RUST ON TURFGRASS
Rust is a common fungal disease is showing up in many areas. These diseases can be found on most species of grasses around the World. Yellow flecks on the leaf blades are the first signs of rust disease on turfgrass. The yellow flecks enlarge which cause the leaf epidermis to rupture and release yellow-orange powdery spores. These fungal spores easily get on shoes, mowers, and pets but are not harmful to humans or animals. In severe incidences, infected grass can thin and inpidual shoots may die.
Grasses Affected: Perennial Ryegrass (most common), Kentucky Bluegrass, Tall and Fine Fescues and Zoysiagrass.
Rust is favorable in warm moist conditions in conjunction with prolonged leaf wetness from dew. Wetness of the leaf blade for more than 10 hours with air temperatures between 68° and 86°F, are optimum growing conditions for this pathogen.
There are many types of fungi that cause rust. The most common are Puccinia graminis (Black Stem Rust), Puccinia coronate (Crown Rust), Uromyces dactylidis (Leaf Rust), and Puccinnia striiformis (Yellow Stripe Rust).
Genetic host resistance:
Today there are many new cultivars that have a high resistance to rust diseases. It is important before seeding to make sure you select a resistant cultivar. Visit the National Turfgrass Evaluation Program (NTEP) at www.ntep.com to find more information on rust resistant turf.
The most effective control for preventing rust is to establishing a healthy turf. Providing enough nitrogen and maintaining a proper irrigation regime will minimize the chance of rust. The following are key cultural practices to prevent this disease: maintain a good fertiligy program adequate for healthy turf growth; avoid moisture stress; avoid irrigating in evenings; raise height of cut; and manage soil to avoid compaction.
Fungicides are commonly not used to control this disease if proper plant health practices are being done. However, if a severe rust outbreak exists on a healthy turf stand, two fungicide families, DMIs and Strobilurins, are the most effective in suppressing the disease. Remember to follow application rates and make sure the fungicide is labeled for your area of application. Here are a few of the effective fungicides for rust: Rubigan, Eagle, Bayleton, Banner, Trinity, Tourney, Triton, Heritage, Compass, Insignia, and Disarm.
COMMERCIAL TURFGRASS UPDATE
Golf course samples continue to come into the clinic, during the past two weeks the following were diagnosed:
- Many samples with environmental stress, no infectious disease.
- Annual bluegrass (Poa annua) decline, heat & humid conditions on weak stands and biotypes.
- Wear and Mowing Damage
- Decline from poor drainage and Black Layer
- Wet Wilt (on Poa annua and creeping bentgrass)
- Anthracnose (on Poa annua and creeping bentgrass)
- Copper Spot (on creeping bentgrass)
- Pythium Blight (on Poa annua and creeping bentgrass)
- Necrotic Ring Spot (on Kentucky bluegrass)
- Summer Patch (on Poa annua)
- Bacterial Wilt (confirmed on one course in Ohio on Poa annua in other state on creeping bentgrasses, Indiana and the East coast)
This continues to be a very tough year, BE CAREFUL! Keep it simple. DO NOT do anything to add to environmental stresses. When in doubt …. Do NOTHING. If there are questions, feel free to contact us.
TURF SAMPLES - WHERE DO YOU SEND THEM?
There is confusion on where turfgrass samples should be sent for diagnostic work. Please send all turfgrass samples to the following address NOT to Reynoldsburg.
C. Wayne Ellett Plant and Pest Diagnostic Clinic
Department of Plant Pathology
201 Kottman Hall
2021 Coffey Road
Columbus, Ohio 43210
EVENTS & TURFGRASS FIELD DAYS
- 2010 Turfgrass Research Field Day – Wednesday August 11 @ OTF Research and Educational Facility OSU Columbus, Ohio
- 16th Annual Ohio Lawn Care Summer Seminar – Thursday August 12 @ OTF Research and Educational Facility OSU Columbus, Ohio