Virginia Turfgrass Journal - May / June 2014

Journal of the Virginia Turfgrass Council

Tenth Annual Digest of Turfgrass Research in Virginia Science-Based Information for the Management of Golf Courses, Sports Fields, Lawns and Sod Farms

May/June 2014

Virginia Turfgrass Council / P.O. Box 5989 / Virginia Beach, VA 23471 / ADDRESS SERVICE REQUESTED

Journal of the Virginia Turfgrass Council | May/June 2014

Tenth Annual

DIGEST OF TURFGRASS RESEARCH IN VIRGINIA Upcoming Events 11 H ampton Roads AREC Turfgrass Field Day, Pesticide Recertification and Certified Fertilizer Applicator — June 24, 2014

Research Articles 12 Summary of Bermudagrass NTEP Results: 2007 to 2012 14 The Impact of Turf Fans on Bentgrass Putting Greens 16 E ffects of Fertility on Putting Green Recovery After PoaCure Applications 18 Quantifying the Water Movement and Leachate Nutrient Composition of a Sand-Based Athletic Field 20 A New Liquid Formulation of Quinclorac for Smooth Crabgrass Control in Cool-Season Turf 22 Pylex Evaluation for Goosegrass Control and Bermudagrass Safety

Summaries of More Research Projects 26 E valuating the Potential Benefits of Adding Compost and/or Microclover to Turf Stands

27 Postemergence/Residual Crabgrass Control with Cavalcade PQ in Cool-Season Turf

28 Preemergence and Postemergence Control of Arthraxon hispidus

28 R imsulfuron Plus Metsulfuron for Spring and Fall Transition of Overseeded Bermudagrass Turf

29 Goosegrass Control and Bermudagrass Response to Pylex™

Departments 6 8 10 30 30 30

President’s Message from Fred Biggers, CGCS Director’s Corner from Tom Tracy, Ph.D. VTF Report from Betty Parker Calendar of Events Contact Information for VT Researchers Index of Advertisers

Virginia Turfgrass Council (VTC) serves its members in the industry through education, promotion and representation. The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, or its board of directors, Virginia Turfgrass Journal, or its editors. Likewise, the appearance of advertisers, or VTC members, does not constitute an endorsement of the products or services featured in this, past or subsequent issues of this bimonthly publication. Copyright ©2014 by the Virginia Turfgrass Council. Virginia Turfgrass Journal is published bimonthly.

Subscriptions are complimentary to members of VTC. POSTMASTER: Send change of address notification to VTC, P.O. Box 5989, Virginia Beach, VA 23471.

Postage guaranteed. Third-class postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: Virginia Turfgrass Journal allows reprinting of material published here. Permission requests should be directed to VTC. 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 37068-0142, (615) 790-3718, Fax (615) 794-4524. Deadlines are the first of the month prior to the following month’s publication. (Example: August 1 for the September issue.)

President’s Message

Fred Biggers, CGCS 2014–2015 VTC President

Lots Going On!

It

seems like everything breaks loose each spring.

After just one or two days in the 60s, daffodils and crocus start popping up, and golfers start coming out to the courses to play again.

As soon as the annual VTC Conference is over in January, the planning starts on the next year’s conference. In mid-March, a VTC Conference and Show planning committee meeting was held, and many fresh, new ideas were brought forward that will help direct how next year’s conference is put together. All of the different segments of the Virginia turfgrass industry were present for this meeting: VSTMA, VGCSA, VTC, Virginia Sod Producers, VPGMS, VTF, DCR, VT and the RPLCA. With all of this great input from so many different groups, we are sure to have a much-improved educational program for next year’s conference.

One of our main goals for next year’s VTC Conference and Show is to have a block of time on the opening day of the Conference (Tuesday morning) when we get all of the attendees in one main conference room to present many of the ideas for promoting turfgrass in Virginia that have come out of the Turfgrass Summit. We are planning on having an interesting keynote speaker, and also we will give out all of the VTC annual awards.

Much effort will go into presenting a “Unified Voice” in support of the turfgrass industry in Virginia.

At the March meeting of the VTC board of directors, the Turfgrass Summit working committees (Education, Fundraising, Public Relations, Stewardship and Unified Voice) were added to the existing VTC committee structure (Membership, Legislative, Conference Program and Tournament) as ad hoc committees. The VTC board members felt strongly that this was a much-needed step in making sure that all of the different turfgrass-related organizations in Virginia are represented on the VTC board. Mr. Gil Gratten and his committee, who represent the Fundraising committee, are working on tightening up the Virginia Seed Law, which taxes companies that bring in and sell grass seed in Virginia. If a higher rate of reporting and tax compliance can come about through

6 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

this effort, many additional funds can be made available to support turfgrass research in Virginia.

Recently, I attended a meeting held by Dr. Mike Goatley (Virginia Tech) where he presented his idea to start a Certified Turfgrass Professional program here in Virginia. Also present were VTC executive director Dr. Tom Tracy, Virginia Cooperative Extension associate director Dr. Bobby Grisso and Derek Cataldi from the Virginia DCR. The creation of a Virginia Certified Turfgrass Professional program would benefit all of the present allied Virginia turfgrass working groups. Crew leaders, spray technicians, greens foremen, landscape foremen, sod farm managers and municipal, parks and school-system grounds managers throughout Virginia can greatly benefit by gaining more education and timely training from this CTP program. Right now, this program is in the planning stages, but if it does happen, it will have the VTC’s support and will enjoy the cooperation of VCE, DCR, VT and many other Virginia turfgrass industry support groups. Right now, Dr. Goatley thinks that it will include a three- to fiveday school with different segments taught each day and a comprehensive half-day exam given at the end of the week’s classes. Much planning work and input from industry leaders is needed to help this important program get off the ground this year.

Remember to send in your registration form to participate in the 2014 Bob Ruff Jr. Memorial Research Tournament on Monday, June 2, at the Stoney Creek Course at Wintergreen Resort. Come out to have fun and enjoy the networking and camaraderie of your fellow Virginia turfheads!

The VTC needs your contributions of time and talent. Give one of our committee chairmen a call, and get involved. We can grow and serve our membership and our Virginia Turfgrass industry only through your involvement.

Fred Biggers, CGCS 2014–2015 VTC President

We do this … so you get this.

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Whatever the game, choose a champion. Make TifGrand® your next choice and see firsthand what we do best.

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Director’s Corner

The Meaning Tom Tracy, Ph.D. VTC Executive Director

of service

A

phrase comes to mind as the best description of persons who have occupied the office of VTC president during my short years as executive director: Let each of you look not only to his own interests, but also the interests of others (Philippians 3:4). I have become reflective in this column because Frank Flannagan, who was VTC president for 2012 and 2013, is retiring on May 31. For 35 years, he has been with the County of Henrico, making sure that Belmont Golf Course is a top-notch facility. (As a point of trivia, Frank worked at the course before it was purchased by Henrico County. The county gave the course its current name and hired Frank; thus, he has actually been at those 18 holes for 40 years!)

As VTC members, please take a minute to think back on the persons who have

8 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

served as your president. I can only intelligently speak of the ones who have been in that office since my tenure as executive director. From Louis Brooking, who was president when the VTC board decided to hire me, to Fred Biggers, the current president, the word service is the best description.

These persons have served without pay, and they have given untold hours for the betterment of Virginia’s turfgrass industry. They have not hesitated to make critical phone calls; they attended — and, sometimes organized — meetings; they visited members of the General Assembly; they worked with Virginia Tech; and they diligently worked to stay abreast of trends that affect our industry. All this was done in addition to ensuring that their real job, the one that paid the bills, did not suffer.

From Rick Viancour’s emphasis on committees to Fred Biggers’ working with Mike Goatley to develop the Turfgrass Summit and its committees, each president has left his or her mark on the VTC. I have truly been blessed to work with such persons!

