Tennessee Turfgrass - August / September 2012

August/September 2012

The Official Publication of the Tennessee Turfgrass Association, the Tennessee Valley Sports Turf Managers Association and the Tennessee Golf Course Superintendents Association

Aerification of Heavy Clay Soils

Managing Pesticide Resistance

in Golf Course Turfgrass

Plus, Sneak Preview of the

UT Turf & Ornamental Field Day —

September 13 in Knoxville

The Official Publication of the Tennessee Turfgrass Association, Tennessee Valley Sports Turf Managers Association and the Tennessee Golf Course Superintendents Association

TABLE OF CONTENTS

12

August/September 2012

FEATURED ARTICLES

16

Upcoming Event — University of Tennessee Turf & Ornamental Field Day, September 13 in Knoxville

18

Cover Story — Aerification of Heavy Clay Soils

22

Turf Talk — Managing Pesticide Resistance in Golf Course Turfgrass

16

DEPARTMENTS From the TTA President, Bob McCurdy

6

From the TVSTMA President, Wayne Treadway

8

From the MAGCSA President, Ben Haddad

10

News from TTA — Call for Nominations

12

Calendar of Events

25

Advertiser Index

26

22

From the TTA President Bob McCurdy

Don’t Make Excuses —

Be There, September 13!

Many

years ago, when I was in high school, the long-time Ag instructor retired. The following year, the attitudes of the students in that curriculum became defiant and rowdy, quickly overwhelming the substitute teacher. She quit and was replaced by a retired soil and water engineer. By Christmas, he had decided we were unmanageable. Next, the principal brought in an experienced instructor with a reputation for handling trouble. He stayed about a month. By this time, we had become seasoned delinquents. The Ag students had declared themselves independent of any teacher or discipline, and it was working — or so we thought.

One Monday morning, we walked into class to find another new instructor. He was 30 years old, lean and solidly built, with arms that any bodybuilder would envy. He didn’t have a neck. His head just sat down between his shoulders, and his cold, dark eyes had seen two tours in Vietnam.

Mr. Will spoke to the class and told us how impressed he was with our reputation for running off teachers. Then, he talked to us about choices and how important they are. He laid out our options for the rest of the year. They were simple. We could get involved with the program, or we could sit quietly in the rear of the room and finish the semester. Emphasis on quietly. He promised that if we caused any trouble, he would inflict serious injury upon us, and we believed him.

Mr. Will told us what he expected from us and detailed a plan of how we were going to achieve our goals. He urged us to never stop learning. And one of his most famous sayings was “Don’t make excuses.”

The plan worked, and the program was soon recognized as one of success. Mr. Will never had to hurt anyone, and I was surprised that the hardcore troublemakers were soon part of his team.

6

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

What’s the lesson? As turf managers, we need to understand what is expected of us and how important our choices are.

We must also convey this message to our employees. To do this, we should continuously be learning. Your board, your boss or your customers (or whomever you are responsible to) expect you to know as much as you can about turf management and the turfgrass industry.

The UT Turf Team is preparing a field day that will help us reach these goals.

I challenge each of you to meet me in Knoxville on Thursday, September 13.

Take a minute to put the date into your calendar. And as Mr. Will would say, “Don’t make excuses.”

Bob McCurdy 2012–2013 TTA President

From the TVST M A President Wayne Treadway

Thank You,

Dr. Samples I

want to take this opportunity to thank a person who has meant so much to me in turf management. I became interested in turf management in Middle Tennessee when the little league club in Stewart County had to build baseball and softball fields. I have a degree in Plant and Soil Science, but I had worked as a soil scientist for five years. Turf management was not my expertise.

The local Extension office scheduled a meeting for me with Dr. Tom Samples. I had met Dr. Samples at The University of Tennessee, but I was more familiar with the UT professors in the Plant and Soil Science Department (the four S’s: Skold, Swindell, Smith and Springer — only older UT graduates will know them). When I explained to Dr. Samples what we wanted to construct, he gave us great advice. His best quality is that he never criticizes. If I exposed my ignorance, he would always answer, “Have you ever considered this variety?” or “You might consider doing this…” I’m sure he was thinking, “How dumb is this guy?”

Over the years, I have attended many meetings and field days. Dr. Samples has always been encouraging. Even today when I ask an ignorant question or make a dumb statement, he never criticizes.

The department of turfgrass management at UT has grown. I think those of us in sports-turf management owe a great deal of gratitude to Dr. Tom Samples. I also think that The University of Tennessee sportsturf management program is the best in the world.

If you have attended the field days and seen the research facility, I believe that you would agree. Dr. Samples and his colleagues have contributed greatly to the facility.

8

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

Another reason I respect Dr. Samples’ greatness is the respect that his colleagues at other universities and in the industry show him. All the leaders in the industry know Dr. Samples.

My knowledge of turf management has greatly increased from knowing Dr. Samples. I just wanted to take this opportunity to express my gratitude to him.

Throughout life, one meets very few great people. Dr. Samples is at the top of my list. I hope my colleagues in the sportsturf industry will join me in saying, “Thank you, Dr. Samples!”

Wayne Treadway 2012 TVSTMA President

From the M AGCSA President Ben Haddad

A Busy Year for MAGCSA The

Memphis Area Golf Course Superintendent’s Association has had a great season thus far this year. In April, we heard an awesome talk on sun safety and skin-cancer prevention. We followed that up in May with an outstanding workday at the First Tee of Memphis (a charitable organization that offers youngsters, primarily minority and inner-city youth, the opportunity to participate in our sport). We accomplished many needed projects, including trenching power wire to their irrigation satellites, fertilizing 12 acres of turf and aerifying and topdressing their greens.

The MAGCSA board wants to thank all those who attended and donated equipment, fertilizer and time to give back to the community and to the game that we love. We are

eager to continue our partnership with this great organization that is in the business of molding the lives of children through golf.

We are looking forward to our annual Scholarship and Research Tournament hosted by Doug Estes at Germantown Country Club on September 13. We are pleased to announce that we have renamed it “The Scott McNeer Scholarship and Research Tournament.” This tournament has not only provided needed funding to many turf students, but it also allows us to make considerable donations to local universities for research in our field. I’m sure that Scott would be proud to have his name associated with such a great tournament.

Also, please join us on October 15 when defending champion Casey Nerren will host the 2nd Annual Bushwood Classic at Stonebridge Golf Club to determine who will be honored to hoist the Carl Spangler trophy for the 2012 MAGCSA season. Our season will end up on November 13 at Cherokee Golf Club where we will have a panel discussion on the latest trends and topics relating to our profession.

I look forward to seeing you soon!

Ben Haddad 2012 MAGCSA President

10

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

The Official Publication of the Tennessee Turfgrass Association, the Tennessee Valley Sports Turf Managers Association and the Tennessee Golf Course Superintendents Association

Tennessee Turfgrass is the official publication of The Tennessee Turfgrass Association 400 Franklin Road Franklin, Tennessee 37069 (615) 591-8286 tnturfgrassassn@aol.com www.ttaonline.org Published by Leading Edge Communications, LLC 206 Bridge Street Franklin, Tennessee 37064 (615) 790-3718 Fax (615) 794-4524 Email: info@leadingedge communications.com Editor Mr. Bill Marbet TTA OFFICERS President Bob McCurdy McCurdy Sod Farms (731) 692-3515 Vice President Paul Carter Bear Trace at Harrison Bay (423) 344-6374 Secretary/Treasurer Theo Lankford Clarkland Sports Fields (615) 799-8664 Past President Jay Willis Glen Eagle Golf Course (901) 508-1986 Executive Secretary Jim Uden Tennessee Turfgrass Assn.

(615) 591-8286 TTA 2012 BOARD OF DIRECTORS Bob Elliott Thomas Garner Cal Hill Joe Hill Robert A. Main, CGCS Bill Marbet Mitch Parker Jason Pooler Jason Sanderson Chris Simon Sean VanHoose Doug Ward TTA ADVISORY MEMBERS OF THE BOARD Bill Blackburn Lynn Ray Jeff Rumph Dr. Tom Samples Dr. Dennis Shepard Dr. John Sorochan

NEWS FROM T HE TTA

Who Would You Select As

TTA Professional of the Year?

Do

you know an outstanding turfgrass professional in Tennessee who deserves the recognition of his or her peers? If so, now’s the time to let the TTA know who you believe should receive one of the association’s highest honors — the TTA Professional of the Year Award — at the TTA Annual Conference and Tradeshow this coming January.

Please take a moment to mail in the nomination form below. Nominees will be reviewed by the TTA Awards & Scholarship Committee, which will make a recommendation for approval by the TTA Board of Directors. Nominations must be postmarked no later than October 28, 2012.

TTA Professional of the Year — Nomination Form —

?

Person Being Nominated:_________________________________________________ Person Making the Nomination:____________________________________________ Reason for Nomination:__________________________________________________ _____________________________________________________________________

Nominations must be postmarked no later than October 28, 2012.

_____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________

12

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

Please send entries to: TTA Awards Program Paul L. Carter 8919 Harrison Bay Road Harrison, TN 37341 (423) 344-6374 paul.carter@tn.gov

2013 TTA Environmental Stewardship Award

The

Tennessee Turfgrass Association (TTA) would like to recognize outstanding contributions by individuals, organizations, businesses, educational institutions and agencies for successful projects or activities designed to improve the environment through wildlife-habitat preservation, water and resource conservation and reduction, and educational outreach. Through our Environmental Stewardship Award, we can create greater knowledge and awareness of environmental and conservation practices and projects by members of TTA who have demonstrated outstanding contributions to environmental protection and improvement.

All entry materials must be submitted according to the procedures outlined below. The TTA Awards Committee, consisting of highly regarded TTA professionals, will independently judge the entries. The winner will be notified in November 2012, and the Environmental Stewardship Award will be presented at the TTA Awards Ceremony at the 2013 TTA Annual Conference.

Criteria for Consideration The following criteria must be met to submit for the TTA Environmental Stewardship Award: • Property must be fully managed by an active and in-goodstanding member of TTA. • Property must have been in use for at least two years.

• All materials must be submitted in one application packet.

How to Apply In order to be considered for the TTA Environmental Stewardship Award, the following materials must be submitted to the TTA Awards Committee no later than October 28, 2012: 1. A type-written essay, no longer than one page in length, that includes the following information: • Name and location of the property • Name and contact information of the person in charge of the property

• A detailed account of how the property has improved, protected and/or promoted environmental protection and conservation. The Awards Committee is looking for unique and innovative ways in which individuals have changed practices or programs on the property to either reduce the use of (and conserve) natural resources, improved or created natural habitats, or encouraged environmental awareness through outreach and education.

2. A minimum of two original photographs of the property, with captions.

The committee encourages creative photos that show how actions and activities on the property have improved or benefitted the environment. Documentation of environmental certifications from Audubon International, The Groundwater Foundation or the Environmental Institute for Golf is encouraged. Materials prepared for education and outreach, as well as any published articles or case studies promoting environmental stewardship, are also encouraged. Photos of wildlife, unless unique in nature, should not be submitted.

All entries must be postmarked no later than October 28, 2012.

Please send entries to: TTA Awards Program Paul L. Carter 8919 Harrison Bay Road • Harrison, TN 37341 (423) 344-6374 • paul.carter@tn.gov

TENNESSEE TURFGRASS ASSOCIATION • TENNESSEE VALLEY SPORTS TURF MANAGERS ASSOCIATION • Tennessee Golf Course Superintendents Association

13

NEWS FROM T HE TTA

2013 TTA Golf Course of the Year Award

The

Tennessee Turfgrass Association (TTA) recognizes that golf course superintendents make personal and professional contributions to our industry and to the organizations/golfers that they serve. Therefore, the TTA would like to distinguish golf courses across the state with the Golf Course of the Year Program. Through this program, we are able to greatly further one main element of our mission: To gain acknowledgement for the professionalism of our members.

This year, based on the results of the judging, the following awards may be presented at the TTA Awards Ceremony at the TTA Annual Conference in January 2013: • TTA Private Golf Course of the Year • TTA Public Golf Course of the Year All entry materials must be submitted according to the procedures outlined below. The TTA Awards Committee, consisting of highly regarded TTA professionals, will independently judge the entries. Winners will be notified in November 2012.

Criteria for Consideration The following criteria must be met to submit for the TTA Golf Course of the Year Awards Program: • The golf course must have had two full seasons of play.

• All materials must be submitted in one application packet.

How to Apply

that you feel the Awards Committee should know about why this golf course should be recognized as Golf Course of the Year. Include anything unusual or new that you have done to overcome these challenges. The Awards Committee is looking for innovative solutions to turfgrass-management problems.

2. A minimum of two original photographs of the golf course, with captions.

The committee encourages creative photos — photos that show the versatility of the course, display unique characteristics of the course and show the crew’s unique talents. Focus on issues specific to your golf course that tell the story (issues such as drainage, environmental stewardship, weather, etc.). Do not simply provide “beauty shots” of the course, as they do not reflect the true struggles and triumphs of you and your crew.

All entries must be postmarked no later than October 28, 2012.

Please send entries to: TTA Awards Program Paul L. Carter 8919 Harrison Bay Road • Harrison, TN 37341 (423) 344-6374 • paul.carter@tn.gov

In order to be considered for the TTA Golf Course of the Year Awards Program, the following materials must be submitted to the TTA Awards Committee no later than October 28, 2012: 1. A type-written essay, no longer than one page in length, that includes the following information: • Name and location of the golf course • Level of play (i.e., private, public) • Name and contact information of the golf course superintendent • An explanation any special challenges faced by you and/or your team. These challenges may include funding, lack of labor, weather, drought, event preparations/conversions or anything else

14

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

2013 TTA Sports Field of the Year Award

The

Tennessee Turfgrass Association (TTA) recognizes that sports field managers make personal and professional contributions to our industry and to the organizations/athletes that they serve. Therefore, the TTA would like to distinguish athletic fields across the state with the Sports Field of the Year Program. Through this program, we are able to greatly further one main element of our mission: To gain acknowledgement for the professionalism of our members.

This year, based on the results of the judging, the following awards may be presented at the TTA Awards Ceremony at the TTA Annual Conference in January 2013: • TTA Professional Sports Field of the Year • TTA Collegiate Sports Field of the Year • TTA Public High School Sports Field of the Year • TTA Private High School Sports Field of the Year • TTA Municipal Sports Field of the Year All entry materials must be submitted according to the procedures outlined below. The TTA Awards Committee, consisting of highly regarded TTA professionals, will independently judge the entries. Winners will be notified in November 2012.

Criteria for Consideration The following criteria must be met to submit for the TTA Sports Field of the Year Awards Program: • For the purposes of this program, a “field” constitutes ONE natural grass playing surface.

• A field must have had two full seasons of play (may be concurrent — i.e., football and soccer on the same field in the fall, etc.).

• All materials must be submitted in one application packet.

• Name and contact information of the head turf manager • An explanation any special challenges faced by you and/ or your team. These challenges may include funding, lack of labor, weather, drought, event preparations/conversions or anything else that you feel the Awards Committee should know about why this sports field should be recognized as Field of the Year. Include anything unusual or new that you have done to overcome these challenges. The Awards Committee is looking for innovative solutions to playing-surface problems.

2. A minimum of two original photographs of the field, with captions.

The committee encourages creative photos — photos that show the versatility of the field, display unique characteristics of the field and show the unique talents of the crew. Focus on issues specific to your field that tell the story (issues such as drainage, environmental stewardship, weather, etc.). Do not simply provide “beauty shots” of your field, as they do not reflect the true struggles and triumphs of you and your crew. T

All entries must be postmarked no later than October 28, 2012.

Please send entries to: TTA Awards Program Paul L. Carter 8919 Harrison Bay Road • Harrison, TN 37341 (423) 344-6374 • paul.carter@tn.gov

How to Apply In order to be considered for the TTA Sports Field of the Year Awards Program, the following materials must be submitted to the TTA Awards Committee no later than October 28, 2012: 1. A type-written essay, no longer than one page in length, that includes the following information: • Name and location of the field • Level of play (i.e., professional, collegiate, high school – public, high school – private, municipal)

TENNESSEE TURFGRASS ASSOCIATION • TENNESSEE VALLEY SPORTS TURF MANAGERS ASSOCIATION • Tennessee Golf Course Superintendents Association

15

Upcoming Event University of Tennessee

Turf & Ornamental Field Day September 13 in Knoxville

The

2012 Annual UT Turf & Ornamental Field Day will be held on September 13 at the East Tennessee Research and Education Center in Knoxville, TN. One of the largest and fastest-growing field day events in the United States, the program features current research on managing weed, disease and insect pests of warmand cool-season turfgrasses, as well as strategies for maximizing the quality of athletic-field playing surfaces.

What’s new in 2012?

By popular demand, the program has been expanded to feature three breakout sessions on managing ornamental plants in landscape settings. Information on weed, disease and insect pests will be presented, in addition to content on plant growth regulators (PGRs) and electronic tools for managing pest activity. A full copy of the entire Field Day program can be accessed at htpp://tennesseeturfgrassweeds.org.

Live demonstrations will be held on overseeding bermudagrass athletic fields and mowing practices for creeping bentgrass putting greens. Also, attendees will be asked in an interactive quiz to identify mistakes made in managing turfgrass and ornamental plantings.

Golf Course Superintendents Association of America (GCSAA) continuing education credits will also be available.

Registration Discounted pre-registration rates are available for businesses registering multiple employees. Additional employees of a single business can be registered at a 50% discount!

How to register There are several ways to register for the 2012 UT Turf & Ornamental Field Day. We encourage everyone to pre-register in

Credits Attendees will earn 5 pesticide re-certification credits in categories C3, C10, C12.

16

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

order to take advantage of reduced fees and guarantee themselves lunch and a copy of the proceedings booklet. The deadline to pre-register is August 30, 2012.

