Tennessee Greentimes - Winter 2010

VOL. 11/ NO. 4

Winter 2010

Walnut Twig Beetle and Thousand Cankers Disease Make Sure Your Bare-Root Liners Get “A” Grades for Quality Save Money with New Greenhouse-Plastic Disposal System

Keynote Speaker Mr. Tom Shay

2011 TNLA

Winter Education & Exhibits Program

Tennessee

GREENTIMES The Official Publication of The Tennessee Nursery and Landscape Association

Table of Contents

PESTS IN THE SPOTLIGH T Walnut Twig Beetle and Thousand Cankers Disease of Black Walnut

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VOL. 11/ NO. 4

WINTER 2010

NURSERY NOTES Make Sure Your Bare-Root Liners Get “A” Grades for Quality

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OTHER F EAT URES UPCOMING EVENT TNLA’s 2011 Winter Education & Exhibits Program .......................................... 8

departments From the President, Tim Gallagher .......................................................................... 6 TNLA New Members .................................................................................................. 7 Calendar of Events...................................................................................................... 22 Index of Advertisers .................................................................................................. 22

BUSINESS MAT TERS Save Money and Go Even “Greener” with New Greenhouse-Plastic Disposal System

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The Tennessee Nursery and Landscape Association serves its members in the industry through education, promotion and representation.

The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, or its board of directors, Tennessee Green Times, or its editors.

Likewise, the appearance of advertisers, or their identification as Tennessee Nursery and Landscape Association members, does not constitute an endorsement of the products or services featured in this, past or subsequent issues of this quarterly publication.

Copyright ©2011 by the Tennessee Nursery and Landscape Association. Tennessee Green Times is published quarterly. Subscriptions are complimentary to members of the Tennessee Nursery and Landscape Association.

POSTMASTER: Send change of address notification to Tennessee Nursery and Landscape Association, 115 Lyon Street, McMinnville, TN 37110. Postage guaranteed.

Third-class postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: Tennessee Green Times allows reprinting of material. Permission requests should be directed to the Tennessee Nursery and Landscape Association. We are not responsible for unsolicited freelance manuscripts and photographs. Contact the managing editor for contribution information.

Advertising: For display and classified advertising rates and insertions, please contact Leading Edge Communications, LLC, 206 Bridge Street, Franklin, TN 37064, (615) 7903718, Fax (615) 794-4524.

f rom t h e p r e s i d e n t Tim Gallagher

Contemplating

THE FUTURE

W

hat does the future hold for the nursery industry? No one can really tell where it will go because our industry is so dependent on the climate of the economy and how much progression is taking place. The nursery industry tends to follow six to twelve months behind a rise in our economy.

Folks in the nursery business have been forced to cut back and tighten their belts to try and survive the downward turn in hopes of staying in business until an upswing in our economy. We must plan and plant for the future while watching our spending.

There are rising costs to consider — particularly fuel, insurance, labor and supplies — while the prices of plants seem to be decreasing. All indications are showing a plant shortage in 2012–2013. I’ve often been told that “we do not inherit from our parents, but borrow from our children.” In saying that, we need to make smart choices.

I have been fortunate to be a part of the TNLA board, working with a great crew of people who care so much about our green industry. I’ve learned how the association works towards making our industry better. We need — and welcome — more input from our members to make our organization even stronger. Attend the Mid-States Horticultural Expo (January 28–29, 2011) and the TNLA Winter Education (February 14–15, 2011) to learn and grow a better business. Let’s all work towards a better future for our industry.

Have a great and prosperous 2011.

Don’t Miss These TNLA Business Meetings JANUARY 29 (during the Mid-States Horticultural Expo) 8:00 a.m.

Kentucky International Convention Center Louisville, KY

Tim Gallagher

FEBRUARY 14

TNLA President

(during TNLA’s Winter Education Program) 12:15 p.m.

Music Road Convention Center Pigeon Forge, TN

TNLA Would like to Thank the following companies for being Membership Sponsors

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Gold Membership Sponsors

Silver Membership Sponsors

Oldcastle Adams Products / Belgard Randall Walker Farms Swafford Nursery, Inc.

Allen Landscape Management American National Insurance Barky Beaver Mulch & Soil Mix, Inc. Common Grounds Dutchman Tree Spade Nashville Landscape Systems, Inc. Packs Nursery Tennessee 811

New TNLA Members The Tennessee Greentimes is the official publication of The Tennessee Nursery & Landscape Association, Inc. 115 Lyon Street McMinnville, Tennessee 37110 (931) 473-3951 Fax (931) 473-5883 www.tnla.com Email: mail@tnla.com Published by Leading Edge Communications, LLC 206 Bridge Street Franklin, Tennessee 37064 (615) 790-3718 Fax (615) 794-4524 Email: info@leadingedgecommunications.com Editors Dr. Bill Klingeman Dr. Bob Trigiano Associate Editors Dr. Donna Fare Dr. Nick Gawel Mr. Mark Halcomb Dr. Frank Hale Mr. Gray Haun Dr. Sandy Reed Dr. John Sorochan

Welcome, TNLA New Members!