Next time you consider what is meant by a person who serves, look to your VTC presidents. They flesh out the meaning of that word! Frank has assured us his work with the VTC will not end any time soon, as he will continue to serve as our immediate past president. c

Virginia Turfgrass Journal is the official publication of The Virginia Turfgrass Council P.O. Box 5989 Virginia Beach, VA 23471 Office: (757) 464-1004 Fax: (757) 282-2693 vaturf@verizon.net Published by Leading Edge Communications, LLC 206 Bridge Street Franklin, Tennessee 37064 (615) 790-3718 Fax: (615) 794-4524 Email: info@leadingedgecommunications.com Editor Mark Vaughn, CGCS VTC OFFICERS President Fredrick Biggers, CGCS Wintergreen Resort (434) 325-8252 Vice President Rick Owens, CGCS Laurel Hill Golf Club (703) 674-6934 Treasurer Brian Vincel, CGCS Spring Creek Golf Club (434) 566-2580 Past President Frank Flannagan Belmont Golf Course (804) 262-4939 VTC DIRECTORS Marc Petrus Mark Roberts Christian Sain Michael Skelton Steve Smith Rick Viancour, CGCS Jimmy Viars Scott Woodward ­ VTC ADVISORY MEMBERS OF THE BOARD Mike Goatley, Ph.D. (Chair) Shawn Askew, Ph.D. Jeffrey Derr, Ph.D. Erik Ervin, Ph.D. David McCall Executive Director/ Director of PROGRAMS Tom Tracy, Ph.D. (757) 464-1004 Virginia Turfgrass Foundation Betty Parker (757) 574-9061

Journal of the Virginia Turfgrass Council

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VTF Report

Betty Parker VTF Manager

The

Virginia Turfgrass Foundation convened on Thursday, February 27, and endorsed the following turfgrass research projects this year.

“Evaluation of Seashore Paspalum — a New Turfgrass Species for Virginia” Virginia Tech Researchers: Jeffrey Derr, Ph.D., Mike Goatley, Ph.D., and David McCall Two-Year Project 2013 Funding: $15,469 2014 Funding: $15,873 “IPM for Putting Greens in Virginia: Using Iron Sulfate to Control Poa annua, Moss and Dollar Spot, while Reducing Nitrogen, Phosphorus and Pesticide Inputs” Virginia Tech Researchers: Erik Ervin, Ph.D., and David McCall Two-Year Project 2013 Funding: $8,400 2014 Funding: $8,600

Turfgrass Research Continues

with Support from the VTF

“A Comparison of Turf Blankets for Winter Protection of Bermudagrass” Virginia Tech Researchers: Mike Goatley, Ph.D. Two-Year Project 2013 Funding: $5,000 2014 Funding: $5,000 These projects are well underway and are entering the second year of their two-year duration. An update on all of these projects can be sent to you upon request. Feel free to call the VTF office at 757-574-9061.

Dr. Shawn Askew submitted a new project that was endorsed for funding as well: Investigating the Influence of Annual Bluegrass and Other Factors on Golf Putt Trajectory.” The

“Spatial Impact of Turf Fans on Creeping Bentgrass Putting Greens” Virginia Tech Researchers: David McCall and Erik Ervin, Ph.D. Two-Year Project 2013 Funding: $19,070 2014 Funding: $17,770 10 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

Foundation is supporting this oneyear project for $10,000.

The total being funded for this year is $57,243. In addition to this, the Foundation hopes to contribute at least $12,000 to the endowment, which now stands at just over a half million dollars. Thanks to all who have contributed and especially to those who give of their time and talents in serving on the VTF board: Sean Baskette Jeff Berf Fred Biggers, CGCS Sam Coggin Adam Dixon Frank Flannagan Rick Owens, CGCS c

Upcoming Events

Tuesday, June 24

5th Annual Hampton Roads AREC Turfgrass Field Day, Pesticide Recertification and Certified Fertilizer Applicator Sponsored by

Virginia Tech and the Virginia Turfgrass Council

T

his year’s Turfgrass Field Day in Virginia Beach will be held on Tuesday, June 24, from 7 a.m. to 5 p.m. On this day, participants from all areas of the turfgrass industry will gather to see firsthand the research being conducted at Virginia Tech’s “east side” AREC. Attendees use this gathering to share ideas, discuss problems and their solutions and take advantage of the professional certification programs being offered, while vendors come in to display their latest equipment and services.

Members of the Virginia Tech turfgrass faculty, from both here and Blacksburg, will showcase well over 20 separate research trials. The tour of turf plots will show variety trials, weed and disease control, drought tolerance and other studies in warm- and coolseason turf, including tall fescue, Kentucky bluegrass, hybrid bluegrass, perennial ryegrass, bermudagrass and zoysiagrass. c

VTC members attend FREE!

Non-members: $60 (includes all sessions and lunch) Non-members (tour and lunch only): $25

Preregister for the event at the VTC website:

www.vaturf.org For more information, contact Dr. Jeffrey Derr at:

(757) 363-3912 or email JDerr@VT.edu Schedule at a Glance 7:30 a.m. to 8:00 a.m.

8:00 a.m. to 12:00 p.m.

12:00 p.m. to 1:00 p.m.

1:00 p.m. to 3:00 p.m.

2:00 p.m. to 5:00 p.m.

Registration

SAVE THE DATES! June 2

Bob Ruff Jr. Memorial Research Golf Tournament

Wintergreen Resort Stoney Creek Course Wintergreen, VA

August 26–27 Turfgrass Field Days

Virginia Tech Blacksburg, VA

Tour of Turf Plots Lunch

December 15–19

Pesticide Recertification Certified Fertilizer Applicator

Fredericksburg, VA

Location Hampton Roads AREC 1444 Diamond Springs Road Virginia Beach, VA 23455

Pesticide Recertification in Categories 3A, 3B, 5A, 6, 8, 10 and 60.

Virginia Tech’s Turfgrass Short Course

January 26–29, 2015 VTC 55th Annual Turf & Landscape Conference and Trade Show

Fredericksburg Expo & Conference Center Fredericksburg, VA

Journal of the Virginia Turfgrass Council

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Research Report

Summary of Bermudagrass NTEP Results: 2007 to 2012 Virginia Tech Researchers: Whitnee Askew and Adam Nichols, Senior Technicians; Mike Goatley, Ph.D., Professor and Turfgrass Extension Specialist; and Erik Ervin, Ph.D., Professor of Turfgrass Culture & Physiology (Dept. of Crop and Soil Environmental Sciences) Research Sponsors: National Turfgrass Evaluation Program and Virginia Agricultural Experiment Station

T

his report is a brief summary of the recently completed 5-year national bermudagrass cultivar evaluation trial conducted at 20 university locations, with 31 entries tested. The compiled data can be seen in a 200-page report posted at ntep.org. Here, we review some of the most pertinent transition-zone site data for the top five vegetative entries, along with three seeded cultivars.

Our two Virginia test locations were in Blacksburg and Virginia Beach. Other data reviewed below are from Oklahoma State University and the University of Arkansas (Table 1).

Turfgrass quality

On average over five years, Patriot, Latitude 36 and Northbridge maintained higher visual quality (color, density, texture, uniformity) than Tifway, Premier and the three seeded cultivars. The high quality of the newcomers, Latitude 36 and Northbridge, is not surprising, given that they share some Patriot genetics.

Percent winterkill

Only two of 20 test sites reported any winterkill over the five years of this trial: Oklahoma State and Virginia Tech. Princess 77, known to be cold sensitive, winterkilled at 62%. The five cultivars out of the Oklahoma State breeding program showed only minor winterkill of 2% to 6%, while Tifway and Premier showed moderate sensitivity at 12%.

12 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

Spring dead spot

Rated at the University of Arkansas, SDS was highest in Princess 77 and then 12% or less for the remaining cultivars. Improved cold hardiness, historically, has been associated with less incidence of SDS.

