Mississippi Turfgrass - Summer 2014

Summer 2014

The Mississippi Turfgrass Association Magazine

Preventing and Managing

Herbicide-

Resistant

Weeds

Why Are Nematodes — Which Are Aquatic Animals — a Problem in Turf?

Prepping Sports Fields for the Next Harsh Winter

Summer 2014

Contents • The Mississippi Turfgrass Association Magazine Features

8 Upcoming Event

11 Save the Dates

MSU Turfgrass Research Field Day, August 26

MTA Annual Conference, November 10–12

12

12 Cover Story

Preventing and Managing Herbicide-Resistant Weeds

16 Golf Course Notes

Why Are Nematodes — Which Are Aquatic Animals — a Problem in Turf?

20 Sports Turf Tips

Last Winter Was Harsh — Let’s Prepare for the Next “Big One”

Departments

6 From the MTA President

7 Membership Application

16

22 Mississippi State Turf Team 22 Calendar of Events 22 Index of Advertisers Cover Photo: Dancing Rabbit Golf Club in Philadelphia, MS. Photo by Jay McCurdy, Ph.D., Mississippi State University.

www.msturfassociation.org 4 • Mississippi Turfgrass • Summer 2014

20

President’s message

Welcome to

Josh Quinn

Your new Magazine!

I

hope this letter finds you, your family and your turf doing well. And no, you’re not seeing things; this is our new and very much improved newsletter (now a full-color, glossy magazine!). We have partnered with Leading Edge Communications (in Franklin, TN) to enhance our quarterly publication. This, we’re sure, will more accurately reflect the professionalism of our great association and the Mississippi turf industry as a whole. The articles, photographs and advertisements should be more appealing and effective in “color,” and we hope you enjoy.

Whether managing an ultradwarf putting green, a St. Augustine lawn or a 419 athletic field, our day is much more enjoyable, our message is more effective, and our turf is much more appealing if it is green. And, you, as the turf manager, know that specific green I’m talking about. If it’s not that healthily green you desire, and you can’t figure out why, I encourage you to utilize this association’s members, publications, educational events and vendors for help. The overall expertise, experience and friendliness are abundant assets to you.

I hope you were able to attend our first two events of the year at two great facilities. Many thanks to the staff at Dancing Rabbit for hosting our annual workshop and golf day and to The Refuge staff for hosting the Yarddawg Classic.

A few upcoming opportunities still await us. On August 26, our annual MSU Turfgrass Research Field Day will be held once again back at North Farm, in Starkville. This event, for those who haven’t attended in the past, is a great day of hands-on education where you can examine, walk on and touch turf in the field. Everything from herbicide treatments to shade effects on bermudagrass has been displayed in the past.

We also have our annual MTA Conference taking place November 10–12, again at Bost Conference Center. This event is also a must-attend gathering for those seeking to gain valuable education (for cheap). Dr. Jay McCurdy has already lined up many great speakers who are in high-demand for conferences, such as ours, nationwide. Please make plans to attend these two great events.

I hope your summer continues to go well (or improve), and I look forward to seeing you at one, or both, of our next events.

Josh Quinn MTA President

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 615-790-3718 fax 615-794-4524 info@leadingedgecommunications.com Mississippi Turfgrass Editor James D. McCurdy, Ph.D.

MTA OFFICERS

President Josh Quinn Perfect Turf Lawn Solutions (601) 906-2591 Vice President Toby Thornton Shell Landing Golf Course (601) 507-4254 Secretary/treasurer Wayne Philley Mississippi State University (662) 325-2728 Past President Jeremy Stevens The Preserve Golf Club (228)323-3667 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

Erick Coomer Greenwood Country Club (228) 860-5292 Dan Crumpton Oasis Sod Farms (662) 621-2040 Ken Edwards City of Gulfport (228) 861-5641 Jeremy Ely Sunkist Country Club (228) 669-6745 Al Osteen The Annandale Golf Club (601) 214-9907

Drew Rochelle Agri-AFC (256) 476-3890 Adam Strehle Quality Turf Services (662) 719-8029

6 • Mississippi Turfgrass • Summer 2014

Membership Application Box 9555 • Mississippi State, MS 39762 • 662-325-0517 (Office) • 662-325-2705 (Fax) The Mississippi Turfgrass Association is a non-profit organization of individuals interested in promoting and expanding the turf and landscape industry in Mississippi and surrounding states. The objectives of the organization are to: • Promote quality turf and landscape management.

•D isseminate information and educational material on turf and landscape culture.

•S ponsor needed research, scholarships for deserving students, and conferences on timely topics.

•C ooperate with other organizations in advancing educational opportunities in turf and landscape management.

Any individual interested in the advancement of turfgrass or landscape management is invited to join the organization. This includes professionals in golf course and grounds maintenance, sod and seed producers, landscape contractors, landscape architects, horticulturists, agronomists, nurserymen, educators, athletic field managers, park managers, and representatives of manufacturers, wholesalers, and retailers of turf and landscape equipment, chemicals, and supplies.