ACTIVE MEMBERS

ASSOCIATE MEMBERS

Bullington Land Management Corp.

Travis Bullington 7329 Bonny Kate Drive Knoxville, TN 37920

Bamboo Supply Company Ron Reycraft P.O. Box 5433 Lakeland, FL 33807

Love and Sons Nursery Josh Love 2420 Wharton Springs Road Smithville, TN 37166

Ix Chel Pottery Elbia Slatton P.O. Box 851 McMinnville, TN 37111 Scott Haile & Company Mary Newby P.O. Box 601 McMinnville, TN 37111

TNLA Officers President Tim Gallagher Heather Farms Nursery, Inc. 1st Vice President John Watson, CLP Common Grounds Landscape Mgmt.

2nd Vice President Michael Kassees Forest Nursery Co., Inc. 3rd Vice President Jim Webster The Barn Nursery, Inc. Secretary-Treasurer Randall Walker Randall Walker Farms Associate Director Dwight Burch Ex-Officio Marshall Allen Allen Landscape Management, LLC Executive Director Louree Walker Administrative Assistant Pam Stern

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u p c om i n g ev e n t

TNLA Winter Education & Exhibits February 14–15, 2011 | Music Road Convention Center | Pigeon Forge, TN MONDAY, FEBRUARY 14 7:00 a.m. — 8:00 a.m.

REGISTRATION

8:00 a.m. — 8:15 a.m.

WELCOME & ANNOUNCEMENTS Tim Gallagher, TNLA President, with Dr. Jed Young, Tennessee Tech University and TNLA Education Chair

8:15 a.m. — 9:30 a.m.

Where to be Headin’ in 2011…

Ten Key Factors to Help Your Business Grow Presenter: Mr. Tom Shay, Profits+Plus, St. Petersburg, FL

9:30 a.m. — 10:15 a.m.

Uncover, Discover, Discard…

The May 2010 Floods Brought Destruction, Pests & Diseases** Presenter: Mr. David Bates, Bates Nursery & Garden Center, Nashville, TN

10:15 a.m. — 10:45 a.m.

Break with Tradeshow Exhibitors

A1. Borer Management for Nurseries and Landscapes and New Invasive Species Threats to Tennessee** Presenter: Dr. Jason B. Oliver, TSU Nursery Research Center

11:30 a.m. — 12:15 p.m.

A2. Tree, Shrub and Other Woody-Plant Management Standard Practices** Presenter: Dr. Douglas Airhart, Tennessee Tech University

tennessee greentimes

B1. A New Box of Crayons…

Landscape Trees and Shrubs That Will Dominate 21st Century Landscapes Presenter: Mr. Hugh Conlon, University of Tennessee

11:30 a.m. — 12:15 p.m.

B2. Great Plants from the University of Tennesse Gardens** Presenter: Dr. Sue Hamilton, University of Tennessee

12:15 p.m. — 1:45 p.m.

AWARDS LUNCHEON and VISIT TRADESHOW

AFTERNOON SESSIONS Concurrent Sessions A 1:45 p.m. — 2:30 p.m.

A3. Getting the Most from Your Granular Turf Fertilizer + Preemergence Herbicide Products** Presenter: Dr. Tom Samples, University of Tennessee

2:30 p.m. — 3:15 p.m.

MORNING EDUCATION SESSIONS Concurrent Sessions A 10:45 a.m. — 11:30 a.m.

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Concurrent Sessions B 10:45 a.m. — 11:30 a.m.

WINTER 2010

A4. Best Product Selections Equal Increased Profits** Presenter: Mr. Greg Roman, Valent USA

3:15 p.m. — 3:45 p.m.

Break with Tradeshow Exhibitors

3:45 p.m. — 4:30 p.m.

A5. Immigration Law Basics for the Green Industry — I-9 Worker-Verification Issues, Temporary and Permanent Worker Visas, Criminal Issues (How Does a Person Immigrate into the U.S.?)

Presenter: Attorneys Sean Lewis (Nashville) and Richard Averwater (Memphis)

Concurrent Sessions B 1:45 p.m. — 2:30 p.m.

B3. Dead Plants 101 — Clues to Solving Your Plant Problems** Presenter: Dr. Amy Fulcher, University of Tennessee

2:30 p.m. — 3:15 p.m.

B4. The Phenology Garden Pilot Project in Tennessee…

A Better Way to Monitor Pest Activity?** Presenter: Dr. Bill Klingeman, University of Tennessee

3:15 p.m. — 3:45 p.m.

Break with Tradeshow Exhibitors

3:45 p.m. — 4:30 p.m.

B5. Travel in Search of Garden Design Inspiration** Mr. Garry Menendez, University of Tennessee

TUESDAY, FEBRUARY 15 EDUCATION SESSIONS Concurrent Sessions A 8:00 a.m. — 8:45 a.m.

A6. Invasive Pests Impact TN** Presenter: Dr. Frank Hale, University of Tennessee

8:45 a.m. — 9:30 a.m.

