turfgrass & ornamental field day - university of missouri · stop 9* “characterization &...

Turfgrass & Ornamental Field DayDivision of Plant Sciences - CAFNRUniversity of Missouri

Brought to you by:

South Farm Research CenterColumbia, MO

July 10, 2012

FacultyDr. Brad Fresenburg – Turfgrass Research & ExtensionDr. Lee Miller – Turfgrass PathologyDr. Manjula Nathan – Soil Testing/Nutrient ManagementDr. Chris Starbuck – Woody OrnamentalsDr. David Trinklein – FloricultureDr. Xi Xiong – Turfgrass Management & Physiology

Research SpecialistsDaniel Earlywine – Turfgrass PathologyJohn Haguewood – Turfgrass Management

Graduate Research AssistantsDerek Cottrill, John Haguewood, Natalie Pan, Steve Song, (JB Workman – August 2012)

Find us on the web:turf.missouri.eduturf.missouri.edu/statturfpath.missouri.edumotoc.org

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Editor’s Note

We would like to express our gratitude to our industry sponsors for their incredible support of the Mizzou Turfgrass & Ornamental Programs. Without this assistance, we would not be able to build upon our programs, nor be able to function at a research and extension level that this great state of Missouri needs and deserves. We have listed our contributors on the first page of this booklet to signify our appreciation of their support.

While we strive to get make this list as comprehensive as possible, please let me or another faculty member know if your organization should be on this list. If an error has occurred, please accept our sincere apology, and we will correct it in the future.

Inside this booklet, we hope you will find valuable research and insights that you can bring back to your operation to make it more successful. Whether your operation is a lawn, landscape, golf course, sod farm, nursery, athletic field, (etc., etc.), we would like to assist with your plant health issues. If there is a concern you feel needs to be covered more fully, please don’t hesitate to let us know, or email me at [email protected] or phone at (573) 882-5623. We hope you have a great day and take something back that will be useful.

Sincerely,

Dr. Lee MillerExtension Turfgrass PathologistUniversity of MissouriDivision of Plant Sciences

Note: Reference to products in this booklet is intended to convey objective, unbiased information and not an endorsement of the product over other similar products with similar results. The use of brand names and any mention or listing of commercial products or services does not imply endorse-ment by University of Missouri or discrimination against similar products or services not mentioned. Other brand names may be labeled for use on turfgrasses. Individuals who use pesticides are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your county’s Cooperative Extension agent

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Agrologics*St. Louis, Missouri

MU Ag Research Center*Columbia, Missouri

Agrotain*St. Louis, Missouri

A.L. Gustin Golf Course*Columbia, Missouri

Aquatrols**Paulsboro, New Jersey

Arysta Life Sciences**Cary, North Carolina

Atkins Turf & Tree*Columbia, Missouri

Dave Baker***Columbia, Missouri

BASF**Waukee, Iowa

Bayer Environmental Science**Kansas City, Missouri

Belk Park Golf CourseWood River, Illinois

Bellerive Country Club*St. Louis, Missouri

Capital Sand Company*Jefferson City, Missouri

MU CAFNR*Columbia, Missouri

Columbia Country Club*Columbia, Missouri

Country Club of Missouri*Columbia, Missouri

Cleary Chemical Company**Dayton, New Jersey

Steve Dickinson***Fenton, Missouri

Dow AgroSciences*St. Louis, Missouri

DuPont**Kansas City, Kansas

Eagle Knoll Golf Club*Philadelphia, Pennsylvania

FMC Professional Solutions**Fenton, Missouri

Franklin County CC*Washington, Missouri

Gateway Chapter (STMA)**St. Louis, Missouri

Hallbrook Country Club*Leawood, KS

Heart of America Golf Course Superintendents Association**Kansas City, Missouri

John Deere Landscapes*Fenton, Missouri

Kalo**Overland Park, Kansas

Laser Turf Leveling*St. Charles, Missouri

Macon Granuband*Macon, Missouri

Meadowbrook Country Club*Ballwin, Missouri

Meadowbrook Golf & Country Club*Prairie Village, Kansas

Mid America Green Industry Council*Kansas City, Missouri

Mississippi Valley Golf Course Superintendents Association**St. Charles, Missouri

MoTOC*Columbia, MissouriMO-KAN Chapter (STMA)**Kansas City, Missouri

MU Intercollegiate Athletics*Columbia, Missouri

Norwood Hills CC*St. Louis, Missouri

NTEP**Beltsville, Maryland

Oak Hills Golf Center*Jefferson City, MO

Old Warson Country Club*St. Louis, MO

Ozark Turf Association*Branson, Missouri

Ozarks Chapter STMA**Springfield, Missouri

Pennington Seed*Greenfield, Missouri

PBI Gordon*Kansas City, Missouri

Perfect Play Fields & Links*Belleville, Illinois

Redexim-Charterhouse*St. Louis, Missouri

Research Support Services – South Farm*Columbia, Missouri

SelecTurf Farms*Jefferson City, Missouri

St. Andrews Golf Club*Overland Park, KS

St. Louis Country Club*St. Louis, MO

Syngenta**Greensboro, North Carolina

The Falls Golf Club*O’Fallon, Missouri

The Lawn Company***Columbia, Missouri

Valent**Green Springs, Ohio

Westwood Country Club*St. Louis, MO

Williams Lawn Seed*Maryville, Missouri

Sponsors & Contributors to the2012 Mizzou Turfgrass & Ornamental Research Program

* Gift-in-kind ** Grant-in-aid *** Turf Building Fund

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2012 Field Day Vendor/Sponsors

COMPANY CONTACT DESCRIPTION

Grass Pad Inc. Lloyd Harrison425 N. Rawhide [email protected], KA 66061 913-764-4100

MPR Supply Company Steve Leu Irrigation, Drainage, Landscape Lighting,2541 Link Ave [email protected] Water Features and Hardscape SuppliesSt. Louis, MO 63114 314-426-4838

MTI Distributing Tom Brown Toro Commercial Mowing and Irrigation8901 Springdale Ave [email protected] Products for the Golf & Turf IndustrySt. Louis, MO 63143 314-506-4137

PBI Gordon Allen Baumstark Turf & Ornamental products Manufacturer.P.O.Box 236 [email protected] Gerald, MO 63037 636-432-3350

Pennington Seed Lacy Graham303 Grand Ave [email protected], MO 65661 417-268-7679

Professional Turf Products Brad Davisson We provide products from the Toro Company as well as1010 N. Industrial Blvd. [email protected] many other topflight manufacturers to independent dealers,Euless, TX 76039 817-785-1900 golf courses, schools, municipalities, parks, landscape and irrigation contractors.

St Louis Composting Roy Gross Compost and related soil blends39 Old Elam Ave. [email protected] Park, MO 63088 314-581-6372

Sportsfields Construction Donna Howard Athletic Field Construction/RenovationCool Springs Road [email protected]’Fallon, MO 63366 636-240-5404 Van Wall Equipment Barry Siems John Deere Golf & Turf4972 S 97th Road [email protected], MO 65613 417-770-0289

COMPANY CONTACT DESCRIPTION

Hummert International Dr. Steve Millett Distributors of the finest horticulture and4500 Earth City Expressway [email protected] turfgrass products.Earth City, MO 63045 314-506-4533

Missouri Propane Education Steve Ahrens Propane-powered lawn mowersand Research Council [email protected] 4110 Country Club Drive 573-893-7655Jefferson City, MO 65109

Redexim Turf Products Paul Hollis Turf Maintenance Equipment- Tractors,29 Cassens Court [email protected] Aerators, Seeders, Sweepers, Verti-Cutters,Fenton, MO 63026 636-326-1009 Synthetic Turf Groomers Syngenta Paul Carlson Plant protection products740 Elkington Lane [email protected], MO 63132 314-308-0330

2012 Field Day Vendors

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Table of Contents

Field Day Presentations Stop* Pg

1 Large Evergreen Trees: What can we grow? 1-2 2 Preventive measures for large patch control in zoysiagrass. 3 3 MU soil testing and plant diagnostic service to the Turf & Ornamental Industry 44 Application strategies for improved control of brown patch in tall fescue 5-6 5 Safety and Efficacy of Pre-emergence Herbicides of Crabgrass Control on Creeping Bentgrass Putting Greens 7 6 Herbicide Applications to Control Annual Bluegrass on Kentucky Bluegrass Turf 8-9 7 Future trials on key turf diseases of lawns, sports fields, and golf courses in Missouri 108 Evaluating the Performance of Annual Herbaceous Ornamentals 119 Characterization and management of Pythium root diseases prevalent on bentgrass putting greens in the Midwest 1210 Evaluation of the Differential Responses of Six Common Bermudagrass to AOPP herbicides 13-1411 Suppressing spring dead spot of bermudagrass with an integrated approach of cultural and chemical practices 15-16

* Number is referenced on farm map on back cover of the booklet.

Research Trial Reports National Turfgrass Evaluation Program Trials 17-19 Synthetic Turf Research 20 Use of Avid for ring nematode control on creeping bentgrass putting greens 21 Curative fungicide treatments for dollar spot control: What to expect in a week? 22 Interaction of DMI fungicides and Trimmit applications on disease control and quality of putting greens 23-24 Preventive fungicide applications for fairy ring control in golf putting greens 25 Fungicide evaluation for reduction of spring zoysia yellowing 26 Large patch control on ‘Meyer’ zoysiagrass 27-28 Evaluating Daconil Action for disease control 29Evaluation of multiple fungicide programs for summer disease control on a creeping bentgrass putting green 30 Preventative dollar spot control on a creeping bentgrass putting green 31-32Evaluation of spring dead spot control on bermudagrass 33-34 Evaluation of brown patch control using Velista on creeping bentgrass. 35 Timing of single fungicide applications for preventive large patch control 36 Evaluating the phosphorus runoff potential of current home lawn fertilization practices and recommendations based on soil test results 37-40Evaluating the Chilling Tolerance of Various Common Bermudagrass Cultivars 41 Suppressing Seedheads of Annual Bluegrass on Creeping Bentgrass Putting Green 42Effect of Delayed Watering-In on Insecticide Efficacy against Annual White Grubs on Cool Season Turf 43‘Tribute Total’ on Dicot Weed Control 44Crabgrass Prevention on Bermudagrass Turf in the Transition Zone 45-46The Residue Effect of Mustard (Brassica juncea L. Czern.) Seed Meal for Suppression of Dollar Spot 47-48Evaluation of Experimental Insecticide for Control of Turfgrass Pest Insects 49

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Schedule of Events7:30 – 8:30 a.m.Registration, coffee/donuts and exhibitors

8:30 – 9:00 a.m.Welcome & Introduction: Dr. Lee Miller, Turfgrass PathologyWelcome & Program Update: Dr. Mike Collins, Director of Division of Plant Sciences, Dr. Marc Linit, Associate Dean for Research & Extension, CAFNRDr. Tom Payne, Vice Chancellor and Dean, CAFNRWelcome & MOTOC Update: Melvin Waldron, MOTOC President

9:00 – 10:30 a.m. Morning Session I: Visit 3 of 4 topics Page # Presentations last 20 minutes; 10 minute Q&A/Transit time

STOP 1* Large Evergreen Trees: What can we grow? Chris Starbuck, Associate Professor: Woody Ornamentals 1-2 STOP 2* Preventive measures for large patch control in zoysiagrass. Dan Earlywine, Research Specialist: Turfgrass Pathology 3STOP 3* “MU soil testing and plant diagnostic service to the Turf & Ornamental Industry.” Manjula Nathan, Associate Professor: MU Soil & Plant Testing Laboratory 4STOP 4* “Application strategies for improved control of brown patch in tall fescue.” Lee Miller, Assistant Professor: Turfgrass Pathology 5-6

10:30 – 12:00 p.m. Morning Session II: Visit 3 of 4 topics Presentations last 20 minutes; 10 minute Q&A/Transit time

STOP 5* “Control of crabgrass on creeping bentgrass putting greens by using preemergence herbicides.” Xi Xiong, Assistant Professor: Turfgrass Science 7STOP 6* “Postemergent annual bluegrass control on Kentucky bluegrass turf.” John Haguewood, Research Specialist & Graduate Research Assistant 8-9STOP 7* “Future trials on key turf diseases of lawns, sports fields, and golf courses in Missouri.” Lee Miller, Assistant Professor: Turfgrass Pathology 10STOP 8* “Help evaluate over two dozen recent introductions to the ornamental plant world.” David Trinklein, Associate Professor: Floriculture 11

12:00 – 12:45 p.m. Lunch (Included), Exhibits, & Raffle

12:45 – 3:30 p.m. Offsite Hort./Ornamentals Tour: Location: University of Missouri Campus

1:00 – 3:00 p.m. Afternoon Sessions: Visit all topics Presentations last 20 minutes; 10 minute Q&A/Transit time

STOP 9* “Characterization & management of Pythium root diseases on bentgrass putting greens” John B. Workman, Graduate Research Assistant: Turfgrass Pathology 12STOP 10* “Bermudagrass variety tolerance to AOPP herbicides.” Steve Song, Graduate Research Assistant: Turfgrass Science 13-14STOP 11* “Suppression of spring dead spot of bermudagrass with an integrated approach of cultural and chemical practices.” Derek Cottrill, Graduate Research Assistant: Turfgrass Pathology 15-16

* Number is referenced on farm map on back cover of the booklet.

