For several reasons, winter overseeding programs have been greatly scaled back or completely eliminated at courses in Florida over the past few years. However, at courses with older Tifdwarf or even Tifgreen bermudagrass putting greens, overseeding is still considered a necessary practice to ensure that the desired playing quality and aesthetic character can be provided through the primary season. The process of establishing and maintaining an overseeding cover for six months or longer places additional stress on the base bermudagrass. The overseeded cool-season grasses compete heavily with the underlying bermudagrass, sometimes so intensely that the bermudagrass becomes thin and weak. While invisible to most as long as the overseeding is present, the damaged areas become obvious to everyone once the overseeding dies out. Typically, this transition process begins in the late spring and is completed in four to six weeks. However, based on Turf Advisory Service visits conducted during July and the phone calls being received by our offices, there are courses still struggling with the transition blues.
A mild winter followed by an early and very dry spring would normally promote a gradual and complete transition out of the overseeding cover so that golfers are not even aware this process was underway. However, this year the lack of any significant cold weather resulted in very little slow down in plant parasitic nematode activity. When combined with the lack of systemic, curative type nematicides the task of keeping this soil-borne pest below damaging levels has become extremely difficult. Nematodes, combined with cool nighttime temperatures until mid-June, impeded the resumption of sustained bermudagrass growth which is essential for accomplishing a smooth transition. As noted in the previous Florida regional update, Rains Continue To Bring More Challenges, frequent and light irrigation and fertilization is advised to compensate for the reduced ability of the turf’s root system to take up nutrients and moisture. It is also very important to avoid excessive nitrogen fertilization rates and to make sure that sufficient levels of potassium are maintained so that balanced shoot and root system growth occurs.
The severe to exceptional drought that plagued Central and North Florida until early July weakened bermudagrass across the region and made it more susceptible to fungal diseases. While many courses implemented preventative fungicide programs, all too often these programs did not include Pythium control products. As a result, root rot and in some cases Pythium blight has been found in samples sent to the University of Florida Rapid Turfgrass Diagnostic Lab. Rhizoctoniazeae leaf and sheath spot is also being found in samples submitted to the lab. Accurate identification of these disease problems is essential in determining the proper control treatments.
An early tropical storm and the onset of typical summertime thunderstorm activity has ended the severe drought that was plaguing most of the state. However, remember that the combination of a damaged root system, high sand content greens, and high evapotranspiration rates can result in the rapid onset of drought stress. It is a mistake to assume that continuous adjustment and fine-tuning of the irrigation system is unnecessary because of a few rains. When was the last time a visual inspection of all of the putting green irrigation heads was conducted to make sure that they are operating correctly and are in proper adjustment? Also, when was the last time an irrigation system audit was conducted? The popularity of portable soil moisture meters has been growing rapidly due to their accuracy and cost effectiveness. The moisture meter is a lot faster and simpler than a catch-can test.
The articles found below provide additional information on the advantages of this exciting new tool for turfgrass managers.
Identify Soil Moisture Status More Accurately Than Ever Before
Moisture Meters - A Giant Leap Forward
The Florida Golf Course Superintendent’s Association’s efforts to develop and implement a Best Management Practices Golf Certification continue to move forward. On July 25, 2012, the first BMP seminar and certification test was conducted at the University of Florida/IFAS/Gulf Coast REC in Wimauma, Florida. At this time, BMP certification is voluntary, but encouraged, and the next seminar and certification test will be conducted at the FTGA Conference and Show in Orlando during the last week of September.
Source: John Foy, director, Florida Region (firstname.lastname@example.org, 772.546.2620)