Proceedings of the Sixty-first Annual Meeting of the Northeastern ...

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SEEDHEAD SUPPRESSION OF ANNUAL BLUEGRASS. J.A. Borger and M.B.
Naedel, The Pennsylvania State Univ., University Park.
ABSTRACT
Annual bluegrass is commonly found on golf courses today. Many turfgrass
managers choose to maintain annual bluegrass while others try to eliminate it. Annual
bluegrass can produce many seedheads in the spring, regardless of mowing height.
Seedhead production can create an undesirable sward for a variety of reasons. First,
seedheads can be aesthetically displeasing resulting from an off white color during the
peak production period. This production of annual bluegrass seedheads may result in a
decrease of plant health. Additional stress, such as traffic or lack of moisture, may lead
to an undesirable sward. Second, annual bluegrass seedheads may adversely affect
turfgrass playability, especially in regards to a golf course putting green. Ball roll and
smoothness are often compromised by annual bluegrass seedheads. Chemical
applications of plant growth regulators and other materials have been used for the
suppression of annual bluegrass seedheads. The correct timing of the application of
these materials are imperative. If applications are made too early and temperatures are
not optimal for growing conditions, plant health may be an issue. If materials are applied
too late in the season, seedhead suppression may not be accomplished. Material
application timings can differ. A common material application timing is when the annual
bluegrass is in the boot stage of development. The boot stage should be monitored by
sampling annual bluegrass plants in different areas of the overall sward. Many studies
have been conducted to evaluate various plant growth regulators for the suppression of
annual bluegrass seedheads. For example, Embark T&O is a growth regulator which
provides excellent suppression when applied at the correct rate and timing. Other
options include a tank mix of Primo Maxx and Proxy. This tank mix has shown good
suppression in several studies. Researchers continue to evaluate new products, product
combinations, and application timings to better suppress annual bluegrass seedheads.
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