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Large Evergreen Trees: What can we grow?Chris Starbuck

SummaryA common question in Extension offices is, “What can I plant to establish a tall, evergreen windbreak or privacy screen?” The best answer may be, “Good question.” With our clay soils, humidity and extremes in temperature and moisture, ev-ergreen trees struggle to grow in Missouri. Most pine and spruce species are intolerant of poor soil drainage and may decline quickly during extended periods of soil saturation. Spruces are generally adapted to cooler, climates with lower humidity than we have here. Stress from poor drainage, soil compaction and extremes in temperature and moisture often predispose pines and spruces to attack by diseases and insects.

PineKeep in mind that the only pine native to (southern) Missouri is short-leaf and the only other native conifer is eastern red cedar. White pine is not commonly affected by insects or diseases. However, it is very in-tolerant of poor drainage and subject to drought stress in shallow, clay-pan soils. These stresses may lead to attack by Phytophthora, ips borers or other pests. Scotch pine is not recommended as an ornamental in Missouri because of its susceptibility to pine wilt nematode. Scotch and mugo pine are also susceptible to brown spot needle blight and pine sawfly. Austrian pine is highly susceptible to Diplodia tip blight and Do-thistroma needle blight. Some very old Scotch and Austrian pines on the MU campus died in 2011, following the severe drought stress period in July and early August. Ips beetles were attracted to the stressed trees and finished them off in short order.

Spruce Over the past several years many spruce trees in Missouri landscapes have been infected by fungal diseases that are disfiguring or fatal. Colo-rado blue spruce seems most commonly affected, but Norway and white spruce have recently joined the club. In general, spruces are not well adapted to our hot, humid summers.

Until recently, the main problem with Colorado blue spruce has been Rhizosphaera needle cast. The fungus causing this disease generally gains a foothold on lower branches and, if left untreated, can work its way all the way to the top. Older needles on affected trees turn purplish and eventually drop off. Infected needles have many tiny black fruit-ing structures protruding through the epidermis. Fungicides containing chlorothalonil or copper applied to the new growth during spring and early summer can keep the disease from spreading.

Perhaps due to three successive, abnormally wet springs, other fungal diseases appear to have gained a foothold on spruces in Missouri. Al-though the causal agents are a topic of discussion among pathologists, one “new” fungal malady is referred to as SNEED (sudden needle drop of spruce). In contrast to Rhizosphaera, needles affected by SNEED do not turn purplish and do not exhibit fruiting bodies. Instead the fruit-ing bodies appear on the stems and twigs. Affected branches are more randomly arranged within the tree than in the case of Rhizosphaera. For further information on SNEED see this link.http://na.fs.fed.us/fhp/fhw/csfhw/nov03/sneeddetail.pdf

Management Options for Pine and SpruceAlthough chemical control measures can be effective in managing most of the pest problems mentioned above, good cultural practices can be very helpful. Plant evergreen trees in well drained soil or on raised berms. Space trees to allow

SNEED on blue spruceRapid shedding of older needles

Brown Spot Needle Blight on Mugo Pine

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full sun and good air circulation. Allow needles to collect under trees for self mulching, unless diseased needles and cones are prevalent. Irrigate during extreme drought. Controlling pine and spruce needle diseases requires diligence once they get started. If a tree is just beginning to show symptoms, pruning out affected branches (during dry weather) and burning dead branches may help reduce the spore numbers. Spray-ing new growth with a fungicide containing chlorothalonil or copper several times during needle development can also prevent further spread. Diplodia is very challenging to manage once it gets a foothold. Early intervention with pruning and fungicides is important. Fungicides containing copper, propiconazole, myclobutanil or thiophanate-methyl are effective when applied several times starting at budbreak, but hard to spray on very large trees. There are effective systemic products for-mulated for trunk injection.

What are we left with?As noted earlier, the only native conifer tree in most of Missouri is eastern red cedar (Juniperus virginiana). While it has a

few pest issues, it is much more tolerant of the soils and environmental extremes that we have in our region than any other conifer. There is tre-mendous variation in growth habit within this species. If a male cultivar with upright growth habit were available, this species could make an excellent screen without creating weed problems in nearby pastures. It may be worth looking at some of the older, upright cultivars of J. chi-nensis and J. virginiana like ‘Keteleeri’, ‘Perfecta’, ‘Burki’, ‘Canaertii’ and ‘Glauca’ which can grow up to 20-25 feet.

Given the many problems recently encountered with pines, it is difficult to recommend a dependable Pinus species. We have tested some cold hardy loblolly and pitch x loblolly pines that appear more stress toler-ant than white, Scotch and Austrian. However, their long needles make them susceptible to ice damage (all too com-

mon in our state) and they may develop some pest issues like rust and tip moth. Hardy shortleaf selections (northern seed sources), may prove useful as ornamentals, but all of the southern pines have growth habits more open than most people prefer for ornamental purposes.

Despite the recent upsurge in fungal diseases on spruces, Norway and white spruce are still more dependable than most other large evergreen trees. Picea glauca ‘Densata’, the black hills spruce, is still a good bet, but watch for spider mites, Rhizosphaera and SNEED. Serbian (Picea omor-ika) spruce appears less susceptible to needle blights than Picea pun-

gens, but I am reserv-ing judgment based on multiple mortalities (causes unknown) on campus.

‘Green Giant’ arborvitae (Thuja plicata) is now widely planted in the Midwest. Based on observations on the MU campus and at the Horti-culture and Agroforestry Research Center (HARC), this is a very fast growing upright tree with few pest problems. We have, however, expe-rienced some winter browning on ‘Green Giant’, but trees have greened up quickly in the spring. We also lost a few large specimens during the blast furnace period in July and August of 2011. Since Thuja plicata is native to the Pacific Northwest (considered a weed out there), it should probably not be planted where irrigation during drought is not possible.

Fruiting bodies on stem, not needles.

Second year needles show symptoms.

Dothistroma needle blight on Japanese Black PineTan spots coalesce causing needle tips to brown.

Brown Spot Needle Blight on Mugo PineReddish lesions with yellow margins coalesce caus-ing needle browning.

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Timing of a single fall fungicide application for preventative large patch control on zoysiaDaniel Earlywine and Lee Miller

SummaryLarge patch is the most serious disease affecting zoysiagrass golf fairways and lawns in Missouri. Preventive fall fungi-cide applications are often necessary in areas with a history of the disease. Proper fungicide timing based on pathogen biology can minimize fungicide usage and reduce costs associated with application. This trial was conducted at St. Andrews Golf Club in Overland Park, KS to evaluate the impact of fall application timing on residual large patch control. A single fall application of Heritage WDG and Triton FLO was applied at either the low or high rate. Applications were made on either 14 Sept (A) or 12 Oct (B).

Current FindingsLarge patch was first observed on 28 March, with a sharp increase in disease severity by 5 April. When applied at the early timing (A), Hertiage (0.2 oz/1000 ft2) and Triton Flo (0.55 fl oz/1000 ft2) achieved the same large patch control than treatments at higher rates. Lower rates of both Hertiage and Triton Flo at the (B timing), did not result in satisfac-tory control, and performed the worst among tested treatments. High rates of Triton Flo and Heritage tended to exhibit lower large patch severity than lower rates. However, by mid May, fall applications had broken down and resulted in unacceptable disease control and turf quality. More research needs to be conducted focusing on specific application timings to control large patch.

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Soil Testing and Plant Diagnostic Services Available at University of Missouri for Turf, Lawn Care and Landscaping IndustryManjula Nathan and Bob Heinz

MU Soil and Plant Testing Lab:Provides analyzes of soil, plant, water, manure, compost, greenhouse media and environmental analysis using state of the art technology. The fee-based services are available to farmers, homeowners, horticulturists, golf course managers, landscape managers, consultants, researchers and government agencies. The lab provides quality testing and unbiased, research based recommendations to clients for economically viable and environmentally safe nutrient management practices with a rapid turnaround time.

The lab analyzes about 25,000 to 35,000 field crop (farm) soil samples, 5,000 to 7,000 horticultural crop (lawn and gar-den) soil samples and 1,000 commercial fruits, vegetables and turf soil samples each year. Soil test reports for samples processed through the lab are sent by US mail, email or can be also accessed via online with a password. The regional agronomy/horticulture specialists review reports and make additional comments if needed and mail to the clients.

MU Extension Nematology Lab:This lab tests soil and plant samples qualitatively and quantitatively for the presence of plant parasitic nematodes. Rec-ommendations are provided for management strategies to reduce the effect of nematodes on plant growth and yield. Lab provides soybean cyst nematodes egg counts, plant parasitic nematode identification, HG type “race” test and quar-antine tests for corn, soybeans, ornamentals, turf and vegetable crops.

MU Turf Diagnostic Lab:Provides identification of turf problems and suggests management practices to aid recovery. Dr. Lee Miller conducts this service as portion of his extension program. In addition to the traditional method of shipping samples for diagnosis, Dr. Miller also operates a Mobile Turf Diagnostic Lab that houses microscopes and equipment for on-site investigation of turf issues.

It is important to adopt good sampling techniques and submit a representative sample to the lab for proper diagnostics. Samples submitted to the lab should be accompanied by the sample information forms duly filled in order to get the rec-ommendations. Information on submitting samples to the soil and plant testing and nematolgy labs can be obtained by visiting the lab’s website at: http://soilplantlab.missouri.edu and the turf diagnostics lab at http://turfpath.missouri.edu.

Samples can be submitted directly to the lab or through the University Extension Centers: Mail samples to:

Soil and Plant Diagnostic Services, 23 Mumford Hall, University of Missouri, Columbia, MO 65211

Tel: 573-882-3250 Fax: 573-884-4288 Email: [email protected]

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Application strategies for improved control of brown patch in tall fescueLee Miller and Daniel Earlywine

SummaryRecently, a number of granular fungicide formulations have been introduced to the market. Granular fungicides are considerably easier to apply than spray applications, and are therefore targeted for the lawn market. It is not necessary to purchase and operate specialized equipment, and standard fertilizer spreaders can be used for application. Earlier reports of efficacy of granular products indicated that granulars are slightly less effective than their sprayable counter-parts. However, newer granular formulations seem to be closing this gap in efficacy in recent reports, and need to be further evaluated. This study is designed to evaluate granular vs. sprayable fungicides for control of brown patch on tall fescue. In addition, fungicides will either be watered-in immediately with 0.2” of irrigation to “activate” the product or not watered-in. Three QoI or combination DMI/QoI fungicides were applied initially on May 22, and then on 28 d intervals. Product rates were adjusted so the amount of fungicide active ingredient was consistent among each product group. Inoculum was placed at two points/plot to facilitate brown patch disease pressure and uniformity.

By June 20, brown patch was not occurring in plots due to drought conditions and cool nighttime temperatures in May/early June.

Treatment S/Gx Watery Rate IntervalUntreated - - -PillarPillar G G + 3 lb/1000 ft2 28dPillar G G - 3 lb/1000 ft2 28dInsignia SC + S + 0.7 fl oz/1000 ft2 + 28dTrinity SC 1.02 fl oz/1000 ft2

HeadwayHeadway G G + 4 lb/1000 ft2 28dHeadway G G - 4 lb/1000 ft2 28dHeritage TL + S + 1.98 fl oz/1000 ft2 + 28dBanner Maxx 2.95 fl oz/1000 ft2

Heritage TL + S - 1.98 fl oz/1000 ft2 + 28dBanner Maxx 2.95 fl oz/1000 ft2

Headway S + 3.0 fl oz/1000 ft2 28dHeadway S - 3.0 fl oz/1000 ft2 28dHeritage Heritage G G + 4 lb/1000 ft2 28dHeritage G G - 4 lb/1000 ft2 28dHeritage TL S + 1.98 fl oz/1000 ft2 28dHeritage TL S - 1.98 fl oz/1000 ft2 28dArmadaArmada S - 0.75 oz/1000 ft2 14dArmada S - 1.5 oz/1000 ft2 28d

X S = sprayable formulation. G = granular formulationy ‘+’ = 0.2” of irrigation applied immediately after treatment, ‘-’ = no irrigation

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7

Safety and Efficacy of Pre-emergence Herbicides of Crabgrass Control on Creeping Bentgrass Putting GreensXi Xiong and John Haguewood

SummaryPre-emergence herbicides labeled for creeping bentgrass (Agrostis stolonifera) putting greens on golf courses exhibit differential efficacy. In addition, there is a concern of phytotoxicity to turf on greens. This study was designed to evaluate commercially available pre-emergence herbicides to methiozolin, which is not currently released to the US market, for the efficacy on crabgrass (Digitaria spp.) control and safety on creeping bentgrass putting greens.

