Chutes & Ladders & Dollar Spot
I was recently visiting with a superintendent who asked me, “Are you finding that dollar spot is getting worse every year?”
While it’s true that some courses have overused certain classes of chemistry over the years, resulting in a reduced sensitivity to some diseases, it’s also my opinion that a reduction in cultural practices during the growing season is the main culprit, creating an environment for certain diseases, especially dollar spot, to flourish. Diseases are opportunistic, and if you leave the door open to them, they will sneak in when the time is right.
Dollar spot does appear to be worsening in some areas of Michigan. Weather certainly plays a significant role, but it’s no coincidence that in some of these locations, I also notice a reduction in fairway fertility applications, an elimination of thatch reduction processes such as verticutting and core aerification, the overreliance on tired generic chemistries, and improper water management or lack of sufficient drainage.
Many of these shortcuts appear to be the result of budget savings and labor shortages, as there is more pressure than ever on superintendents to attempt the impossible: “do more with less.”
You can’t do more with less. You can grow more dollar spot with less inputs, though.
In these situations, I try to remind the superintendent that any fungicide has the potential to fail when it has to overcome more than it was intended to do. A thatchy, nitrogen-starved, wet fairway with no drainage is an environment ripe for dollar spot. Asking any fungicide to shoulder the burden of these agronomic shortcuts is not a reasonable expectation.
If you are finding a reduction of disease control from your fungicides, it might be time to look at your cultural practices. Here are a few ways you can help yourself avoid costly curative applications, and further proof that you can’t do more with less:
Dollar spot on overwatered, nitrogen starved green
Stick to the program. A spray program is only good if you adhere to it. There is a trend towardsuperintendents stretching the limits of their program, letting their guard down when the weather seems “easy,” or skipping applications due to projects on the course, only to find themselves playing catch up the rest of the season.
Get out in front. Preventative applications are always more friendly to your budget than curative applications. Keep on schedule with your applications and be prepared to tighten your intervals when disease pressure is higher.
Don’t starve your turf. Keeping greens lean and mean is great for green speed, but it also makes turfgrass much more susceptible to dollar spot. Maintaining adequate fertility creates a stronger plant that will be at less risk for disease, more tolerant of stress, and recover faster when an infection does occur.
PGR’s are your friend. If you rely on contact fungicides such as Daconil Action™ or Secure® for preventative control of dollar spot, consider adding a plant growth regulator to the mix to preserve and possibly extend the life of your fungicide. A contact fungicide is only good for as long as it’s on the surface of the leaf.
Make time for important cultural practices. Reducing thatch will reduce dollar spot pressure. Topdressing, verticutting, brushing, and core aerification spring and fall will all help reduce thatch and create healthier turf. I know a lot of superintendents have lost their “Maintenance Mondays,” which made a lot of these practices easier to accomplish. But where there’s a will, there’s a way to get these things done: “Thatchy Thursdays” perhaps?
Moisture management. Dew sweeping in the morning is a simple way to reduce leaf wetness in the morning and reduce dollar spot pressure. Improve fairway drainage in low areas, and water only what is necessary at night. Too often I find fairways being overwatered to provide lush, green turf, when in reality all you are doing is promoting disease.
Ingredients do matter. Generic chemistries may fit the budget, but they are not always the right fit for your agronomic program. Reduced performance may end up costing you more in the long term. The cheapening of certain chemistries, such as tebuconazole, is leading to many superintendents overusing that group. At some courses, I’ve seen this class of chemistry go in every single tank that leaves the fill pad. This is the quickest way to create a resistance issue, resulting in reduced performance of every single product in that class of chemistry.
Getting back to that superintendent’s original question: “Is dollar spot getting worse every year?”
My answer: “Where too many shortcuts are taking place, yes, it is.”
Shortcuts may be great for Chutes & Ladders, but when it comes to turf management, shortcuts will not earn you a victory against dollar spot.
What do you do to lessen your dollar spot pressure? Join the conversation on Twitter:
About the author
Adam Garr is a Syngenta Turf & Landscape Territory Manager located in the Midwestern US. You may also follow Adam on Twitter: