Mississippi Turfgrass - Fall 2016

Fall 2016

The Mississippi Turfgrass Association Magazine

Resolving s ’ e v r e s e r P e h Tutting Green Problems, Part 2 P

Annual Bluegrass Control in Mississippi Sod Production

Plus, Program for the

Deep South Turf Expo, October 11–13, 2016

Fall 2016

Contents • The Mississippi Turfgrass Association Magazine Features

8 Upcoming Event —

Deep South Turf Expo, October 11–13, 2016

11 Golf Course Notes —

8

Resolving The Preserve’s Putting Green Problems, Part 2

16 Sod Feature —

Annual Bluegrass Control in Mississippi Sod Production

Departments

6 From the MTA President 21 Calendar of Events

22 Index of Advertisers

11

Mississippi Turfgrass is the Mississippi Turfgrass Association magazine.

Subscriptions are complimentary to MTA members. The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, its board of directors, Mississippi Turfgrass, or its editors. Likewise, the appearance of advertisers, or their identification as MTA members, does not constitute an endorsement of the products or services featured in any issue of Mississippi Turfgrass. Copyright ©2016 by the Mississippi Turfgrass Association. Mississippi Turfgrass is published quarterly. Subscriptions are complimentary to members of MTA. Presorted standard postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: MTA allows reprinting of material published here. Permission requests should be directed to MTA. 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.

4 • Mississippi Turfgrass • Fall 2016

16

From the mta president

Help Promote Our Industry to Everyone!

Paul Welborn

I

hope your summer has been great. For those of us in the northern part of the state, it has been a dry summer after a cool, somewhat dry spring. It seems there is always some type of challenge placed in front of us when growing turf. You can better prepare yourself to face those challenges by attending the various events that MTA helps support. Field Day was held August 23. The expanded program made it a great experience. Thank you to those that attended, and thank you to our sponsors that make these events possible. It is always encouraging to hear about the research being conducted on campus. Our Mississippi State turf team does an outstanding job with the resources they have available, and the insight I gain from their research helps me in my business. If you did not take advantage of this opportunity, make plans to attend in 2017.

Your next opportunity to support MTA and learn about the latest developments in the turf industry is our Deep South Turf Expo, October 11–13, in Biloxi. All of the details, including the schedule of events, are contained in this issue. Last year’s inaugural event was great. It had been a number of years since we had such a successful, well-attended annual meeting. I hope you have already made your reservations for Biloxi. You will be sure to see friends and colleagues from all over the South.

If you have not heard, Mississippi State has a vacancy in the turf department. Dr. Christian Baldwin has moved on to pursue other opportunities with Scott’s. His duties involved both teaching and research, so the impact of his departure will be felt across multiple levels. Christian’s background enabled him to bring a fresh perspective to both MTA and his teaching. His departure leaves a void, but it provides an opportunity to bring new ideas into the program. It is vital to our university and the turf industry that his position be replaced soon. Our university staff does a great job operating on available resources, but the departure of a staff member further stretches those resources. As the voice of the turf industry, MTA is advocating for this position to be filled quickly.

It has been an honor to serve as president of your association over the past year. Thank you for the opportunity. For our industry to thrive, we must be vigilant in promoting our industry to the public and to young persons that might be considering a career in the turf industry. We have a great association, and we all need to be working to make MTA stronger. Do not let an opportunity to promote MTA or the turf industry in general pass by. It is vital to our industry that we come together as turf professionals to promote what we do, educate the public and support our professionals at the university in their efforts.

If you know a turf professional who is not involved in MTA, please encourage him or her to join.

For a little over $6 a month, a turf or landscape professional can help support his/her industry. We need more golf, sports turf, sod, lawn care and landscape folks to join MTA. We also need kids to consider our field as a career. Seek out opportunities to speak at high school or junior college career fairs or even at your local high school agricultural classes. You never know when you might spark an interest in a high school student who is searching for a career.

Thanks for supporting MTA. I hope to see you at our upcoming events.

Paul Welborn

2015/2016 MTA President

6 • Mississippi Turfgrass • Fall 2016

Mississippi Turfgrass Association Box 9555 MS State, MS 39762 Office: (662) 325-0517 Fax: (662) 325-2705 www.msturfassociation.org Published by: Leading Edge Communications, LLC 206 Bridge Street Franklin, TN 37064 Office: (615) 790-3718 Fax: (615) 794-4524 info@leadingedgecommunications.com Mississippi Turfgrass Editor James D. McCurdy, Ph.D.