A7. Update on Turf and Ornamental Diseases in the Mid-South** Presenter: Dr. Alan Windham, University of Tennessee

Concurrent Sessions B 8:00 a.m. — 8:45 a.m.

B6. Creative Garden Structure…

One Man’s Trash Becomes Another Man’s Trellis Presenter: Mr. Jason Reeves, University of Tennessee

8:45 a.m. — 9:30 a.m.

B8. Purely Perennials** Presenter: Mrs. Ruth Baumgardner, Mouse Creek Nursery, Riceville, TN

9:30 a.m. — 10:00 a.m.

Break with Tradeshow Exhibitors

Closing Presentations 10:00 a.m. — 10:45 a.m.

Plants with Stories to Tell Presenter: Ms. Carol Reese, University of Tennessee

10:45 a.m. — 12:00 p.m.

If General Patton Ran Your Business Presenter: Mr. Tom Shay, Profits+Plus, St. Petersburg, FL

12:00 p.m.

PROGRAM ADJOURNS

**Pesticide Recertification Points Pesticide recertification points have been assigned to the educational sessions with ** after their titles. One point in Categories C3, C10 and C12 will be given for attendance in each of these sessions. Attendance at all of these sessions would give you 7 points in C3, C10 and C12. One point in Category C2 will be given for attendance in A1, A2 or A6.

TNLA Winter Education HOST HOTELS Music Road Hotel and Music Road Inn Pigeon Forge, TN Room rates will be $69 for single/double.

Call 800-429-7700 to make reservations for either hotel.

p e s t s i n t h e s p ot l i g h t

WALNUT TWIG BEETLE AND THOUSAND CANKERS DISEASE OF BLACK WALNUT

By Frank Hale, Ph.D., University of Tennessee Extension; Bill Klingeman, Ph.D., University of Tennessee; Alan Windham, Ph.D., University of Tennessee Extension; Gray Haun and Steve Powell, Tennessee Dept. of Agriculture Plant Certification; Jason Oliver, Ph.D., Tennessee State University, Otis L. Floyd Nursery Research Center; Anni Self, Tennessee Dept. of Agriculture Plant Certification; Mark Windham, Ph.D., University of Tennessee; and Jerome Grant, Ph.D. and Elizabeth Long, University of Tennessee Extension

In

July 2010, emerald ash borer was discovered in Knox County, Tennessee.

Within days, thousand cankers disease (TCD) — a disease complex composed of Pityophthorus juglandis (walnut twig beetle) and the fungus Geosmithia morbida, which kills black walnuts (Juglans spp.) — was also confirmed in Knox County, becoming the first confirmation of the walnut twig beetle (WTB) and TCD complex east of the state of Colorado. The TCD find in Tennessee is significant because this is the first time TCD, an aggressively virulent disease, has been found within the black walnut’s native range.

Where in Tennessee is TCD? Many species of insect borers, including longhorned and ambrosia beetles, can be found in the wood of walnut trees.

The spread of TCD is unlikely to succeed, though, without the help of a tiny bark beetle (about 1/16" long) called the walnut twig beetle (Photo 1) that is native to Arizona and New Mexico. This beetle is uniquely suited to its apparent role as the vectoring agent of a newly identified fungus in the genus Geosmithia, which has been given a proposed species name of Geosmithia morbida. While the WTB does not appear to kill branches or whole trees by itself, its ability to

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spread G. morbida has proven deadly for infected black walnut and other Juglans spp., with the exception of resistant Arizona walnut (J. major). A second fungus (Fusarium solani) may take advantage of a weakened walnut tree and become associated with canker formation on the trunk and scaffold branches.

Black walnut, native to the East, was planted in many areas throughout the West by pioneers. Over the last decade, TCD has caused widespread mortality of black walnut in several western states. The introduction and spread of TCD into Anderson, Blount, Knox and Union counties in eastern Tennessee, close to the center of the native range of black walnut and butternut, does not bode well for walnut species in the eastern forests and landscape. The Tennessee Department of Agriculture (TDA) has placed an emergency rule for TCD, listing walnut from these infested counties as a regulated item and will continue assessing the distribution of TCD in Tennessee during 2011. Citizens in the quarantined counties cannot move walnut-tree products, including walnut nursery stock and hardwood firewood, outside the quarantined counties without compliance agreements.

Additionally, TDA has designated “buffer” regulated areas that adjoin

the infested counties, including Campbell, Claiborne, Grainger, Jefferson, Loudon, Monroe, Morgan, Roane, Scott and Sevier counties, at the time of this publication. They also have limited movement of walnuttree products, including walnut nursery stock and hardwood firewood.

Citizens in buffer counties/areas can move walnut-tree products and hardwood firewood within buffer counties, but not outside without mitigation (under compliance agreements). Products can also be moved into a quarantine county, but not taken back out.

For the latest regulatory updates, refer to the Tennessee Department of Agriculture TCD website at http://tn.gov/ agriculture/regulatory/tcd.html.

