Don't You Love The Weather?

It's difficult to produce regional updates without first discussing the weather. What makes this season so interesting are the weather patterns in the different parts of the Mid-Atlantic Region. There are parts of this region that are extremely dry. Conversely, there are other parts of the Mid-Atlantic region that are on the opposite end of the spectrum and are very wet. A few miles can make a huge difference in how much rainfall golf courses receive or do not receive.
Problems begin to develop with each scenario. For example, with hot and dry weather, patches of Poa trivialis (a common contaminant in grass seed) go dormant. The result is a patch of bare ground. Is the Poa trivialis dead? Probably not, it will come back when temperatures moderate in the fall. Nonetheless, the turf looks bad and golfers question, "what happened?"
The other extreme is Pythium . Pythium is a water mold and its development is favored by free water on the soil surface. The result of a Pythium attack is another patch of bare ground. Thus, while one superintendent may be fighting the dry wilt of Poa trivialis and Poa annua , another superintendent is fighting Pythium , brown patch and wet wilt.
August also is the month that many courses implement aggressive renovation work. Labor is still available, especially college kids, a high percentage of golfers are away on vacation, and it may be too hot for other golfers to play. With lighter play schedules and no tournaments, many golf courses use this time to core aerate, slice and overseed, apply heavy rates of topdressing, etc. Be careful; the last thing anyone wants to do is to make an otherwise good stand of grass worse. Watch the weather and adjust renovation work accordingly. You need to make the judgment about when to be aggressive and when to be conservative. After all, this is the time of the year when cool-season grasses are at their weakest.
Another problem we are seeing is weeds. Breakthroughs with preemerge herbicides are common; for example, warm-season grassy weeds like yellow nutsedge, kyllinga and dallisgrass. Remember, when cool-season grasses are at their weakest, herbicides should only be applied when there is good moisture in the soil. Herbicides applied to drought stressed grass do not kill the weeds very well and you run the risk of damaging the grass you are trying to maintain.
What's the bottom line? Be careful and either pray for rain or pray for it to stop raining. It has been that kind of year!!!
As always, if the Mid-Atlantic regional agronomists can be of assistance, contact Stan Zontek ( szontek@usga.org ) or Darin Bevard ( dbevard@usga.org ) at 610/ 558-9066 or Keith Happ ( khapp@usga.org ) at 412/ 341-5922.