MTA OFFICERS

President Paul Welborn Lawn and Pest Solutions (662) 316-1347 Vice President Erick Coomer The Bridges Golf Course (228) 860-5292 Secretary/Treasurer Wayne Philley Mississippi State University (662) 325-2728 Past President Toby Thornton Timbercreek Golf Club (601) 507-4254 Administrative Secretary Linda Wells Mississippi State University Box 9555 MS State, MS 39762 Office: (662) 325-0517 Cell: (662) 769-7558 lmw218@pss.msstate.edu

Directors

Jordan Carlisle LADD’S (601) 818-7586 Jay Coalter Castlewoods Country Club (601) 317-1641 Dan Crumpton Oasis Sod Farm (662) 621-2040 Ken Edwards City of Gulfport (228) 861-5641 Jeremy Ely Shell Landing Golf Course (228) 669-6745 David Leon Turf & Aquatic Specialties, Inc. (601) 529-2458 Wayne Wells MSU Professor Emeritus (662) 418-4205 The Mississippi Turfgrass Association Magazine • 7

upcoming event

Deep South

Turf Expo October 11–13, 2016 Beau RIvage • Biloxi, MS

By Tricia Roberts, ATA Executive Director

We

are growing deep roots in Biloxi, MS, at the second annual Deep South Turf Expo. Make your plans to head down to the coast on October 11–13 for the event of the year. This regional conference will bring turf managers from all over the Southeast for three days of educational sessions, networking opportunities and a tradeshow with industry suppliers exclusively for the turf industry.

Back in 2014, the DSTE originated from the collaborative effort of five independent organizations: Mississippi Turfgrass Association, Alabama Golf Course Superintendents Association, Alabama Turfgrass Association, Gulf Coast Golf Course Superintendents Association and Louisiana-Mississippi Golf Course Superintendents Association. The first Deep South Turf Expo, held last October, was a success by all measures. Turf managers, sponsors, exhibitors and professors came out in full force to support this effort as our roots were planted. The support was contagious, and immediately plans for this year’s event were on the way! This year, the roots are growing, and we ask for everyone’s support of this effort as we forge forward with an expo that is beneficial to everyone in the turf world!

An abbreviated schedule of events is included here. Some highlights of the event include a golf tournament at The Preserve Golf Course, a skeet and trap tournament at Gulf Coast Gun & Rifle Club and a sports field tour of the local sports fields on the first day, followed by a Home Run Derby Dinner at the new MGM Park, home of the Biloxi Shuckers.

The next day will consist of educational sessions on the latest turfgrassmanagement topics, a luncheon and an afternoon dedicated to visiting the tradeshow exhibitors. The expo will wrap up with a reception on the tradeshow floor that evening. Educational sessions will continue to the last day and will be industry specific. Take a look at the program and our great lineup of speakers. v 8 • Mississippi Turfgrass • Fall 2016

Schedule at a Glance

Tuesday, October 11 8 a.m. – 9:30 a.m..............Annual Business Meetings 8 a.m. – 8:30 a.m............ATRF & MTA 8:30 a.m. – 9 a.m............ATA and LMGCSA 9 a.m. – 9:30 a.m............AGCSA and GCGCSA 8 a.m. – 5 p.m................. Pesticide Training and Testing (additional fees for state tests will apply) 10 a.m. – 5 p.m...............Exhibitor Move-In 12 p.m............................. Golf Tournament at The Preserve Sponsored by BWI, Inc.

S keet and Trap Tournament at Coastal Rifle and Pistol Club Sponsored by Aquatrols, Inc.

Sports Field Tour (Meet in Beau Rivage lobby)

6 p.m............................... Past Presidents Reception (Invitation only at Beau Rivage) Sponsored by Greenville and Beard Equipment 7 p.m............................... Home Run Derby & Dinner at MGM Park, Home of the Biloxi Shuckers Sponsored by Harrell’s & Bayer. Entertainment sponsored by AQUA-AID and Regal Chemical Co.

Wednesday, October 12 11 a.m. – 1 p.m.......... Spouse and Family Schooner Cruise

8 a.m. – 12 p.m............Exhibitor Move-In

(Meet at Schooner Pier Complex)

8 a.m.......................... General Session “Choosing the Correct Weed Control Program, Turfgrass Cultivar and Light Beer: Deciphering Opinion, Data and Marketing To Make The Best Decision,” Scott McElroy, Ph.D., Auburn University

12 p.m........................ Luncheon & Tradeshow Opening Luncheon sponsored by Jacobsen

12 p.m. – 6 p.m........... Tradeshow Open

“The Drainage Debacle — Issues in Constructed Rootzone,” Bill Kreuser, Ph.D., University of Nebraska

Tradeshow bags sponsored by Sod Solutions

10 a.m. – 12 p.m.......... Educational Breakout Sessions

During the tradeshow, attendees will go by all 36-hole challenge participants to get scorecards stamped. Scorecards can be redeemed during the late-afternoon reception for beverages. Exhibitors, be sure to register to be a hole sponsor!

