TURF TALK
To Spray or Not to Spray
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Spring Transition of Bermudagrass Overseeded with Perennial Ryegrass By J. Scott McElroy, Ph.D., Turfgrass Weed Scientist; Greg K. Breeden, Extension Assistant; and John C. Sorochan, Ph.D., Turfgrass Scientist, University of Tennessee
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verseeding bermudagrass with perennial ryegrass in the transition zone is a good idea for many reasons. It provides a year-round green turf surface, increases winter playability and durability, and potentially provides greater attraction of fall, winter and early-spring play. However, in Tennessee, and the rest of the transition zone, one of the major problems with overseeded bermudagrass is the spring transition. During spring transition from a turf stand dominated by perennial ryegrass to a stand of bermudagrass, maintaining a uniform green turf is very difficult. In
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most situations, perennial ryegrass can prevent 100% bermudagrass green-up. In non-overseeded areas, the bermudagrass achieves complete green-up while the overseeded bermudagrass is still partially dormant. However, applying an herbicide to kill the ryegrass can leave empty brown patches until the turf greens up completely. This mottled green/brown turf can lead turf managers to think that simply letting the ryegrass die out on its own would be a better option. Problems with natural transition If you do choose to simply let the perennial ryegrass “burn out,” or
TENNESSEE TURFGRASS FEBRUARY/MARCH 2005
transition naturally, several new problems arise, including one that is potentially worse than the mottled turf — clumpy volunteer ryegrass (see photo above). You see, some of the perennial ryegrass never burns out, even in the hottest of summers, and then it often turns into volunteer “clumpy” ryegrass. In fact, in every Tennessee area where turf managers have claimed to have completely transitioned their perennial ryegrass with no herbicide, we have found clumpy ryegrass. Unfortunately, volunteer ryegrass is very difficult to control. Many herbicides and herbicide rates that are used to control
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