus that infects Kentucky bluegrass and survives as mycelium from season to season in infected foliage. Primary inoculum is urediniospores produced in pustules on overwintering sources; secondary inoculum is produced in pustules from primary infections. Several urediniospore cycles can occur in a growing season. Teliospores are two-celled and develop with urediniospores in fall; they often are covered by epidermis.

Cause A fungus, Gloeotinia temulenta, that lives in infected grass seed. Over 40 species of grass are susceptible. The disease is most common in annual ryegrass, perennial ryegrass, and tall fescue. In spring, the fungus emerges as stalked, cup-shaped apothecia (one to several per seed). Ascospores are ejected from the apothecia into the air; only those that land on flowers of a susceptible grass host will infect.

Cause A fungus, Sordaria sp., that is commonly found in the feces of herbivores. It is not considered a pathogen of grass or other plants. It showed up in Oregon seed fields during 2011 in areas of fields treated with high rates of chicken litter under unusually warm and wet early fall conditions. The fungus produces masses of black ascospores, which can coat leaf blades.

Cause Barley yellow dwarf virus (BYDV) infects many cultivated and wild grasses, including tall fescue, Chewing's fescue, ryegrass, orchardgrass, and bluegrass.

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Lawn and Turf