Symptoms of infested walnut trees TCD produces many small cankers on branches and the trunk at points of beetle attack (Photo 2), which are initially hard to see. Geosmithia does not move systemically within the inner bark of the walnut. Instead, these cankers coalesce to collectively girdle the trunk and branches by destroying the outer cambium layer just below the bark where tree growth occurs (Photo 3), thus irreversibly stopping the movement of water and nutrients up to the foliage and the storage

products of photosynthesis down to the roots. Like the expression, “death by a thousand cuts,” the aptly named thousand cankers disease is indeed death by a thousand cankers.

From a distance, the earliest visible symptom of TCD is the yellowing foliage that can quickly become brown wilted foliage. Closer examination of the bark will reveal the many tiny entry and exit holes of the walnut twig beetles. A shallow cut into the beetle-infested area of the branch or trunk will reveal the roughly circular- to oval-shaped cankers.

Within these cankers are horizontal (across the grain) egg galleries made by the adults and vertical (with the grain) larval galleries (Photo 4). The reddishbrown adult beetles, white eggs and C-shaped larvae can be found within these galleries.

The decline of a mature walnut tree is rapid and evident (Photo 5, page 14; also see the sidebar description of Stages of Walnut Tree Decline). Opinions vary about how trees will respond to TCD in the East, but in general, trees are expected to die within three to five years of the initial infection and as quickly as one year after the onset of visible symptoms. It is possible that trees in good health may survive as long as 10 to 15 years after initial attacks.

(Above) Photo 1. An adult walnut twig beetle is only about 1/16” long.

Can a walnut tree survive a WTB attack?

Thousand Cankers Disease is very aggressive. Once a tree is symptomatic, it will not recover. Dead canopy portions and branches with brown leaves will not recover or re-leaf. Basal sprouts (epicormic shoots) on trees attacked by WTB are common. These shoots are not well attached to the trunk; thus, they pose future risks of trunk collapse if they are permitted to grow into large trees.

How does WTB overwinter?

How fast does it reproduce?

From experiences with the WTB in the western U.S., we understand only broad outlines about the WTB life history. Its developmental timeline may be considerably different in the warmer and wetter Tennessee climate. In colder regions,

(Above) Photo 2. TCD produces many small cankers on branches and the trunk at points of beetle attack.

(Below) Photo 3. The cankers coalesce to girdle the branches by destroying the outer cambium layer just below the bark.

p e s t s i n t h e s p ot l i g h t

Photo 4. Within TCD cankers are horizontal egg galleries made by the adults and vertical galleries made by the larvae.

Symptoms and Signs that Something Is Amiss with Your Walnut Tree Early Stage Symptoms of TCD in Walnut • Once walnut twig beetles (WTB) attack a walnut tree, branches in any portion of the tree canopy may begin to thin. The thinning becomes evident between late June and late August.

• Within the crown, leaves may wilt (“flag”) and yellow, but generally do not detach. Wilted and brown leaves from earlier attacks may be retained within the affected canopy.

• Leaves may appear smaller than normal.

Mid-Stage Symptoms: Active Walnut Crown Decline • For several weeks following initial canopy thinning, foliage on affected limbs undergoes rapid wilting and collapse.

• Cankers may become evident on affected branches, below the wilted and chlorotic leaves.

• When gray-brown outer bark is thinly scraped to reveal cream-to-yellow inner-bark tissue, small dark lesions or cankers associated with WTB attack are observed on branches.

• In the year following initial attack, affected trees will add little live growth to the canopy.

Late-Stage Symptoms of TCD • In Tennessee, TCD-infected black walnut trees have died quickly, usually within three years of observed flagging symptoms from initial beetle attacks.

• In the final stages of tree decline, epicormic sprouts may develop from the lower trunk and crown.

• Dead and dying branches greater than 1" or 1-1/2" in diameter will have numerous extremely small WTB exit holes.

• Beneath gray-brown outer bark of branches, main stems and trunks, the inner-bark tissues contain widespread dark patches and sunken cankers where individual lesions have coalesced into large, dead areas.

• Carefully shaving away thin slices of inner bark will reveal the meandering WTB tunnels and galleries.

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beetles overwinter primarily as adults and have been seen to move during the fall into the thick outer bark of trunks, where they appear to produce overwintering chambers. As such, Geosmithia morbida might be introduced into the trunk during overwintering, thus accelerating overall tree decline.

In Colorado, adult beetles leave overwintering refuges from mid - to - late April to early May, fly to limbs and then begin tunneling beneath the bark. One or two females will typically join a male and together create egg galleries under the bark. Larvae develop in the living phloem and bark tissues, where they excavate shallow tunnels that branch from the egg gallery. Pupation occurs at the end of the tunnels, and then adults bore through the bark, producing a minute exit hole. Because a generation can be completed in about six to seven weeks, we expect that two or more overlapping generations will be produced during a growing season in Tennessee.

Adult WTB are relatively weak fliers and can be carried by wind. Based on experiences in the western U.S., if left to their own design, TCD is expected to move relatively slowly with WTB across the native range of black walnut.