(by subject, 1 hour sessions)

Weed Management

Fertility & Soils

Knowst Thou Herbicide Modes of Action, Jay McCurdy, Ph.D., Mississippi State University

Turfgrass Response to Fe, Mn and Mg Raw Materials, Travis Shaddox, Ph.D., University of Florida

Insect Disease

10:00 a.m.

Tradeshow Talks (on small stage in tradeshow, 20 min. each) Neonicotinoids and Their Effect on Bees, David Held, Ph.D., Auburn University

11:00 a.m.

Herbicide Chemistry — Application and Movement, Ramon Leon, Ph.D., University of Florida

Maximizing Foliar Fertilizers, Beth Guertal, Ph.D., Auburn University

Nematode Control for Warm-Season Turf, Billy Crow, Ph.D., University of Florida

1:40 p.m.

Hacking Putting Green Speed, Scott McElroy, Ph.D., Auburn University

2:40 p.m.

How Much Light Is Your Turf Receiving?

Beth Guertal, Ph.D., Auburn University

3:40 p.m.

New Turfgrass Varieties, Wayne Philly, Mississippi State University

4 p.m. – 6 p.m.............. Reception & Silent Auction on Tradeshow Floor Reception sponsored by Jerry Pate Turf & Irrigation Attendees turn in scorecards from 36-hole challenge for beverages.

Thursday, October 13 7 a.m..................................................................................................................................................................................... Continental Breakfast in hallway Sponsored by Syngenta 8 a.m. – 12 p.m.............................................................................................................................................................. Educational Breakout Sessions (by industry, 1 hour sessions) Golf

Lawn Care

Sports Turf

The Growing Degree Day Model for Primo Application on Putting Greens, Bill Kreuser, Ph.D., University of Nebraska

Management of Centipede and St. Augustinegrass, Bryan Unruh, Ph.D., University of Florida

Baseball Infield Management: Become a Dirt Expert, Barry Stewart, Ph.D., Mississippi State University

Deciphering the Interactions of Primo, Nitrogen and Management, Jim Harris, Austin Brown and Scott McElroy, Ph.D., Auburn University

Bermudagrass Cultivar Selection and Management, Dave Han, Ph.D., Auburn University

Non-Herbicidal Strategies to Manage Annual Bluegrass, Beth Guertal, Ph.D., Auburn University

Sod Production

Landscape

Pre-Emergence Herbicides for Sod Production, Jay McCurdy, Ph.D., Mississippi State University

Proper Planting and Pruning of Shrubs and Trees, Chris Francis, Chris Francis Tree Care

New Worker Protection Standards & How They Affect Your Business, Sonja Thomas, ACES

Colorful Commercial Landscapes, Geoff Denny, Ph.D., Mississippi State University

Sod Farm Nutrient Management, Bryan Unruh, Ph.D., University of Florida

Designing Sustainable Landscapes, Michael Symour, Ph.D., Mississippi State University

Turfgrasses in Changing Times, Ken Morrow, The Turfgrass Group

Irrigation Troubleshooting, Tom Burns, Ewing Irrigation

8:00 a.m.

9:00 a.m.

10:00 a.m.

Blights of Bermudagrass Putting Greens, Maria Tomaso-Peterson, Ph.D., Mississippi State University

Disease Management for Warm-Season Lawns Bruce Martin, Ph.D., Clemson

Irrigation Maintenance and Design for Sports Fields, Tom Burns, Ewing Irrigation

Disease and Nematode Management for Bermudagrass Greens, Bruce Martin, Ph.D., Clemson University

Weed Management in Centipede and St. Augustine, Ramon Leon, Ph.D., University of Florida

Weed Management on a Shoe-String Budget, Jay McCurdy, Ph.D., Mississippi State University

11:00 a.m.

8 a.m. – 12 p.m......................................................................................................................................................................................................................... Exhibitor Break-Down 12 p.m........................................................................................................................................................................................................ Conference Adjournment & CEU Sign-Ups

Registration is officially open online at www.DeepSouthTurfExpo.org. Be sure to register early, and make your hotel reservations at our host hotel, the Beau Rivage, a five-diamond resort overlooking the Mississippi Sound.

A link to the hotel’s online reservation service can be found on our website. Help us grow deep roots, and be part of this invaluable event exclusively for turfgrass managers across the Southeast!

