With all of the rain over the Mid-Atlantic Region the last several weeks, the last thing turfgrass managers needed was a shift to instant summer conditions. Highs in the mid- 90’s have exposed turf areas that have been weakened by spring rains. Active Pythium (a water mold most active when it is hot, humid and wet) developed, shallow root systems are suffering, the turf has begun to change color, and growth has slowed. It may seem a bit counter-intuitive, but the weak grass will require close attention with hand-held irrigation. Wilting grass has already been seen at several Turf Advisory Service visitations in recent weeks, and we have had only a few days of very hot weather.
Turf managers who have completed aeration -- venting with small-diameter coring or solid tine procedures -- have good internal and surface drainage and are tolerating the weather changes well. Turf managers who have had to react are already struggling. Weaker bio-types of Poa annua are wilting, and the goal now should be to maintain surface density first and playability second. Trying to do too much early in the season could create problems later in the growing season.
Significant populations of Annual Bluegrass Weevils (ABW) are now active during Turf Advisory Service visit. It seems as though we are about two weeks behind 2010 activity. First, instar damage has already been observed, and the grub populations have emerged from the crowns of Poa annua plants. In fact, callow adults have been seen on collars and edges of greens, with generation overlap in some areas of the region. It will be important to monitor population activity for all stages of ABW development. Larvacide and/or adulticide sprays will be necessary. This will be the only way to minimize damage and prevent damage in the future.
NOTE: damage from this insect is now occurring throughout the Northeast and Mid-Atlantic Regions, including the mountains of western North Carolina. Don’t take wilting grass for granted; dig into the soil and look for this insect pest, or use one of the soapy water techniques to flush the insects out of the soil.
Most superintendents who had problems with summer patch (Magnaporthe poae) on greens, fairways or bluegrass rough, should start preventative treatment regimes. Soil temperatures at the two-inch depth of 65 F or greater for four to five days, will allow this soil-inhabiting pathogen to infect the root systems of susceptible grasses. Product application must be placed where it will be effective, and fungicides must reach the root systems to protect the turf.
Although it is still spring on the calendar, now is the time to monitor maintenance activity and control physical damage. Machinery operations, height of cut on greens, spray overlap with plant protectants and/or fertilizers, and watering techniques are all elements of turf management that allow the turf to be presented in a desired manner or create stresses that could lead to damage later in the season. Don’t take anything for granted, and don’t rush even the most simple elements of course preparation. Take full advantage of every teaching moment to improve techniques to help sustain grass health.
As always, remember that the agronomists of the Mid-Atlantic Region are part of your agronomic support team. If you have a question or concern, especially now, give us a call or send an e-mail. You may contact the agronomists of the Mid Atlantic Region, Stan Zontek (firstname.lastname@example.org) or Darin Bevard (email@example.com) at 601-558-9066 or Keith Happ (firstname.lastname@example.org) at 412-341-5922.