DUES Annual dues are $50 for individuals and single business representative membership *$100 for businesses requesting two to four individuals receiving newsletter * Attach names and addresses for additional newsletter mailings (business only).

Membership year runs January 1 – December 31.

Mail to: MTA, Box 9555, Mississippi State, MS 39762

Work Association

Name*: Firm or Club Name:

o Golf Course

Street Address:

o Grounds Maintenance

City: State: Telephone: Work (

)

Cell (

)

Zip:

o City/State Park Maint. o Lawn Care

Email:

o Sod

Make check payable to Mississippi Turfgrass Association (MTA)

o Product Representative

If you prefer, you may pay by credit card:

o Education

o Visa

Card Number: Expiration Date: Signature:

o MasterCard

o American Express

o Athletic Fields o Other

Upcoming event

SCHEDULE AT A GLANCE 8:00 a.m.

Registration and Vendor Social (coffee and donuts) 8:45 a.m.

Welcome by Jay McCurdy, Ph.D. Assistant Professor 9:00 a.m. – 11:00 a.m.

Concurrent Educational Sessions (see below) 11:00 a.m. – 1:00 p.m.

Vendor Expo and Meet the Experts (field demos and vendor meet-up) 12:00 p.m.

Lunch, Presentation of Honors, Prizes Closing Remarks and Raffle

CONCURRENT EDUCATION SESSIONS

AUGUST 26, 2014

MISSISSIPPI STATE TURFGRASS RESEARCH FIELD DAY Rodney Foil Plant Science Research Center Starkville, MS

The

2014 Turfgrass Field Day, slated for Tuesday, August 26, will showcase the most recent developments from the Mississippi State Turfgrass Team. Learn about the latest and greatest bermudagrass varieties for Mississippi athletic fields, home lawns and golf courses. Increase your knowledge of turf disease and weed management. Enjoy the innovative designs and plant selections at the Mississippi State Trials Garden. Testdrive machinery, and visit with sponsors during the vendor expo. Bring your plant and disease samples to have them identified. And feast on Little Dewey’s famous pork barbecue.

Parking is free, and pre-registrants receive a discounted entry ($25 for turf and ornamental professionals), with lunch and a t-shirt. The deadline for preregistration is August 1, 2014. You may download the registration form at http:// blogs.msucares.com/turfgrass/events/, or call the MTA office at (662) 325-0517. v

Attendees will receive 0.3 GCSAA Continuing Education Points and Recertification for Mississippi Categories 3 and 10 of the Pesticide Applicators License.

8 • Mississippi Turfgrass • Summer 2014

Turfgrass Selection for Mississippi Presenters: Christian Baldwin, Ph.D., Wayne Philley and Benton Hodges Learn about the latest turfgrass selections being evaluated and released onto the market.

Technologies for Turfgrass Evaluation Presenter: Barry Stewart, Ph.D. Learn about the practical and innovative science that affects the future of our profession.

Turf Disease Management Presenters: Maria Tomaso-Peterson, Ph.D., and Phillip Vines Learn about the latest strategies for disease management on warm- and cool-season turf.

Turfgrass Weed Management Presenter: Jay McCurdy, Ph.D. Hear an update on turfgrass weed management in fine turf, resistance management and herbicide safety.

Ornamentals for Mississippi Landscapes Presenter: Geoff Denny, Ph.D. Learn about innovative designs and plant selections that make sense in today’s landscape industry.

Save the dates

November 10–12, 2014

MTA Annual Conference & Tradeshow Bost Extension Center, Starkville, MS

H

ere’s a sneak peak at the schedule for this year’s annual Mississippi Turfgrass Association Conference & Tradeshow. Watch for more details in the Fall issue of Mississippi Turfgrass. Mark your calendar for this must-attend event for networking with your peers, catching up on the latest turfgrass research and seeing all the best and newest products and equipment to make your job easier and keep your turf at top quality!

Monday, November 10

»D ollars for Scholars Golf Tournament »M ississippi State Univ. Sports Field Tours »W elcoming Reception

Tuesday, November 11 »G eneral Sessions at Bost Extension Center » L unch and Research Updates » T radeshow, Auction and Intern Interview Extravaganza

Wednesday, November 12 »B usiness Meetings: MTA and LMGCSAA »B reakout Educational Sessions »1 2 p.m. Adjourn and CEU/Pesticide Signup v

The Mississippi Turfgrass Association Magazine • 11

Cover Story

Preventing and Managing

Herbicide-Resistant

WEEDS

By Jay McCurdy, Ph.D., Assistant Professor, Mississippi State University; Scott McElroy, Ph.D., Professor, Auburn University; and John Byrd Jr., Ph.D., Professor, Mississippi State University

H

erbicide-resistant weeds are among the most troublesome issues facing the turfgrass industry. The loss of effective and economically viable herbicides results in lower-quality turf and increases weed-management budgets.

Preventing and managing herbicide resistance is crucial to preserving the key chemistries that turfgrass managers use to provide a playable and aesthetically pleasing turf surface.