Traffic tolerance and recovery

Percent turfgrass cover in November, following a fairly intense simulation of a fall football season, indicated that Northbridge, Princess 77, Riviera, Yukon and Latitude 36 were the most tolerant, at 20% to 26% remaining cover. The ability to recover in the spring following a fall football season was rated as percent cover in May. Tifway, Northbridge and Yukon showed the most aggressive spring fill-in by reaching over 50% cover. Latitude 36 and Patriot were not far behind, at 49% to 50%.

Summary

A review of the 2007 to 2012 NTEP data indicates that the newly released cultivars from Oklahoma State University, Northbridge and Latitude 36, have equivalent quality and perhaps better traffic tolerance when compared to Patriot. These data also indicate that Northbridge and Latitude 36 may have equivalent winterkill resistance as Patriot. Given that 2013 was the first year of widespread planting of these new cultivars across Virginia, and that the 2013–2014 winter was one of the coldest in more than a decade, it will be interesting to see if their tested winterkill resistance holds up on in-play plantings. c

Table 1: Selected Summary Data from the 2007 to 2012 Bermudagrass NTEP. Cultivar

Quality Average at Blacksburg & VA Beach (9 = best)

Winterkill % Average (VA and OK)

Spring Dead Spot % (tested at Univ. of Ark.)

Cover % in November after Fall Traffic

Cover % in May after Fall Traffic

Patriot

8.3

3%

8%

13%

49%

Latitude 36

8.0

3%

12%

20%

50%

Northbridge

7.9

3%

5%

26%

56%

Premier

7.7

12%

8%

18%

44%

Tifway

7.5

12%

5%

9%

56%

Yukons

7.2

2%

5%

21%

52%

Rivieras

7.2

6%

8%

23%

40%

Princess 77s

5.8

62%

23%

25%

34%

LSD0.05

0.5

14

15

13

16

s = seeded cultivar; others are vegetative hybrids.

Journal of the Virginia Turfgrass Council

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Research Report

The Impact of Turf Fans on Bentgrass Putting Greens Virginia Tech Researchers: David McCall, Turfgrass Pathologist and Research Associate, Camden Shelton and Andrew Landreth, Undergraduate Research Assistants Research Sponsors: Virginia Ag Council and Virginia Turfgrass Foundation (in-kind donations by SubAir Systems, Toro and TurfVu)

The

physiology of creeping bentgrass is negatively impacted during periods of stress, decreasing the efficiency of many plant functions. Creeping bent and other cool-season grasses grow optimally between 50°F and 65°F. Bentgrass root development slows as the soil temperature rises above 80°F, with a loss of functionality at temperatures above 86°F. To mitigate environmental stresses to creeping bentgrass, turf fans are used on many golf courses to provide needed airflow and increase transpiration.

With limited data available that does not address the impact of improved

fan technologies with increased air velocity, we designed our research to quantify the potential benefits of turf fans on putting greens. The primary objective was to determine the distal benefits of turf fans on in-play golf putting greens. A secondary objective was to determine the benefits of activating fans earlier in the season to prolong optimal growing conditions.

Our research

As reported in last year’s Research Edition of the Virginia Turfgrass Journal, a pilot study in 2012 on a single putting green indicated that soil temperatures were approximately 6 degrees cooler at 20 feet from the fan base than at 80

feet. This exploratory research provided a strong backbone to support the need for future research.

During summer 2013, the spatial impact of turf fans was explored in Richmond, VA. Oscillating 5hp Electric Turf Breeze 50" (TB-50-Premium) (from SubAir Systems, LLC) fans were installed on 6 in-play putting greens.

Data were collected from these greens and compared to conditions on three greens without fans. Three fans were activated when soil temperatures consistently reached 70°F for three consecutive days and 18 days later when temperatures reached 80°F for three days. Using historical data, this 10°F increase in soil temperature was

Figure 1.

Figure 2.

Figure 3.

Figure 1. Soil temperatures (at a depth of 1.5”) were collected every 10 feet from the base of fans and regressed to indicate distal changes across the putting green.

Figure 2. Rooting depth measurements were collected every 10 feet from the base of fans and regressed to indicate distal changes across the putting green.

Figure 3. Canopy temperatures were collected using thermal imagery with turf fans off (left) and after running for 45 minutes (right). Canopy temperature was decreased by 18°F closest to the fan and by 6°F approximately 110 feet away.

14 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

estimated to extend over four weeks.

Once activated, each fan ran continuously throughout the summer until after all data collections.

Measurements of rootzone and canopy temperatures, soil moisture and maximum and average wind speeds were collected on three dates in July and August. Because of mild growing conditions throughout June and July, the data from August 13 captured the greatest impacts. These measurements were compared with geo-referenced reflectance data using an online data processing service to determine its effectiveness in quantifying and predicting stress.

Figure 4.

Results

Rooting depth, rootzone temperatures and canopy temperatures were positively impacted by air movement during peak summer stress (midAugust 2013). Impact was directly correlated to distance from the fan and surface wind speed, but it was most apparent for the first 50 feet.

Wind speed ranged from 12 mph (at 20 feet) to 4 mph (at 70 feet), compared to a relatively constant 2 mph on greens with no fans.

The maximum possible decrease in soil temperature was 9°F, with a 3°F decrease at 50 feet from the fan base (Figure 1). Ultimate impact on rooting development was most apparent at distances closest to the fan base, with an expected increase of 1.3", compared to the rooting depth of greens with no fan (Figure 2).

At 50 feet from the base of the fan, our results documented an increase of root length of approximately 0.6".

Average root depth increased by approximately 0.25" when fans were activated when soil temperatures reached 70°F, compared to greens with fans activated at 80°F. Thermal imagery was used to document the impact of air movement by temporarily reducing canopy temperature by up to 18°F nearest the fan (Figure 3). Reflectance mapping correlated closely with collected measurements, detecting the highest turf quality typically being within the first 30 to 40 feet from the fan (Figure 4). c

Figure 4. Turf quality measurements using geo-referenced reflectance data on four greens utilizing turf fans. Relative turf quality is highest in dark green areas, followed by light green, blue, yellow, orange and red.

Journal of the Virginia Turfgrass Council

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Research Report

Effects of Fertility on Putting Green Recovery Following Methiozolin (PoaCure) Applications Virginia Tech Researchers: Shawn D. Askew, Ph.D., Associate Professor and Extension Turfgrass Weed Specialist, and Katelyn A. Venner, Graduate Research Assistant Research Sponsors: Moghu Research Center, Daejeon, South Korea

M

aintaining superior putting green quality is an integral part of a golf course superintendent’s job. Unfortunately, many factors, including weed pressure, make it difficult to maintain greens at the level of quality expected by many golfers. Annual bluegrass (Poa annua) is a problematic grassy weed on golf course putting greens due to its light green color, excessive production of seed and need for intensive management during the summer months. Few effective herbicidal controls exist for annual bluegrass on creeping bentgrass putting greens, and even more are used on greens without proper labeling.

Fortunately for superintendents, a new herbicide, methiozolin (PoaCure), has demonstrated its ability to completely control annual bluegrass with the utmost safety to creeping bentgrass when applied at appropriate rates. Sometimes, however, methiozolin removes

annual bluegrass more quickly than desired, resulting in a voided turfgrass canopy. Previous research performed in 2012 at Virginia Tech determined that methiozolin rate does not affect turfgrass recovery. Another experiment performed at the Blacksburg Country Club resulted in rapid annual bluegrass loss following an aeration event.

These earlier trials helped steer a series of small trials in 2013 to investigate the effects of fertility from foliar fertilizer alone or in conjunction with a Primo growth regulator program or from a biostimulant program on the lateral recovery of creeping bentgrass turf following canopy voids. Canopy loss in these studies was caused by rapid loss of annual bluegrass cover due to high-rate PoaCure treatments on mixed annual bluegrass and creeping bentgrass greens and from an intensive aeration event on predominately creeping bentgrass greens.