Golf course notes

Resolving

The Preserve’s

Putting Green Problems, Part 2

By Stephen Miles, CGCS, Director of Operations, The Preserve Golf Club, with Bill Kreuser, Ph.D., Assistant Professor, Extension Turfgrass Specialist, and Glen Obear, Research Technologist and Doctoral Student, University of Nebraska-Lincoln

In Part 1, issues with water were found to play an underlying role in The Preserve Golf Club’s diminished Tifdwarf greens performance. Furthermore, issues with air movement were addressed, but there was still more at play, and ultimately the decision to reconstruct greens was made.

In

2013, the spring transition was again a major issue, with many of the same historically stressed areas dying again. After correcting many of the short-comings to the putting greens, we began to question if the Tifdwarf bermudagrass on our putting greens could meet the standards required for our facility. We began exploring the possibility of converting the greens to an ultradwarf variety.

Soil

Prior to resodding the dead areas on our greens again that spring, we took several samples of greensmix from 6" to 12" below the surface to be tested in the lab. This was to ensure that the new sand bought for the resurfacing project would be the same particle size and shape as the original greens mix.

Finally, we had a major breakthrough when one of the samples sent to the The Mississippi Turfgrass Association Magazine • 11

Golf course notes

Photo 1. On the left, clay accumulation in the putting greens soil at the Preserve Golf Club. On the right, the top photo (A) shows a close-up of the clay layer at the sand-gravel interface. The bottom photo (B) shows a close-up of aerification channels with reddish margins, presumably from iron-rich clay.

lab did not meet USGA specifications.

With this new information, attention again turned to our greensmix.

During the summer of 2013, we completely rebuilt three greens to get a better understanding of what was going on underneath the surface of our putting greens. We chose the chipping green, teaching green and nursery green. Since each green was built with a different greens mix, this would be a great opportunity to compare how each green performed below the surface. The chipping green was historically one of our major problems, while the teaching and nursery greens were always in perfect condition.

The chipping green was built with the original greens mix, consisting of a 90/10 blend of sand and calcined clay.

The rootzone was saturated near the sand/gravel interface and had a tan color. There also seemed to be a light pinkish layer right above the gravel (Photo 1). You could literally take the sand in your hand and squeeze water from it. The sand had plasticity and would form a perfect ball when being rolled in the hand, an indication of high clay content. The drainage lines 12 • Mississippi Turfgrass • Fall 2016

and gravel underneath also had a high percentage of clay (Photo 2).

The teaching green was built with sand from Honey Island in Louisiana.

This sand was blended with calcined clay at the same 90/10 ratio. This green’s rootzone looked fantastic. The greens mix had great soil tilth, a white color and moisture content that was the same throughout the profile. The roots were white and healthy. We had to use this sand because the original greens mix quantity had been exhausted, and producing more at the pit was not an option. The Honey Island sand closely resembled the original sand in particle size and shape.

The nursery green was the last green originally constructed. This green also looked great. It was built using sand from yet another provider — Hurricane Katrina had wiped out the pit on Honey Island, so the sand used to construct the teaching green was no longer available.

We chose this sand because it was from a reputable provider; it was clean, and it had a more course particle size to allow for greater drainage. If we couldn’t use the same sand as the original greens to

construct the nursery green, then we wanted to make sure it had a more course particle size so it would not cause layering issues when transplanting plugs into greens constructed with the original mix. It was constructed with straight sand.

The differences from the green built with the original mix versus the other two mixes could not have been more striking. I found an article discussing potential problems with newly constructed greens during this time. It mentioned dirty sand being used for the rootzone mix of putting greens as a common problem.

In essence, a dirty sand could pass USGA specs because the clay fines would be coating the sand particles.

The author stated that the best way to determine if a sand was dirty was to place it in water and shake the contents up. If the water was still cloudy after 10 minutes, then the sample was contaminated with clay. I performed this test on samples from all three greens. The original greens mix looked like a strawberry milk shake a day later, while the samples from the other two greens were

Photo 2. The chipping green’s drainage lines and gravel underneath also had a high percentage of clay.

Photo 3. The “dirty sand” test showed that the greens mix under the chipping green was filled with clay fines.

clear in less than 10 minutes (Photo 3).

What this demonstrated was that even with the extremely poor water quality at our course, a green constructed with a properly sized and clean USGA sand would still function extremely well. It appeared that the clay fines had migrated down through the profile and collected at the sand/ gravel interface, clogging the internal drainage of the green. This removed all doubt from my mind — we had no choice but to completely rebuild our greens. After getting a second and third opinion to verify what we had discovered, the decision was made to move forward with the rebuild during the summer of 2014.

but they wanted to rule out other sources. They collected samples of the calcined clay amendment used for construction, and they also sampled the compacted subsoil below the gravel.