Current FindingsThe herbicides Bensumec® 4LF, Dimension® 0.25Gupersan® 50%, Andersons® Goosegrass/crabgrass control at label rates along with methiozolin at 3 different rates, were applied initially on April 6, 2012 with a sequential application on April 20th, 2012. Plots were arranged in a completely randomized block design with 4 replications. Minor phytotoxic-ity was induced by Andersons® shortly after the initial application and turf recovered within 2 weeks. We also found significant differences in herbicide efficacy for control of crabgrass emergence. Detailed results will be discussed at the Field Day.

Treatment # Treatment Name Rate(kg ai/ha) Transformed Rate # of Apps Re-Application

Interval1 Methiozolin* 0.5 0.445 LB A/A 1 ---2 Methiozolin* 0.5 0.445 LB A/A 2 14 d3 Methiozolin* 0.75 0.67 LB A/A 1 ---4 Methiozolin* 0.75 0.67 LB A/A 2 14 d5 Methiozolin* 1.0 0.89 LB A/A 1 ---6 Methiozolin* 1.0 0.89 LB A/A 2 28 d7 Bensulide 14.0 9.6 FL OZ/1000 FT2 1 ---8 Bensulide 14.0 9.6 FL OZ/1000 FT2 2 28 d

9 Indaziflam 5.0 0.0212 FL OZ/1000 FT2 1 ---

10 Dithiopyr 0.56 0.5 LB A/A 1 ---11 Dithiopyr 0.28 0.25 LB A/A 2 28 d

12 Bensulide +Ozadiazon 16.82 5.25 LB/1000 FT2 1 ---

13 Siduron 3.36 3 LB A/A 1 ---14 Untreated --- --- ---

Table 1. Treatment list and Application Description

*Applied with 0.125% V/V Non Ionic Surfactant

8

Herbicide Applications to Control Annual Bluegrass on Kentucky Bluegrass TurfJohn Haguewood and Xi Xiong

SummaryAnnual bluegrass (Poa annua L.) has been identified by many as the hardest-to-control weed in the turfgrass industry for many years. Selective control has proven difficult in cool season grasses and continues to challenge turfgrass man-agers. This research is being conducted to evaluate chemical control options in Kentucky bluegrass (Poa pratensis L.). Treatments (Table 1) were designed in a randomized complete block with four replications, with individual plots mea-suring 5 ft X 5 ft. Five annual bluegrass plants (4 inch diameter) were transplanted into each plot and established prior to the onset of treatments. Plots were maintained at a mowing height of two inches and provided adequate manage-ment practices for survival of Kentucky bluegrass throughout the experiment. Initial treatments were applied on June 1st, 2012 with a CO2-presurized backpack sprayer calibrated to deliver 44 gal/acre using XR 8004 flat-fan spray tips. Turfgrass quality, phytotoxicity and percent annual bluegrass control were evaluated weekly throughout the course of the experiment.

Current FindingsTo date, all treatments except Velocity not resulted in phytotoxicity or a reduction in turf quality. Velocity exhibited un-acceptable phytotoxicity to Kentucky bluegrass 10 days after treatment. Data collection continuesis still being collected on this experiment.

Table 1. Description of herbicides and application intervals for control of annual bluegrass in Kentucky bluegrass.

Treatment Product Rate Rate Unit Application Interval (days)

1 Untreated --- --- ---2 Methiozolin1 0.5 lb/A 143 Methiozolin1 0.5 lb/A 284 Methiozolin1 1.0 lb/A 145 Methiozolin1 1.0 lb/A 286 Tenacity 5.0 fl oz/A 147 Velocity 9 oz/A 148 Prograss 26 fl oz/A 28

1Methiozolin applications also included 0.125% v/v non-ionic surfactant.

9

Figure 1. Description of plot layout for herbicide treatments to control annual bluegrass in Kentucky bluegrass.

Methiozolin(0.5 lb/A )

14d

Tenacity(5.0 fl oz/a)

14d


28dUntreated

Velocity(9.0 oz/a)

14d


14d

Prograss (26 fl oz/a)

28d

Methiozolin(1.0 lb/A)

28d

UntreatedVelocity

(9.0 oz/a)14d


28d


28d


28d


14d


14d


14d


14d


28d


14d


28d


14dUntreated


28d

Velocity(9.0 oz/a)

14d

UntreatedMethiozolin(0.5 lb/A)

14d


28d


14d


28d


14d

Velocity(9.0 oz/a)

14d


28d

10

Future trials on key turf diseases of lawns, sports fields, and golf courses in MissouriLee Miller

IntroductionIn accordance with our new conference affiliation, the turf research farm is also expanding its southern borders. In the last 18 months, our three turf programs have established seven new plots measuring 60 ft × 180 ft each. This amounts to an extra 75,000 ft2 of research plot area for us to evaluate turf cultivars and pest management practices, and provide this information back to Missouri turf managers. This presentation will focus on the four new research blocks constructed for the Mizzou turfgrass pathology program, and discuss plans for research on turf diseases important to the region. Pathogen inoculation procedures to allow disease uniformity across treatments will be discussed and demonstrated.

Plot DetailsPlot 1: Zoysiagrass cv. ‘Meyer’. Zoysia is used throughout Missouri in golf course fairways and home lawns. To some, it is considered a low maintenance turf, and compared to cool season turf species, zoysia is fairly resistant to most turf disease. Large patch, however, is the Achilles heel of zoysia and causes arguably more damage than any other zoysia pest. Research planned on this plot area will focus on the environmental conditions necessary for large patch epidemics, and management techniques for controlling this disease.

Plot 2: Bermudagrass cv. ‘Patriot’. Bermudagrass is valued for athletic field use due to its higher wear tolerance and recuperative potential compared to Kentucky bluegrass or zoysiagrass. Newer cultivars have also been developed with increased winter tolerance, allowing bermuda use as far north as Philadelphia on the East Coast and locally in St. Joseph, MO. Like zoysia, bermudagrass also has its disease Achilles heel in spring dead spot. This soil borne disease is extremely difficult to handle once established, and a combination of cultural and chemical practices is necessary to achieve acceptable control. Newer cold tolerant cultivars, such as ‘Patriot’, were thought to be tolerant of this disease, but several reports from the Midwest are proving this isn’t the case. Spring dead spot inoculation will be attempted on this plot, and if established, management practices will be evaluated and developed for this disease.

Plot 3: Creeping bentgrass cvs. “Penneagle II” & “Crystal Bluelinks”. Creeping bentgrass is being used at fairway height (0.5” – 1.0”) on tee complexes and some fairways in Missouri. During the spring and fall, creeping bentgrass performs exceptionally well for this purpose, but during the summer heat several diseases take advantage of this compromised cool season species. “Penneagle II” was specifically planted for evaluating dollar spot control practices. “Crystal Bluelinks” is a newer variety, which we will evaluate for quality and turf disease occurrence.

Plot 4: Kentucky bluegrass cv. “Langara”. Kentucky bluegrass is dearly beloved by many for its lush green color and higher recuperative potential due to its stoloniferous growth habit. The species is used prominently in baseball athletic fields and many home lawns throughout Missouri. It is unfortunately very disease prone, and is affected by three key turf diseases: summer patch, dollar spot, and Pythium blight. Research in this block will focus on all three of these diseases. Summer patch is the most difficult of these three diseases to control, because like spring dead spot the pathogen is soil borne and targeted controls are difficult to deliver. Summer patch will be inoculated into ½ of this plot area to evaluate both chemical and cultural control practices. The other half of the plot area will be inoculated annually with the dollar spot and Pythium blight pathogens to evaluate control tactics for these two foliar diseases.

Special Donor AppreciationWe are indebted to several donors that made this research farm expansion possible. They are listed in the table below, along with their special contribution. Without these donations, these research plans would not have become a reality. The program is extremely appreciative of your efforts and sacrifices in making this expansion project a success. Thank you!

Donor List for New Research BlocksCompany Key Individual Service or MaterialAtkins Lawn Care Dave Fore Irrigation installation pipe pulling John Deere Landscapes Keith Schweiger Irrigation installation parts, labor, knowledgeLaser Turf Leveling Jerry Meyer Plot leveling/grade workPerfect Play Fields & Links Mike Munie Bermudagrass donation & sprigging serviceSelecTurf Jim Keeven Zoysiagrass donation & sprigging serviceSouth Farms John Poehlman Equipment useWilliams Lawn Seed Bill Tritt Seed Donation

11

Evaluating the Performance of Annual Herbaceous OrnamentalsDavid TrinkleinSummaryAnnual flowering plants have become an important component of the created landscape. The season-long color they provide often is thought of as the “finishing touch” to the landscape. This is true for public areas as well as for private businesses and residences. The demand for annual flowering plants has been strong over the years, in spite of the recent downturn in our country’s economy. Many annual herbaceous plants carry the stigma of exhibiting poor perfor-mance, especially under severe heat and water stress conditions typical of a Missouri summer. This fact has, in certain cases, prevented them from being more widely used in large-scale plantings such as those typical of color beds on golf courses, surrounding commercial buildings, etc. Plant improvement via introduction and breeding has produced many new cultivars of herbaceous ornamentals over the past several years. Their ability to tolerate Missouri conditions is, in most part, unknown. The purpose of this trial was to evaluate the performance of a number of new herbaceous orna-mental cultivars under Missouri conditions.

Thirty-seven cultivars representing sixteen species of annual herbaceous ornamental plants (refer to evaluation hand-out) were transplanted into demonstration plots located at the University of Missouri Turf Research Center located on the South Farm near Columbia, Mo. Trial plants were started from seed or received as established plants and grown to transplantable size in a campus greenhouse. On May 15, 2012 the plants were established in outdoor plots that had been amended with 3-18-19 fertilizer at the rate of 6 oz./100 ft2. Additional nitrogen in the form of calcium nitrate was applied June 14, 2012 at the rate of 10 oz./ 100 ft2 . Plants were supplied with one and one-half inches of water per week when rainfall was insufficient. Weed control was achieved through the use of trifluralin (Preen®) and via hand weeding. Data was/will be collected for early performance, mid-summer performance, and late season performance using a rating scale of 1 - 10.

12

Characterization and management of Pythium root diseases prevalent on bentgrass putting greens in the MidwestJB Workman and Lee Miller

SummaryCreeping bentgrass (Agrostis stolonifera L.) is a cool-season species commonly used for golf course putting greens in the Midwest. This species is preferred because it tolerates low mowing heights and produces a uniform putting surface (Beard, 1992). During the summer months, bentgrass management is difficult do to physiological stresses that often result from persistent heat. To further complicate matters, impairment of root function by soil borne plant pathogens, particularly Pythium species, can lead to rapid and severe decline of creeping bentgrass during summer stress periods (Smiley et al., 2005). Despite the importance of creeping bentgrass to the Midwest, confusion exists among researchers and turf managers on the type of Pythium diseases (i.e. pythium root rot and pythium root dysfunction) that occur in the region. Pythium root rot causes a distinct browning or blackening of affected roots, and is usually exacerbated by wet soil conditions. Symptoms of Pythium root dysfunction do not include a distinct root necrosis, and is more prevalent in well-drained soil profiles on younger bentgrass greens (< 5 years) (Hodges and Coleman, 1985). Confusion between the two pathogens may be leading to fungicide applications at the wrong time or incorrect fungicide selection. An improved method of identifying Pythium species from infected root tissue and confirmation of pathogenicity is needed to allow for effective design of preventative programs.

ObjectivesThe objectives of this study are to identify the distribution of Pythium species affecting bentgrass putting greens in the Midwest, and to provide superintendents with control measures that are best suited to the specific Pythium pathogen predominant on their site. Collection, isolation, and identification of Pythium isolates were initiated in May 2012 and will continue through the next two seasons. Virulence assessment will begin in the fall of 2012, and those species that are most virulent will be selected for inoculation into microplots for field management studies. Upon completion, this study should provide superintendents, researchers, and diagnosticians with a reliable way of knowing if summer bent-grass root decline is due to Pythium infection or from another source.

FundingThe Heart of America GCS, the Ozark Turfgrass Association, & the Wisconsin GCS are funding this project as co-sponsors of a EIFG-GCSAA Chapter Cooperative Program Grant.