Herbicide resistance

Herbicide resistance is the inherited ability of a plant population to survive and reproduce after being treated with a normally lethal dose of herbicide.

12 • Mississippi Turfgrass • Summer 2014

This is not a new issue. Simazine- and atrazine-resistant groundsel (Senecio vulgaris) was reported as early as 1970.

Simazine-resistant annual bluegrass (Poa annua) has plagued golf courses, sports fields, industrial turf and sod producers in the Southeast for more than two decades.

As of 2014, more than 420 unique cases of herbicide-resistant weeds have been reported globally. This equates to 232 species having evolved resistance to 22 of 25 known herbicide sites of action and to 152 different herbicides. Table 1 lists the herbicideresistant turfgrass weeds of Mississippi as of 2014.

Mode of action (MOA)

Herbicides are active at one or more target site(s) within plants. Target sites are often enzymes that play a critical role in plant metabolism. The term “site of action” is used interchangeably with MOA; however, the terms have somewhat different connotations. The MOA is how a herbicide kills a plant. For instance, atrazine inhibits photosystem II, subsequently leading to a buildup of oxidative free radicals and a decrease in photosynthesis. Site of action is where the herbicide binds in order to kill a plant. Atrazine inhibits photosystem II by binding to a specific site

Table 1

Herbicide-resistant turfgrass weeds of Mississippi, reported by the International Survey of Herbicide Resistant Weeds. Readers should note that there are likely instances of resistance not yet reported.

Resistant Weed

Mode of Action

Active Ingredient

Trade Name

State

Goosegrass

Mitotic Inhibition

pendimethalin, trifluralin

Pendulum, Treflan

MS

Goosegrass

EPSP synthase Inhibition

glyphosate

Roundup

MS

Poa Annua

Photosystem II Inhibition

atrazine, simazine

AAtrex, Princep

MS

Table 2

Modes of action of herbicides commonly used by turfgrass managers, listed with active ingredients and trade names for reference.

Mode of Action

of action, the Quinone B binding niche on the D1 protein.

Table 2 lists common turfgrass MOAs and example trade names. The fundamental principle for managing herbicide resistance is this: repeatedly relying upon a single MOA selects for populations that are resistant. Herbicides do not cause a mutation; they merely select for populations that tolerate a dose of herbicide. Subsequently, those populations expand in number.

Preventing herbicide resistance requires rotating herbicide MOAs in order to avoid the expansion of resistant populations. Classification systems have been developed to help herbicide appli-

WSSA

HRAC

Active Ingredient

Trade Name

Acetyl CoA Carboxylase (ACCase) Inhibition

1

A

diclofop clethodim

Illoxan Envoy

Acetolactate Synthase (ALS or AHAS) Inhibition

2

B

bispyribac-sodium foramsulfuron

Velocity Revolver

Photosystem (PS) II Inhibition

5

C1

simazine

Princep

Photosystem (PS) I Inhibition

22

D

diquat

Reward

Protoporphyrinogen Oxidase (Protox) Inhibition

14

E

oxidiazon sulfentrazone

Ronstar Dismiss

Carotenoid Biosynthesis Inhibition

28

F2

mesotrione topramezone

Tenacity Pylex

Enolpyruvyl Shikimate-3-Phosphate (EPSP) Synthase Inhibition

9

G

glyphosate

Roundup

Glutamine Synthase Inhibition

10

H

glufosinate

Finale

Mitotic Inhibition

3

K1

prodiamine

Barricade

Cellulose Synthesis Inhibition

29

L

indaziflam

Specticle

Fatty Acid and Lipid Biosynthesis Inhibition

16

N

ethofumesate

Prograss

Synthetic Auxins

4

O

dicamba

Banvel

cators alternate MOAs. The most common are those developed by the Weed Science Society of America (WSSA, http://wssa.net) and the Herbicide Resistance Action Committee (HRAC, www.hracglobal.com).

The WSSA system assigns each herbicide a number based upon the MOA. The HRAC system assigns a letter based upon an alphabetized list of herbicide MOAs; hence, the inhibition of acetyl CoA carboxylase (ACCase) is assigned the HRAC grouping of A. HRAC further amends herbicide groupings with a subscript numbering system that indicates different binding behaviors.

In the case of photosystem II-inhibiting

herbicides, subclasses C1, C2 and C3 indicate different behaviors with a key binding protein.

Resistance development

From a biochemical standpoint, plants develop resistance either through targetsite or non-target-site-based resistance.

Target-site resistance is a change in the biochemical target of a plant that prevents the herbicide from binding to the site of action or acting as it would normally. Many herbicides are very specific in their activity; for example, acetolactate synthase-inhibiting herbicides, such as Revolver, bind to the enzyme acetolactate synthase (ALS), thus The Mississippi Turfgrass Association Magazine • 13

Cover Story • Continued

Table 3

Mode of action and classification of common turfgrass herbicide site of action according to the Weed Science Society of America (WSSA) and the Herbicide Resistance Action Committee (HRAC).