Regardless, transportation of infested wood (firewood, untreated mulch, logs or lumber with bark and yard waste) by humans will continue to pose the biggest threat to the future of walnut in the eastern U.S.

Will TCD damage the walnut wood?

The name walnut twig beetle is something of a misnomer. These beetles will attack large limbs and even the trunk of mature walnut trees, yet they tend to prefer branches and stems that are greater than 1" in diameter, while not noticeably attacking fine-diameter twigs.

Beetles do not reproduce or attack the fleshy walnut husk or nut. Indeed, the beetle reproduces almost exclusively within the inner bark (phloem) tissues and may only shallowly score the sapwood just beneath the cambium.

The beetle and the fungus will not penetrate into the darker heartwood and, therefore, will not stain the wood.

Are other tree species at risk from TCD? The only known vector of thousand cankers disease is WTB, and the disease is believed to be restricted to walnut trees. Black walnut (J. nigra) is particularly threatened in Tennessee. TCD can attack Persian/English walnuts (J. regia) and butternut (J. cinerea). Pecan and other hickories (Carya) are not known hosts of TCD, although they also belong to the same plant family (Juglandaceae).

Controlling TCD Without a better understanding of the biology of WTB and the TCD pathogen, we have very little idea about which controls for TCD will be effective. Adult beetles are expected to be active for an extended period in Tennessee, so insecticide spray applications will likely have limited or no effectiveness. Indeed, treatment with an insecticide would not stop Geosmithia colonization of the bark and cambium even if adult beetles or larvae were killed. In turn, both fungal decay and beetle-tunneling activity are expected to limit systemic insecticide action. To date, rapid detection and removal of infested trees currently remains the primary means of managing TCD. Give TCD-free trees a fighting chance by maintaining strong tree vigor and good health. The TDA recommends watering trees at 2- to 3-week intervals, with at least 15 gallons per inch of trunk diameter through the summer months.

A 10-inch-diameter tree, for example, should receive 150 gallons of water every 2–3 weeks. Because roots can continue to grow during winter months, it is a good idea to provide at least supplemental light watering on warmer days through the winter. Remember that trees with large energy reserves are likely to survive longer than trees under greater stress.

It is also important to practice good sanitation by removing dead or declining walnut trees from your property. Dispose of the wood properly — by burning on-site, disposing of it in the nearest landfill or mechanically chipping branches and smaller-diameter wood

p e s t s i n t h e s p ot l i g h t

Photo 5. The decline of a mature walnut tree attacked by TCD is rapid and evident.

— to reduce the likelihood of attacks on healthy walnut trees. Evidence suggests some beetles may survive passage through a chipper, so chipped debris could be composted or burned, but should be retained within the quarantined region. Walnut wood should not be kept for firewood because WTB can attack and develop within attached bark for some time; if wood is kept to be milled or used in woodworking projects, it must be debarked to prevent the beetles from emerging and attacking other walnut trees.

It is also generally good practice to avoid using limbs and trunks of landscape trees, including walnuts, to hang swings, mount basketball hoops and for other recreational uses. Avoid damaging tree trunks and roots by protecting these areas during lawn maintenance and construction projects. Consider consulting a certified arborist for advice about managing and protecting existing trees.

Suspect that your walnut tree has TCD? Go to the TDA website (http://tn.gov/ agriculture/regulatory/tcd.html) where you can submit a report concerning the suspect walnut tree(s). Either a TDA Forester or Plant Inspector will contact you to follow up on your concerns.

For further information, concerning the WTB and the TCD of walnut, visit the UT TCD web site that includes fact sheets and pest alerts (http://eppserver. ag.utk.edu/ThousandCankers.html), as well as resources at the TDA website, listed above, which will also have the most recent regulatory map and quarantine information. Updates and notes from a 2009 regional planning conference about TCD are posted on the Missouri Department of Agriculture website: http://mda.mo.gov/plants/pests/ thousandcankers.php. All of these, plus the USDA Forest Service “Thousand Cankers Disease” Pest Alert, at http://na.fs.fed.us/pubs/palerts/cankers_ disease/thousand_cankers_disease_scre en_res.pdf, were resources from which this article was adapted. C

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n u r s e ry n ot e s

Make Sure

YOUR BARE-ROOT LINERS Get “A” Grades for Quality

By Drew Jeffers, Bill Klingeman, Marco Palma and Charlie Hall

To

make ends meet in today’s green industry economy, successful growers are staying proactive and tightening production efficiency. Growing high-quality nursery stock remains a keystone principle for sound business management and is essential to competitive success in our industry. That said, characteristics of liner “quality” are seldom clearly defined. In fact, other than minimum height and caliper measurements, ANLA guidelines provide few clear standards for quality measurements of nursery liner stock.

To address this challenge, some growers might just evaluate the overall appearance of a crop, while other growers emphasize overall stock uniformity.

