Plant Disease Management Handbook

Cause A fungus, Blumeria graminis (syn. = Erysiphe graminis; anamorph Monilia hyalina), that overwinters on infected plants or as chasmothecia associated with debris and is most commonly observed on tall fescue, fine fescue, and Kentucky bluegrass but all cool season grasses are susceptible, including native perennial grasses. Spores can be dislodged easily and spread by wind.

Cause Several species of the nematode genus Anguina can affect orchardgrass, annual ryegrass, bentgrass, and fescue. Recent DNA studies point to the likelihood of a different Anguina species evolving on each susceptible grass genus. These studies also suggest that Anguina agrostis may be limited to infecting only bentgrass. DNA testing can be used to identify the Anguina nematodes to species.

See:

Grass for Seed - Head Smut (Loose Smut)

See:

Grass for Seed - Kernel Smut

Cause Puccinia crandallii, a fungus that survives from season to season on infected plants. Red, Chewing's, and sheep fescue are susceptible. The alternate host for fine fescue rust is snowberry (Symphoricarpos spp.), a common plant throughout the West. Primary inoculum is urediniospores; secondary inoculum (urediniospores) is produced in initial pustules and disseminated by wind.

Cause A fungus, Claviceps purpurea, that affects about 400 species of grass as hosts, including all species grown for seed. The disease is most common in bluegrass, bentgrass, and Chewing's fescue but may occur in perennial ryegrass or tall fescue. Sclerotia of the fungus overwinter on or near the soil surface and germinate in spring, giving rise to stalked, spherical structures that eject ascospores. The flower is the only part susceptible to infection.

Cause Neotyphodium coenophialum and N. lolii are fungi that grow within tall fescue and perennial ryegrass, respectively. The name endophyte describes this life habit of the fungi. Natural transmission occurs only by planting endophyte-infected seed; no transmission from infected to uninfected plants has been observed in nature. Both plant and fungus benefit from the relationship.

Cause A fungus, Tilletia controversa, which survives as spores in soil or in smut balls in seed.

Cause Drechslera spp. and Bipolaris spp. are fungi that survive as conidia and dormant mycelia in infected plant tissue and debris. Cool season grasses such as tall fescue, perennial ryegrass, bluegrass, fine fescue, bentgrass, and orchardgrass are all affected. This is one of the more common leaf spot diseases of ryegrass and tall fescue. Conidia are spread by wind, rain, irrigation water, or equipment. Cool, wet spring weather favors the disease.

Cause Several soil-inhabiting or seed-contaminating fungus-like microorganisms such as Pythium and Globisporangium spp. as well as the fungi Fusarium spp. and Rhizoctonia spp. Any soil condition that prevents rapid germination and emergence increases the possibility of seed rot, damping-off, or seedling blight.