Timing

Mode of Action

WSSA

HRAC

Active Ingredient

Trade Name

Pre

Mitotic Inhibition

3

K1

dithiopyr

Dimension

Pre

Mitotic Inhibition

3

K1

pendimethalin

Pendulum

Pre

Mitotic Inhibition

3

K1

prodiamine

Barricade

Pre

Lipid Biosynthesis Inhibition

8

N

bensulide

Bensumec

Pre

Photosystem II Inhibition

7

C2

siduron

Tupersan

Pre

Protoporphyrinogen Oxidase (PPO) Inhibition

14

E

oxadiazon

Ronstar

Pre/Post

Mitotic Inhibition

15

K3

dimethenamid

Tower

Pre/Post

Mitotic Inhibition

3

K1

pronamide

Kerb

Pre/Post

Mitotic Inhibition

15

K3

metolachlor

Pennant Magnum

Pre/Post

Photosystem II Inhibition

5

C1

amicarbazone

Xonerate

Pre/Post

Photosystem II Inhibition

5

C1

atrazine

AAtrex

Pre/Post

Photosystem II Inhibition

5

C1

metribuzin

Sencor

Pre/Post

Photosystem II Inhibition

5

C1

simazine

Princep

Pre/Post

Cellulose Synthesis Inhibition

29

L

indaziflam

Specticle

Pre/Post

Lipid Biosynthesis Inhibition

16

N

ethofumesate

Prograss

Pre/Post

Carotenoid Biosynthesis Inhibition

28

F2

mesotrione

Tenacity

Pre/Post

Protoporphyrinogen Oxidase (PPO) Inhibition

14

E

flumioxazin

SureGuard

Post

Synthetic Auxin

4

O

2,4–D

multiple

Post

Synthetic Auxin

4

O

dicamba

Banvel

Post

Synthetic Auxin Inhibition of Cell Wall Synthesis

4 27

O L

quinclorac

Drive

Post

Acetolactate Synthase (ALS) Inhibition

2

B

bispyribac-sodium

Velocity

Post

Acetolactate Synthase (ALS) Inhibition

2

B

foramsulfuron

Revolver

Post

Acetolactate Synthase (ALS) Inhibition

2

B

imazaquin

Image

Post

Acetolactate Synthase (ALS) Inhibition

2

B

metsulfuron

Manor

Post

Acetolactate Synthase (ALS) Inhibition

2

B

rimsulfuron

TranXit

Post

Acetolactate Synthase (ALS) Inhibition

2

B

sulfosulfuron

Certainty

Post

Acetolactate Synthase (ALS) Inhibition

2

B

trifloxysulfuron

Monument

Post

Acetyl CoA Carboxylase (ACCase) Inhibition

1

A

diclofop

Illoxan

Post

Acetyl CoA Carboxylase (ACCase) Inhibition

1

A

clethodim

Select

Post

Enolpyruvyl Shikimate-3-Phosphate (EPSP) Synthase Inhibition

9

G

glyphosate

Roundup

Post

Glutamine Synthase Inhibition

10

H

glufosinate

Finale

Post

Photosystem II Inhibition

6

C3

bentazon

Basagran

Post

Photosystem I Inhibition

22

D

diquat

Reward

Post

Photosystem I Inhibition

22

D

paraquat

Gramoxone

14 • Mississippi Turfgrass • Summer 2014

Continued

preventing the production of branchedchain amino acids. Enzymes such as ALS are several-hundred amino acids long. A change in just one amino acid may prevent the herbicide from binding.

Non-target-site herbicide resistance is a change in the ability of the herbicide to be absorbed, translocate throughout the plant or be metabolized by the plant. To change absorption, the plant may develop a thicker epicuticular wax layer or change the cutin amount in the cuticle. Glyphosate resistance in horseweed (Conyza canadensis) occurs due to reduced translocation of the herbicide.

•

Cover Story

Image 1. Many agro-chemical companies have adopted a strategy of clearly labeling modesof-action on the product label. Quinclorac (Drive) is a WSSA classified group 4 herbicide, which means it is a synthetic auxin.

Steps to prevent and manage herbicide resistance

Herbicide resistance is real, but steps can be taken to prevent resistance and control already resistant populations.

The WSSA and HRAC classification systems are tools for the development of resistance-management strategies, but they should not be relied upon solely.

Principally, proper cultural management enhances turfgrass vigor and reduces the reliance upon chemical weed control.

Mechanical weed removal and application of non-selective herbicides via spotspraying are also crucial elements of resistance prevention and management.

Rotate modes of action.

Repeat applications of the same MOA will select for resistant plants within a population. The more frequently a turf managers uses herbicides with the same MOA, the more quickly that resistant weed populations will develop. Rotation from Brand A to Brand B does not slow resistance development if both herbicides have the same MOA. Not only must managers rotate different herbicides, but they also must use different MOAs. For instance, using atrazine in rotation with simazine is a futile approach, as both are photosystem II inhibitors (Group 5 herbicides). See Table 3 for a more complete list of WSSA and HRAC classifications.

