Scouting Report: April 9th
After another bout of unwanted rain, turfgrass conditions are improving and drying out across the area. This week I visited golf courses on the North, West, and South side of Chicago. This picture showcases 007 creeping bentgrass fairways at Ridgemoor Country Club.
On the South side of town, greened up fairways and swollen water features were a familiar site. This undulating and lengthy par 3 at Calumet Country Club will surely test the rusty swings of golf course superintendents in the upcoming April 25th golf outing.
Fortunately, many facilities were able to put in a fairway mow on Monday before the cold rain began.
Widespread rain was prevalent across Illinois early in the week. Many areas received between 1–2 inches of rain. It seems as though most of the recent rainfall has come early in the week and cleared out by the weekend. This most certainly pleases golfers, but this has been a maintenance nightmare for superintendents. Maintenance nightmares and Masters weekend is not the most ideal circumstance.
Over the last 30 days, areas in the northern half of the state have exceeded more than twice the amount of normal precipitation. Conversely, areas in the southeastern portion are running at a 50% deficit. Fortunately, the excess rain in the north is causing more of a maintenance issue, rather than a disease or pest issue. Luckily, precipitation should subside for much of next week.
Increasing sunshine and limited rainfall (coupled with seasonal temperatures) will allow many golf courses to begin a more routine management program. As we look forward to these conditions, lets take a step back and recap what we have seen last week.
Diseases
This is good news/bad news. The bad news is…many areas got hit with the disease yellow patch this week. The good news is…yellow patch shouldn’t be a disease that keeps you up at night. Yellow patch is usually the first disease we see in the spring after episodes of pink snow mold. In most instances, a keen eye should be placed on yellow patch development. Yellow patch is a disease that can both appear quickly, and dissipate quickly.
For much of the state, we are still early to worry about active dollar spot. That being said, early season fungicide applications that target dollar spot should be considered. Early season dollar spot fungicide applications are not necessarily meant to prevent dollar spot in the short term. They are meant delay the onset of disease development in the long term, and to limit the severity of season-long epidemics. From speaking with superintendents, dollar spot remained severe until late into the fall of last season.
Dollar spot that developed late into autumn may provide a fresh inoculum source for spring infection. As we consider our management approach for this common disease, I’d like to highlight a dependable resource for determining which fungicide is most appropriate for an array of diseases.
The classic rendition of Drs. Paul Vincelli’s and Gregg Munshaw’s Chemical Control of Turfgrass Diseases 2017 has been updated. It has been updated with the contribution of the Rutgers turf pathologist Dr. Bruce Clark. This resource describes important disease control management considerations and provides a fungicide efficacy ranking for most of the chemistries on the market.
Beyond dollar spot and yellow patch, other diseases that attack beneath the ground should be considered. Fairy ring, patch diseases (summer patch & take-all), and Pythium root diseases.
Fairy ring can be active over a wide range of soil temperatures. However, as daily average soil temperatures creep into the mid-50’s, it’s time to consider preventive control. Fungicides applied for fairy ring control should be delivered at a high spray rate volume (2–4 gal/M). Some research also suggests that a soil surfactant be added into the spray mixture. Post application also improves fungicide performance.
Take-all patch is also active over a similar soil temperature range (55–65 degrees F) when conditions are wet. Golf courses that have recently fumigated and re-grassed putting green surfaces are at the most risk. Take-all is primarily a disease on creeping bentgrass. If you manage annual bluegrass putting greens, you may begin to worry about summer patch. The summer patch pathogen is active when soil temperatures are between 65–85 degrees F.
With the tremendous amount of rain throughout the area, those with a known history of Pythium root rot should consider a fungicide application. Pythium root rot is active over a wide temperature range and relies on saturated soil conditions. For those concerned about fairy ring, take-all patch, summer patch, and Pythium root rot….Consider a drench of a strobilurin fungicide on putting greens. Many strobilurin fungicides including pyraclostrobin and azoxystrobin are labelled for these aforementioned soilborne diseases. Remember, it is very important to water in these types of fungicide applications.
Moss
Moss has been problematic on lower height of cut areas, such as putting greens. It appears that moss has taken advantage of spring rains across the region.
Moss is almost taylor made for occupying putting green space that is deficient in sunlight and available nutrients (do you see what I did there?). If left untreated and neglected, moss can proliferate and spread with the production reproductive structures.
Moss control can be accomplished with both physical and chemical methods. Physical strategies involves plugging out existing moss populations. Chemical control can be achieved with repeated applications of the active ingredient carfentrazone.
It should be noted that applications of carfentrazone on creeping bentgrass putting greens are most appropriate when daily maximum temperatures are below 85 degrees F. The CDGA Turfgrass Programs will be conducting a moss experiment this year.
Dr. Zane Raudenbush (Ohio State) recently discussed strategies for moss control in a Q&A article in Golfdom.
Check plots
The last topic in this report is the use of check plots. These areas can be extremely valuable in determining the effectiveness of our management practices. I encourage those to use check plots whenever possible. As a pathologist, the nontreated control tends to be among my favorite plots.
Many golf courses can create there own check plots by simply placing a piece of plywood on-top of the turf just prior to an application. Check plots are also great tools to educate your members to showcase why your practices are so important. If your facility will be using check plots, I encourage you to send pictures to me via twitter (@TurfResearch) or email (jbenelli@CDGA.org). In time, I would like to include a ‘check plot of the week’ in our weekly reports.