Donor List for New Pythium Research Putting Green Company Key Individual Service or Material

Perfect Play Fields & Links Mike Munie Excavation, Grading, & Construction Services

Capitol Sand & Gravel Chad Launie Sand & Pea Gravel Donation

13

Evaluation of the Differential Responses of Six Common Bermudagrass (Cynodon dactylon) to Aryloxyphenoxypropionate Herbicide Fenoxaprop-p-ethylEnzhan Song and Xi XiongSummarySelectively removing bermudagrass (Cynodon spp.) in zoysiagrass (Zoysia spp.) has been problematic. Recent research found that the aryloxyphenoxypropionate (AOPP) herbicides, such as fenoxaprop-p and fluazifop-p, can effectively con-trol bermudagrass with acceptable phytotoxicity on zoysiagrass. The objective of this research is to investigate the potential intra-species variations of six common bermudagrass (Cynodon dactylon) cultivars in response to AOPP her-bicide.Experiments were conducted repeatedly in two growing seasons in the greenhouse at the University of Missouri. With a randomized block design, untreated control and fenoxaprop-p (Acclaim® Extra) at 0.2 ka ai/ha (40.1 fl oz/a) was ap-plied on six common bermudagrass cultivars with 4 replications. Plant responses were visually monitored by evaluation of turf quality on a 1 to 9 scale (1 = complete plant death; 9 = ideal density and size; 6 = acceptable), and discoloration rate on a 0 to 100% scale (0% = no discoloration; 100% = complete discoloration). Vegetative growth conditions were also evaluated by weekly clipping biomass and final root biomass at 8 weeks after treatments (WAT). Turf quality and weekly clipping biomass were converted into relative turf quality (RTQ) and percent clipping biomass production (PCB) by comparing the data of treated plants to untreated controls. Higher RTQ or PCB value indicates better turf quality or shoots growth. The area under percentage discoloration curves (AUPIC) was also calculated for each cultivar by 8 WAT where higher AUPIC indicated more accumulated injury.

Current FindingsThere were significant intra-species variations among six tested common bermudagrass cultivars in responses to fenoxaprop-p. Treatment effects were shown as discoloration and stunting of shoot growth and impact on root devel-opment. ‘Riviera’ and ‘Yukon’ showed significantly less phytotoxicity with 30 to 75% lower accumulated injury (AU-PIC) compared to ‘Celebration’, ‘NuMexSahara’, and ‘Princess 77’ (Fig. 1). Bermudagrass cultivars ‘Riviera’ and ‘Yukon’ showed 14 to 58% higher RTQ compared to ‘Celebration’ and ‘Princess 77’ (Table 1). Similarly, ‘Riviera’ and ‘Yukon’ also showed better shoot growth in both years (Table 2).Root biomass collected at 8 WAT found significant variations among the six bermudagrass cultivars (Table 3). Bermu-dagrass ‘Riviera’ produced the highest roots compared to other cultivars in both years. In comparison, bermudagrass ‘Princess 77’ showed the lowest root growth after treatment with fenoxaprop-p. Studies are ongoing to evaluate the mechanism of bermudagrass in response to AOPP herbicides.

Table 1. Relative turf quality (RTQ) influenced by the AOPP herbicide treatment in 2010 or 20111.

Cultivars 1WAT 2WAT 3WAT 4WAT 5WAT 6WAT 7WAT 8WAT------------------------------------ Year 2010 ----------------------------------

Celebration 57 bc2 25 d 25 d 51 d 64 b 57 c 65 b 65 cPrincess 77 54 bc 30 cd 39 c 46 d 54 c 56 c 63 b 61 cQuickstand 70 a 63 a 72 a 78 a 80 a 80 a 88 a 88 aRiviera 55 bc 45 b 52 b 76 ab 79 a 77 a 81 a 86 aNuMexSahara 51 c 27 d 41 c 60 c 68 b 66 b 68 b 66 cYukon 60 b 35 c 47 bc 71 b 78 a 78 a 78 ab 81 b

------------------------------------ Year 2011 ----------------------------------Celebration 67 cd 25 c 25 c 44 d 67 cd 67 cd 72 b 77 cPrincess 77 71 bcd 45 b 45 b 55 b 71 bc 71 bcd 85 a 88 bQuickstand 63 d 25 c 25 c 38 e 63 d 63 d 66 c 76 cRiviera 86 a 56 a 56 ab 73 a 86 a 86 a 88 a 88 bNuMexSahara 75 b 57 a 57 a4 50 c 75 b 75 b 86 a 93 ab

1 Due to significant years by cultivars interaction, data was presented in 2010 and 2011 separately.2 Means within the same columns labeled by the same letters are not significantly different.

14

Table 2. Treatment effects on relative clipping biomass (RCB) (%) in 2010 or 20111.

Early stage2 Late stageCultivars 1WAT 2WAT 3WAT 4WAT 5WAT 6WAT 7WAT 8WAT

------------------------------------ Year 2010 ----------------------------------Celebration 0 b3 0 b 14 c 12 c 35 c 37 c 44 c 42 dNuMexSahara 0 b 4 b 27 bc 14 c 57 bc 62 bc 68 b 63 cdPrincess 77 0 b 4 b 16 c 9 c 32 c 35 c 61 b 78 cQuickstand 79 a 41 a 51 ab 35 bc 75 ab 83 ab 134 a 140 bRiviera 6 b 19 b 65 a 65 a 75 ab 83 ab 80 ab 82 cYukon 25 b 6 b 53 ab 51 ab 88 a 100 a 153 a 170 a

------------------------------------ Year 2011 ----------------------------------Celebration 4 a 0 b 83 b 42 d 51 b 57 b 63 bc 68 bcNuMexSahara 7 a 4 b 58 c 80 b 28 c 53 b 82 a 78 bPrincess 77 3 a 0 b 82 b 102 a 54 b 65 ab 77 ab 73 bQuickstand 3 a 0 b 93 ab 38 d 56 b 59 b 60 bc 69 bcRiviera 7 a 18 a 70 c 67 c 79 a 60 b 47 c 52 cYukon 9 a 5 b 96 a 100 a 77 a 83 a 91 a 121a

1 Due to significant years by cultivars interaction, data was presented in 2010 and 2011 separately.2 Results were divided into early (1 to 4 WAT) and late (5 to 8 WAT) growth stages.3 Means within the same columns labeled by the same letters are not significantly different.

Table 3. Bermudagrass root biomass (g) influenced by the AOPP herbicide treatment at 8 WAT.

Control1 Treated2

Cultivars Year 2010+2011 Year 2010 Year 2011Celebration 2.78 a3 1.79 ab 2.06 bNuMexSahara 1.87 b 1.5 b 1.98 bPrincess 77 1.83 b 0.7 c 1.82 bQuickstand 2.89 a 2.53 a 2.05 bRiviera 2.85 a 2.37 a 3.73 aYukon 1.79 b 1.86 ab 1.99 b

1 No interaction between years and cultivars, data was pooled together for control groups.2 Significant years by cultivars interaction, data was presented separately in two years for treated plants.3 Means within the same columns labeled by the same letters are not significantly different.

Figure 1. Area under percentage discoloration curves (AUPIC) of six common bermudagrass cultivars in response to the treatment. Due to significant years by cultivars interaction, results were presented in separated graphs with A: 2010; and B: 2011. Means with the same letters are not significantly different.

BA

15

Suppressing spring dead spot of bermudagrass with an integrated approach of cultural and chemical practices.Derek Cottrill and Lee MillerSummarySpring dead spot caused by Ophiosphaerella herpotricha, O. korrae, and O. namari, is the most destructive disease of ber-mudagrass. Spring dead spot limits performance of bermudagrass swards in areas where temperatures induce winter dormancy. As the name implies, symptoms become evident in the spring as bermudagrass comes out of winter dorman-cy. Above ground symptoms include sunken and necrotic patches (6”- 3’ in diameter) that may coalesce over time. Below ground, infected roots and rhizomes are black and necrotic. Spring dead spot control is difficult, with variable suppres-sion resulting from a combination of cultural and chemical practices necessary over multiple years. Recent research indicates nitrogen source may be an important factor in management of this disease. This 3-year field trial investigates the effects of nitrogen source, nitrification inhibitors, sulfur, and fungicide treatments on a spring dead spot epidemic.

Current FindingsNitrogen was applied once a month in June, July and August of 2011 at 1 lb. N/1000ft2. Nitrogen sources included urea (46-0-0), ammonium sulfate (21-0-0), calcium nitrate (15.5-0-0), UFlexx (46-0-0), and UMaxx (47-0-0). Sulfur (2 lb S/1000ft2) was applied at the same time as nitrogen. Tebuconazole (Torque, 0.6 oz. /1000ft2) was applied either once on September 16th, 2011 or twice on September 16 and October 14. Initial disease severity ratings were taken on June 10, 2011 before any treatments were applied. Only plots treated with ammonium sulfate, sulfur, and two fungicide ap-plications had lower spring dead spot severity (7%) in May 2012 than the initial June 2011 rating date. Combination treatments of Torque and sulfur with nitrogen application provided quicker recovery by early June 2012 than nitrogen applications alone. Disease ratings presented here are based on visual estimation of % diseased area. Digital photos have also been taken over the course of the study, and will be analyzed with image analysis software to provide an objec-tive measure of treatment impact over time.

Spring Dead Spot SeverityTreatment June 10, 2011 May 8, 2012 May 22, 2012 June 8, 2012Urea (46-0-0)- Fungicide, - Sulfur 26.0 def 29.0 e-h 22.0 c-h 13.0 d-h- Fungicide, + Sulfur 24.0 ef 27.0 fgh 14.4 f-i 9.4 e-jFungicide-1 app., -Sulfur 25.0 def 29.0 e-h 23.0 c-h 8.4 f-jFungicide-1 app., +Sulfur 25.0 def 24.0 h 11.4 hi 11.2 e-jFungicide-2 app., -Sulfur 28.0 c-f 29.0 e-h 17.0 e-i 10.0 e-jFungicide-2 app., +Sulfur 33.0 b-f 30.0 e-h 17.0 e-i 8.0 f-jAmmonium Sulfate- Fungicide, - Sulfur 33.0 b-f 42.0 b-f 21.0 c-i 18.0 b-e- Fungicide, + Sulfur 30.0 c-f 31.0 e-h 16.8 e-i 9.2 f-jFungicide-1 app., -Sulfur 33.0 b-f 35.0 c-h 27.0 b-g 13.0 d-hFungicide-1 app., +Sulfur 35.0 b-f 25.0 gh 14.0 ghi 11.0 e-jFungicide-2 app., -Sulfur 41.0 a-d 40.0 b-g 28.0 b-f 12.0 d-iFungicide-2 app., +Sulfur 43.0 abc 37.0 c-h 24.0 c-h 3.4 ijCalcium Nitrate- Fungicide, - Sulfur 39.0 a-f 49.0 abc 31.0 bcd 20.0 bcd- Fungicide, + Sulfur 43.0 abc 47.0 a-d 30.0 b-e 15.0 c-gFungicide-1 app., -Sulfur 32.0 c-f 41.0 b-f 31.0 bcd 16.0 b-fFungicide-1 app., +Sulfur 39.0 a-f 39.0 c-h 23.0 c-h 12.0 d-i

16

Means followed by the same letter do not significantly differ (P=.05,LSD)

Treatment June 10, 2011 May 8, 2012 May 22, 2012 June 8, 2012Fungicide-2 app., -Sulfur 26.0 def 38.0 c-h 15.0 f-i 6.2 hijFungicide-2 app., +Sulfur 29.0 c-f 29.0 e-h 13.0 hi 6.4 g-jUflexx- Fungicide, - Sulfur 49.0 ab 61.0 a 51.0 a 34.0 a- Fungicide, + Sulfur 43.0 abc 55.0 ab 40.0 ab 24.0 bFungicide-1 app., -Sulfur 39.0 a-f 48.0 a-d 32.0 bc 13.4 d-hFungicide-1 app., +Sulfur 37.0 a-f 38.0 c-h 25.0 c-h 6.8 g-jFungicide-2 app., -Sulfur 26.0 def 33.0 d-h 22.0 c-h 9.0 f-jFungicide-2 app., +Sulfur 28.0 c-f 35.0 c-h 19.0 c-i 5.8 hijUMaxx- Fungicide, - Sulfur 52.0 a 59.0 a 40.0 ab 23.0 bc- Fungicide, + Sulfur 38.0 a-f 43.0 b-e 27.0 b-g 13.0 d-hFungicide-1 app., -Sulfur 27.0 c-f 33.0 d-h 18.0 d-i 8.0 f-jFungicide-1 app., +Sulfur 40.0 a-e 35.0 c-h 18.0 d-i 6.4 g-jFungicide-2 app., -Sulfur 34.0 b-f 37.0 c-h 15.0 f-i 6.0 hijFungicide-2 app., +Sulfur 23.2 f 25.0 gh 7.4 i 2.6 j

1 1 1 1 1 Urea

2 2 2 2 2 NH4SO4

3 3 3 3 3 CaNO3

4 4 4 4 4 UFLEXX

5 5 5 5 5 UMAXX

6 6 6 6 6 Fertilizer

1 1 1 1 1 3 apps: June, July, August

6 6 6 6 6

5 5 5 5 5

2 2 2 2 2

3 3 3 3 3

4 4 4 4 4 1 - Fung, - Sulfur

6 6 6 6 6 2 - Fung, + Sulfur

1 1 1 1 13

Torque - 1 app, - Sulfur

4 4 4 4 44

Torque - 1 app, + Sulfur

2 2 2 2 25

Torque - 2 apps, - Sulfur

5 5 5 5 56

Torque - 2 apps, + Sulfur

3 3 3 3 3

2 2 2 2 2 Sulfur

1 1 1 1 1 + Sulfur = 2 lb/M applied with fertilizer in June, July, and August

5 5 5 5 5

3 3 3 3 3

6 6 6 6 6All applications immediately watered-in with 0.2” of irrigation 4 4 4 4 4

3 3 3 3 3

6 6 6 6 6

5 5 5 5 5

4 4 4 4 4

2 2 2 2 2

1 1 1 1 1

17

National Turfgrass Evaluation Program TrialsBrad Fresenburg

SummaryThe National Turfgrass Evaluation Program (NTEP)* has been and still is one of the most widely known sources for in-formation on turfgrass species, cultivar selections and evaluations. NTEP is designed to develop and coordinate uniform evaluation trials and now covers 17 species in their program within 40 U.S. states and six provinces of Canada.