They measured elemental fingerprints of these samples and compared the fingerprint to the pinkish clay layer. Their analysis showed that neither the calcined clay nor the subgrade was the source of the clay. These findings supported what we thought all along: that the clay most likely came from dirty sand during construction. Dr. Kreuser will speak about their findings at the Deep South Turfgrass Conference this October.

Research

Just before renovation in 2014, Dr. Bill Kreuser and his Ph.D. student, Glen Obear, came to collect soil samples and study the clay layers that had formed at the interface of sand and gravel. They sampled the soil profiles of 13 different locations on two putting greens. Their findings confirmed that the light pinkish layer above the gravel was enriched with clay and holding considerably more water than the sand above. They also found that there was more clay in the lower areas of the greens, where water drains laterally.

They performed a forensic investigation to try to pin down the source of the clay; we suspected that it came from dirty sand during construction,

14 • Mississippi Turfgrass • Fall 2016

Light

The last fundamental that needed to be addressed during our renovation was light. Research at Clemson in the early 2000s by Todd Bunnell and Bert McCarty (Burnell et al. 2005) defined the minimum daily light integral (DLI) needed to maintain TifEagle bermudagrass greens as 32.6 moles per square meter per day. In more recent research at Mississippi State by Ben Hodges and Christian Baldwin (Hodges et al.

2016), 30.1 moles were required for at least 70% TifEagle cover. Based upon this range, we had a target amount of light necessary for turf health.

During summer of 2013, a shade analysis was performed with the goal of meeting the new DLI recommendation.

Trees were catalogued surrounding our greens complex. Using data from the

shade study, selected trees were removed.

And today… the greens look great, and the conversion has increased playability and eased maintenance.

Understanding basic agronomic principles isn’t just something we learn in classrooms or at workshops. These basics are fundamental to what we do as professional turfgrass managers.

We look forward to Dr. Bill Kreuser’s discussion of these and other issues at Deep South Turf Expo.

Acknowledgments

We would like to thank the consultants involved with our project for their valuable insight and contributions to solving our putting green issues.

Dr. Ron Duncan Dr. Bob Carrow Chris Hartwiger Robert Oppold

Sources

Bunnell, B.T., L.B. McCarty, J.E. Faust, W.C. Bridges, and N.C. Rajapakse. 2005b. Quantifying a daily light integral requirement of a ‘TifEagle’ bermudagrass golf green.

Crop Sci.45:569–574.

Hodges, B.P., C.M. Baldwin, B. Stewart, M. Tomaso-Peterson, J.D. McCurdy, E.K. Blythe, and H.W. Philley. 2016 in Press. Quantifying a Daily Light Integral for Establishment of Warm-Season Cultivars on Putting Greens. Crop Sci. v

Sod Feature

Annual Bluegrass Control in Mississippi S

od Production

By Jay McCurdy, Ph.D., Assistant Professor, Turfgrass Extension Specialist, Mississippi State University

A

nnual bluegrass (Poa annua) is a troublesome annual weed in both warm-and cool-season grass scenarios, whether home lawns, sports fields, golf courses or sod farms. However, sod production practices tend to promote annual bluegrass as a weed with limited chemical-control options.

Cultural practices such as contaminated sprigging stock, barren soil repeatedly left fallow and contaminated harvesting and maintenance equipment are just a few of the predominant causes for annual bluegrass proliferation on sod farms.

Annual bluegrass emerges from seed in late summer and early fall when soil temperatures drop below approximately 70°F. Seeds are produced throughout

16 • Mississippi Turfgrass • Fall 2016

the following winter, spring and early summer months. Preventing annual bluegrass emergence and achieving success within Mississippi sod farms require an integrated approach. Cultural practices, such as using clean foundation sprigs and limiting the introduction and spread of seeds on equipment, are important, but they are not guarantees for success.

Due to the size of most sod farms, successful control requires a combined approach with cultural methods plus herbicides. Herbicides can be broken into three categories: preemergence, postemergence and those with both preemergence and postemergence activity (Table 1). Preemergence herbicides are applied prior to germination of annual

bluegrass. Dates for annual bluegrass germination range considerably from year to year; however, standard preemergence applications are made as early as August 15 (in northern Mississippi) to as late as October 1 (on the coast). In most cases, it is better to apply early rather than late. Late applications should contain a preemergence in combination with a postemergence or should be a product with both preemergence and postemergence activity.