Is there a better way? Can Tennessee’s growers capitalize on an opportunity to differentiate their liner products and gain a profitable edge on their competition? If so, can we seize this opportunity at the grading table during fall and winter?

Our search for answers In March 2007, we brainstormed about ways to tackle these questions. In sum,

we agreed that until we better understood what growers and buyers expect to see when viewing “high-quality” bare-root nursery liners, we wouldn’t be able to find practical answers. And although we know that physiological measurements are well-established predictors of both liner transplant success and growth potential, it simply costs too much and takes too much time for a grower to collect physiological data.

Instead, our approach was to design a study in trade-off analyses. We chose regional and price-point factors, as well as easy-to-see physical liner attributes that can be quickly taught to employees and then used to grade field-grown bare-root liners. To make sure we were on the right track, we started by informally surveying bare-root liner producers and validated several individual physical attributes that growers believed were important to defining liner quality. Among these attributes were root architecture and uniformities of stem caliper, stem height and canopy architecture. We were also told that price and U.S. region of production were important when assessing nursery liner stock value.

Next, we defined a liner as a tree seedling grown for one year either in a seedbed or in field soil, then lifted and bare-rooted for sale or transplant as nursery planting stock. This type of seedling would also be referred to as a 1+0 seedling.

For root architecture, we considered only first-order lateral root (or FOLR) number, defined as roots < 1mm diameter that emerge 30mm below the root collar, thus providing initial root architecture. In fact, other researchers have found that, for bare-rooted liners of several different woody-plant species, higher FOLR counts correlate with better transplant success and growth potential… similar to the predicted outcome from some physiological measures.

We took photos of 1+0 Nuttall oak (Quercus nuttallii) bare-root liners (Photo 1) because dormant roots and shoots look similar to a wide variety of tree species. After setting levels for price, region of production, FOLR number and uniformities of liner height, canopy density and caliper, we used a conjoint model to create a large, visual display showing nursery liners

(Above) Photo 1. How will buyers assess the quality of your liner stock? Study participants acted on three key characteristics when giving their highest ratings of quality: higher numbers of large-diameter lateral roots, presence of a uniformly dense canopy and uniform liner height.

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with various combinations of our attribute levels that buyers could evaluate through trade-off, or conjoint, analysis (Photo 2). We also designed a short paper questionnaire that, when paired with the visual display, helped us evaluate buyer purchasing preferences and perceptions of quality.

We took our survey to the 2007 Southern Nursery Association Trade Show, the Tennessee Green Industry Field Day, the Eastern Region Nursery Tour and the 2008 Mid-States Horticultural Exposition, where we received completed surveys and demographic information from 248 study participants (Photo 3). When the data were all in, we used statistical tools to produce utility values and relative importance-to-purchasing-decision weights for each product attribute, that we could compare to pre-determined holdout products. These options were used

to judge the accuracy of our conjoint preference model, based on the decisions made by our study participants.

So who participated and what did we learn?

Our respondents were mostly from Southern states and were mostly male (76%), and more than half had 12 years or more of green-industry experience. About 85% reported that they had either bought, sold or grew nursery liners, with half reporting that they purchased about 5,000 liners per year.

Their nurseries generally made less than $250,000 per year.

Our tests using two pre-selected hold-out products embedded within the display confirmed that our experimental model successfully predicted buyer behavior and preference based on respondent decisions. And prospective buyer decisions behaved

differently from what they said was important (Table 1).

For example, price was stated as the 3rd most important characteristic in a purchase decision, but was ranked 5th in importance by respondent choices, followed by U.S. region of production, which was least important to participants.

By contrast, prospective buyers not only said that root numbers were very important, but they also acted on that characteristic in response to the graphic display. About 65% of a prospective buyer’s decision about liner quality was made in response to the presence of high numbers of first-order lateral roots. Another 16% of their quality evaluation was attributed to uniform canopy density. An additional 11% was ascribed to uniform liner height.

Surprisingly, caliper uniformity and price turned out to not be very impor-

Table 1. Photographs used for Drew’s survey depicted 1+0 bare-root nursery liners with different attributes and attribute levels that allowed participants to contribute to our knowledge about the relative importance of each character in a hypothetical pointof-purchase experience. This table and additional information about the study can be found in the June 2009 issue of HortScience.