Results can be used to determine if a cultivar is well adapted to a local area or level of turf maintenance. Each trial is designed to have a specific maintenance program followed during the life of the trial at a particular location. That infor-mation can be found on their website.

Information such as turfgrass quality, color, density, resistance to diseases and insects, tolerance to heat, cold, drought and traffic is collected and summarized by NTEP annually. NTEP information is used by individuals and companies in thirty countries. Plant breeders, turfgrass researchers and extension personnel use NTEP data to identify improved environmentally-sound turfgrasses. Local and state government entities, such as parks and highway departments, use NTEP for locating resource-efficient varieties. Most important, growers and consumers use NTEP extensively to pur-chase drought tolerant, pest resistant, attractive and durable seed or sod. It is the acceptance by the end-user that has made NTEP the standard for turfgrass evaluation in the U.S. and many other countries worldwide.

*Information from NTEP website.One NTEP trial is being conducted at the University of Missouri Turfgrass Research Facility - the 2010 Perennial Rye-grass trial. We are in the second season of the perennial ryegrass trial and this trial is scheduled to run for 4 years. All plots were showing excellent quality during the early spring we had this year; however things changed during that wet weather we experienced in April followed by that first weekend of 90 degree temperatures. The parameters of the pe-rennial ryegrass trial are listed below. Maintenance guidelines:

Perennial Ryegrass Trial:Mowing height: 1.5 to 2.5 “Nitrogen rate: 0.3 to 0.5 lb/1000 sqft**Irrigation: None, only to prevent dormancyHerbicides: Minimal to prevent stand lossFungicides: NoneInsecticides: None**Per growing month, however not monthly applications, 2-4 applications annually.

Attached is the plot plan for this trial. Feel free to look through the numerous cultivars on-site and try to pick your fa-vorites. While the tall fescue trial was completed in 2011, we are scheduled to establish a new tall fescue trial this fall.

18

2010 NTEP Perennial Ryegrass N

49 45 83 15 79 40 59 5

38 39 43 8 3 46 80 44

25 61 36 37 50 11 4 88

71 32 47 70 86 54 68 67

69 58 21 10 77 82 56 42

73 20 31 19 51 66 81 33

23 16 85 22 84 35 65 78

74 60 28 12 72 62 87 30

57 24 18 75 64 7 53 29

34 14 63 13 2 41 76 17

27 52 1 26 6 9 55 48

72 26 32 70 68 14 63 2

8 13 17 51 64 76 11 33

20 74 59 10 65 41 52 84

77 15 5 45 61 25 46 24

7 58 1 50 18 30 29 4

57 9 44 27 78 60 25 12

56 39 49 62 69 36 22 21

40 6 79 38 75 3 66 28

55 80 54 48 19 16 47 37

81 34 43 86 83 85 71 67

88 87 82 42 53 31 23 73

75 22 42 20 38 84 77 78

30 16 14 28 49 7 25 70

59 19 13 12 24 4 18 87

65 60 58 82 81 76 32 83

6 23 21 54 31 15 5 86

48 73 37 8 11 66 29 46

55 51 53 1 3 2 69 36

39 64 72 56 68 33 74 85

40 17 10 35 61 47 88 80

26 52 27 43 67 71 63 50

41 62 44 45 34 9 79 57

5 X 5 plots, RCBD, 3 replications, 88 cultivars (40’ X 165’) Planted: Oct. 1, 2010

19

2010 NA

TION

AL PEREN

NIA

L RYEGRA

SS TEST Entries and Sponsors

Entry No.

Nam

e

Sponsor

Entry No.

Nam

e

Sponsor

1

Rinovo

Sem

illas Fito

46

ISG-31

Integrated Seeds 2

CL 11601

The Scotts Com

pany

47

A

-35

A

llied Seeds 3

PR 909

Turf Merchants, Inc.

48

CS-PR66

Columbia Seeds

4

CL 11701


49

CST

Colum

bia Seeds 5

A

PR 2036

Brett Young Seeds Ltd.

50

JR-178

Jacklin Seed by Simplot®

6

Linn

Standard Entry

51

JR-192

Jacklin Seed by Simplot®

7

Uno

Standard Entry

52

PSRX-3701

Pickseed USA

& Seed Research of O

R 8

D

LF LGD

-3026

DLF International Seeds

53

Pick 10401

Pickseed USA

, Inc. 9

D

LF LGD

-3022


54

Mach I

Standard Entry 10

PSRX-S84

Pickseed U

SA &

Seed Research of OR

55

RA

D-PR62

Radix Research

11

SRX-4RHD

Seed Research of Oregon

56

RAD

-PR55R

Lewis Seed

12

P02

N

ovel AG

57

IS-PR 409

Brett Young Seeds Ltd. 13

S85

Novel A

G

58

IS-PR 463

D

LF International Seeds 14

LTP-RA

E

Lebanon Turf Products

59

IS-PR 469

D


A

llante

Ledeboer Seed/Pro-Turf Solutions-O

VS 60

IS-PR 479

D


Insight

Ledeboer Seed/Pro-Turf Solutions-OVS

61

IS-PR 487


17

Sienna

Ledeboer Seed/Pro-Turf Solutions-O

VS 62

IS-PR 488

D


Brightstar SLT

Standard Entry

63

IS-PR 489

D


CL 307

Pennington Seed Company

64

IS-PR 491


20

APR 2320

Pennington Seed Com

pany

65

IS-PR 492

D


A

PR 2038

Smith Seed Services

66

DLF LG

T 4182 DLF

International Seeds 22

PPG

-PR 121

Am

pac Seed Company

67

ISG-30

Integrated Seeds 23

PPG

-PR 128

Integra Turf, Inc.

68

PST-204D

Landm

ark Native Seeds

24

PPG-PR 133

M

ountain View Seeds

69

PST-2NKM

Landmark N

ative Seeds 25

PPG

-PR 134

Mountain View

Seeds

70

PST-2D

R9

Pure-Seed Testing 26

LTP-PR 135

Lebanon Turf Products

71

PST-2MG

7


PPG

-PR 136

Lewis Seed

72

PST-2TQ

L


PPG

-PR 137

Columbia Seeds

73

PST-2A

G4

Brett Young Seeds Ltd.

29

PPG-PR 138

A

mpac Seed Com

pany

74

PST-2M

AG

S


30

PPG-PR 140

M

ountain View Seeds

75

PST-2K9

The Scotts Company

31

PPG-PR 142

Peak Plant G

enetics

76

PST-2BN

S


PPG

-PR 143

Columbia Seeds

77

PST-2A

CR


PPG

-PR 164

Mountain View

Seeds

78

Rio Vista

Burlingham

Seeds 34

PPG

-PR 165

Peak Plant Genetics

79

Octane

Burlingham Seeds

35

BAR Lp 10969

Barenbrug U

SA

80

Bonneville

Burlingham

Seeds 36

BA

R Lp 10972

Barenbrug USA

81

PSRX-4CAG

L

Pickseed USA

& Seed Research of O

R 37

BA

R Lp 10970

Barenbrug USA

82

GO

-DH

S

Grassland O

regon 38

2N

JK

Barenbrug U

SA

83

G

O-PR60

G

rassland Oregon

39

BAR Lp 7608

Barenbrug U

SA

84

G

M3

Landmark N

ative Seeds 40

Pinnacle

Standard Entry

85

PRX-4G

M1

Pickseed U

SA &

Seed Research of OR

41

APR 2445

ProSeeds M

arketing

86

SRX-4M

SH

Seed Research of O

regon 42

Fiesta 4

Standard Entry

87

Pick 4DFH

M

Pickseed U

SA, Inc.

43

GO

-G37

G

rassland Oregon

88

Palmer V

Standard Entry

44

CS-20

Colum

bia Seeds 45

ISG

-36

Integrated Seeds

UPD

ATED

9/10/10

20

Synthetic Turf ResearchBrad Fresenburg

SummaryInstalled June of 2010, these synthetic turfs will allow us to answer on-going questions about maintenance, hardness, heat, syringing, and bacterial growth. The site provides a randomized block design for conducting research trials as well as having an area for demonstrations (grooming & cleaning equipment, paint and paint removal, etc.). Plots were installed on a 6 inch gravel bed over flat drains. In-fills were topdressed according to the manufacturer’s installation guidelines.

Initial research on heat began August of 2010. Plans are to bring on a graduate student this fall to study the potential of bacterial growth on synthetic surfaces.

This would not have been possible without contributions made by:Paul Hollis, Redexim-CharterhouseMike Munie, Perfect Play Fields & LinksSteve Bohlken, Capital SandDavid Coleman, Macon Granuband LLCJerry Meyer, Laser Turf Leveling

Sprinturf

Shaw Sportexe

Field Turf XP

AstroTurf MT

Shaw Sportexe

Sprinturf

Field Turf XP

AstroTurf 3D

Field Turf XP

Sprinturf

AstroTurf MT

Shaw Sportexe

AstroTurf 3D

Field Turf XP

AstroTurf MT

Shaw Sportexe

Sprinturf

AstroTurf 3D

Synthetic Turf Research

Brad Fresenburg

Installed June of 2010, these synthetic turfs will allow us to answer on-going questions about maintenance, hardness, heat, syringing, and bacterial growth. The site provides a randomized block design for conducting research trials as well as having an area for demonstrations (grooming & cleaning equipment, paint and paint removal, etc.). Plots were installed on a 6 inch gravel bed over flat drains. In-fills were topdressed according to the manufacturer’s installation guidelines. Initial research on heat began August of 2010. Plans are to bring on a graduate student this fall to study the potential of bacterial growth on synthetic surfaces.

This would not have been possible without contributions made by:Paul Hollis, Redexim-CharterhouseMike Munie, Perfect Play Fields & LinksSteve Bohlken, Capital SandDavid Coleman, Macon Granuband LLCJerry Meyer, Laser Turf Leveling

21

Use of Avid for ring nematode control on creeping bentgrass putting greensLee Miller and Daniel Earlywine

SummaryOver the past three seasons, disturbingly large ring nematode populations have been found in bentgrass putting greens in Missouri. The threshold level for ring nematode populations is 1000 per 100 cc of soil, a relatively high number compared to other species. In some putting greens 4-8x that number have been detected, (see below) leading to real concerns for turf health during stressful summer conditions. With the nematicide Nemacur (fenamiphos) pulled from the market in May 2008, very few options remain for control. In spring 2012, the Missouri EPA authorized a 24c Special Local Need (SLN) label for Avid (abamectin) use for ring nematode control. The SLN label allows for Avid use on putting greens with demonstrated high levels of ring nematodes. Trials conducted in OK, SC, and FL report numerical reduc-tions in ring nematode populations, increased root growth and no phytotoxicity with Avid applications. This trial, at Old Warson Country Club in St. Louis, investigates the use of Avid and its impact on turfgrass health and ring nematode populations.