• Online — with a credit card (at the website below) • Via mail — download and return the pre-registration form • On-site registration on the day of the event. Note that on-site registration costs are higher than pre-registration and do not include a guaranteed lunch or proceedings booklet. T

htpp://tennesseeturfgrassweeds.org

Cover St ory

Aerification of Heavy Clay Soils

By Charles H. Peacock, Ph.D., NC State University

1

2

Above: Photo 1. Intact soil cores from an aerification. Photo 2. A recently aerated turf surface, showing the distance between coring holes.

A

lmost forty years ago, Dr. James Beard published his now well-known textbook titled Turfgrass: Science and Culture. This classic work combined the science behind what was known, and not known, at that time about techniques in turfgrass management with an understanding of how real-life application of management techniques should be used. It set the stage for prioritizing turfgrass-research programs and brought a focus as to how these must be structured to fill the gaps in knowledge and application.

This is important because Beard pointed out that once we establish a turfgrass area, we expect it to be usable for many years (if not decades) without a need for major renovation. With use, however, turf areas are subject to wear and compaction, especially under specific soil, climatic and traffic conditions.

This adversely affects soil properties as well as the grass plant itself by limiting the root system. In order to optimize conditions for turfgrass growth so that recovery from wear can be rapid and the turf is most resistant to pest pressure, then cultivation of the soil profile must be included in a sound turf-management program.

The importance of aeration Cultivation is defined as the tilling of the soil profile without damaging the turf so severely it cannot rapidly recover. This requires specialized equipment and techniques. Of the cultivation techniques available, coring (often called aeration or aerification) is most often used.

18

The effects of compacted soil on the ability of turfgrass plants to grow include the following: • Increased bulk density, resulting in decreased gas exchange (decreased oxygen levels).

• Roots have trouble penetrating the soil.

• Greater surface runoff.

• Greater heat conductivity.

The goal of a coring or aeration process is to improve the exchange of air and water between the atmosphere and soil (see Table 1). Air exchange is important since the root system requires oxygen in order to properly function, while allowing excess carbon dioxide (which builds up from the respiration process) to Table 1. Benefits of aerification.

• Decreases bulk density (reduces compaction).

• Increases gas exchange (for better rooting).

• Improves water infiltration and reduces runoff.

•O pens the soil to allow incorporation of materials such as fertilizers or lime.

• Enhances seed-to-soil contact (during seeding).

• Removes thatch.

• Penetrates compacted subsurface layers.

• Prepares an existing turf for renovation.

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

3

4

Above: Photo 3. A core cultivator in operation. Photo 4. Close-up of a set of hollow coring tines.

escape, thus preventing damage to the root system cells. Water exchange is important because improvement of water infiltration and percolation in the soil profile improves the efficiency of rainfall capture, thus reducing the irrigation requirement.

Deep coring can also be beneficial in breaking up layering of different soil textures to improve drainage and prevent waterlogged soils in the root zone. An additional effect is the severing of rhizomes and stolons, which forces buds on these secondary lateral stems to initiate new growth, resulting in an increase in turf density.

Aeration frequency The philosophy behind the need for an aeration process has changed over the years. At one time, it was recommended that this technique be used only as needed to correct soil compaction and to help with water penetration into localized dry spots, which are more of a problem on sandy soils. As management programs have evolved, the need for aeration on a regular basis (even on lower-management-level turf areas such as home lawns) has become more apparent.

Traffic of any kind — such as people, animals and, especially, equipment — can create compaction problems. This is particularly true in the Southeast, where our annual rainfall creates soil conditions that are conducive to compaction. Soil is most prone to compaction when it is at what is known as field capacity, or that point after rain or irrigation when the larger soil pores have drained due to gravity, but there is good soil moisture for optimum turf growth. Water acts as a lubricant around the soil particles and, when pressure is applied, the soil particles are prone to move, reducing the pore space and creating compaction.

To maximize opportunities for achieving the desired effects, aeration should be timed to a period of active turfgrass growth and when other management factors are considered. For example, cool-season grasses have two growth cycles in the transition zone as to optimum temperatures — spring and fall. However, the recommendation for aeration of these grasses is that fall is a more favorable time since the turf will recover from any damage by the process. There is also less pressure from annual grassy weeds (such as crabgrass and goosegrass) at this time of year. Additionally, if the aeration procedure is conducted in conjunction with the application of seed to improve stand density (overseeding or interseeding), the process can improve seed-to-soil contact, which is crucial for successful germination and growth of the new seed.

