This afternoon a new agronomic session debuted at GCSAA's Education Conference in Las Vegas. "Agronomic Solutions I: Disease and weed control from North to South" was moderated by Beth Guertal, Ph.D., professor at Auburn University, and six panelists -- John Boyd, Ph.D., professor, University of Arkansas; Jim Kerns,Ph.D., assistant professor, University of Wisconsin; Brandon Horvath, Ph.D., assistant professor, University of Tennessee; John Inguagiato, Ph.D., University of Connecticut; Patrick McCullough, Ph.D., University of Georgia; and Zac Reicher, Ph.D., professor, University of Nebraska --- answered all the questions that superintendents could throw at them.
Hands down the favorite weed was Poa annua. More than one panelist pointed out that there is no silver bullet for Poa annua control, and, as Zac Reicher said, "When it comes to chemistry, what works for you, may not work for the guy next to you." Poa annua is tricky because it adapts quickly to its circumstances, and several biotypes may be found on the same golf course or even the same green.
Plant growth regulators such as Trimmit have been somewhat successful in controlling Poa annua. And PGRs also help control seedheads.
Panelist Patrick McCullough also pointed out that it's important to know how much Poa you have before you try to get rid of it. Many superintendents have actually missed their Poa when it was gone -- because not much grass was left. In addition, superintendents to remember that no one herbicide should be relied on for control because Poa can quickly become resistant.
Crabgrass, knotweed, goosegrass, and tropical signalgrass were also weeds of concern.
One superintendent asked about the plant health effects attributed to some fungicides by their manufacturers. Panelist Brandon Horvath said that some products seem to have a positive on turf because of the pigment that has been added to the product, which may screen out UV light and protect plants from oxidative stress. Superintendents are cautioned to use products for their primary purpose -- for example, use a fungicide because you need a fungicide -- and do not apply prooducts repeatedly to attain additional plant health effects.
The panelists cautioned that biological products such as Bacillus can work on a small scale, but trying to apply the numbers necessary to work on an entire golf course or even a fairway are, at this point, nearly impossible.
The panel also discussed bacterial wilt and the concerns superintendents have about losing massive amounts of turf to a sudden assault. Jim Kerns acknowledged that bacterial wilt has become a hot button issue, but it is difficult to diagnose because turfgrass monocultures naturally have massive amounts of bacteria, and bacteria can be found in every turf sample. Kerns reassured the audience that a bacterial disease will not wipe out huge amounts of turf overnight, and Zac Reicher said "Don't lose sleep over it, you can't control it."
Brandon Horvath reminded the audience that researchers are working hard to learn more about bactrial wilt and other diseases that are poorly undestood. However, to attain these goals, researchers need time and funding, and he urged superintendents to support research efforts and the Environmental Institute for Golf.
"Agronomic Solution II" will take place tomorrow with "Go against the grain on ultradwarf bermudagrass" from 1:00 to 3:30 in room N110 of the Las Vegas Convention Center.