Methods and Current ResultsLarge 10 × 10 ft plots are being used to facilitate multiple soil samplings. Treatments include an untreated control, Avid (1.3 fl oz/1000 ft2), Avid (1.3 fl oz/1000 ft2) + Revolution (6 fl oz/1000 ft2) tank-mix, and an Avid (1.3 fl oz/1000 ft2) + Revolution (6 fl oz/1000 ft2) + Heritage TL (1.0 fl oz/1000 ft2) tank-mix. Since only 4 applications are allowed under label directions, two applications were made on 4 April and 18 April, and two more will be applied in late July and early August. Soil samples are being taken every 7-14 days during treatment periods to assess ring nematode populations. No differences in ring nematode populations have been observed yet in treated vs. untreated plots. As of early summer, turf quality in all plots has been excellent and no nematode damage has been noted.

22

Curative fungicide treatments for dollar spot control: What to expect in a week?Lee Miller and Daniel Earlywine

SummaryPreventive fungicide applications have historically been the preferred method for dollar spot control, particularly on high amenity playing surfaces such as creeping bentgrass putting greens. But which fungicide should be selected if dollar spot does break through and become active? This research evaluates several standard and new fungicides for curative dollar spot control. Treatments were applied on day 0 (11 June), when dollar spot severity in plots was 5-10%. Visual ratings of disease severity including % area and # of $ spot infection centers/plot were taken over the next 7 days to assess the recovery rate provided by treatments.

Current FindingsNo significant differences were noted among treatments up to 3 days after treatment (DAT). Differences in recovery among treatments were apparent by 5 DAT, and were statistically different by 7 DAT according to means separation by least squares difference (LSD). All treatments, except Emerald applied at the high rate, had statistically higher rates of recovery than the untreated control. This result concurs with previous research that demonstrated excellent levels of preventive control with Emerald but lower curative activity. Plots treated with two new fungicides, Lexicon and Encar-tis, had higher rates of recovery than other treatments. These two BASF fungicides have not yet been released on the market.

23

Interaction of DMI fungicides and Trimmit applications on disease control and quality of putting greensLee Miller and Daniel EarlywineSummaryRecent research found two early spring applications of some DMI fungicides significantly suppress fairy ring on creep-ing bentgrass putting greens. For those that use paclobutrazol for spring suppression of Poa annua populations in their greens, this can be a problem since the DMI fungicides have a similar chemistry and are also potent growth regulators. This 2 year study was initiated in 2011 to 1) evaluate the potential negative impacts of applying paclobutrazol (Trim-mit) with the DMIs during the spring, 2) examine methods of scheduling paclobutrazol in coordination with DMI ap-plications, and 3) investigate residual efficacy of spring DMI applications on diseases of creeping bentgrass. Treatments include an untreated check, two 28 d applications of: Trimmit alone, four DMI fungicides alone, tank mixtures of the two, and Trimmit applied 7 & 14 days after the DMI application. In 2012, chlorophyll readings are being measured with a FieldScout CM-1000 meter to obtain an objective measure of turf health. The experiment was replicated on ‘Penncross’ and ‘Penn A-4’ to evaluate potential cultivar differences.

Current FindingsPhytotoxicity (bronzing discoloration) was first noted in plots on 29 May after the second DMI fungicide application was made on 22 May. Plots treated twice with paclobutrazol (Trimmit: 16 fl oz/A) or DMI fungicides alone exhibited significantly less phytotoxicity than a tank mixture or subsequent 7 or 14 d paclobutrazol application. Unlike 2011, temperatures have been mild in early June, and discoloration was not as severe. This result indicates heat stress is a major factor in the phytotoxic response, and Trimmit applied in conjunction with the DMIs should be scheduled earlier in the season. Dollar spot was first observed in untreated and Trimmit treated plots on 29 May (13 May in 2011). No dollar spot was observed in plots treated with Torque, Bayleton FLO, or Trinity until the June 20th rating date. Bayleton treated plots had numerically lower dollar spot incidence than other treatments on this date, but a statistical difference between treatments was not observed.

Phytotoxicityx $ Spot Incidence (# of infection centers)

6/12/12 5/29/12 6/20/12

Treatment Penncross A4 Penncross A4 Penncross A4

Untreated 0 f 0.3 ef 7.5 a 24.5 a 44.8 a 71.5 a

Trimmit Alone (16 fl oz/A) 0.3 ef 0 f 1.8 a 2.0 b 42.8 a 54.8 ab

Torque (0.6 fl oz/1000 ft2)

Alone 0.5 def 0 f 0.0 b 0.0 b 2.3 b 14.5 c

Tank-mixed with Trimmit 1.3 a-d 0.4 def 0.0 b 0.0 b 0.5 b 7.3 c

Trimmit 7 d later 1.1 a-d 1.1 a-e 0.0 b 0.0 b 2.3 b 0.0 c

Trimmit 14 d later 1.5 ab 1.7 ab 0.0 b 0.0 b 0.5 b 0.0 c

Bayleton FLO (1 fl oz/1000 ft2)

Alone 1.1 a-d 0.6 c-f 0.0 b 0.0 b 0.5 b 2.0 c

Tank-mixed with Trimmit 1.3 a-d 1.4 abc 0.0 b 0.0 b 0.0 b 0.5 c

Trimmit 7 d later 1.4 abc 1.3 a-d 0.0 b 0.0 b 0.5 b 0.5 c

Trimmit 14 d later 1.9 a 2.0 a 0.0 b 0.0 b 0.8 b 0.0 c

Tourney (0.28 oz/1000 ft2)

Alone 0.3 ef 0.9 b-f 0.0 b 0.0 b 8.5 b 22.0 bc

Tank-mixed with Trimmit 1.9 a 1.3 a-d 0.0 b 0.0 b 2.8 b 10.3 c

Trimmit 7 d later 0.6 c-f 0.5 c-f 0.0 b 0.0 b 2.8 b 15.3 c

Trimmit 14 d later 1.3 a-d 0.5 c-f 0.0 b 0.0 b 3.5 b 8.0 c

Trinity (1 fl oz/1000 ft2)

Alone 0 f 0.4 def 0.0 b 0.0 b 5.8 b 8.3 c

Tank-mixed with Trimmit 0.6 c-f 1.1 a-e 0.0 b 0.0 b 4.3 b 11.8 c

Trimmit 7 d later 0.3 ef 0.3 ef 0.0 b 0.0 b 0.0 b 8.5 c

Trimmit 14 d later 1.0 b-e 1.0 b-e 0.0 b 0.0 b 0.8 b 8.0 c

X Phytotoxicity measured on a 0-9 scale. 0 = green turf, 2-3 = significant bronzing, 9 = total turf loss.

24

Plot

s are

5 ×

5 ft

and

repl

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ed o

n ‘P

enn

A-4

’ and

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(1 fl

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ity(1

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d

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M) +

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25

Preventive fungicide applications for fairy ring control in golf putting greensLee Miller and Daniel Earlywine

SummaryRecent research indicates two low rate spring applications of some DMI fungicides are effective at suppressing fairy ring in golf putting greens. The initial application should be made when target 2” average soil temperatures range from 55 – 60°F, and the second application should be made 28 days later. It is necessary to water-in both applications with at least ⅛ – ¼” of irrigation immediately (preferable) or during that night’s irrigation cycle. This research investigates different variations of this preventive application strategy, using new products or products at different intervals.

Methods & Current ResultsThis research is being replicated at two sites, Franklin County Country Club and Meadowbrook Country Club. Treat-ments (listed below) are arranged in a randomized complete block design with four replicates. All treatments are watered in with 0.2” of overhead irrigation immediately after application. No fairy ring or any other disease has been observed in plots so far this season. No phytotoxicity or difference in turf quality has been detected among treatments.

# Treatment Rate Rate Unit1 Untreated --- ---2 Bayleton FLO 1.0 fl oz/ 1000 ft2 AB3 Bayleton FLO 1.0 fl oz/ 1000 ft2 A3 Triton FLO 0.75 fl oz/ 1000 ft2 B3 Triton FLO 0.75 fl oz/ 1000 ft2 C4 Torque 0.6 fl oz/ 1000 ft2 ABC5 Torque 0.9 fl oz/ 1000 ft2 ABC6 Velista +

Bayleton FLO0.3 fl oz/ 1000 ft2 +

1.0 fl oz/ 1000 ft2AB

7 Velista + Bayleton FLO

0.5 fl oz/ 1000 ft2 +

1.0 fl oz/ 1000 ft2AB


0.3 fl oz/ 1000 ft2 +

2.0 fl oz/ 1000 ft2AB


0.5 fl oz/ 1000 ft2 +

2.0 fl oz/ 1000 ft2AB

10 Tourney 0.28 fl oz/ 1000 ft2 AB

Application Date: A = April 9th, B = May 8th, C = May 29th

26

Fungicide evaluation for reduction of spring zoysia yellowingLee Miller and Daniel Earlywine

SummarySeveral zoysia golf fairways have exhibited an intense yellow chlorosis in early-mid spring and again late fall when turf growth is slowed. Symptoms can also include a “witch’s broom” characteristic in which a large number of tillers emerg-es from a single stolon node. As temperatures rise in the summer, plants normally outgrow the chlorotic condition over time, but growth is repressed compared to unaffected plants. Past explanations for this phenomenon include yellow tuft disease of zoysiagrass, eriophyid mite infestation, or early stages of zoysia decline, but the true cause is still unknown. This research evaluated several curative treatments targeted for control of this condition.

Current FindingsA single curative treatment was applied on March 29th at Norwood Hills Country Club. Plots were arranged in a ran-domized complete block design with 4 replications. Treatments included an untreated control and representatives from major fungicide classes including the beta-tubulin inhibitors (3336F), dicarboximides (Chipco 26GT), carboxi-mides (ProStar), sterol biosynthesis inhibitors (Banner Maxx II), QoIs (Heritage TL), and Oomycete (i.e. Pythium and Scleropthora) targeting fungicides (Signature & Subdue Maxx). Although Signature and Banner Maxx II applications numerically reduced chlorosis over time, none of the fungicides resulted in satisfactory control of the condition. It is still unknown what causes zoysia yellowing in spring and fall, but a single curative spring application does not seem to be a good method for providing curative control.

% ChlorosisTreatment Rate 3/29 4/17 5/15

Untreated - 40.0 a 48.8 a 40.0 aCleary 3336F 6 fl oz/ 1000 ft2 33.8 a 38.8 a 27.5 aChipco 26GT 4 fl oz/1000 ft2 33.8 a 46.3 a 37.5 aBanner Maxx II 4 fl oz/1000 ft2 40.0 a 37.5 a 33.8 aHeritage TL 2 fl oz/1000 ft2 31.3 a 55.0 a 45.0 aProStar 4.5 oz/1000 ft2 38.8 a 45.0 a 37.0 aSubdue Maxx 1 fl oz/1000 ft2 41.3 a 55.0 a 36.3 aSignature 6 oz/1000 ft2 37.5 a 30.0 a 25.0 a

27

Large patch control on ‘Meyer’ zoysiagrassDaniel Earlywine and Lee Miller

SummaryLarge patch is the most serious disease of zoysiagrass on golf fairways and home lawns. Two trials were initiated at the MU turf farm in fall 2011 on zoysiagrass (cv. ‘Meyer’ @ 0.75”) to evaluate preventive fungicide treatments for large patch control. On 9 Sept 2011, 20 cc of rye grain infested with Rhizoctonia solani AG2-2 LP was inoculated in the center of each plot to ensure uniform disease pressure for all treatments.

Trial I. Treatments consisted of Velista (0.7 oz/1000 ft2), Heritage (0.4 oz/1000 ft2), Heritage followed by Velista, ProStar (2.2 oz/1000 ft2), Triton Flo (0.75 fl oz/1000 ft2), and Disarm 480 (0.18 oz/1000 ft2). Treatments were applied twice in the fall (AB), once in the fall and spring (AC), or twice in the fall and once in the spring (ABC).

Trial II. Treatments consisted of Heritage G (3.0 lbs/1000 ft2), Heritage TL (1.5 fl oz/1000 ft2), Headway G (4 lbs/1000 ft2), and Renown (3.75 fl oz/1000 ft2). All treatments were applied as a single application on 21 Sept. Granular products, such as Heritage G and Headway G were applied with a shaker bottle and immediately watered in with 0.2 inches of water. The two sprayable formulations, Heritage TL and Renown, were applied when the grass was dry.

Current FindingsTrial I. Large patch was first observed in early April in the trial area. All treated plots showed significantly lower large patch compared to the untreated control. As large patch severity increased, plots treated with Heritage (0.4 oz/1000 ft2) (AC) and Heritage (0.4 oz/1000 ft2) (A) followed by Velista (0.7 oz/1000 ft2) (BC) exhibited acceptable large patch control (<5%) compared to other treatments. Similar trends were also noted in turf quality, with minimal statistical differences within treated plots. On 10 May, turf quality in Velista (0.7 oz/1000 ft2) (AC), and Velista (0.7 oz/1000 ft2) (ABC) were not significantly different compared to the untreated control due to an increase in large patch severity (>10%).

