July 2013 Newsletter (vol.20)   >>   No Spots in the Turf

 

 

Perfect Turf

Summer is finally here and that means vacations, being outdoors and hot and humid weather here in the Midwest. With all of the fun that is upon us, there is also a down side; summer turf problems. Some of the most common are brown patch, dollar spot, leaf spot and summer patch. Turf issues can be tricky to identify, but never fear, we have a guide to help you identify the most common turf diseases.

Not all grasses are susceptible to the same kind of turf diseases. To identify which disease is affecting your lawn, you first must know which variety is planted. Once the variety is determined, you can then begin narrowing down the diseases and selecting curative and prevention practices.

Brown Patch Brown Patch

Susceptible grasses: bluegrass, annual bluegrass, fescues, and ryegrass
Conditions favoring disease: moist, hot weather on over fertilized lawns
Symptoms: First appears as small, dark, water- soaked looking grass; turns into brown circular areas several inches to several feet in diameter
Prevention: Improve soil aeration, water drainage, avoid excess nitrogen, water deeply but infrequently, mow high and remove excess thatch
Curative: Alternate Dyna Green Rx T-Methyl and Dyna Green Rx Eagle to prevent resistance. Apply Infuse Lawn and Landscape granular, any of the Daconil products, or Infuse Lawn and Landscape RTS.

Dollar Spot Dollar Spot

Susceptible grasses: bermudagrass, annual bluegrass, fescue, ryegrass, seashore paspalum, and zoysiagrass
Conditions favoring disease: affects lawns in heavy dew periods that are low in nitrogen and stressed by drought
Symptoms: small, circular spots from 1-5” in diameter, reddish band across the leaf, fine cobweb-like threads seen in early morning
Prevention: fertilize adequately, reduce thatch, and maintain air circulation
Curative: Alternate Dyna Green Rx T-Methyl and Dyna Green Rx Eagle to prevent resistance. Apply Infuse Lawn and Landscape granular, any of the Daconil products, or Infuse Lawn and Landscape RTS.

Leaf Spot Leaf Spot

Susceptible grasses: bermudagrass, bluegrass, fescues, kikuyugrass, ryegrass, and zoysiagrass
Conditions favoring disease: low clipped grass, excess nitrogen fertilization or deficiency, warm temperatures (70°-90°F) for bluegrass, ryegrass, and fescue, cool temperatures (60°-70°F) for bermudagrass, and zoysiagrass
Symptoms: circular to elongated brownish spots with brown centers and dark brown or purple borders on leaf blades, sheaths, and stems
Prevention: improve soil aeration and water drainage, avoid dry spots and too much nitrogen fertilizer, and maintain a high cutting height
Curative: Alternate Dyna Green Rx T-Methyl and Dyna Green Rx Eagle to prevent resistance. Apply Infuse Lawn and Landscape granular, any of the Daconil products, or Infuse Lawn and Landscape RTS.

Summer Patch Summer Patch

Susceptible grasses: bluegrass and fine fescues
Conditions favoring disease: high temperatures (> 85°) in late spring through the summer, turf mowed too low or when soil moisture is excessive
Symptoms: circular, yellow or tan areas of dead and dying plants up to 1’ in diameter, might have green healthy looking plants in the center, which is called frog eye pattern
Prevention: aerate soil, and apply slow release nitrogen, improve drainage, reduce compaction, reduce soil pH if higher than 7
Curative: Alternate Dyna Green Rx T-Methyl and Dyna Green Rx Eagle to prevent resistance. Apply Infuse Lawn and Landscape granular, any of the Daconil products, or Infuse Lawn and Landscape RTS.

 

Fusarium Blight Fusarium Blight

Susceptible grasses: Kentucky bluegrass
Conditions favoring disease: daytime temperatures (85°-95°F), drought stressed areas in full sun, and it survives in thatch and grass residues
Symptoms: small, circular, grayish green areas, ranging from a few inches up to a foot in diameter, some plants in the center can survive, dead foliage appears bleached
Prevention: don’t apply more than 1 pounds nitrogen/1,000 square foot/application or more than 6 pounds annually, mow at the highest recommended rate
Curative: Alternate to prevent resistance
Dyna Green Rx T-Methyl and Dyna Green Rx Eagle. Apply Infuse Lawn and Landscapegranular, Actinovate, or any of the Daconil products.

 

Pythium Blight Pythium Blight

Susceptible grasses: all grasses
Conditions favoring disease: low spots that remain wet, warm temperatures, and look for it when nighttime temperatures (Fahrenheit) plus relative humidity equals 150
Symptoms: small circular spots 2-6” that run together, blackened leaf blades rapidly wither, turn reddish brown, lie flat, stick together, and appear greasy
Prevention: improve soil aeration, and water drainage, avoid mowing wet grass and applying high levels of nitrogen during hot, humid weather
Curative: Apply Actinovate.

Red Thread Red Thread

Susceptible grasses: bentgrass, bermudagrass, bluegrass, fescues, and ryegrass
Conditions favoring disease: mild temperatures (60°-75°) and extended periods of wetness, deficiency of nitrogen with adequate moisture (excess irrigation or rainfall)
Symptoms: red threadlike structures which extend from the upper part of the grass blade, and grow in patches that are 2-8” in diameter
Prevention: proper irrigation and fertilization, prevent drought stress, and provide adequate air circulation
Curative: Apply Infuse Lawn and Landscape RTS

Rust Rust

Susceptible grasses: all grasses
Conditions favoring disease: moderately warm temperatures (70°-75°F) and extended periods of leaf wetness, deficient in nitrogen
Symptoms: irregular patches of weak turf covered with rust colored (spores), the colored spore residue will rub off when touched
Prevention: maintain turfgrass vigor by following proper irrigation and fertilization requirements, mow regularly and remove clippings to reduce the number of spores if lawn is infected
Curative: Apply Infuse Lawn and Landscape RTS

Rhizoctonia Rhizoctonia Blight

Susceptible grasses: bluegrass, annual bluegrass, fescues, and ryegrass
Conditions favoring disease: excess thatch and mat along with high temperatures (80°-95°F), high humidity, soft, lush growth due to excessive nitrogen
Symptoms: first appears as small, irregular brown patches or rings that can enlarge to many feet in diameter, the leaves and sheaths become water soaked, wilt, turn light brown, and die
Prevention: improve soil aeration and water drainage, and avoid excess nitrogen
Curative: Apply Actinovate.

We stock a wide variety of products to help cure the diseases in your turf.

While you are outside enjoying the summer, remember to look at your lawn and see if you notice any diseases starting to form. Remember the steps in identifying the disease; identify your grass type, find the types of disease that affect that specific grass variety, then identify the disease and treat. Once you have a beautiful disease free lawn, you will be able to enjoy the outdoors even more.

Sources

Lawn Disease: Prevention and Management. www.ipm.ucdavis.edu

Summer Lawn Diseases. www.yardcare.com

Turf Disease Identification. http://turfdiseaseid.ncsu.edu/