Use tank mixtures.

By utilizing herbicide tank mixtures

with different MOAs that are active on the same species, the weedy population would need to have tolerance to two different MOAs at the same time in order to survive. This may decrease the potential for resistance, although differences of opinion surround the issue. It is, however, likely that multiple MOAs improve the spectrum of weeds controlled, simultaneously reducing plants that need follow-up applications.

Use both pre- and postemergence herbicides.

Integrating both pre- and postemergence herbicides into a weedmanagement plan will diversify MOAs and eliminate weeds before they mature and develop seed. In such a plan, it would also be necessary to rotate both the pre- and post-emergence MOAs used each year. Atrazine followed by simazine would again be futile, because they possess the same MOA. For more information, see publication 1532 for Weed Control Guidelines for Mississippi, available online at http://msucares. com/pubs/publications/p1532.pdf.

Maximize control, and minimize escapes.

It is important that herbicide applicators use the maximum-labeled application

rates in order to maximize control.

Plants that escape control should be removed manually or may be removed chemically using a high rate or nonselective spot-spray application, according to label recommendations.

Optimize the environment for turf plants.

As always, the most important approach for weed management is to simply optimize the environment for the desired turf species. Doing this will decrease the number of weeds that are actually treated by herbicides, thus decreasing the potential for resistance development.

In summary

Herbicide-resistant weeds are an increasing problem. An effective cultural- and chemical-management plan is required to achieve maximum weed control in turfgrass systems; however, emphasis should be placed upon rotating herbicide modes of action and eliminating escaped weeds after herbicidal treatments have been applied. The Weed Science Society of America has developed a five-part training module on herbicide-resistance awareness and education. Those modules can be accessed online at http://wssa.net/weed/resistance/. v The Mississippi Turfgrass Association Magazine • 15

Golf course notes

Why Are

Nematodes

— Aquatic Animals — a Problem in Turf?

By Alan Henn, Ph.D., Professor and Extension Plant Pathologist, Mississippi State University

E

ven when soil has gotten so dry that plants are wilting and the spaces around the soil particles are filled with air, a film of water still surrounds each soil particle. Nematodes swim in that water, moving somewhat like snakes.

While nematodes do not move very far in the soil horizontally (maybe an inch), they can move surprising distances vertically. In Mississippi, they seem to move toward the lowest levels of the putting green during cold weather and move higher in the soil when it is warmer. This means that soil samples taken during colder weather could underestimate the nematode numbers if only the upper four inches are sampled.

That nematodes are found in the water means that a product targeting nematodes (a nematicide of some type, chemical or biological) must (1) move through the turf, (2) move through the thatch or stolon and root mass in ultra-dwarfs, (3) move into the water surrounding the soil particles and (4) enter the nematode through the cuticle.

The need for water solubility is one of the major reasons we no longer have most of our “good” nematicides. Most 16 • Mississippi Turfgrass • Summer 2014

of them have been found contaminating ground and surface water around points of use. This should also caution us to use the products we do have wisely, by following label directions.

How do nematodes hurt turf?

Although really small (about 0.02 inches long), nematodes damage turf by feeding on the plants’ roots. Two factors about this feeding help us understand the damage we see: method of feeding and location of feeding.

Method of nematode feeding

Nematodes with the simplest feeding style simply poke a hole in a root cell using a “stylet.” Imagine a stylet to be something like a roofing nail with a tunnel (like a straw) along the axis.

Once the stylet has penetrated the cell wall, the nematode injects digestive enzymes to liquefy the cell contents, which are sucked out through the “tunnel” or lumen in the stylet.

The feeding of the root-knot nematode is much more complicated.

The newly hatched juvenile pokes a hole in a cell and then burrows inside it to a favored feeding spot. Once there,

it secretes substances that modify the cells to make them larger and pull in more nutrients from the rest of the root.

The female nematode stops moving and enlarges to look something like a balloon, the head being the tie area of the balloon. Her head moves from side to side, feeding on the swollen cells. The combination of the swollen cells and enlarged female make the small gall that can be seen on the turf roots.

Dagger and sting nematode feeding methods fall between these two extremes — some cellular modification and some “eat and run.”

Feeding location

Root-knot nematodes and sting nematodes like to feed near the root tips. In some greens infested with sting nematodes, the end of the “stung” root can look similar to DNA herbicide injury. That is, the root tip may be slightly swollen or truncated. Rootknot-infected roots will be more swollen, ending in a “knot,” or may have a few knots along it. Since the nematodes are feeding near the root tip, the plant tries to put out side roots, which in turn are fed on by the

A green infested with sting nematodes. Note the differences in turf density and coloration. These patterns can be used to sample the area for nematodes.

nematodes. Fine feeder roots are the preferred diet. The entire root system starts to take on the appearance of a stunted tree. The more nematode pressure, the more stunted and distorted the root.