Trial II. No differences in turf quality were observed in granular (Heritage G and Headway G) versus sprayable (Heritage TL and Renown) treatments. Heritage TL provided the least amount of large patch control among the treatments tested and was not significantly different from the untreated control. Headway G and Heritage G treated plots showed slightly lower large patch severity than sprayable treatments. This effect could due to the variation in watering in the granular applications and not watering in sprayable formulations. Further testing will focus on the effect of application strategy on large patch control.

28

Table 1. Turf Quality and Large Patch Severity (%) in Trial I.

Turf Qualityy Large Patch Severity (%)z

Treatment Rate/1000 ft2 Application Interval 13 Apr 10 May 13 Apr 10 MayUntreated Control 2.8 bx 3.2 b 36.8 a 43.3 aVelista 0.7oz ACw 5.0 a 5.3 ab 4.8 b 12.8 bVelista 0.7oz ABC 4.2 ab 5.1 ab 10.0 b 10.0 bHeritage + Velista

0.4 oz0.7 oz

ABC 5.6 a 6.3 a 0.0 b 3.0 b

Heritage + Velista

0.4 oz0.7 oz

AC 4.8 a 5.6 a 3.5 b 5.3 b

Heritage 0.4 oz AC 5.3 a 6.1 a 0.5 b 2.8 bProStar 2.2 oz AC 5.1 a 6.6 a 3.8 b 5.3 bTriton Flo 0.75 fl oz ABC 5.2 a 5.7 a 1.3 b 9.5 bDisarm 480 0.18 oz ABC 5.6 a 5.5 a 0.0 b 8.0 b

zLarge Patch severity based on a scale of 0 to 100% (0= no incidence, 100= entire plot completely covered).yTurfgrass quality using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity.xValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).wApplication code indicates application date of each application: A-16 Sep 2011, B-14 Oct 2011, C- 26 Apr 2012.

Table 2. Turf Quality and Large Patch Severity (%) in Trial 2.

Turf QualityyLarge Patch Severity (%)z

Treatment Rate/1000 ft2 Application Interval 26 Apr 24 May 26 Apr 24 MayUntreated Control 4.6 ax 4.0 a 12.5 a 28.3 aHeritage G 3.0 lb Aw 5.5 a 6.5 a 1.0 bc 2.8 bHeritage TL 1.5 fl oz A 5.0 a 4.1 a 8.0 ab 15.0 abHeadway G 4.0 lb A 5.3 a 6.2 a 0.3 c 4.3 bRenown 3.75 fl oz A 5.1 a 6.1 a 0.8 c 6.8 b

zLarge Patch severity based on a scale of 0 to 100% (0= no incidence, 100= entire plot completely covered).yTurfgrass quality using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity.xValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).wApplication code indicates application date of each application: A-21 Sep 2011

29

Evaluating Daconil Action for disease controlDaniel Earlywine and Lee Miller

SummaryDaconil Action (chlorothalonil + acibenzolar-S-methyl) is a new fungicide that was released in the fall of 2011. Daconil Action provides control of a wide range of turf diseases and with the addition of acibenzolar, will increase plant defenses to combat diseases and improve turf health. A trial was initiated on a ‘Pennlinks’ creeping bentgrass green located at Eagle Knoll Golf Course, in Hartsburg, MO. Daconil Action is being applied every 14 days in this study and is being com-pared to an untreated control.

Current FindingsTreatments were initiated at Eagle Knoll golf course on 9 May. Currently, no disease has been observed in the trial area and no differences in turf quality have been noted. Ratings are ongoing and will continue throughout the season.

Turf Qualityz

Treatment and Rate/1000 ft2 Application Interval 23 May 6 JuneUntreated Control 6.3 ay 6.8 aDaconil Action 3.5 fl oz 14 days 6.1 a 6.6 a

zTurfgrass quality using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity.yValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).

30

Evaluation of multiple fungicide programs for summer disease control on a creeping bentgrass putting greenDaniel Earlywine and Lee Miller

SummaryFungicide programs are designed by turf managers to control the wide variety of diseases that may be encountered throughout the season. Rotating fungicides with different chemistries and modes of action can provide better control of diseases and decrease the possibility of fungicide resistance. This trial is designed to evaluate fungicide programs us-ing new fungicide chemistries for summer disease management on a creeping bentgrass putting green (cv. ‘Penncross’). Fungicide applications were initiated on 28 May for both program 1 and 2. Fungicide applications will continue every 14 days until mid September.

Current FindingsInitial dollar spot symptoms were first observed on 11 June, but no statistical differences among treatments have yet to be observed. Similar trends in turf quality have also been noted, with only minimal differences between programs 1 and 2 and the untreated control. As the season continues, ratings will continue every two weeks throughout the season to measure any changes in disease activity or turf quality.

Trial Map

Plot Size is 5 X 5 ftProgram 1 Program 2 Untreated

Untreated Program 1 Program 2

Program 2 Untreated Program 1

Untreated Program 1 Program 2

Program 1 Program 2Treatment Rate/1000 ft2 Treatment Rate/1000 ft2 Application DateHeadway 1.5 fl oz Headway 1.5 fl oz May 28Daconil Action +Banner Maxx II

3.5 fl oz +1.0 fl oz

Daconil Action +Briskway


June 11

Daconil Action +Medallion

3.5 fl oz +0.25 oz

Daconil Action +Medallion+Appear

3.5 fl oz +0.25 oz +6.0 fl oz

June 25

Headway +Medallion +Subdue Maxx

1.5 fl oz +0.25 oz +1.0 fl oz

Briskway +Medallion +Subdue Maxx + Appear

0.7 fl oz +0.25 oz +1.0 fl oz +6.0 fl oz

July 9

Daconil Action +Chipco Signature +Subdue Maxx

3.5 fl oz+4.0 oz +1.0 fl oz

Daconil Action +Appear+Subdue Maxx

3.5 fl oz+6.0 fl oz+1.0 fl oz

July 23

Daconil Action +Chipco Signature+26 GT

3.5 fl oz +4.0 oz +4.0 fl oz

Daconil Action +Appear +Secure

3.5 fl oz +6.0 fl oz +0.5 fl oz

August 6

Daconil Action +Chipco Signature

3.5 fl oz +4.0 oz

Daconil Action +Appear


August 20

Heritage +Curalan

0.4 oz +1.0 oz

Heritage +Secure

0.4 oz +0.5 fl oz

September 3

Headway 1.5 fl oz Headway 1.5 fl oz September 17

31

Preventative dollar spot control on a creeping bentgrass putting greenDaniel Earlywine and Lee Miller

SummaryDollar spot is caused by the fungal pathogen Sclerotinia homoeocarpa. Heavy dews and temperatures ranging from 59-86°F are conducive to disease development and infection. This trial is to evaluate new fungicides for dollar spot control on Penncross’ creeping bentgrass golf green. This purpose of this trial is to evaluate new and standard fungicide treat-ments using various application intervals and mix rates for preventive dollar spot control. On 8 June, rye grain infested with three isolates of Sclerotinia homoeocarpa was uniformly applied at 15cc per plot using a small broadcast spreader. Inoculum was left on the turf surface for 3 days to enable pathogen establishment.

Current FindingsAll treatments were initiated on May 11 before dollar spot was observed. By 20 June, numerical but not statistical differ-ences in dollar spot incidence were observed in treated plots compared to the untreated control. Similarly, turf quality is also numerically and in most instances statistically higher in fungicide treated plots than in untreated plots. Cool nights, low humidity, and below normal rainfall in May has kept dollar spot incidence at lower levels than in previous years. This trial will continue throughout the summer and early fall to assess fungicide treatment on the increasing dollar spot epidemic.

Turf Qualityy Dollar Spot Incidence (# of infection centers)z

Treatment Rate/1000 ft2 Interval 18 May 7 June 18 May 7 JuneUntreated Control 7.1 ax 5.8 b 0.0 a 16.0 aBAS 640 4.0 fl oz* 14d 7.1 a 7.2 ab 0.0 a 0.0 a

BAS 640 4.0 fl oz* 21d 7.3 a 7.7 a 0.0 a 0.0 aCuralan 1.0 oz* 14d 7.5 a 7.2 ab 0.0 a 0.0 aCuralan 1.0 oz* 21d 7.5 a 8.1 a 0.0 a 0.0 a

Daconil Ultrex 3.0 oz* 14d 7.8 a 7.3 ab 0.0 a 2.3 a

Interface 3.0 fl oz 21d 7.8 a 8.2 a 0.0 a 0.0 a

Interface 4.0 fl oz 21d 7.8 a 7.6 a 0.0 a 0.0 a

Honor 0.83 oz 21d 7.7 a 7.6 a 0.0 a 0.0 a

Iprodione Pro 4.0 fl oz 21d 7.6 a 7.7 a 0.0 a 0.0 a

Bayleton Flo 1.0 fl oz 28d 7.3 a 7.6 a 0.0 a 0.0 a

Bayleton Flo followed by Triton Flo followed by Trion Flo

1.0 fl oz 0.75 fl oz0.75 fl oz

28 d then 21d

7.3 a 7.1 ab 0.0 a 0.0 aTorque 0.6 fl oz 28d then 21d 8.0 a 8.0 a 0.0 a 0.0 a

Briskway 0.6 fl oz 14d 7.8 a 8.3 a 0.0 a 0.0 a

Briskway 1.2 fl oz 14d 7.6 a 7.6 a 0.0 a 0.0 a

Briskway alternated with Daconil Action

0.6 fl oz 3.5 fl oz

14d7.7 a 7.7 a 0.0 a 0.0 a

Secure 0.5 fl oz 14d 7.6 a 7.6 a 0.0 a 0.0 a

Secure + Appear

0.5 fl oz + 6.0 fl oz

14d8.2 a 8.3 a 0.0 a 0.0 a

Daconil Action 3.5 fl oz 14d 7.3 a 8.1 a 0.0 a 0.0 azDollar spot infection centers are means of counts per plot. yTurfgrass quality using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity. xValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).* Treatments were applied at 44 gallons per acre instead of 87 gallons per acre.

32

Plot

s are

5 ×

5 ft

Dac

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1.

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1.2

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1.

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Flo

1.0

fl oz

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0.75

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3.0

fl oz

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0.6

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Flo

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ition

Flo

0.

75 fl

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d

Torq

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0.6

fl oz

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d fo

llow

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by 2

1 d

Brisk

way

0.6

fl oz

/M

14

d

Brisk

way

1.

2 fl

oz/M

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way

0.

6 fl

oz/M

al

tern

ated

with

D

acon

il Act

ion

3.5

fl oz

/M

14 d

Secu

re

0.5

fl oz

/M

14

d

Secu

re

0.5

fl oz

/M

+

App

ear

6.0

fl oz

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14

d

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n

3.5

fl oz

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4.

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alan

1.0

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alan

1.

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Dac

onil U

ltrex

3.

0 oz

/M

14 d

Inte

rface

3.0

fl oz

/M

21

d

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4.0

fl oz

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21

d

Hono

r

0.83

oz/

M

21

d

Ipro

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ne P

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4.0

fl oz

/M

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33

Evaluation of spring dead spot control on bermudagrassDaniel Earlywine and Lee Miller

SummarySpring dead spot (SDS) is caused by the pathogen (Ophiosphaerella sp.). This pathogen infects roots of bermudagrass in the fall and doesn’t allow the plant to go into winter dormancy correctly. In spring when bermudagrass greens up, dead sunken patches from 6 inches to several feet in diameter will remain. This causes uniformity and playability concerns and in many cases allows weeds to establish in SDS affected areas. Two trials were initiated on ‘Riviera’ Bermudagrass at MU Turf Farm and on ‘Westwood’ bermudagrass at Westwood Country Club in St. Louis. MO. Fall preventive fungicide applications were evaluated for spring dead spot control in two trials conducted at the MU Turf Farm (cv. ‘Riviera) and Westwood Country Club (cv. ‘ Westwood).

Current FindingsTreatments were applied at Westwood CC on 19 Sept and 17 Oct, and at the turf farm on 22 Sept (A) and 21 Oct (B). SDS was first observed at Westwood CC on 27 March and at the turf farm on 29 March.