Warm-season grasses can be aerated anytime there is active growth, but preferably in early summer to allow varieties with a slower growth rate the most time to recover prior to fall dormancy.

Hollow-tine versus solid-tine aeration and problems with heavy clay soils By definition, true compaction relief requires that the mass/ volume relationship change. In other words, a core or plug of soil must be removed from the soil profile to allow lateral expansion of the soil, thus reducing compaction.

This is best accomplished by using a hollow-tine coring machine. During this aerification process, soil cores that range from 0.25" to 1" in diameter and 3" to 16" in depth are removed.

While it would be difficult to core too deeply in the profile, most

TENNESSEE TURFGRASS ASSOCIATION • TENNESSEE VALLEY SPORTS TURF MANAGERS ASSOCIATION • Tennessee Golf Course Superintendents Association

19

5

7

6

8

9

Above: Photo 5. Coring holes in the turf after a hollow-tine aeration. Photo 6. A Verti-Drain coring machine with solid tines.

Photo 7. A walk-behind aerator used for small turf areas such as home lawns. Photo 8. Close-up of a set of hollow coring tines set on a rotating disc. Photo 9. Close-up of an aeration core.

aerifying units have a limited penetration of only 2" to 4". These include those that operate on a vertical motion-type core cultivator and those with tines mounted on disks or on a drum. Deeptine aerifiers can make holes 6" to 16" deep, but these are most often used on specialized areas, such as athletic fields or golf courses. The cores removed in the process can be picked up on closely mown turf, such as golf course putting greens, but on areas where the grass is mowed at higher heights, they are typically left on the turf and break up over time. The amount of surface area affected by core aerification depends on tine diameter and spacing (Table 2).

On heavy textured clay soils, it is often difficult to get penetration more than several inches deep. Soil moisture plays a key role in a core aerator’s ability to penetrate the profile. For optimum results, the soil should be moist, but not overly wet or saturated. This ensures the removal of an intact plug from the aerification hole.

In some instances, on heavy textured clay soils (especially if they are intensely compacted where soil strength often impedes penetration), solid tines are used on the core aerator. This allows for greater penetration depth in the soil profile, but actually creates compaction around the penetration site. However, although it does improve air and water exchange, it does not relieve compaction.

• Controlling traffic. If possible, try to limit traffic or disperse it more uniformly over the turf area.

• Avoiding traffic on wet soil. Allow as much time as possible between the last rainfall or irrigation to allow the soil to dry and not be as prone to compaction.

• Enlarging turf areas to distribute play or traffic.

• Establishing turf on sand-based root zones. Sandy root zone mixes better resist compaction, thus reducing the probability of compaction Once the soil on which the turf is grown becomes compacted, it is difficult to bring it back completely where there are no problems. Core cultivation or aerification can help, but proper site preparation prior to establishment and then managing for preventing compaction are preferable. T Table 2. Percent of area affected by tine diameter and spacing.

Tine Spacing

Tine Diameter (in inches)

2" X 2"

2" X 4"

4" X 6"

1/4"

1.2%

0.6%

0.2%

3/8"

2.8%

1.4%

0.5%

1/2"

4.9%

2.5%

0.8%

Managing compaction

5/8"

7.7%

3.8%

1.3%

While core cultivation or aerification can be used to alleviate problems caused by compaction, other considerations for compaction relief include the following:

3/4"

11.0%

5.5%

1.8%

1"

19.6%

9.8%

3.3%

20

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

Turf T alk

Managing Pesticide Resistance in Golf Course Turfgrass

By Kyle Miller, Senior Technical Specialist, BASF Professional Turf & Ornamentals

G

olf course superintendents are prudent stewards of proper pesticide use, but pesticide resistance can confuse even seasoned pros. While seemingly unpredictable, resistance is manageable once its principles are better grasped and preventative best practices are put in place. For superintendents, understanding resistance realities improves the health of turfgrass and maximizes pesticide investments.

Pest pressure and resistance realities Healthy turfgrass can be difficult to sustain for extended periods of time, even under the best conditions. The fact is, the threat of pests is ever-present. Pests, including diseases, weeds and insects, constantly threaten turfgrass.

For example, the classic “Disease Triangle” illustrates how a host plant growing in a suitable environment along with an infectious pest is likely to result in a 22

Figure 1. The Disease Pyramid

Host Plant

Induced Stress – Human Influences Suitable Environment

Infectious Pest

disease infection. The triangle refers to disease, but its principle also explains weed and insect infestations. The “Disease Pyramid” expands on the “Disease Triangle” by adding environmental and human-induced stresses, such as mowing

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

height, altered fertility (excessive or lean) or plant growth regulator use, any of which can subject turfgrass to even more pest pressure. All of these factors play an integral part in managing pests and pest resistance.