Product

First Order Lateral Root Number (FOLR)z

Liner height uniformity

Liner caliper uniformity

Liner canopy density uniformity

Price per liner

1

4 to 5 roots

Mixed

2

4 to 5 roots

Mixed

Mixed

Mixed

Mixed

Uniform

3

4 to 5 roots

Mixed

Uniform

4 5

4 to 5 roots

Mixed

4 to 5 roots

Uniform

6

4 to 5 roots

7

4 to 5 roots

8

U.S. Region of production

Position in display

$1.30

Unspecified

10

$1.30

Northwestern

5

Mixed

$1.60

Northwestern

11

Uniform

Uniform

$1.60

Southeastern

1

Mixed

Mixed

$1.90

Northwestern

4

Uniform

Mixed

Uniform

$1.90

Southeastern

3

Uniform

Uniform

Mixed

$1.30

Unspecified

17

4 to 5 roots

Uniform

Uniform

Uniform

$1.30

Northwestern

2

9

6 to 7 roots

Mixed

Mixed

Uniform

$1.30

Northwestern

6

10

6 to 7 roots

Mixed

Uniform

Uniform

$1.90

Unspecified

8

11

6 to 7 roots

Uniform

Mixed

Uniform

$1.60

Northwestern

13

12

6 to 7 roots

Uniform

Uniform

Mixed

$1.30

Southeastern

15

13

8 to 9 roots

Mixed

Mixed

Mixed

$1.30

Southeastern

9

14

8 to 9 roots

Mixed

Uniform

Mixed

$1.90

Northwestern

16

15

8 to 9 roots

Uniform

Mixed

Uniform

$1.60

Unspecified

12

16

8 to 9 roots

Uniform

Uniform

Uniform

$1.30

Northwestern

7

HO 1

8 to 9 roots

Uniform

Uniform

Uniform

$1.60

Southeastern

14

HO 2

4 to 5 roots

Mixed

Mixed

Mixed

$1.30

Unspecified

18

z FOLR = side roots ≥ 1mm diam

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17

n u r s e ry n ot e s

tant to respondents. In fact, price seldom influenced liner preferences after considering the display images. It is possible that our per-liner price range was set too narrowly and did not allow the true effect of price to be accurately explained. Similarly, liner caliper differences may have been too slight to have elicited strong feelings about liner quality.

Take-home message

Photo 2. Drewâ&#x20AC;&#x2122;s visual survey used a series of captioned photographs to help rate participant perceptions of 1+0 bare-root nursery liner quality. The entire graphic display was 55" wide by 35" tall and included 18 experimental images, a photo of a typical bundle of bare-root liners and an instructional example.

Photo 3. Drew Jeffers takes a break during his survey work at SNA to show Hugh Conlon how his study will evaluate hypothetical liner buyer perception and opinions regarding attributes of nursery liner quality.

Table 2. Respondents differed in what attributes they said were important for 1+0 bare-root nursery liner quality, compared with how their decisions gave choice-based relative importance values for each attribute. (Numbers in parenthesis represent ranked order of ratings from highest to lowest for comparison purposes).

Attribute

Self-stated importance (1-5 scale)

Relative importance (%)

FOLR number

4.2 (1)

65 (1)

Canopy density uniformity

3.8 (4)

16 (2)

Height uniformity

3.9 (2)

11 (3)

Caliper uniformity

3.8 (5)

3 (4)

Price

3.9 (3)

2 (5)

Region of production

3.0 (6)

1 (6)

18

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Regardless, Tennessee growers can take advantage of these behaviors at the grading table. To create bundles of highquality bare-root liners, take the time to grade effectively and efficiently. If grading in teams, first group bare-root liners with the highest counts of largediameter lateral roots. Then, secondarily grade liners for uniform canopy form and height. The highest-quality liners should command a price premium.

Finally, be aggressive about assigning liners to conservation-grade status, and be sure to cull both weakly formed and damaged liners.

For proactive growers who want to increase FOLR numbers and optimize root architecture, try reducing inground planting densities in both rowrun fields and poly-covered beds. In addition, prune to create uniform liner height and canopy density. Always seek out superior propagation stock that can optimize all of these traits.

Be sure that senescing foliage has been removed and that roots and shoots stay free of fungal growth in overwintering coolers. Last, be sure to package your liners neatly, using shredded, moistened newspaper and plastic wrap to keep roots healthy during shipping. C

Editorâ&#x20AC;&#x2122;s notes: Additional information about the study can be found in the June 2009 issue of HortScience. This article was adapted from the June 2010 issue of NMPro magazine and is reprinted with permission.

b u s i n e s s m at t e r s

Save Money AND GO EVEN

“GREENER” with New 1

Greenhouse-Plastic Disposal System

By Nick Gawel, Ph.D., Tennessee State University Nursery Research Center, and Mark Halcomb, University of Tennessee Extension

For

growers who use greenhouse plastic, a new program is available that will allow you to save money and reduce labor costs while practicing good environmental stewardship. Using a specialized plastic rolling machine, overwintering poly plastic from a typical house can be rolled up by a single person in less than four minutes. In fact, up to 400 pounds of plastic can be spooled onto one roll, which can then be dropped off at a collection site for recycling. This process will save labor and disposal fees, while keeping needless tons of used plastic out of landfills.

2

3 20

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A pilot program was conducted in spring 2010, in which Middle Tennessee nursery producers recycled over 60,000 pounds of greenhouse plastic. Growers in Warren and Dekalb counties used a roller (offered free of charge) to collect their plastic into compact rolled bales.

These rolls were collected at drop-off points provided by the TSU Nursery Research Center and Tri-Tech Molded Plastics.

Delta Plastics, an irrigation-tubing manufacturer in Arkansas, recycles the used plastic into pellets that are sold to various plastic fabricators. Even better, Delta Plastics employs an extensive cleaning process for the used plastic;

hence it is perfectly acceptable if the plastic is dirty or has staples.