Trial 2. April 20, 2013

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Our research

Two trials were initiated on March 22, 2012. Trial 1 was conducted at the Virginia Tech Golf Course and replicated on two separate, push-up-style practice greens maintained at 0.13".

The entire trial was treated with methiozolin at 3.6 oz./1,000 ft2, followed by 0.6 oz./1,000 ft2 twice at 2-week intervals in order to facilitate rapid removal of annual bluegrass.

Trial 2 was conducted at the Turfgrass Research Center (TRC) on a USGA specification ‘L-93’ green that is maintained at 0.125". This trial was aerated to remove 30% of the turfgrass canopy on May 5, 2013. In trial 2, plots contained either no methiozolin or methiozolin applied at 0.6 oz./1,000 ft2 6 times at 2-week intervals.

All cultural treatments were the same between trials and were as follows: • No cultural treatment • Increased fertility using Bulldog 20-20-20, a commercially available N-P-K product • Increased fertility plus trinexapacethyl (Primo) at 0.125 oz./1,000 ft2 • Increased fertility via Floratine biostimulant products All fertility treatments were applied every two weeks beginning on April 14, 2013, and plots subject to increased fertility received an extra 0.125 lb. N on top of the normal fertility regime. The biostimulant program provided an equal amount of macronutrients to the other increased fertility programs. Light box images, normalized differential vegetative index (NDVI) and visual ratings were taken weekly for the duration of the study.

Results Trial 1 At trial initiation, turfgrass was dormant, and creeping bentgrass cover ranged from 15% to 19%. Turfgrass cover increased approximately 5% across all treatments each week for the next three weeks. Fertility was applied beginning on April 14, when turfgrass green cover was between 50% to 60%. One week after the initiation of cultural treatments, biostimulanttreated plots were significantly greener than increased fertility alone and the untreated plot, but not more than the treatment of increased fertility plus Primo. By six weeks after initial treatment (WAIT), all increased fertility treatments were significantly greener than the untreated, but not different from one another. At the conclusion of the trial, cover in treated plots ranged from 95% to 96%, and 90% in the untreated.

Trial 2 At trial initiation, turfgrass was dormant, and percent green cover ranged from 11% to 20% across the trial area.

One week after initiation of fertility, percent green tissue on treated plots ranged from 72% to 78%, whereas the untreated plot was 54%. The green was aerated to remove roughly 30% of the turfgrass canopy and topdressed heavily with sand. At 2 weeks after aeration (WAA), biostimulant plots recovered more than all other treatments. Increased fertility alone was equivalent to increased fertility plus Primo. At the conclusion of the study, approximately 8 WAA, there were no significant differences between treatments.

Trial 1. Effect of Fertility, Biostimulant & PGR on Bentgrass Recovery Following Rapid Poa Removal.

Trial 2. Bentgrass Cover as Affected by Methiozolin.

Trial 2. Bentgrass cover as affected by methiozolin.

Conclusions

The results from both of these studies suggest that increasing the fertility of a putting green to recover from rapid annual bluegrass loss or aeration is not influenced by methiozolin, and that either biostimulants or commercial fertilizers can be used to effectively speed recovery. Biostimulant programs may be advantageous compared to fertilizer in the first two to three weeks of recovery. c Journal of the Virginia Turfgrass Council

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Research Report

Quantifying the Water Movement and Leachate Nutrient Composition of a Sand-Based Athletic Field Virginia Tech Researchers: Ben Kraemer, Student; Mike Goatley, Ph.D., Professor and Turfgrass Extension Specialist; Erik Ervin, Ph.D., Professor of Turfgrass Culture & Physiology; Whitnee Askew, Laboratory Specialist (Crop & Soil Environmental Sciences Dept.); Brian Benham, Ph.D., Associate Professor and Extension Specialist; Laura Lehmann, Environmental/Agricultural Research Manager (Biological Systems Engineering); and Stephen Schoenholtz, Ph.D., Director, Water Resources Research Center Research Sponsors: Virginia Agricultural Experiment Station and Virginia Turfgrass Foundation

The

primary goal of the project is to quantify the nutrient content of leachate leaving sand-based athletic fields through subsurface drainage lines. To accomplish this goal, we are collecting water samples from drainage lines beneath the University of Virginia’s Scott Stadium, using an ISCO automatic water sampler. Once samples

Inside the ISCO.

have been collected, the next step is to have them analyzed to determine the amount of dissolved nitrate and phosphate present in the leachate. Tests will also be performed to determine the physical and chemical composition of the soil at Scott Stadium.

Water sampling

Aside from collecting and storing water samples, the ISCO sampler is also capable of monitoring the amount of water flowing through the drainage system over time. Since its installation at Scott Field in 2011, the ISCO has been creating flow charts that trace the spikes in water content that occur during storm and irrigation events. By studying the flow charts and precipitation records, we have identified certain flow rates to be associated with small storms, large storms and typical irrigation applications. The flow rates are then used to formulate the ISCO’s sampling programs.

The ISCO is capable of running up to five different programs, allowing us to install different programs for large storms, small storms and irrigation events. The primary differences between programs are (1) the flow level that initiates sampling and (2) the time interval between samples.

Adjusting these variables allows us to accomplish the main goal of sampling, which is to catch as much of the event as possible, especially the peak in flow.

Soil analysis

The purpose of the soil tests is to determine the physical and chemical composition of the rootzone. By identifying how much carbon, nitrogen and phosphorous is currently present, as well as physical characteristics (such as infiltration capacity and bulk density), we will be able to better understand the dynamics of water and nutrient movement through the soil. Having a sound understanding of the field’s soil characteristics will also allow us to more accurately identify connections between management practices and their impacts on the nutrient content of leachate leaving the field.

18 | Virginia Turfgrass Journal May/June 2014

Summary

The motivation behind the project is to provide the sports-management community (and possibly golf turf managers who are managing sand-based putting greens) with a benchmark on the current levels of impact that standard management practices have on water quality. Our hope is that once a benchmark is established, the turf community as a whole will be in a better position to work towards achieving long-term environmental sustainability.

Special thanks to Jesse Pritchard and the University of Virginia grounds crew staff for all of their help with the water sampling process, and to Dr. Stephen Schoenholtz, Director of the Virginia Water Resources Center in the College of Natural Resources and Environment, and Dr. Brian Benham and Laura T. Lehmann of the Biological Systems Engineering Department of Virginia Tech for their technical support and guidance on this project. c

Installing the ISCO flume in the drainage vault at the University of Virginia.

Journal of the Virginia Turfgrass Council

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Research Report

A New Liquid Formulation of Quinclorac for Smooth Crabgrass Control in Cool-Season Turf Virginia Tech Researchers: Sandeep S. Rana, Doctorate Student, and Shawn D. Askew, Ph.D., Associate Professor, Turfgrass Weed Science, Plant Pathology, Physiology and Weed Science Dept.

Research Cooperators: Quali-Pro

C

urrently, many herbicides (Balan, Ronstar, Barricade, Dimension and Tupersan) are labeled for preemergence control of smooth crabgrass (Digitaria ischaemum (Schreb.) Schreb. Ex Muhl.) in both warm- and cool-season turf; however, postemergence control options (MSMA/DSMA, dithiopyr, fenoxaprop and quinclorac) for smooth crabgrass are limited. The control options are even more limited since the loss of MSMA in sports turf and restrictions placed for golf and sod production.

Presently, quinclorac is among the most effective postemergence herbicides for smooth crabgrass control, but quinclorac has only been offered as a dry formulation throughout its entire patent life. Although dry formulations require “softer” packaging, have less shipping weight and impart less exposure risk to handlers, recent market analyses continue to indicate that liquid formulations of sprayable pesticides are most desirable among turf managers.