Other nematodes, such as the lance, will tunnel for some distance inside the roots. Then they pop out and feed on the outside (feeder roots and smaller roots). This will leave discolored (brown to very dark brown/black) areas in the roots and, once again, very few fine roots.

Effect of feeding

The reduction in fine feeder roots (the workhorses of the root system), the reduction in overall root length and the reduced function of the remaining roots mean that the turf’s water and nutrient absorption is impaired. The turf starts to wilt during the hotter parts of the day, will turn off-color and will not be able to spread and fill in damaged areas.

Reduction in plant vigor, color and growth occurs slowly, so the first time many superintendents realize they have a nematode problem is when they lower the cutting height for a tournament, and the turf can’t grow back.

Management

Juvenile (J2) root-knot nematode orienting to the root tip (Champion cultivar) immediately behind the root cap. This is the preferred feeding area for root-knot nematodes.

Remember that most southern turfgrasses lose their old roots and regrow new ones during spring greenup. I recommend that treatments start at greenup because if the replacement roots become sufficiently stunted by nematode feeding, they will be unable to support the plant during the coming hot weather.

When a turf stand’s root system has been impaired by nematodes, management of the infested area must be intensified. More frequent, light and balanced fertilizations and irrigation will be required. Stresses such as herbicide applications, vertical mowing and dethatching should be performed delicately and at appropriate times.

Control with nematicides will be discussed in the next issue of Mississippi Turfgrass.

The Mississippi Turfgrass Association Magazine • 17

golf course notes • Continued

Close up of typical early symptoms of “thinning” or “fading out” of turf infected with nematodes.

It is only this dramatic after a sudden, severe impact on turf, such as a lowering of the normal cutting height for a tournament or after a herbicide application that has also stressed the turf.

thinner. If the greener area represents about 15% of the green, the browner area 25% and the thin area 35%, then take 15% of the samples from the green area, 25% from the browner area and 35% from the thin area, etc.

Managing the samples

As you take the samples, place them in a bucket. When you have drawn all the samples, break them up, and mix the soil together well. Pour at least one pint of the well-mixed soil into a plastic bag. Immediately place the plastic bag in a cooler. The cooler does not need to contain ice.

It is important that you keep the sample out of the sun. Nematode die quickly with exposure to even weak winter sun and moderate temperatures.

Sending a sample

Determining whether nematodes are a problem on your turf Sampling for nematodes is not difficult, but it can be somewhat involved, depending on the type of answer you want and the degree of surety desired.

Both will change the way you sample.

Types of sampling questions

• If you want to compare two areas, say a particularly bad patch to a wellgrowing patch, then a simple cupcutter core from each area will suffice.

• If you want to compare one area of the green to another area of the green, then a number of roughly 1-inchdiameter cores will need to be drawn from the area and mixed together.

• If you want to know if the entire green is at risk, then you need to pull lots of samples. If the potentially damaging nematode is sting, then about 33 1-inch-diameter cores will need to be drawn from an averagesize green. If the potential nematode 18 • Mississippi Turfgrass • Summer 2014

is root-knot, then you would want to pull a larger amount of cores, possibly 45 to 50. The number of samples required is due to the fact that nematodes are tightly clustered in the soil.

Sample depth

The depth of the sample will somewhat depend on the turf cultivar. Four inchdeep samples will be OK for warmweather sampling of ultra-dwarfs, whereas six-inch-deep samples will be needed for others. During late fall, winter and early spring, you should extend the depth of the sample significantly due to nematode movement deeper into the soil.

Sample pattern

If you are sampling the entire green or a good portion of it, then a great deal of advantage in the surety of the results can be gained from “stratifying” the samples. Examine the green, and pick out areas that look different. Some may be greener or browner, denser or

Send the sample the quickest way you can to the laboratory. If it is close to the weekend, hold the sample in an airconditioned office. Keep the sample away from sunlight, vents and fans.

Samples that sit over the weekend in the post office have fewer nematodes than samples that arrive directly at the laboratory.

Choosing a laboratory

Pick a laboratory that you feel comfortable working with. Make sure that it processes your samples the same way every time. Different laboratories process samples using different methods and will give you different results. Therefore, once you have chosen a laboratory, stick with it, unless you have no interest in comparing one sample to another.

I would suggest choosing a laboratory that can give you guidance about what the number of nematodes in your sample means for your turf. Not all laboratories have this data. Of course, I recommend our laboratory: Mississippi State University Nematode Diagnostic Laboratory Room 90 Bost North, Room 9 Mississippi State, MS 39762-9612 The cost is only $11.00 per sample.

If you have questions, please call me at (662) 325-4535. v

Sports turf tips

r e t n i W t s a L h s r a H s a WLet’s Prepare for the” e —

n O g i B “ Next

By Barry Stewart, Ph.D., Associate Professor, Mississippi State University

One

thing the severe winter of 2013–2014 did was that it identified areas of turf that were weak going into winter.