It is important to remember that while pesticides are used to control pests, pesticides do not change the pest — they change only the pest population structure.

Resistance does not stem from a mutation induced by pesticide applications, but rather is naturally inherent in each disease pathogen’s biology. Pesticide resistance can be monogenic, conferred by one gene (for example, benomyl), or polygenic, conferred by more genes (for example, DMI fungicides). With disease, for instance, the level of naturally occurring pest resistance varies among any population of fungi, bacteria and mold species.

This means that not every individual within a specific population structure can be controlled. Different individuals within the population contain different levels of tolerance or susceptibility. Resistant characteristics surface when the repeated, uninterrupted use of the same pesticide mode-of-action eradicates a portion of the pest population whose genetic traits were susceptible to that particular modeof-action. Since not every pest within a given population can be controlled, some pests with resistant (or tolerant) characteristics survive.

Then, the surviving pests that carry resistant genes reproduce, bringing to life a new population that exhibits genetic traits not affected by the chemistry that controlled their susceptible ancestors.

This “survival of the fittest” biology creates pest populations that can evolve beyond the control of available pesticide chemistries.

So, if the same mode-of-action is repeatedly used on a population of pests, it will eventually lose effectiveness because the susceptible pests it once controlled are no longer predominant in the population. What we see here is essentially a genetic shift — from susceptibility to resistance Low-resistance levels can occur without complete loss of efficacy, making it difficult to predict an onslaught of resistant pests. Resistant subpopulations must reach a sufficient level of economic importance in order to compromise performance and become immune to a mode-of-action.

This performance compromise or genetic shift usually takes place over a long period

NEWS FROM T HE TTA of time, often years. Unfortunately, though, once resistance develops to a certain pesticide, all products with the same modeof-action are affected.

Resistance risks The last thing golf course superintendents want to do is fuel the creation of an impervious pest population on their courses. Pesticides should to be selected and applied responsibly in order to avoid resistance and sustain efficacy.

The risk of overusing current pesticide products is compounded because only a limited number of basic manufacturers, such as BASF, are investing in new chemistries that control pests using new modesof-action. Pesticide developments are dwindling due to the high cost of research and development and intense registration and regulatory processes.

In fact, a recent CropLife America study cites a nearly 40% increase in investment expenditure over the past decade in the discovery, development and registration of new pest- and disease-control products in the U.S. and Europe. Bringing a new product to market reached an average of $256 million per product in 2005–2008, and the number of products actually mak-

ing it through the research and development stages to market introduction declined from four in 1995 to only 1.3 in 2005–2008.

Product stewardship is critical to sustaining a mode-of-action’s vitality in the market. Chemical manufacturers and golf course superintendents must work together to implement best practices that prevent resistance and support investments in future pest-control products that serve superintendents’ evolving turfgrass protection needs.

Pesticide selection and rotation Growers should work to use pesticides as a last line of defense against pests. It is important to implement an integrated pest-management plan that brings pesticides into play only when the viable threat or presence of pests reaches an economically important threshold.

When controlling diseases, for example, knowing the benefits and effects of a diverse range of fungicide products is important because relying on a single product or type of fungicide can spur the development of areas that resist fungi-

Figure 2. Illustration of “survival of the fittest” biology, which can create pest populations that evolve beyond the control of available pesticide chemistries.

This transformation usually takes place after numerous, repeated exposures to a specific mode-of-action. This population shift may take years reach the level of immunity. Note: the blue represents a pesticide applied to the existing population.

Initial Population

Resistant Population

Reproduction Naturally occurring resistant individual Survivor Population

24

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

cides — an increasingly common trait among fungal diseases.

When using pesticides, follow these resistance-management tips: • Instead of applying pesticides on a calendar schedule, monitor growing and environmental conditions to determine when chemical controls are imperative.

• Identify chemistries proven to be “at risk” for resistance in your pesticide shed, to avoid any confusion between similar chemistries with different product names. For example, fungicides containing benzimidazole, dicarboximide, phenylamide and strobilurins utilize just one mode-of-action and are considered “at risk” for resistance.

• When possible, limit the use of “at-riskfor-resistance” pesticide chemistries, or consider tank-mixing them with a “lowrisk-for-resistance” product. Combination products containing two or more modes-of-action are good alternatives to products with a singular chemistry that may have proven successful in past rotations.

