What if it happens again?

Features - Agronomics

A late-arriving spring ruined agronomic plans for superintendents in multiple regions last year. Experts offer lessons from the miserable season.

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March 11, 2019

A cold start to the spring of 2018 caused severe problems to roots in multiple agronomic regions.
© dr. lee miller/ university of Missouri

At the risk of making Midwest, Mid-Atlantic and Northeast superintendents cringe in fear, we will recall the chaos caused by the late-arriving spring last year with the aim of helping to prevent the chaos if it happens in 2019.

“One of the biggest issues we saw was uneven growth of the turf caused by the cold weather late into spring and the delayed warm-up,” USGA Green Section director of education Adam Moeller says. “This uneven growth on greens resulted in bumpy conditions in many cases.” Complicating matters, Moeller adds, was a wet summer followed the cold spring, affecting turf on courses that didn’t aerate in the spring.

“The cold spring led some superintendents to not aerate as usual or go to a smaller tine size so that the turf wouldn’t take as long to recover,” Moeller says. “As the year turned out, it would have been better if folks that didn’t aerate had pulled the trigger to some degree in the spring, at least with smaller tines. Without aeration, rooting was shallow and superintendents missed an opportunity to improve the soil oxygen diffusion rates within the upper rootzone profile. This ultimately left putting green turf roots more vulnerable to the stress from the persistently wet and hot conditions later in summer. But supers had decisions to make and they could not have known what the summer would bring.”

Ah, if we only had a crystal ball.

Dr. Cale Bigelow of Purdue University reports the Lower Midwest had one of the coldest Aprils and warmest Mays on record, which led to slow grass green-up and a “disadvantaged” cool-season turf compared to those “pesky warm-season summer annuals.” This produced much more pressure from all summer annuals.

“As far as insects, we had lots of activity, but ‘normal’ damage, likely due to the abundant moisture,” Bigelow says. “Disease in mid-to-late summer, particularly dollar spot was very problematic for many, as were other diseases associated with very wet soil conditions.” Probably the most concerning issue from 2018, he adds, was widespread damage associated with what one of his mentors, Dr. Peter Dernoeden, referred to as “Hot-Wet-Stinky Soils.” Says Bigelow, “Scald and wet-wilt, were very big issues, especially where soil drainage was lacking and/or a heavy thatch/organic layer was present.”

A late warm-up can negatively affect both cool- and warm-season turfgrasses, says John Daniels, a USGA Green Section Central Region agronomist. A late warm-up will delay recovery from winter injury and is particularly a cause for concern for cool-season turf in the event it is followed by rapid increase in temperature.

Shade from trees can severely hinder turfgrass recovery and is especially troublesome when mild temperatures persist late into the spring.
© john Daniels

Managing turf and personal stress

The University of Tennessee’s Dr. Brandon Horvath offers multiple steps to avoiding the difficulties of 2018.

“Having a stress management plan can go a long way, meaning that one should seriously think about how we water; usually too much,” he says. Using a moisture meter, he adds, can help superintendents maintain moisture in greens at an optimum amount about halfway between wilt point and field capacity. “Doing this will help reduce the need to constantly hand water, and improve conditions daily, while reducing stress from overwatering,” he says.

Anther key part of stress management should be a mowing height and rolling plan that uses the current conditions to alter how turf is managed to reduce stress. Horvath somewhat jokingly adds, “Remember the line from the movie `Spy Game,’ where Robert Redford says, ‘When did Noah build the Ark, Gladys? BEFORE the flood.’ Having a plan in place before the stress hits will help you when it does hit.”

“Fungicides don’t solve all the problems,” Horvath adds. “Remember the cultural practices from my first tip will help you manage stresses better than what is in a jug. Fungicides should only be used when indicated by the presence of disease, and/or weather conditions that will result in disease (thus, a preventative approach).”

Horvath also advises superintendents to invest in weather management technology. “It isn’t enough to know what is happening in your zip code. Most of the weather offerings from the various websites and companies out there offer zip code-based weather info. You need location-based data to really be confident in your observation of weather. Seek recommendations from your local National Weather Service meteorologists, or check out some upstart companies, like Mesur.io. Monitoring the weather at your location is critical to managing stressful environments.”