Recently, a liquid formulation of quinclorac became available by BASF Corporation under the trade name Drive® XLR8. Previously, Quali-Pro had only offered a dry formulation of quinclorac, but it has now developed a liquid formulation of quinclorac (Quali-Pro Quinclorac 1.5 L) that uses new formulation technology, allowing faster dispersion, better cold-water mixing and safer inert materials and surfactants.

Our research

Field trials were initiated on July 25, 2013, on a perennial ryegrass fairway (0.6" height) at the Turfgrass Research Center (TRC) at Virginia Tech in Blacksburg to evaluate smooth crabgrass control efficacy of and perennial ryegrass sensitivity to the liquid formulation of quinclorac [QualiPro Quinclorac 1.5 L (QPQ 1.5 L)] compared to the dry

formulation [Quali-Pro Quinclorac 75 DF (QPQ 75 DF)] and the industry standards, Drive® XLR8 [quinclorac (DXQ 1.5 L)] and Acclaim Extra® [fenoxaprop) (AEF 0.57 EW)]. The herbicide treatments included: • QPQ 75 DF 75 DF at 16 oz. wt./A • QPQ 1.5 L at 64 fl. oz./A • DXQ 1.5 L at 64 fl. oz./A (Drive XLR8) • AEF 0.57 EW at 21.1 fl. oz./A (Acclaim Extra) All herbicide treatments included methylated seed oil (MSO) at 0.25% v/v to simulate conditions of limited absorption, a common problem while using dry formulations of herbicides.

Research results

None of the herbicide treatments injured perennial ryegrass (data not shown). At 7 days after treatment (DAT), QPQ 1.5 L and DXQ 1.5 L controlled smooth crabgrass equivalently at 94% and 95%, respectively, and greater than QPQ 75 DF (77%) and AEF 0.57 EW (68%) (Figure 1a., Figure 2). Lower smooth crabgrass control from QPQ 75 DF is because of lower rate of MSO (0.25% v/v) used in this study. Moreover, smooth crabgrass control from AEF 0.57 EW peaks at 14 DAT. At 14 DAT, QPQ 1.5 L, AEF 0.57 EW and DXQ 1.5 L controlled smooth crabgrass equivalently at 93%, 97% and 95%, respectively, and greater than QPQ 75 DF (63%) (Figure 1b., Figure 2). At 28 DAT, QPQ 1.5 L, AEF 0.57 EW and DXQ 1.5 L continued to provide equivalent higher levels of smooth crabgrass control at 93%, 96% and 92%, respectively; whereas, smooth crabgrass control with QPQ 75 DF decreased even further (47%) (Figure 1c., Figure 2).

Researchers at Maryland and New Jersey have also reported quinclorac and fenoxaprop to effectively control smooth crabgrass postemergence, both in warm- and cool-season turf.

20 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

Figure 1. Smooth crabgrass control (percentage green tissue reduction) at (a) 7 DAT, (b) 14h DAT and (c) 28 DAT. *Uppercase letters separate smooth crabgrass. control among herbicide treatments using Fisher’s Protected LSD at ι = 0.05.

Conclusions

The liquid quinclorac formulation (QPQ 1.5 L) is safe on perennial ryegrass, with smooth crabgrass control better than QPQ 75 DF, especially under conditions of limited absorption, and equivalent to industry standard herbicides, DXQ 1.5 L and AEF 0.57 EW. In the future, we would like to conduct experiments to evaluate tankmixing compatibility of the new liquid formulation of quinclorac with other herbicides, and to determine the adjuvants needed for the liquid quinclorac to achieve maximum levels of weed control. c

Figure 2. Treatment response at 28 DAT

Research Report

Pylex Evaluation for Goosegrass Control and Bermudagrass Safety Virginia Tech Researchers: Jeffrey Derr, Ph.D., Professor of Weed Science, and Adam Nichols, Research Assistant, Hampton Roads AREC, Virginia Beach Research Sponsors: Virginia Turfgrass Council and Virginia Turfgrass Foundation Table 1. Injury to ‘Tifsport’ Bermudagrass Following Single and Repeat Herbicide Applications. z

Trt. No. 1

Treatment Name Nontreated

2

Pylex + MSO

3

Pylex + MSO

4

Pylex + MSO

5

Pylex + MSO

6

Pylex + MSO

7

Pylex + MSO

8 Revolver 9 Acclaim Extra LSD (P = 0.05)

Rate

Application v Timing

4 DATA

Turfgrass Injury (1-9: 1= No Injury, and 4 = Unacceptable injury) 19 DATA 29 DATA 36 DATA 42 DATA 7 DATA 13 DATA w 6 DATC 16 DATC 23 DATC 29 DATC 1.0 d 1.0 d 1.0 e 1.0 f 1.0 f 1.0 f

x

v

1.0 d 0.5 fl. oz./a 0.5 % v/v 0.75 fl. oz./a 0.5 % v/v 1 fl. oz./a 0.5 % v/v 0.5 fl. oz./a 0.5 % v/v 0.75 fl. oz./a 0.5 % v/v 1 fl. oz./a 0.5 % v/v 26 fl. oz./a 28 fl. oz./a

50 DATA 37 DATC 1.0 e

AB

1.4 c

3.1 c

5.3 c

8.3 a

5.0 d

3.0 e

1.8 e

1.0 e

AB

2.0 b

4.0 b

6.0 b

8.3 a

5.8 cd

3.9 d

1.9 e

1.0 e

A

2.9 a

4.8 a

7.3 a

7.5 b

3.9 e

1.4 f

1.0 f

1.0 e

CD

1.0 d

1.0 d

1.0 d

3.5 c

7.0 b

7.6 b

7.0 c

3.1 c

CD

1.0 d

1.0 d

1.0 d

3.0 c

7.6 b

8.5 a

7.6 b

4.3 b

CD

1.0 d

1.0 d

1.0 d

3.5 c

8.5 a

6.4 c

3.0 d

1.5 d

CD CD

1.0 d 1.0 d 0.2

1.0 d 1.0 d 0.2

1.0 d 1.0 d 0.5

1.0 e 2.0 d 0.7

1.0 f 6.1 c 0.8

1.0 f 7.5 b 0.6

1.0 f 8.3 a 0.4

1.0 e 5.0 a 0.3

zTurfgrass injury rated on a 1-9 scale where 1 = no injury, 4 = unacceptable injury, and 9 = complete death. yLetters correspond to the timing and growth stage in the Our Research section. xDATA = Days after treatment A = May 30, 2013. wDATC = Days after treatment C = June 12, 2013. vMeans are the average of four replicates. Means followed by the same letter do not differ significantly according to the Least Significant Difference test (a = 0.05)

Table 2. Goosegrass Control Following Singe and Repat Herbicide Applications.

