www.superintendentmagazine.com/article.php?id=631 -
[Cached Version]
Published on: 10/8/2008
Last Visited: 7/31/2008
Control isn't easy, and any cultural practices that a superintendent follows must revolve around the entire golf course environment, regardless of whether the turf consists of bermudagrass or bentgrass, or whether the course resides in a sunny links location or a shaded mountain area, says Shawn Askew, associate professor of turfgrass weed science in the department of plant pathology, physiology and weed science at Virginia Tech in Blacksburg, Va.
Askew says that cultural practices include limiting soil compaction by using lightweight equipment; aerating regularly; and reducing foot and equipment traffic, especially in wet conditions.
...
"These cultural practices should be combined with an herbicide or plant growth regulator (PGR) program that is designed around the type of turfgrass," Askew says."Preemergence herbicides can be used on several species of turfgrass cut at fairway or rough height and are applied in late summer or early fall to kill Poa that will attempt to germinate in the fall."
He says some of these preemergence herbicides include oxadiazon, prodiamine, dithiopyr, bensulide, pendimethalin and oryzalin.
A few postemergence herbicides in active bermudagrass include trifoxysulfuron (Monument), rimsulfuron (Tranxit) and foramsulfuron (Revolver).
In dormant bermudagrass, Askew says superintendents can use glyphosate (Round-Up), simazine and ethofumesate (Prograss).When working with tall fescue, bentgrass, bluegrass and ryegrass, Askew says superintendents can apply Prograss in November, December and March at the recommended label rates for each species.In ryegrass and bentgrass, he recommends using bispyribac sodium (Velocity) applied at or after seed head production.They also can apply sulfosulfuron (Certainty) on bentgrass at the same time they use Velocity.
On greens, Askew says most superintendents use PGRs to "selectively suppress Poa and manage a more uniform bent/Poa mix."
...
"Trinexapac ethyl [Primo] does not harm Poa, and may improve survival of Poa," Askew says, "but it does improve the quality of a bent/Poa mix by darkening the color and smoothing out differences in height between bent and various Poa ecotypes.Primo is also added with ethephon [Proxy] for Poa seed head suppression."
Askew adds that paclobutrazol (Trimmet) and flurprimidol (Cutless) are both used to selectively suppress Poa annua."These products can't be applied to greens with 50 percent or more Poa, as thinning of turf may occur if too much Poa is in the mix," he says."These products' rates must be manipulated based on the growth rate of creeping bentgrass to avoid bentgrass injury and maintain an acceptable level of Poa suppression."
He says that superintendents often use Trimmet and Cutless in the spring and fall when bentgrass is growing most.They apply Primo during the stressful summer months.Askew says, "Some turf managers choose to use these products season long and just adjust rates according to seasonal growth patterns of the bentgrass."
...
"Eliminating seed heads makes things look good," Askew says, "but this practice increases survival of Poa in the summer by avoiding the massive depletion of carbohydrates that the Poa plant endures due to seed production."
26 online sources [ view sources ]
Profile is not claimed [ this is me ]