Using synthentic mats is a way to protect vulnerable turf during tough spring growing conditions.
© john Daniels

Furthermore, Horvath emphasizes the importance of drainage, adding “anywhere that doesn’t drain like it should just means that area will be a stress spot later.”

Traffic management represents another way to avoid turfgrass stress and damage resulting from less than favorable spring conditions. “Think about the entry and exit points on each hole and green complex, then plan how you’re going to move players around and spread out the traffic to help reduce the impact of stress by foot traffic,” Horvath says.

Hole location management is also a consideration. “Many courses allow the set-up person to place holes wherever or use a 3 to 9 zone management style. There are many technologies out there to manage hole locations and move holes around to spread foot traffic out. Check out StrackaLine or EZ Locator. Both of these companies will help you manage hole locations.”

Finally, properly manage and monitor your team when weather turns tricky. “Take care of yourself and your crew,” Horvath says. “This year has been a breakout year of removing the stigma of taking care of oneself in a stressful industry. I’d echo those comments by saying when stressful conditions hit, it is tremendously important to make sure you plan time for both you and your crew to de-stress and have fun even in the heat of the battle. It is easy to suggest that this is time wasted, but I would argue that under very stressful conditions, this small amount of time away helps to freshen your perspective and improve your well-being.”

Not business as normal

The University of Missouri’s Dr. Lee Miller reports Pythium root rot as the No. 1 biotic disease diagnosed on greens in his region. What to do if this occurs? “Watered in preventative fungicide applications are the obvious, but limiting soil moisture to what the plant is using is another key aspect of management. Stagnant, unused water in the soil column is a precursor for many problems. The use of TDR technology has made the art of dancing the line between too much water and not enough a bit more of a science for many superintendents, but it is only one tool in the bag.”

Adjusting the aerification schedule can help superintendents handle cold spring weather.
© john daniels

Miller recommends sampling soil often with the “trusty” ½-inch soil corer to determine where water goes on a green, and, “every once in a while,” lean on it to view the whole column down to the pea gravel layer. “Take a hard look at greens drainage on historically poor performing greens very early in the spring,” Miller says. “Run water, or go out during a downpour, and make sure water is exiting out of the soil column correctly through the pipes.”

The best way to remove water out of the soil column is “through the plant,” he adds. Consider fan use a bit earlier than just when temperatures soar, but also when high humidity keeps water on the surface. A drier, cooler canopy will result in open stomates that move water, and an overall healthier plant system from leaf to root tip. “Last but not least, regular venting throughout the season will help dry out some of the profile, and facilitate air exchange for root growth,” Miller says.

Don’t be rigid with the fertilization schedule. Instead, fertilize as dictated by temperature. The temptation is to “juice” bentgrass putting greens a little in a late warm-up, but heavy nitrogen applications may turn into a stressor for compromised roots that can’t sustain higher foliar growth. “Slide into a spoonfeeding regime quickly if temperatures rise rapidly,” Miller says. “Additionally, if nitrogen was applied earlier when temperatures were cooler, don’t forget it, since it may release quickly in high temperatures.”

Visually monitoring and promoting turf density is an important aspect of management. This could include adjusting mowing heights – “mow as high as practically possible,” Bigelow says – and judicious use of nitrogen fertilizer as appropriate. Also, be mindful of mechanical damage that could reduce overall vigor and handicap turf entering stressful weather.

Moeller advises collecting clippings from at least one green (a consistent performer), measure and monitor growth. Compare clipping yields with recent cultural practices like nitrogen and PGR apps to understand their impact on turf growth. Also, don’t try to outcompete cool weather with fertilizer applications because it will likely result in a significant growth flush once the turf finally begins to grow more evenly with warmer temperatures. Not only could this likely result in a flush of growth, which negatively impacts playing conditions, it will consume valuable energy reserves the turf needs to survive during summer.

“Probably the worst thing one can do if there is a late warm-up is for turf managers to go about their business like normal,” Daniels says. Turf managers need to avoid focusing on the events on the calendar and instead concentrate on the condition of the turf. “Rushing to complete a particular maintenance practice by a specific date or trying hit a certain green speed right out of the gate can result in damage that last well into summer,” he adds. “Instead, let the condition of the turf dictate the agronomic program.”

Unlike a popular movie, let’s hope there is no sequel to “The Miseries of 2018.” But if the worst-case scenario returns, there are steps to ensure turfgrass comes through in much better shape.