Areas that were damaged by traffic or suffered from poor drainage or shade issues were some of the areas that recovered most slowly this spring or experienced turf loss. Even many sod producers noticed that their harvested field areas that did not recover were cut earlier in the year than normal. For example, sod cut as early as July suffered winter injury where, in a more normal winter, the cut-off harvest date for winter injury in bermudagrass may have been in August.

I hope that your sports turf has recovered from the winter and that you are heading into the fall playing season with a full turfgrass canopy. In this space, I would like discuss what we can do to assure that we will lose minimal amounts of turf when we experience another severe winter.

Fertilization

First, I hope you have a recent soil test that you can work from or have been working from. Soil testing is one of the best investments you can make in your field. With the exception of some fall adjustments for N and K application, I would follow the test-result recommendations, as they will ensure that your soil fertility is in an optimal (or at least adequate) state with respect to bermudagrass.

20 • Mississippi Turfgrass • Summer 2014

Some soil tests do not typically call for N application after August 15, but I recommend another application of N late in the season. One school of thought is that late-season N application leads to succulent growth and leaves the bermudagrass susceptible to winterkill, but research at Mississippi State in the late 1980s and work done at numerous other locations have proven that this is not actually the case. Furthermore, bermudagrass that received late-season N was found to green up more quickly the following spring.

Some potassium (K) should also be applied with this N unless soil test levels are already in the high range of the soil test. The uptake of N will stimulate growth and a simultaneous and subsequent uptake of K. The K will act as a stress fighter and will allow the grass to go into dormancy and greenup with less stress.

It is interesting to try to locate the origin of the concept of not feeding our grass after August 15. Late-season N applications in some of our other warmseason grasses, including centipedegrass and St. Augustinegrass, can be detrimental due to incidence of brown patch disease. Perhaps someone once made a blanket recommendation to all warmseason turf, and it stuck. Another possibility is that the August 15 cutoff came from home lawns that do not receive the traffic that athletic fields do.

Keeping the turf growing and succulent

in the fall can lead to insect infestations and disease concerns, and this might be a reason not to fertilize a home lawn.

Late-season N applications are not practiced in forage bermudagrasses, so that is another possibility.

An athletic field that is still receiving traffic, however, needs fertility to recover. Rapid recovery outweighs the risks of disease and insects that can be controlled when they occur.

Depending on soil type and field expectations, I would recommend applying 2 to 4 lbs. of N per 1,000 ft2 approximately 9 or 10 weeks before the average first killing frost. Clayey fields or fields with less traffic would be on the lower end of this, and sandy fields or fields with heavy traffic would be on the high end. In Starkville, the first killing frost is usually about November 6, so this last N application would come in the last week of September.

For this application, my recommendation would be for a product that is 50% soluble N and 50% waterinsoluble N. This should allow for even growth throughout the end of the season. If your soil test calls for K, apply an amount one half of what you applied in N. For example, if you applied 3 lbs. of N, then apply 1.5 lbs. of actual K. This application will take the turf through the end of the season and allow it to go into the spring with increased carbohydrate reserves for spring greenup. In most years, we

have very good bermudagrass growing weather in September and October, and extending our fertilizer applications allows us to use this time for bermudagrass growth and the accumulation of carbohydrate reserves The soluble portion of this N application will be taken up quickly after application. The water-insoluble portion will be released more slowly, and some may not be released until the following spring. With this nitrogen available, fall weeds may also grow faster.

Weed control

we are usually better off in the drier falls since field managers have control of the water and wet traffic. Other years, it seems to rain every Friday night, leading to fields that get torn up quickly.

Summary

If you have a bermudagrass athletic field, your fall mantra should be “Grow bermudagrass!” as long as you can, and

that requires a late-season application of N. You wouldn’t put your baby to bed hungry, so why would you send a hungry field into a harsh winter?

Note: The dates used in this article are for Starkville, MS. For northern MS, the dates mentioned would be about two weeks earlier, and for south MS about two weeks later. v

After a harsh winter, many athletic fields have experienced turf loss due to traffic, poor drainage and winter injury. Going into the next winter with a healthy turfgrass canopy and a strong late-season fertility program will help prepare your fields for the next “big one.”

The best defense against these weeds is to maintain a thick, dense turf. But even with the best intentions, the normal wear and tear of athletic field use can lead to holes in the turfgrass stand where some weeds may get a foothold.

On fields that keep a dense turf throughout the fall, with few or no areas of open soil, a good pre-emergence herbicide applied on September 15 will likely keep them weed-free though the spring.

On fields that experience turf loss (i.e., football fields and high-traffic areas on soccer fields), the root inhibiting PRE herbicides are probably not the best choice, and a post-emergence control approach prior to dormancy is probably the best option, followed by some dormant turf application of POST products to clean up any weed infestations. In the spring, on any areas where turf needs to be regrown, root inhibiting PRE herbicides should not be applied.

