Most golfers have heard of the weed Poa annua, also known as Annual Bluegrass. It's an especially troublesome weed because it produces seedheads at low mowing heights. Take a look at this picture of Poa annua in the rough.
The seedheads are especially a problem on greens where it affects ball roll. Also, Poa annua is not as tolerant to stressful weather periods in the summer and will die out. Leaving areas without turf. Plus, the color of the weed is more yellow as opposed to the greener turf that is predominantly grown throughout the course.
One way that we control this weed is by applying plant growth regulators in the spring. Certain plant growth regulators affect the Poa annua more then the bentgrass thus giving the desired species, creeping bentrgrass, a chance to outcompete the less desirable Poa annua. Here's a look of a picture of Poa annua in a fairway.
Notice how less pronounced it looks as opposed to the rough. The application of plant growth regulators does however slow the growth of the creeping bentgrass in the fairways.
Currently there are no post-emergent herbicides label for Poa annua control. Making this one of, if not the most difficult to control weeds in golf course management. However, we are fortunate enough to have on-hand an experimental herbicide which has shown great results against Poa annua. While we only have enough to treat a small area it will give us invaluable insight in how best to use this product at Fieldstone when it is available on the market next year.