Successful Goosegrass Management in Cool-Season Turf
Goosegrass used to be a weed that only impacted southern and transitional regions in the country. If you had warm-season turf, you knew you were going to have to manage for this troublesome, persistent weed. But if you had cool-season turf, goosegrass was only a horror story you heard about…until recently at least. Over the past few growing seasons, the presence of goosegrass has been identified well into the Mid-Atlantic states and throughout the Midwest.
The appearance of this pernicious, summer annual weed in cool-season turf has grown to the point where weed management strategies and plans are being completely overhauled and revamped. Here’s what you need to know about controlling goosegrass in cool-season turf.
Goosegrass, while certainly new in cool-season turf, is very much like other turf weeds in regards to the cultural practices to help control it. Maintaining a healthy, dense turf stand is still the foundation of every weed management program. These include mowing at the correct height and adequately maintaining the nutrition and moisture levels for the desired turf species. Goosegrass explicitly favors compacted soils, so aerification practice are critical in culturally controlling goosegrass. It is also extremely competitive against turf at lower mowing heights such as fairways and greens where it is more problematic than in roughs.
Herbicide control is inevitable when managing goosegrass. Pre-emergent herbicides are the absolute cornerstone of a goosegrass management program. These products form a “barrier” in the soil and when the weed seed germinate, they absorb the herbicide and are controlled before they emerge from the soil.
For the maximum pre-emergent control, herbicide active ingredient (AI) and application timing is extremely critical. The herbicide Ronstar® with the active ingredient oxadiazon is extremely effective at controlling goosegrass and is widely considered to be the industry standard. Other AI’s such as prodiamine and dythiopyr also provide a level of goosegrass control.
Most importantly is the timing of the pre-emergent application. Goosegrass, typically, germinates a little later (3-6 weeks) than crabgrass does, so the application strategies need to be adjusted to match the germination periods between these two. In heavily infested areas, its common practice to do “split” applications to maximize the amount of total control of goosegrass. This tactic increases the length of time that the barrier is in the soil and will be able to control goosegrass.
New Cool-Season Ronstar Products
To help address this growing goosegrass threat in cool-season turf, LebanonTurf has developed Country Club mini-sized Ronstar combination products, featuring MESA, designed to control goosegrass in fairways and other areas with closely mown turf.
These new products can be applied at several application rates to ensure that optimum goosegrass control is achieved while delivering the necessary nutrients to keep fairways healthy. Each of these products includes LebanonTurf’s proprietary nitrogen source, MESA; a homogeneous granular components that combines methylene urea and ammonium sulfate in a single granule. MESA is the only industry source that provides nitrogen in three different ways: slow release, quick release and controlled release, which results in an extended green-up but without the surge growth…so there’s less mowing needed to maintain fast and firm fairway playing surfaces.
It appears that goosegrass is here to stay in cool-season and will only continue its march northward into more and more cool-season turf. Be sure to plan properly for this new threat to ensure your golf course and sports field are consistently weed free and healthy.