Nostoc Balls, Color Loss, Crabgrass and More

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May 27, 2010
LAWNS
 
* NOSTOC BALLS. There was a reported case of nostoc balls (cyanobacteria) from Logan County. This strange phenomenon looks like a green rubbery bubbling mass on the soil surface which is caused by “an algae composed of moniliform cells imbedded in a gelatinous substance.” Nostoc balls can occur in landscape situations and lawns especially during wet periods. Since this is a blue-green algae, it does not infect the plants or turf but does reflect that the turf is thin and growing poorly. The substance grows on the soil surface in a lawn area and can be raked from the area. For a long-term solution, identify why the lawn is thin and correct those elements in the landscape to encourage a dense, thick turf. Correcting factors that affect turf health (such as drainage, sunlight, and soil nutrient issues) would be recommended.
 
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Nostoc Balls from a Lawn in Logan County, Ohio May 2010
 
* LAWN DISEASS. Red thread and leaf spot in lawns that continue to be quite widespread. The long period of wet weather last week created an environment ideal for these to be active. Affected areas may appear more as brown grass this week as the damage to leaf tissue results in leaf dieback.
 
* COLOR LOSS OF TURFGRASS. Lawns may be beginning to lose color and to become somewhat pale. A number of factors can result in this such as: extensive rain fall, rapid growth, heavy Kentucky bluegrass seed head production, cutting grass that is excessively tall, lack of fertilizer, etc…. If lawns are being maintained on poor quality soil or subsoil, late May and early June is the period when a second application of a lawn maintenance fertility program is often applied. Keep mowing as high and frequently as possible.
 
* CRABGRASS. Has germinated and can be found in many lawns especially in the areas where it is most common (along sidewalks and streets or other thin areas) where the turf stand is thin and sunlight can directly penetrate the soil which is required for crabgrass seed to germination. The time for the use of preemergent’s crabgrass materials is past. However, there are a number of postemergent materials that can be utilized to manage this plant if desired.
 
 
 
Golf Course Turf. Several diseases have become quite prevalent on golf courses.
 
* DOLLAR SPOT. Is has become quite active and widespread with the recent wet, humid, warmer weather across the state. Do not let this disease get ahead of you or you will be chasing it all year.
 
bygl 2 5-27-10
Dollar spot on creeping bentgrass and Poa annua, Columbus, Ohio May 26, 2010

*LEAF SPOT ON CREEPING BENTGRASS. Leaf spot on creeping bentgrasses have been reported on numerous golf courses in the central, western and northern parts of Ohio. We even have it at the OSU turfgrass research facility. The key to identification lies in the fact that the creeping bentgrass is affected, but the annual bluegrass is healthy and normal. The affected areas are irregular in shape and a darker brown color then dollar spot. Usually there is a slow and continual decline with active leaf tissue if no affective fungicides are applied. If leaf spot is left untreated, it can cause significant deterioration of the turf.

bygl 3 5-27-10
Leaf spot on creeping bentgrass, May 26, 2010

To manage this disease, use a two-step approach.  First, suppress the advance of the fungus that is causing the disease and second, encourage growth and recovery of the bentgrass. There are a number of fungicides that are effective on leaf spot including iprodione (Chipco 26GT), mancozeb (Fore), fludioxonil (Medallion) and azoxystrobin (Heritage).  Iprodione is one of the best and widely used.  Mancozeb is a contact fungicide which gives a very quick knockdown, but frequent applications are required (at least every 7 days). Medallion is another contact material.  Use all of these according to label rates.  Due to the fact that the disease has progressed, use the highest label rates at the shortest intervals until recovery has been achieved. In conjunction with an effective fungicide program, the greens should be fertilized and managed in a way to encourage growth and recovery.

* BROWN RING PATCH / WAITEA PATCH. This disease has been reported over the last few weeks in several areas of the state. This is a rather superficial disease even though it can be quite alarming with its yellow rings on golf greens. With more consistent warmer temperatures, it will subside.

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Brown Ring Patch, SW Ohio May 2010