Trt. No. 1

Treatment Name Nontreated

2

Pylex + MSO

3

Pylex + MSO

4

Pylex + MSO

5

Pylex + MSO

6

Pylex + MSO

7

Pylex + MSO

8 Revolver 9 Acclaim Extra LSD (P = 0.05)

Rate

Application z Timing

7 DATA

13 DATA

Goosegrass Control (%) 19 DATA 29 DATA 36 DATA x 6 DATC 16 DATC 23 DATC 0d 0d 3d

42 DATA 29 DATC 1d

50 DATA 37 DATC 1c

v

0b

AB

38 b

88 a

99 a

89 ab

99 a

100 a

98 a

AB

41 b

85 a

95 a

95 a

100 a

90 bc

58 b

A

60 a

86 a

24 bcd

0d

0d

0d

0c

CD

0c

0b

51 b

58 c

90 ab

99 a

100 a

CD

0c

0b

49 b

67 bc

95 ab

100 a

100 a

CD

0c

0b

50 b

68 bc

96 ab

100 a

100 a

CD CD

0c 0c 5

0b 0b 7

18 cd 35 bc 29

68 bc 55 c 24

85 b 48 c 12

96 ab 88 c 6

99 a 91 a 24

0c 0.5 fl. oz./a 0.5 % v/v 0.75 fl. oz./a 0.5 % v/v 1 fl. oz./a 0.5 % v/v 0.5 fl. oz./a 0.5 % v/v 0.75 fl. oz./a 0.5 % v/v 1 fl. oz./a 0.5 % v/v 26 fl. oz./a 28 fl. oz./a

y

zLetters correspond to the timing and growth stage in the Our Research section. yDATA = Days after treatment A = May 30, 2013. xDATC = Days after treatment C = June 12, 2013. w Means are the average of four replicates. Means followed by the same letter do not differ significantly according to the Least Significant Difference test (a = 0.05)

The

objective of this research trial was to evaluate the efficacy of Pylex (topramezone), a postemergence herbicide, for the control of goosegrass at the 2–3 leaf stage and the 2–3 tiller stage in both single and split applications. We also evaluated the safety of these applications to bermudagrass.

by Application C in both the bermudagrass and secondary area.

Research results

Unacceptable bermudagrass injury was visible from Pylex applications, regardless of application timing or rate (Table 1). Plots receiving two

applications did result in greater injury, and the injury persisted for a longer period of time. However, plots for most treatments returned to acceptable or no injury by the final rating. The maximum injury to the turfgrass from Pylex was similar to the injury caused by Acclaim Extra,

Our research

Treatment applications were made on the following schedule with the accompanying weather data.

Application A Applied on May 30, 2013, to both a ‘Tifsport’ bermudagrass stand and a secondary stand containing goosegrass and southern crabgrass. Weather conditions for this application were sunny, 83°F, a relative humidity of 54%, and a southwest wind of 12 MPH. At the time of application, the goosegrass in the treated plots was mostly 2–4 leaf plants with sporadic 2-tiller plants. The bermudagrass was at 100% greenup.

Application B Applied on June 12, 2013, as the second application to the plots treated at Application A in both the bermudagrass and the secondary area. Weather conditions for this application were sunny, 82°F, a relative humidity of 54%, and a west wind of 6 MPH. Both the goosegrass and the bermudagrass were showing signs of injury from the previous application.

Application C Applied on June 12, 2013, as the first application to both ‘Tifsport’ bermudagrass and the secondary stand. The goosegrass in the secondary area was in the 2-3 tiller stage. Weather conditions at the time of application were sunny, 82°F, a relative humidity of 54%, and a southwest wind of 12 MPH. Application D Applied on June 28, 2013, as the second application to the plots treated Journal of the Virginia Turfgrass Council

| 23

Research Report

Table 3. Crabgrass Control Following Single and Repeat Herbicide Applications.

Crabgrass Control (%) Trt. No.

Treatment Name

1

Nontreated

Application z Timing

Rate

13 DATA

19 DATA x 6 DATC

29 DATA 16 DATC

36 DATA 23 DATC

42 DATA 29 DATC

50 DATA 37 DATC

0d

0c

0c

0d

1e

3c

0c

7 DATA

y

w

2

Pylex + MSO

0.5 fl. oz./a 0.5 % v/v

3

Pylex + MSO

0.75 fl. oz./a 0.5 % v/v

AB

46 b

91 a

79 ab

96 a

100 a

95 a

79 ab

4

Pylex + MSO

1 fl. oz./a 0.5 % v/v

A

58 a

91 a

24 c

0d

0e

0c

0c

5

Pylex + MSO

0.5 fl. oz./a 0.5 % v/v

CD

0d

0c

53 b

60 c

90 c

75 b

49 b

6

Pylex + MSO

0.75 fl. oz./a 0.5 % v/v

CD

0d

0c

53 b

53 c

97 abc

84 ab

70 ab

7

Pylex + MSO

1 fl. oz./a 0.5 % v/v

CD

0d

0c

53 b

55 c

94 abc

89 ab

83 ab

8

Revolver

26 fl. oz./a

CD

0d

0c

24 c

54 c

34 d

16 c

0c

9

Acclaim Extra

28 fl. oz./a

CD

0d

0c

20 c

73 bc

91 bc

100 a

100 a

2

4

27

23

7

20

40

LSD (P = 0.05)

AB

35 c

86 b

91 a

95 ab

99 ab

93 ab

76 ab

zLetters correspond to the timing and growth stage in the Our Research section. yDATA = Days after treatment A = May 30, 2013. xDATC = Days after treatment C = June 12, 2013. wMeans are the average of four replicates. Means followed by the same letter do not differ significantly according to the Least Significant Difference test (a = 0.05)

Table 4. Percent Weed Cover Following Single and Repeat Herbicide Applications.

Weed Cover (%) Goosegrass

Trt. No.

Treatment Name

1

Nontreated

2

Pylex + MSO

0.5 fl. oz./a 0.5 % v/v

3

Pylex + MSO

4

Rate

Application Timing

z

Crabgrass

Yellow Nutsedge y

61 DATA /48 DATC w

Flatsedge

x

5 bc

73 a

3a

6c

AB

1 bc

8c

15 a

68 a

0.75 fl. oz./a 0.5 % v/v

AB

10 b

8c

4a

71 a

Pylex + MSO

1 fl. oz./a 0.5 % v/v

A

24 a

50 b

0a

14 c

5

Pylex + MSO

0.5 fl. oz./a 0.5 % v/v

CD

0c

17 c

16 a

57 ab

6

Pylex + MSO

0.75 fl. oz./a 0.5 % v/v

CD

0c

11 c

13 a

61 ab

7

Pylex + MSO

1 fl. oz./a 0.5 % v/v

CD

0c

8c

5a

75 a

8

Revolver

26 fl. oz./a

CD

2 bc

43 b

1a

28 bc

9

Acclaim Extra

28 fl. oz./a

CD

0c

2c

18 a

55 ab

9

19

23

35

LSD (P = 0.05)

zLetters correspond to the timing and growth stage in the Our Research section. yDATA = Days after treatment A = May 30, 2013. xDATC = Days after treatment C = June 12, 2013. wMeans are the average of four replicates. Means followed by the same letter do not differ significantly according to the Least Significant Difference test (a = 0.05)

24 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

but it occurred more rapidly, and the bermudagrass began to recover faster from Pylex injury.

Two applications of Pylex gave excellent goosegrass control at both growth stages. A single application of Pylex at the 2-leaf stage initially gave good goosegrass control but control decreased over time, probably due to new germination. Two applications of Revolver and Acclaim Extra also provided excellent goosegrass control. Pylex gave greater control of goosegrass than of southern crabgrass. Crabgrass control with Pylex was improved when the two applications were started in May, compared to starting in June, probably due to the smaller plant size at the earlier timing. Revolver did not control southern crabgrass.

Rice flatsedge invaded all treated plots during the course of the trial. c

Journal of the Virginia Turfgrass Council

| 25

Research Summaries

Evaluating the Potential Benefits of Adding Compost and/or Microclover to New and Established Turfgrass Stands Virginia Tech Researcher: Mike Goatley, Ph.D., Professor and Turfgrass Extension Specialist; Whitnee Askew, Senior Technician; Jeffrey F. Derr, Ph.D., Professor of Weed Science; and Adam Nichols, Research Assistant Cooperators: National Fish and Wildlife Foundation, University of Maryland, Penn State University, Mike Zirkle and Robert Habel (Winton Country Club, Amherst, VA)

V

irginia Tech (along with Penn State) is conducting satellite demonstrations as part of a University of Maryland–funded grant from the National Fish and Wildlife Foundation examining the potential benefits of compost and/or microclover addition as part of turfgrass management programs. The research is being conducted at Winton Country Club in Amherst, VA, and at the Hampton Roads Agricultural Research and Extension Center in Virginia Beach.