Irrigation

In Mississippi, September and October are two of our driest months. If rainfall is deficient, then irrigation must be applied for your fertilizer applications to be effective. Although fall days are shorter and may be somewhat cooler than days in July and August, and water demands may not be as high, irrigation will still be needed to take advantage of lateseason fertility. Watering early in the week so the field can dry out prior to late-week games is likely a workable strategy.

In some falls, we get timely rains; in other years, we do not. In my mind,

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The Mississippi Turfgrass Association Magazine • 21

Mississippi State Turf Team

Gary Bachman, Ph.D. Associate Extension/ Research Professor Dept. Coastal Research and Extension Center Specialty: Ornamental Hort.

Phone: (228) 546-1009 gbachman@ext.msstate.edu Clarissa Balbalian, M.S. Diagnostics Lab Manager Dept. Biochemistry, Molecular Biology, Entomology, & Plant Pathology Specialty: Plant Pathology Phone: (662) 325-2146 cbalbali@ext.msstate.edu Christian Baldwin, Ph.D. Assistant Professor Dept. Plant and Soil Sciences Specialty: Turfgrass Mgmt.

Phone: (662) 325-8280 cmb907@msstate.edu John Byrd, Ph.D. Professor Dept. Plant and Soil Sciences Specialty: Invasive Weed Mgmt.

Phone: (662) 325-4537 jbyrd@pss.msstate.edu Geoff Denny, Ph.D. Assistant Extension Professor Dept. Plant and Soil Sciences Specialty: Commercial Ornamental Horticulture Phone: (662) 325-1682 gcd42@msstate.edu Alan Henn, Ph.D. Professor Dept. Biochemistry, Molecular Biology, Entomology, & Plant Pathology Specialty: Ext. Plant Pathologist Phone: (662) 325-4535 ahenn@ext.msstate.edu Lelia Kelly, Ph.D. Extension Professor Dept. North MS Research and Extension Center Specialty: Consumer Hort. Specialist Phone: (662) 566-2201 leliak@ext.msstate.edu

Calendar of events

Blake Layton, Jr., Ph.D. Professor Dept. Biochemistry, Molecular Biology, Entomology, & Plant Pathology Specialty: Extension Plant Entomologist Phone: (662) 325-2085 blayton@entomology.msstate.edu

AUGUST 26

OCTOBER 28–30

James McCurdy, Ph.D. Assistant Professor and Turfgrass Weed Scientist Specialty: Turfgrass Extension Specialist Dept. Plant and Soil Sciences Phone: (662) 325-2331 jmccurdy@pss.msstate.edu

SEPTEMBER 15

LMGCSA SuperPro Shell Landing Golf Club Biloxi, MS

NOVEMBER 10

Wayne Philley, M.S. Senior Research Associate Specialty: Turfgrass Breeding and Evaluation Dept. Plant and Soil Sciences Phone: (662) 325-2728 wphilley@pss.msstate.edu Mike Phillips, Ph.D. Department Head and Professor Dept. Plant and Soil Sciences Phone: (662) 325-2311 jmp657@msstate.edu Wayne Porter, Ph.D. Regional Extension Specialist Specialty: Horticulture Dept. Ext. Southeast Region Phone: (601) 482-9764 wporter@ext.msstate.edu Barry Stewart, Ph.D. Associate Professor Dept. Plant and Soil Sciences Specialty: Sports Turf Science Phone: (662) 325-2725 bastewar@pss.msstate.edu Maria Tomaso-Peterson, Ph.D. Associate Professor Dept. Biochemistry, Molecular Biology, Entomology, & Plant Pathology Specialty: Turfgrass Pathology Phone: (662) 325-2593 mariat@pss.msstate.edu Jeff Wilson, Ph.D. Regional Extension Specialist Specialty: Ornamentals, Landscape, Turfgrass, Fruits and Vegetables Dept. North MS Research and Extension Center Phone: (662) 566-8019 jwilson@ext.msstate.edu

22 • Mississippi Turfgrass • Summer 2014

Mississippi State Turfgrass Research Field Day Rodney Foil Plant Science Research Center Starkville, MS

OCTOBER 14–16

NRPA Congress and Expo (Nat. Parks & Rec. Assn.)

Charlotte Convention Ctr. Charlotte, NC

OCTOBER 22–25

School of Grounds Mgmt. and Green Industry Expo Galt House Hotel and Kentucky Expo Center Louisville, KY

ATA Annual Turfgrass Conference & Tradeshow (AL Turfgrass Association) Auburn University Hotel & Conference Center Auburn, AL Dollars for Scholars Golf Tournament MSU Golf Course Starkville, MS

NOVEMBER 10–12

MTA Annual Conference and Tradeshow Bost Conference Center Starkville, MS

JANUARY 13–16, 2015 STMA Conference and Exhibition Denver, CO

FEBRUARY 21–26, 2015 Golf Industry Show Henry B. Gonzalez Convention Center San Antonio, TX

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Harrell’s LLC................................9 www.harrells.com Humphries Turf Supply..............11 www.humphriesturf.com

Winstead Turf Farms................Inside Back Cover www.winsteadturffarms.com

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