• Rotate pesticides’ modes-of-action after one to two consecutive applications, to avoid prolonged disease exposure to one mode-of-action. Rotation exposes the infectious pest population to multiple, unique modes-of-action and reduces the chance for resistance development to any one specific mode-of-action.

• Maintain a log of the effectiveness of pesticide use against the prevalent pests you face. If you suspect resistance, alert your Extension office or the manufacturer’s technical specialists.

For more information on disease control and healthy plants, visit www.betterplants. basf.us and www.basfturftalk.com, follow our Twitter at www.twitter.com/ basfturf_us, or contact Kyle Miller at kyle.miller@basf.com. T

Calendar of Events September 11

MTGCSA Meeting

McCabe Golf Course • Nashville, TN

September 13

UT Turfgrass Field Day

University of Tennessee • Knoxville, TN

September 13

Scott McNeer Scholarship & Research Tournament

Germantown C.C. • Germantown, TN

October 15

MAGCSA 2nd Annual Bushwood Classic

Stonebridge Golf Club • Lakeland, TN

October 17

MTGCSA Scholarship & Research Tournament Vanderbilt Legends Course Franklin, TN

October 22

ETGCSA Scholarship & Research Tournament

The Virginian • Abingdon, VA

October 24–26

Green Industry & Equipment Expo Kentucky Exposition Center Louisville, KY

November 13

MAGCSA Meeting

Cherokee Golf Club • Olive Branch, MS

November 15

MTGCSA Fall Educational Seminar Brentwood C.C. • Brentwood, TN

January 7–9, 2013

47th Annual TTA Conference and Trade Show

Marriott Cool Springs • Franklin, TN

January 15–19, 2013

STMA Annual Conference & Exhibition Daytona Beach, FL

February 6–7, 2013 Golf Industry Show

San Diego Convention Center San Diego, CA

TTA • TVSTMA • TGCSA

25

Digital Marketplace

Advertiser Index Bayer.................................................. 7, 9 www.bayerprocentral.com BWI Companies, Inc................................17 www.bwicompanies.com

Scan the QR code: Download your favorite QR reader to your phone and scan the code to learn more about these companies.

Covermaster, Inc......................................3 www.covermaster.com Direct Solutions........................................3 www.aatdirectsolutions.com Ewing Irrigation.......................................17 www.Ewing1.com Firestone Specialty Products....................25 www.firestonesp.com Greenville Turf & Tractor, Inc......Back Cover www.JohnDeere.com Harrell’s, LLC..........................................26 www.harrells.com John Deere Landscapes..........................11 www.johndeerelandscapes.com Kesmac Inc..................... Inside Back Cover www.kesmac.com Kirk Grading and Sodding........................10 Mid Tenn Turf.........................................23 www.midtennturf.com Modern Turf, Inc.....................................23 www.modernturf.com Redexim Turf Products............................15 www.redeximturfproducts.com Sigma Organics, Inc................................21 www.sigmaturf.com Sur-Line Turf, Inc....................................21 surlineturf.com Tennessee Crop Improvement.................26 www.superiorseeds.org The Andersons Technologies, Inc............21 www.andersonsgolfproducts.com

The Tennessee Turfgrass Association serves its members in the industry through education, promotion and representation. The statements and opinions expressed herein are those of the individual authors and Turfgrass Magazine, or its editors. Likewise, the appearance of advertisers, or Turfgrass Association

The Turfgrass Group.................................5 www.theturfgrassgroup.com

members, does not constitute an endorsement of the products or services featured in this, past or subsequent

Tri-Turf Sod Farms.................................26

do not necessarily represent the views of the association, its staff, or its board of directors, Tennessee

issues of this quarterly publication. Copyright Š 2012 by the Tennessee Turfgrass Association. Tennessee Turfgrass is published bi-monthly. Subscriptions are complimentary to members of the Tennessee Turfgrass Association. Third-class postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: Tennessee Turfgrass allows reprinting of material. Permission requests should be directed to the Tennessee Turfgrass Association. We are not responsible for unsolicited freelance manuscripts and photographs. Contact the managing editor for contribution information. Advertising: For display and classified advertising rates and insertions, please contact Leading Edge Communications, LLC, 206 Bridge Street, Franklin, TN 37064, (615) 790-3718, Fax (615) 794-4524.

26

The Pond Lady.......................................14 www.thepondlady.com

TENNESSEE TURFGRASS August/September 2012 Email TTA at: tnturfgrassassn@aol.com

Turf Mountain Sod, Inc............................16 www.turfmountain.com Turfgrass of Tennessee...........................11 Winstead Turf..................Inside Front Cover www.winsteadturf.com