The objectives of this project are: (1) to evaluate and promote the adoption of compost incorporation prior to turf establishment as a best management practice within new residential developments; (2) to reduce lawn nitrogen (N) fertilizer use by promoting the use of lawn seed mixtures that contain microclover; and (3) to show that stormwater volume will be reduced and stormwater quality improved by implementing the first and second objectives within a residential development.

The work at Winton C.C. is utilizing tall fescue for its establishment trial and an existing mixed-stand of cool-season grasses for the incorporation of compost and microclover into an existing turf stand at its site, while the Virginia Beach site is utilizing bermudagrass as its predominant turf cover for both trials.

Microclover is essentially a smaller version of the traditional white clover (Trifolium repens L.). Our observations suggest that it flowers deeper in the turf 26 | Virginia Turfgrass Journal

canopy, thus not being as disruptive to turf uniformity as traditional stands of white clover. The premise is that the microclover, as a legume, will release some of the N fixed by the symbiotic relationship between the grass and soil-borne Rhizobium bacteria that fix the N. To date, we have not observed a significant turf color or quality enhancement from the incorporation of the microclover into the newly planted or Compost response on tall fescue.

established turf plots. The compost treatments (2" pre-plant incorporated into the establishment trial site; 1/4" depth topdressing annually for the established site where materials are introduced) continue to benefit the overall enhancement of color and density of the grasses at both sites (Figure 1), and there is a trend for the compostamended soils to have increased water infiltration and percolation rates. This research continues through 2014. c

Postemergence and Residual Crabgrass Control with Cavalcade PQ in Cool-Season Turf Virginia Tech Researcher: Adam Smith, Graduate Research Assistant, and Shawn Askew, Ph.D., Associate Professor and Extension Specialist; with George Hackman, Research & Development Representative, SipcamAdvan

Q

uinclorac is a postemergence control option for crabgrass in cool-season turfgrass. Preemergence products containing quinclorac allow some flexibility in application by combining preemergence residual control with early postemergence crabgrass control from quinclorac.

Our research evaluated products containing prodiamine and quinclorac for control efficacy against smooth crabgrass and broadleaf weeds. Two trials were initiated in fairway-height perennial ryegrass on June 12 and July 9, 2013. On June 12, smooth crabgrass was 3–4 leaf stage. On July 9, smooth crabgrass was 1–2 tiller stage.

Treatments were as follows: • Cavalcade (prodiamine) at 0.37 oz./1,000 ft2 • Cavalcade PQ (prodiamine + quinclorac) at 0.85 oz./1,000 ft2 • quinclorac at 0.365 oz./1,000 ft2 • dithiopyr at 1.5 fl oz./1,000 ft2 • Cavalcade PQ at 0.7 oz./1,000 ft2 • Cavalcade PQ at 0.7 oz./1,000 ft2 with methylated seed oil (MSO) at 0.55 fl. oz./1,000 ft2 • non-treated check, for comparison Crabgrass and broadleaf control was rated 1, 2, 4, 6, 8, 12, 16 and 20 weeks after treatment (WAT). In 3–4 leaf stage crabgrass, initial control was excellent for all products containing quinclorac. At 2 WAT, products containing quinclorac controlled crabgrass 91% or better. The best control was 100% from Cavalcade PQ + MSO and quinclorac alone. Dithiopyr controlled crabgrass 25%.

At 4 WAT, products containing quinclorac controlled crabgrass 99% or better. Dithiopyr controlled crabgrass 94%. At 8 WAT, quinclorac alone and dithiopyr controlled crabgrass 78%.

Cavalcade did not provide sufficient control. Cavalcade PQ at both rates and with MSO controlled crabgrass 94% to

98%. The same treatments controlled white clover 100% and common dandelion 88% to 98%. At 12 WAT, all Cavalcade PQ treatments controlled smooth crabgrass 90% or better. Quinclorac alone and dithiopyr controlled crabgrass 79 and 70%, respectively.

In 1–2 tiller crabgrass, dithiopyr and Cavalcade provided minimal crabgrass control; only treatments containing quinclorac controlled crabgrass. At 1 WAT, quinclorac alone and Cavalcade PQ controlled crabgrass 81% to 86%.

At 2 WAT, crabgrass control ranged from 81% to 93%. Cavalcade PQ at 0.85 oz./1,000 ft2 controlled crabgrass 93%.

At 4 WAT, crabgrass control ranged from 73% to 89%. Quinclorac alone controlled crabgrass 86%. Cavalcade

PQ at 0.7 oz./1,000 ft2 controlled crabgrass 73%. Cavalcade PQ at 0.7 oz./1,000 ft2 + MSO and Cavalcade PQ at 0.85 oz./1,000 ft2 controlled crabgrass 88% and 89%, respectively.

For 6, 8 and 12 WAT, treatments maintained similar control across dates.

Cavalcade PQ at 0.85 oz./1,000 ft2 and at 0.7 oz./1,000 ft2 + MSO averaged 80% to 81% control. Quinclorac alone averaged 76% to 77%. Cavalcade at 0.7 oz./1,000 ft2 without MSO controlled crabgrass 60% to 70%.

These results suggest that the inclusion of MSO to Cavalcade PQ at a lower rate can provide sufficient control of smooth crabgrass and can significantly increase crabgrass control when applied to more mature crabgrass. c

Research Report continued

Preemergence and Postemergence Control of Arthraxon hispidus Virginia Tech Researcher: Jeffrey F. Derr, Ph.D., Professor of Weed Science, and Adam Nichols, Research Assistant, Virginia Tech, Hampton Roads Agricultural Research and Extension Center, Virginia Beach Research Sponsors: Virginia Turfgrass Council and Virginia Turfgrass Foundation

J

ointhead arthraxon [Arthraxon hispidus (Thunb.) Makino], also referred to as small carpetgrass, is a native of Asia. Jointhead arthraxon is a low-growing grass with ovate leaf blades and hairs along the margins of the leaf blades, and the cordate bases of the leaves encircle the stem. The flowers are borne on digitate spikes. This summer annual grass prefers sunny, wet habitats. It can be a weed in turfgrass and other areas.

Little information is available on the control of this weed. In our research,

we conducted greenhouse trials to evaluate commonly used preemergence and postemergence herbicides in turfgrass for control of jointhead arthraxon.

Pendulum (pendimethalin), Barricade (prodiamine), Tenacity (mesotrione), Ronstar (oxadiazon), Dimension (dithiopyr), Tupersan (siduron), Specticle (indaziflam) and Dacthal (DCPA) all gave 80% or greater preemergence control of jointhead arthraxon. Pylex (topramezone) and Drive (quinclorac) provided lower control.

In postemergence trials, single applications of Acclaim Extra (fenoxaprop) and Fusilade (fluazifop) and two applications of Tenacity, Pylex or MSMA all gave 70% or greater control of jointhead arthraxon. Dimension and Specticle provided overall lower postemergence control, while Drive did not control this weed when applied postemergence.

Control strategies for jointhead arthraxon appear to be similar for this weed and for crabgrass, with the exception of Drive application. c

Rimsulfuron Plus Metsulfuron for Spring and Fall Transition of Overseeded Bermudagrass Turf Virginia Tech Researcher: Michael C. Cox, Graduate Research Assistant, and Shawn D. Askew, Ph.D., Associate Professor and Turfgrass Extension Specialist

N

egate™ is a new herbicide developed by Quali-Pro and released in 2013 into the turf market. Negate contains the active ingredients rimsulfuron and metsulfuron to form a bermudagrass-transitioning herbicide that should offer a broader spectrum of grass and broadleaf weed control than other products currently on the market.