Postemergence herbicide applications are applied when weather cooperates in the fall through early spring. This approach may be expensive and jeopardize recovery from winter dormancy.

Because these herbicides are applied

Fundamental considerations for Mississippi sod producers

after emergence of weed seedlings (postemergence), they control only emerged weeds. If using selective herbicides (herbicides safe to the sod), applications can be made that effectively control bluegrass plants prior to seed production. Dormant winter applications of non-selective herbicides (herbicides like glyphosate that may injure sod) should be made only when turfgrass is fully dormant. This approach often fails to prevent seed dispersal and contamination of the following year’s crop.

This article attempts to review common sod-production herbicide options in order that the sod producer may make appropriate choices to limit emergence and success of annual bluegrass.

• Herbicide selection for warm- and cool-season sod production differs.

For more information about herbicide safety, consult with your state Extension specialist.

•A lways read and follow label directions. Some products exclude use within sod production entirely. Others have restrictions on when sod can be harvested after their use.

•A ll preemergence herbicides inhibit root growth in some form or fashion, which is critical to sod production.

Some are safer than others, but safety is rate dependent. Commercial products typically have lower labeled rates intended for sprigged scenarios or where sod is being regrown after harvest.

•M ost preemergence herbicides can be applied to centipedegrass and St. Augustinegrass; however, these species rely upon stolon growth (aboveground stems) to a greater extent than either bermudagrass or zoysiagrass, which have both rhizomes and stolons.

For this reason, preemergence herbicide selection should be made based upon prior experience and/or discussion with your Extension specialist.

•T he effects of fall preemergence herbicides on sod tensile strength are not well understood, nor has the long list of preemergence herbicides been researched extensively. Spring applications may be more likely than fall applications to inhibit the most opportune timing for warm-season sod growth, ultimately leading to decreased sod strength. However, caution should be used any time that preemergence herbicides are applied to very young sprigs and plugs.

• Preemergence herbicides typically lack postemergence control; however, there are exceptions. Pre/post herbicides, like those discussed on pages 18-20, allow for control of already germinated weeds. Postemergence herbicides may also be applied in combination with preemergence herbicides in order to “reach back” and control previously germinated weeds but still provide The Mississippi Turfgrass Association Magazine • 17

sod feature • Continued

Table

1

Mode of action and classification of common herbicides for annual bluegrass control.

Site of action is listed according to the Weed Science Society of America (WSSA) and the Herbicide Resistance Action Committee (HRAC).

Timing

Mode of Action

WSSA Group

HRAC Group

Common Name

Trade Name

Pre

Mitotic inhibition

3

K1

dithiopyr

Dimension

Pre

Cellulose synthesis inhibition

29

L

indaziflam

Specticle

Pre

Very long chain fatty acid synthesis inhibition

15

K3

metolachlor

Pennant Magnum

Pre

Protoporphyrinogen oxidase (PPO) inhibition

3

K1

oryzalin

Surflan

Pre

Protoporphyrinogen oxidase (PPO) inhibition

14

E

oxadiazon

Ronstar

Pre

Mitotic inhibition

3

K1

pendimethalin

Pendulum

Pre

Mitotic inhibition

3

K1

prodiamine

Barricade

Pre

Mitotic inhibition

3

K1

trifluralin

Barricade

Pre/Post

Photosystem II inhibition

5

C1

atrazine

Aatrex

Pre/Post

Protoporphyrinogen oxidase (PPO) inhibition

14

E

flumioxazin

SureGuard

Pre/Post

Mitotic inhibition

3

K1

pronamide

Kerb

Pre/Post

Photosystem II inhibition

5

C1

simazine

Princep

Post Selective

Acetolactate synthase (ALS) inhibition

2

B

foramsulfuron

Revolver

Post Selective

Acetolactate synthase (ALS) inhibition

2

B

rimsulfuron+ metsulfuron

Negate

Post Selective

Acetolactate synthase (ALS) inhibition

2

B

rimsulfuron

TranXit

Post Selective

Acetolactate synthase (ALS) inhibition

2

B

trifloxysulfuron

Monument

Post Non-selective

Enolpyruvyl shikimate-3 phosphate (EPSP) synthase inhibition

9

G

glyphosate

Roundup

Post Non-selective

Glutamine synthetase inhibition

10

H

glufosinate

Finale

“residual” control of weeds yet to germinate.

• In high-end turf scenarios, split preemergence applications are recommended roughly eight weeks apart (approximately August or September, followed by October or November applications in MS). Due to the size and scale of most sod farms, a single application is more reasonable and can be very effective when appropriately timed or combined with a postemergence herbicide program.

