COURSE CARE
Has Spring Sprung? May 15, 2013 By Keith Happ

Annual bluegrass weevils have begun their aggressive migration from overwintering sites to golf course turf.

Calls are coming in about unusual growth of putting green turf. Bentgrasses and Poa annua do not grow at the same rate especially if Poa annua is producing seedheads, which it does every spring. Weather remains the all-important variable that we cannot control when preparing golf course turf for play. Lately, it seems that as soon as we experience better conditions the weather quickly changes otherwise. Case in point, last week temperatures dropped and bermudagrass, which was beginning to break dormancy, stopped growing. This necessitates adjusting fairway maintenance programs until the turf once again responds to warmer temperatures and resumes active growth. When turf is growing it can be fertilized, mowed and groomed for play. When the grass is not growing, these practices could prove more damaging than helpful. Last week, for example, central Virginia experienced torrential rain and nighttime temperatures in the 40s (°F). While this is good for cool-season turfgrasses, it hampers conditioning efforts for warm-season species. The good news is that days are getting longer and the turf will respond.

Superintendents from the northern tier of the Mid-Atlantic Region have begun to see activity from annual bluegrass weevils. Adults are on the march and in several areas the numbers reported are alarming. Continue to scout and treat to control adult weevils. If there is any concern about resistance to treatments give us a call. There are test kits available to determine if this is an issue at your golf facility. The test for pyrethroid insecticide resistance will quickly provide accurate information.

We are approaching the peak of Poa annua flowering, i.e., seedhead development. This means that the bumpiness of greens should diminish and ball roll should improve. There has been wide ranging effectiveness of Poa annua seedhead control programs this season. No matter what level of control you experienced, continue to make every effort to grow healthy grass this spring. This begins with sound water management and effective fertilization. Check the sprayer to make sure product is being applied effectively and efficiently. Using a “one nozzle fits all approach” may not achieve the best results.

One of the water management programs commonly used in the spring is benchmarking soil moisture levels. Even though those difficult-to-manage areas may not be showing stress on the surface, it will be important to benchmark the level of moisture present in the soil. If we experience even a few low humidity days, stress can occur rapidly. That stress can be in the form of off-color turf or loss in turf density. Off-color turf is not necessarily bad, but it is an indicator that the area may need attention. I have already seen many soils that are extremely hydrophobic. Rain and/or irrigation will likely be lost to surface runoff from these sites if water cannot penetrate the soil. Take action to remediate hydrophobic soils before high heat and low humidity conditions prevail. Again, call us if questions arise regarding the management of these conditions.

Source: Keith Happ (khapp@usga.org)

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