Field trials were conducted in spring 2012 and 2013 and fall 2013 in Blacksburg, VA, at the Glade Road Research Facility to determine how Negate™ compares to industry standards for perennial ryegrass/bermudagrass transitioning and how perennial ryegrass establishment is affected from different overseeding timings after application of these herbicides. Trial locations were on ‘Patriot’ bermudagrass fairways maintained at a 0.5"

mowing height. The perennial ryegrass control studies were initiated on May 16, 2012, and May 29, 2013.

The perennial ryegrass establishment study was conducted exactly like the perennial ryegrass control study with the addition of four perennial ryegrass overseeding times per herbicide treatment to assess perennial ryegrass stand establishment.

Herbicide treatments for both studies included Negate at 1.5 oz./A, QP rimsulfuron at 1.0 oz./A, Monument™ (trifloxysulfuron) at 0.35 oz./ A, Revolver® (foramsulfuron) at 17 fl. oz./A and Katana™ (flazasulfuron) at 1.5 oz./A. All treatments contained a nonionic surfactant at 0.25% v/v, and an untreated check was included for comparisons.

Negate controlled perennial ryegrass, annual bluegrass, common dan-

28 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

delion and white clover equivalently to or better than the industry standards QP rimsulfuron, Monument, Revolver and Katana, 35 days after treatment (DAT). All treatments reduced perennial ryegrass stand biomass by greater than 20%, 8 weeks after treatment, except Negate and QP rimsulfuron at the 28 DAT seeding and Revolver® at all seeding times. Bermudagrass was not injured at any time during these studies.

These data suggest that Negate™ is an effective herbicide for controlling perennial ryegrass, annual bluegrass, common dandelion and white clover in a spring bermudagrass-transitioning situation, but they should not be applied later than approximately four weeks before overseeding with perennial ryegrass in the fall to avoid perennial ryegrass biomass reduction exceeding 20%. c

Research Report continued

Goosegrass Control and Bermudagrass Response to Pylex™ Virginia Tech Researcher: Michael C. Cox, Graduate Research Assistant, and Shawn D. Askew, Ph.D., Associate Professor and Turfgrass Extension Specialist

T

opramezone is an HPPDinhibiting herbicide recently labeled for use in turfgrass (in June 2013) by BASF Corporation under the trade name Pylex™. In previous non-replicated experiments, Pylex™ controlled mature goosegrass at rates much lower than those required to suppress bermudagrass in cool-season turf species. The addition of Turflon® Ester (triclopyr) to HPPD inhibitors, such as Pylex, has been shown to broaden the spectrum of weed control and significantly reduce whitening symptoms. Due to the recent ban and/or restrictions placed on MSMA in turf, more research is warranted to elucidate new herbicide programs for goosegrass control in bermudagrass turf.

Greenhouse and field trials were conducted in spring and summer 2013 in Blacksburg, VA, at the Glade Road Research Facility and Turfgrass Research Center at three sites infested

with goosegrass and at one site containing 31 bermudagrass varieties to determine the lowest rate at which Pylex, with or without the addition of Turflon, controls goosegrass while maintaining commercially acceptable bermudagrass quality. After the extensive dose-response greenhouse study was analyzed, Pylex and Turflon rates were refined and used for field studies.

In the field, Pylex was applied twice, three weeks apart, at 0.25 and 0.5 fl. oz./A alone and with the addition of Turflon at 4 fl. oz./A. Each treatment contained a methylated seed oil surfactant at 0.5% v/v, and an untreated check was included for comparison.

All treatments reduced goosegrass cover below 3% and 7% with and without the addition of Turflon, respectively, 70 days after initial treatment.

Injury from Pylex alone was higher within three weeks of application; however, injury persisted longer from treatments containing Turflon.

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Bermudagrass varieties most sensitive to Pylex plus Turflon include ‘Tifway’, ‘Veracruz’, ‘Premier’ and ‘Northbridge’ (OKC 1134). All bermudagrass varieties recovered completely by 4 weeks after treatment (WAT) under normal maintenance practices.

These data suggest that Pylex applied twice at 0.25 fl. oz./A controls mature goosegrass, and the addition of Turflon at 4 fl. oz./A seems to suppress regrowth, as well as eliminate whitening symptoms. Although all bermudagrass varieties recovered by 4 WAT from all treatments, these Pylex and Turflon rates still appear to be higher than required to achieve goosegrass control and maintain acceptable bermudagrass quality. Future work should continue to refine Pylex and Turflon rates, as these herbicides show potential for use in a postemergence goosegrass control program in bermudagrass turf. c

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Journal of the Virginia Turfgrass Council

| 29

Turfgrass Calendar June 2

Virginia Tech’s Turfgrass Researchers Shawn D. Askew, Ph.D.

Bob Ruff Jr. Memorial Research Golf Tournament

Wintergreen Resort/Stoney Creek Golf Course Wintergreen, VA

Virginia Tech 435 Old Glade Road Blacksburg, VA 24061 (540) 231-5807 saskew@vt.edu

June 16–22

Jeffrey F. Derr, Ph.D.

U.S. Open

Pinehurst Resort & C.C. Pinehurst #2 Village of Pinehurst, NC

June 17

VTC Regional Seminar Pesticide Recertification/ Fertilizer Certification

(VTC members attend free!)

Hampton, VA

June 24

Hampton Roads AREC Turfgrass Field Day, Pesticide Recertification and Certified Fertilizer Applicator

Hampton Roads AREC Virginia Beach, VA

July 27–29

PLANET Legislative Day on the Hill

Washington, D.C.

July 29 – August 1 TPI Summer Convention & Field Days

(Turfgrass Producers International) Ritz Carlton, Philadelphia Philadelphia, PA

Virginia Tech Hampton Roads Agricultural Research Station 1444 Diamond Springs Rd. Virginia Beach, VA 23455 (757) 363-3912 jderr@vt.edu Erik H. Ervin, Ph.D.

Virginia Tech 339 Smyth Hall, CSES Dept.

Blacksburg, VA 24061 (540) 231-5208 ervin@vt.edu Mike Goatley Jr., Ph.D.

Virginia Tech 420 Smyth Hall, CSES Dept.

Blacksburg, VA 24061 (540) 231-2951 goatley@vt.edu David McCall

Virginia Tech 435 Old Glade Road Blacksburg, VA 24061 (540) 231-9598 dsmccall@vt.edu

August 26–27 VT/Blacksburg Turfgrass Field Days

Virginia Tech Blacksburg, VA

December 15–19

Virginia Tech’s Turfgrass Short Course

Henrico County, VA

January 26–29, 2015 VTC 55th Annual Turf & Landscape Conference and Trade Show

Fredericksburg Expo & Conference Center Fredericksburg, VA

30 | Virginia Turfgrass Journal May/June 2014 www.vaturf.org

Index of Advertisers Alliance Material Handling, INC...........27 www.alliancemat.com Aqua-Aid, Inc...........................................27 www.aquaaid.com Arctech, Inc...............................................9 www.arctech.com Bayer..........................................................5 www.bayerprocentral.com Buy Sod......................... Inside Back Cover www.buysod.com Capitol Sports Fields..............................19 www.capitolsportsfields.com Collins Wharf Sod Farm.........................10 www.collinswharfsod.com Colonial Farm Credit..............................29 www.colonialfarmcredit.com Egypt Farms Inc........................................8 www.egyptfarms.com Horizon Distributors..............................23 www.horizononline.com Kesmac Inc.................. Inside Front Cover www.kesmac.com Landmark Turf & Native Seed..............13 www.turfandnativeseed.com Leading Edge Communications.............25 www.LeadingEdgeCommunications.com Lebanon Turf...........................Back Cover www.countryclubmd.com Luck Stone Corporation.........................15 www.luckstone.com Modern Turf, Inc......................................9 www.modernturf.com Smith Seed Services................................29 www.smithseed.com Southern States Cooperative....................3 www.southernstates.com The Turfgrass Group...............................7 www.theturfgrassgroup.com