• A fall/winter (October through February) selective herbicide application (such as atrazine, simazine, Kerb, Monument, Revolver, TranXit or Negate) is commonly applied where sod hasn’t reached true dormancy.

18 • Mississippi Turfgrass • Fall 2016

• A winter (January or February) nonselective herbicide application (such as Roundup or Finale) may be applied after true dormancy has been reached and forecasted temperatures prolong dormancy. These non-selective options are discouraged in centipedegrass and St. Augustinegrass. This application is sometimes combined with a preemergence herbicide intended to prevent spring-germinating weeds, such as crabgrass and goosegrass.

“TRUE PREEMERGENCE” OPTIONS dithiopyr (Dimension 2EW, Dithiopyr 2L, Dithiopyr WSB) oryzalin (Surflan, Oryzalin 4 Pro and others)

pendimethalin (Pendulum Aqua Cap, Pendulum 3.3EC, Pre-M) prodiamine (Barricade 4L, Prodiamine 65WG, Resolute) trifluralin (Treflan) Prodiamine, pendimethalin, oryzalin and trifluralin are dinitroaniline herbicides, while dithiopyr is a pyridine herbicide.

Despite separate chemical classes, these herbicides act similarly in that they inhibit cell division within young roots of developing plants. Read and follow label directions and suggested rates.

In some instances, labels prohibit use of these and other products as much as three months prior to harvest. metolachlor (Pennant Magnum) This option is often combined with simazine or atrazine for enhanced preemergence activity. oxadiazon (Ronstar WSP, Ronstar Flo, Oxadiazon 50 WSB) When applied as a liquid to nondormant turf, oxadiazon injures sod.

However, when dry formulations are applied on a granular carrier, such as fertilizer or other inert particle, turf injury is minimal. indaziflam (Specticle) Indaziflam is an inhibitor of cellulose biosynthesis. It is labeled for use on bermudagrass, zoysiagrass and centipedegrass sod farms, but it must not be applied prior to regrowth from ribbons reaching 80% cover or greater and up to 4 months prior to harvest. Apply no sooner than 16 months after sprigging to allow for good stand establishment.

PRE AND POST CONTROL atrazine (Aatrex and others) simazine (Princep and others) Atrazine and simazine are both photosystem II-inhibiting herbicides. Annual bluegrass resistance to these and other PSII-inhibiting herbicides limit their effectiveness at most Mississippi sod farms (see MSU publication 2844, “Preventing and Managing HerbicideResistant Weeds in Turfgrass”). However, these herbicides still have great

value. Although they sometimes have limited activity on annual bluegrass, they are both pre- and post-emergently active and typically control a broad spectrum of other broadleaf winter annuals. At labeled rates, these herbicides are considered safe postemergence herbicides for application in centipedegrass and St. Augustinegrass. Atrazine is a common addition to other herbicides applied in the fall; however, it can be particularly injurious to bermudagrass when applied as a liquid application, especially during warmer growing months. flumioxazin (Sureguard, Panther) Flumioxazin is similar to oxadiazon, except it is sometimes used for postemergence burn-down of existing annual bluegrass and broadleaf weeds. When applied as a liquid to non-dormant turf, flumioxazin injures sod. Dry formulations applied on a granular carrier may limit turf injury; however, there are currently no commercially marketed granular products sold for turf.

Photo

1

Annual bluegrass (Poa annua) seedhead.

Photo

2

Annual bluegrass (Poa annua) leaf tips are distinctly “boat-shaped.”

The Mississippi Turfgrass Association Magazine • 19

Sod feature • Continued

pronamide (Kerb) Pronamide provides pre- and early postemergence control where resistance to simazine, dinitroanalines and ALSinhibiting herbicides (next section) is common. It is cost prohibitive in some instances, but is labeled for use in St. Augustinegrass, bermudagrass, centipedegrass and zoysiagrass.

SELECTIVE “POSTEMERGENCE ONLY” With the exception of pre/post active herbicides previously mentioned, postemergence herbicides for annual bluegrass control are limited to the same mode of action, acetolactate synthase-inhibiting herbicides.

foramsulfuron (Revolver) rimsulfuron (Tranxit or Quali-Pro rimsulfuron 25 DF) rimsulfuron + metsulfuron (Quali-Pro Negate 37 WG) trifloxysulfuron (Monument) Products detailed here are not labeled for application to centipedegrass or St. Augustinegrass. Use of the same mode of action means that selecting for herbicide resistance is likely. In fact, many annual bluegrass populations are already reported resistant throughout the state and Southeast. Rotation between preemergence and postemergence herbicides, as well as rotating between herbicides with different modes of action, is critical to the continued viability of these herbicides. Adequate spray volumes (20 to 40 gallons/acre) will increase effectiveness. Many postemergence products require an added surfactant or oil to help them enter the plant foliage.