For the plastic to be recycled, it must be rolled as tightly as this system allows.

In fact, the recycler’s processing method can only use the tightly rolled plastic produced by this type of roller. Such tightly rolled plastic is necessary for ensuring that enough weight can be packed per trailer load (40,000 pounds) to make the shipping costs worthwhile.

Everyone who used the roller said it was much easier and faster than the usual methods that required a lot of hand labor to pull, fold and load the plastic. It is easy to pull the roller to a poly house, roll the plastic and then

(At left, top to bottom) Photo 1. Spooling the plastic; Photo 2. A tightly wrapped bale; and Photo 3. Easy to transport by tractor.

(Below, left to right) Photo 4. A semi-truck load of rolled, recyclable plastic; and Photo 5. Bales ready to load.

4

5

just pull forward to the next house to repeat the process. The roller does it all faster and easier than doing it by hand. Recycling the plastic not only saved disposal fees, but also the roller made the job quick and efficient. Even better, the roller does not have to be on your site when you remove the poly.

Simply lay the plastic sheeting on the ground beside the house until you can borrow the roller.

The recycling program, jointly operated between UT Extension and the TSU Nursery Research Center, plans to add another roller for use this coming season. The roller machines are available for use free of charge, but they need to be scheduled in advance.

To reserve a roller, simply contact the TSU Nursery Research Center at (931) 815-5140. If you need someone to bring the roller to your business and get you started, contact Mark Halcomb with the Warren County office of UTTennessee State University Extension at (931) 473-8484. C

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21

calendar of events

Index of Advertisers

JANUARY 10–14

JANUARY 28–29

NCAN “Green & Growin’ Show” (North Carolina Assn. of Nurserymen) Greensboro Coliseum Greensboro, NC Contact: 919-816-9119 Email: info@ncan.com Mid-America Horticultural Trade Show Navy Pier Chicago, IL Contact: 847-526-2010 www.midam.org

Mid-States Horticultural Expo (a partnership of TNLA and KNLA) NEW LOCATION! Kentucky international Convention Center Downtown Louisville, KY For advertising, contact: Betsie A. Taylor 502-695-0106 or knla@gmail.com www.knla.com For booth information, contact: Louree Walker 931-473-3951 or louree@tnla.com

JANUARY 24–26

FEBRUARY 3–5

Central Environmental Nursery Trade Show (CENTS) Columbus, OH Contact: 800-825-5062 Email: tracelzody@only.org

South Carolina Horticulture Industry Trade Show Myrtle Beach Convention Center Myrtle Beach, SC Contact: 864-592-3868 www.scnla.com

JANUARY 19–21

JANUARY 26–29 ANLA Management Clinic (Amer. Nursery & Landscape Assn.)

Louisville, KY Contact: 202-789-2900 Fax: 202-789-1893 www.anla.org

FEBRUARY 14–15 TNLA Winter Education & Exhibits Music Road Convention Center Pigeon Forge, TN Contact: 931-473-3951 Fax: 931-473-5883 Email: mail@tnla.com www.tnla.com

Braun Horticulture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 www.braungroup.com Camm Too Camellia Nursery . . . . . . . . . . . . . . . . . . . . 14 www.camtoocamellia.com Coleman Farms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 D & D Agri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Discount Pond Supplies, Inc. . . . . . . . . . . . . . Back Cover Ewing Irrigation . . . . . . . . . . . . . . . . . . Inside Back Cover www.ewing1.com Farm Credit Services of Mid America . . . . . . . . . . . . . 13 www.farmcredit.com Griffin Greenhouse & Nursery Supplies . . . . . . . . . . . . . . . 15 www.griffins.com Hayes Nursery Enterprises . . . . . . . . . . . . . . . . . . . . . . 22 Herd Farms Nursery / Herd Insurance . . . . . . . . . . . . . 13 Hortica Insurance & Employee Benefits . . . . . . . . . . . . . . . Inside Front Cover www.hortica-insurance.com JG Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Larry A. Gribble Nursery . . . . . . . . . . . . . . . . . . . . . . . 19 Low Falls Wholesale Nursery . . . . . . . . . . . . . . . . . . . . 14 www.lowfallsnursery.com Mid Tenn Turf, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 www.midtennturf.com Motz & Son Nursery . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Pack’s Nursery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 www.packsnursery.com Surface Nursery, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . 19 www.surfacenursery.com Swafford Nursery, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . 15 www.swaffordnursery.com Tennessee 811 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 www.tennessee811.com The Seed Keeper Company . . . . . . . . . . . . . . . . . . . . . . 3 www.seedkeepercompany.com Willamette Nurseries, Inc. . . . . . . . . . . Inside Back Cover www.willamettenurseries.com

classified

Hayes Nursery Enterprises 76 Bellewood Dr. McMinnville, Tennessee 37110 Trudie or James Hayes, 931-235-3911 Liners to Landscape