Forage Diseases: Forage Diseases


Dollar Spot Sclerotinia homoeocarpa : Dollar Spot Sclerotinia homoeocarpa This disease is most likely to be observed from fall through spring. It will be observed on areas with low nitrogen levels. Other factors associated with the disease are a dry root system associated with a humid leaf canopy.


Dollar Spot Sclerotinia homoeocarpa : Dollar Spot Sclerotinia homoeocarpa Brown to straw-colored patches of dead grass will develop. Irregular, light tan lesions with distinct brown borders will be present on the leaves at the outside edge of the patch. White, cottony mycelia may be observed in early morning hours when dew is present.


Control of Dollar Spot: Control of Dollar Spot Keep up N applications Keep up soil moisture


Helminthosporium Leaf SpotBipolaris, Drechslera and Exserohilum spp.  : Helminthosporium Leaf Spot Bipolaris, Drechslera and Exserohilum spp. Occur during periods of high humidity and warm temperatures. Mainly affects bermudagrass Will impact yields and quality of grass/hay The most damage occurs when fungus attacks stems and roots.


Leaf spot: Leaf spot


Dracena Bipolaris leaf spot: Dracena Bipolaris leaf spot


Control of Leaf Spot: Control of Leaf Spot Variety selection Soil fertility Irrigation control Thatch removal Timely harvest


Stunt Virus on Perennial PeanutCucumovirus: Stunt Virus on Perennial Peanut Cucumovirus Leaves from peanut plants infected with peanut stunt virus are malformed and curl up at the edges. Infected leaves may be paler green and/or yellowed. The virus can overwinter in wild or forage legumes Vectored by aphids.


Interveinal chlorosis of Stunt Virus on Perennial Peanut: Interveinal chlorosis of Stunt Virus on Perennial Peanut


Pythium blightPythium aphanidermatum: Pythium blight Pythium aphanidermatum Grease spot, cottony blight, or pythium Affects ryegrasss and cool season grasses overseeded on bermuda Begins as small irregular patches 1-4 inches in diameter Affected blades appear dark and water soaked


Pythium Blight: Pythium Blight


Pythium blight: Pythium blight Occurs where there is little air movement Grass in young seedling stage is most susceptible. Spread to new sites by movement of contaminated soil, mowing implements, grass clippings, or by surface water runoff.


Pythium blight control: Pythium blight control Cultural methods Well-drained soil Promote air movement Minimize traffic over affected areas Overseed as late as possible Remove thatch


ErgotClaviceps purpurea: Ergot Claviceps purpurea Attacks more than 200 grass hosts. Reduces seed production and can be toxic to livestock. The most common sign of ergot is the dark purple to black sclerotia found in the head of cereals and grasses before harvest. After harvest, these dark bodies are evident in the grain.


Ergot Control: Ergot Control Ergot control is aided by crop rotation.   Deep tillage is also beneficial. Clean seed must be used to prevent direct contamination of the new crop. Mowing of grass in pastures and roadsides before flowering may be beneficial


Barley Yellow Dwarf : Barley Yellow Dwarf Barley yellow dwarf of wheat and barley, and red leaf of oats are two small grain diseases caused by the barley yellow dwarf virus (BYDV). This virus is transmitted by many aphid species. Seedlings are most susceptible to infection.


Barley Yellow Dwarf on Oats: Barley Yellow Dwarf on Oats Barley and wheat leaves, particularly the flag leaf, become yellow. Yellowing of the flag leaf can help distinguish infection by BYDV from nutritional deficiencies.


Control of Barley Yellow Dwarf: Control of Barley Yellow Dwarf Avoidance of aphids during seedling stage Plant later in the fall or early in the spring. Control aphids chemically may be an option, but not cost effective Select varieties tolerant of the virus.


Questions?: Questions? Prepared by Libbie Johnson