The ALS inhibitors listed above sometimes have slight preemergence activity upon annual bluegrass. This is a consequence of their soil activity.

That is, they are often root and leaf absorbed. They do not have true preemergence activity like many of the previously mentioned preemergence and pre/post herbicides, but they often have very short-term residual activity if conditions are favorable.

NON-SELECTIVE POA ANNUA CONTROL Non-selective options are viable if warm-season turfgrass is dormant.

Applications to green turf are discouraged but may be tolerated if slowed regrowth and recovery are acceptable. glyphosate (Roundup) Applications of glyphosate are warranted only for non-selective control within the northern transition area or where slowed growth is acceptable.

Resistance to glyphosate is on the rise; therefore, rotating to other nonselectives, as well as fall preemergence and selective winter postemergence control, is crucial to the continued 20 • Mississippi Turfgrass • Fall 2016

calendar of events

October 5–8

NRPA Congress and Expo (Nat. Recreation and Park Assn.)

St. Louis, MO

Photo

3

“Fly-away” stolons due to preemergence-herbicide application are not uncommon.

October 11–13

Deep South Turf Expo

Mississippi Coast Coliseum & Conference Center Biloxi, MS

October 19–21

LANDSCAPES 2016 (formerly the PLANET Green Industry Conference) Louisville, KY

Photo

4

Preemergence annual bluegrass control is best when preemergence herbicides are properly timed prior to the emergence of seedlings or when preemergence herbicides are combined with postemergence herbicides.

viability of this product. Low-volume applications (< 15 gallons/acre) may help reduce potential for turf injury by glyphosate. A high-volume application may re-hydrate desiccated growing meristems, ultimately increasing herbicide uptake by the desired turf. Adequate spray coverage and droplet size are still important for weed control. glufosinate (Finale) This herbicide is an option when rotating modes of action of postemergence winter applications. Glufosinate kills plants quickly and may compromise the uptake of other systemic herbicides.

Glufosinate is a postemergence option where glyphosate resistance is common.

For additional information, see

Mississippi State University Extension Service Publication 1532, “Weed Control Guidelines for Mississippi.”

References:

J.T. Brosnan, G.K. Breeden, A.W. Thoms, and J.C. Sorochan (2014) Effects of preemergence herbicides on the establishment rate and tensile strength of hybrid bermudagrass sod.

Weed Technology 28: 206-212.

The information given here is for educational purposes only. References to commercial products, trade names or suppliers are made with the understanding that no endorsement is implied and that no discrimination against other products or suppliers is intended. v

October 20–21

GIE+Expo and Hardscape North America Kentucky Expo Center Louisville, KY

October 21–24

ASLA — Annual Meeting & Expo (American Society of Landscape Architects) New Orleans, LA

January 24–27, 2017 STMA Conference and Exhibition Orlando, FL

February 4–9, 2017

Golf Industry Show Orange Co. Convention Ctr. Orlando, FL The Mississippi Turfgrass Association Magazine • 21

Advertiser index

Agra Turf Inc................................................. 22 www.agrainc.com Agri-AFC,LLC................................................... 3 www.agri-afc.com Bayou Bend Turfgrass................................... 22 www.bayoubendturf.com Boshancee Nursery Inc.................................. 7 www.boshanceensy.com CoverSports USA........................................... 19 www.coversports.com Greenleaf Technologies..................Back Cover www.greenleaftech.com Harrell’s LLC.................................................. 15 www.harrells.com Humphries Turf Supply.................................. 17 www.humphriesturf.com Jerry Pate Turf & Irrigation........................... 10 www.jerrypate.com Leading Edge Communications.................... 13 www.leadingedgecommunications.com O2YS Corporation............................................ 7 www.o2yscorp.com

RD Murphy, LLC............................................. 22 www.rdmurphy.com Riebeling Farms, Inc....................................... 7 Smith Seed Services..................................... 22 www.smithseed.com Southeast Turf Maintenance........................... 7 www.southeastturf.com

Digital Marketplace

22 • Mississippi Turfgrass • fall Fall 2015 2016

Southern Athletic Fields............................... 22 www.safdirt.com Sur-Line Turf, Inc.......................................... 20 www.surlineturf.com The Turfgrass Group........ Inside Front Cover, 5 www.theturfgrassgroup.com Winstead Turf Farms.............Inside Back Cover www.winsteadturffarms.com

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