Turf Farm Trial (Table 1)- All fungicide treatments resulted in a numerical reduction of SDS compared to the untreated control. Statistically significant reductions in SDS severity were observed in plots treated with two fall applications of Velista (0.7 oz/1000 ft2), Velista (0.7 oz/ 1000 ft2) + Banner Maxx (4.0 fl oz/1000 ft2), Rubigan (4.0 and 6.0 fl oz/1000 ft2), and A9898A (2.6 fl oz/1000 ft2) compared to the untreated control. Acceptable turf quality (>5) was also noted for the same plots, however, only plots treated with Rubigan at (4.0 and 6.0 fl oz/1000 ft2), and A9898A (2.6 fl oz/1000 ft2) had statistically higher quality than the untreated.

Westwood Country Club Trial (Table 2)- Minimal SDS severity was observed in the plot area. On all rating dates, treat-ed plots had significantly less SDS incidence than the untreated control, but no statistical differences were noted among the treatments. By 21 May, turf quality was significantly higher for all treated plots compared to the untreated control.

34

Table 2. Spring Dead Spot Severity at Westwood Country Club.

Spring Dead Spot Severity (%)z

Turf Qualityy

Treatment and Rate/1000 ft2 Application Code 27 Mar 21 May 21 MayUntreated Control 9.3 ax 3.0 a 5.8 aTorque 0.6 fl oz followed by Torque 0.6 fl oz + 3336F 6.0 fl oz

Aw

B 2.8 b 0.8 b 6.5 bTorque 0.9 fl oz followed by Torque 0.9 fl oz + 3336F 6.0 fl oz

AB 1.8 b 0.0 b 6.8 b

Headway 3 fl oz AB 0.8 b 0.0 b 6.7 bzSpring dead spot severity based on a scale of 0 to 100% (0= no incidence, 100= entire plot completely covered).yTurfgrass quality using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity.xValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).wApplication code indicates application date of each application: A-19 Sep 2011, B-17 Oct 2011.

Table 1. Spring Dead Spot Severity at MU Turf Farm.

Spring Dead Spot Severity (%)z Turf QualityTreatment and Rate/1000 ft2 Application Code 16 Apr 24 May 24 MayUntreated Control 27.5 ax 28.8 a 4.0 cdVelista 0.5 oz ABw 14.5 a 14.0 abc 4.8 abcdVelista 0.7 oz AB 5.5 a 5.8 c 5.3 abcVelista 0.7 oz + Heritage 0.4 oz AB 10.5 a 18.0 abc 4.1 bcdVelista 0.7 oz + Banner Maxx 4.0 fl oz AB 7.0 a 6.3 c 5.3 abcRubigan 4.0 fl oz AB 5.8 a 6.3 c 5.7 aRubigan 6.0 fl oz AB 8.0 a 7.3 bc 5.5 abTorque 0.6 fl oz followed by Torque 0.6 fl oz + 3336F 6.0 fl oz

AB 10.8 a 13.8 abc 4.6 abcd

Torque 0.9 fl oz followed by Torque 0.9 fl oz + 3336F 6.0 fl oz

AB 16.3 a 13.8 abc 4.5 abcd

A9898A 0.65 fl oz A 19.3 a 22.5 abc 3.7 dA9898A 0.65 fl oz AB 21.8 a 25.0 ab 3.7 dA9898A 1.3 fl oz A 12.5 a 14.8 abc 4.3 abcdA9898A 1.3 fl oz AB 23.8 a 22.5 abc 3.8 dA9898A 2.6 fl oz A 13.8 a 12.0 abc 4.7 abcdA9898A 2.6 fl oz AB 8.0 a 7.0 bc 5.6 a

zSpring dead spot severity based on a scale of 0 to 100% (0= no incidence, 100= entire plot completely covered).yTurfgrass quality using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity.xValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).wApplication code indicates application date of each application: A-22 Sep 2011, B-21 Oct 2011.

35

Evaluation of brown patch control using Velista on creeping bentgrass.Daniel Earlywine and Lee Miller

SummaryBrown patch is caused by the pathogen Rhizoctonia solani, which infects several cool- season grass species during the hot summer months. Brown patch symptoms appear as a foliar blight affecting circular or irregularly shaped patches. When the pathogen is active during hot and humid weather, a dark purplish or gray border of mycelium called a “smoke ring” may occur. In this trial an array of fungicides were evaluated on a preventative basis to control brown patch throughout the summer. Treatments include Velista (penthiopyrad) + Daconil Ultrex (chlorothalonil) and Velista (pen-thiopyrad) + Heritage TL (azoxystrobin) applied on 14-day intervals.

Current FindingsInitial dollar spot symptoms were first observed on 11 June, but no statistical differences among treatments have yet to be observed. Similar trends in turf quality have also been noted, with only minimal differences between programs 1 and 2 and the untreated control. As the season continues, ratings will continue every two weeks throughout the season to measure any changes in disease activity or turf quality.

Trial Map

Plot Size is 5 X 5 ftUntreated

ControlVelista + Daconil

Velista + Heritage TL


Untreated Control

Velista + Daconil

Velista + Daconil


Untreated Control

Untreated Control

Velista + Daconil


Treatment Rate/1000 ft2 Interval Application DatesFor all Treatments

UntreatedMay 22June 5

June 19

Velista + Daconil Ultrex 0.3 oz + 3.25 oz 14 d July 3July 17

Velista + Heritage TL 0.3 oz + 1.0 fl oz 14 dJuly 31Aug 14Aug 28

36

Turf Qualityy Large Patch Severity (%)z

Treatment Rate/1000 ft2 Application Timing 20 Apr 18 May 20 Apr 18 MayUntreated Control 3.5 ax 3.1 c 26.3 a 48.8 aTorque 0.6 fl oz Aw 5.6 a 6.0 ab 8.3 a 18.8 b

Torque 0.9 fl oz A 6.6 a 6.3 a 0.8 a 7.5 bTorque 0.6 fl oz B 5.7 a 4.6 abc 3.3 a 25.0 bTorque 0.9 fl oz B 5.3 a 4.0 bc 6.5 a 23.8 b

Torque 0.6 fl oz C 6.0 a 5.3 ab 2.3 a 12.5 b

Torque 0.9 fl oz C 5.8 a 5.0 abc 2.5 a 18.8 b

Table 1. Turf quality and Large Patch Severity at Columbia Country Club.

Large Patch Severity (%)z

Treatment Rate/1000 ft2 Application Timing 20 Apr 7 May 18 MayUntreated Control 30.0 ay 23.8 c 27.5 abHeritage TL 1.0 fl oz Ax 11.5 b 16.3 ab 20.8 abc

Heritage TL 2.0 fl oz A 6.3 b 6.3 b 15.0 abcHeritage TL 1.0 fl oz B 2.5 b 1.8 c 6.3 cHeritage TL 2.0 fl oz B 2.0 b 15.0 ab 32.5 a

Heritage TL 1.0 fl oz C 18.8 ab 15.0 ab 11.8 bc

Heritage TL 2.0 fl oz C 3.8 b 5.5 b 11.3 bc

Table 2. Turf quality and Large Patch Severity at A. L Gustin Golf Course.

zLarge Patch severity based on a scale of 0 to 100% (0= no incidence, 100= entire plot completely covered).yValues are means of four replications. Means within columns followed by the same letters are not significantly different according to Waller-Duncan k-ratio t-test (k=100).xApplication code indicates application date of each application: A-20 Sep 2011, B-4 Oct 2011, C-19 Oct 2011.

Timing of single fungicide applications for preventivelarge patch control

Daniel Earlywine and Lee Miller

SummaryTwo fungicide trials were conducted to investigate timing of a single fungicide application for preventive large patch control on zoysiagrass fairways. Trial 1 was conducted at Columbia Country Club using single applications of Torque at 0.6 and 0.9 fl oz/1000 ft2. Trial 2 was conducted at A.L Gustin golf course using single applications of Heritage TL at 1.0 and 2.0 fl oz/1000 ft2. Single fall applications were made at both locations on 20 Sept (A), 4 Oct (B), and 19 Oct (C) and were not watered in.

Current FindingsTrial 1- No statistical differences were noted in turf quality and large patch severity for the 20 Apr rating date. As large patch severity increased into mid May, all treated plots had significantly lower large patch severity than the untreated control; however no statistical differences were noted among the treatments tested. Torque at the 0.9 fl oz /1000 ft2 (A Timing) tended to have the lowest large patch severity among treated plots. Turf quality also tended to be higher in plots treated with Torque 0.6 and 0.9 fl oz/ 1000 ft2 rate at the earliest fall timing (A).

Trial 2 – On 20 Apr, all treated plots except Heritage TL 1.0 fl oz/1000 ft2 (C timing) exhibited statistically lower large patch severity than the untreated control. In mid May, plots treated with Heritage TL @ 1.0 fl oz/1000 ft2 on 4 Oct (B) had the lowest large patch severity among the treatments. Treatments did not vary statistically, however, due to varia-tion in disease uniformity in the plot area.

For both trials, there was significant variation in large patch severity among treatment replications. For this reason, this timing trial will be conducted again in 2012-13 at additional sites and under controlled conditions for disease uniformity.

37

Evaluating the phosphorus runoff potential of current home lawn fertilization practices and recommendations based on soil test resultsXi Xiong and Dan Lloyd

Objectives 1) Determine surface phosphorus runoff from different fertility programs applied to lawns with low (<40 lbs P2O5/acre) and high (>60 lbs P2O5/acre) soil phosphorus. 2) Evaluate the quality of turfgrass in response to phosphorus treatments applied to soils with different concentra-tions of available phosphorus. 3) Visually demonstrate to home owners through permanent demonstration plots the differences in turfgrass qual-ity and phosphorus runoff potential of different fertilization scenarios as related to soil test values.

Current Status/Importance of Research AreaIn Missouri, approximately 850,700 acres were used for turfgrass cultivation in 2005, which according to current esti-mates would make turfgrass the fourth largest crop in Missouri by acreage. Turfgrass is fertilized to apply between 100-200 lbs of N/acre annually. Many home owners regularly use products such as 12-12-12 and apply them at recommend-ed rates for nitrogen (100-200 lbs/acre), which over time has greatly elevated the soil phosphorus and potassium levels. Continual fertilization of phosphorus on soils that are in excess of available phosphorus will increase the likelihood of nutrient loss through surface runoff and without providing additional benefits to turfgrass health. Furthermore, surface runoff of sediment and nutrients, especially phosphorus, into surface water is a growing concern that can lead to eu-trophication of lakes and streams. On January 31st of 2011, the EPA issued a final mandate to the Missouri Department of Natural Resources to reduce storm-water runoff into Hinkson Creek by 39.6% because of excessive pollutants from runoff. This EPA mandate validates the importance of this research, as the Missouri DNR will be seeking areas which can be regulated to reduce pollutants into Hinkson Creek and other surface waters of Missouri. If residential fertilizer restrictions are proposed, this Fertilizer and Lime Council funded project will provide reliable and local data to assist in reasonable and research based regulations in hopes of preventing an unnecessary burden on the turf fertilizer industry.

ProceduresDesign - Twelve plots were established on a laser leveled 4% slope measuring 5 ft by 20 ft with a two foot buffer between each plot. Initial soil phosphorus levels were determined through soil test and plots were assigned to ‘high’ (>60 lbs P/acre) and ‘low’ <40 lbs P/acre) soil phosphorus designations. The differences in soil P were further magnified through triple super phosphate (46% of P2O5) fertilization to develop a substantial difference in soil phosphorus levels for the four corresponding treatments with three replications. The treatments are a homeowner scenario with high soil P (treatment 1), a soil test scenario with high soil P (treatment 2), a soil test scenario with low soil P (treatment 3), and a restricted scenario with low soil P (treatment 4) (Table 1). Once the soil phosphorus level had been adjusted, one single fall phosphorus application in the amount of 50 lbs P/acre was applied to treatment 1 (homeowner scenario with high soil P), and treatment 3 (soil test scenario with low soil P). Treatment 2 (soil test scenario with high soil P) did not receive any phosphorus treatment as based on soil test (no additional P were needed). Similarly, no phosphorus treat-ments were applied to treatment 4 as it is designated as low soil P, yet is a restricted use scenario. After the fall phospho-rus application, simulated rainfalls (4 inches) were applied twice in the fall at 0 day after treatment (DAT) and 5 DAT to induce runoff. The reason 0 day when rainfall was applied was to simulate the extreme condition when homeowners ignored the weather condition and applied the phosphorus fertilizer at the same day when significant rainfall occurs. We also simulated the second rainfall event at 5 DAT to evaluate if residue phosphorus exits. Since we had an unusually dry year, 4 inches of rainfall was necessary to induce runoff from treatment area. Construction - Each 5 ft by 20 ft plot is enclosed by galvanized steel edges that have been imbedded around all the edges. Galvanized steel runoff collection boxes measuring five feet wide, six inches deep, and eight inches wide were con-structed and installed down slope from each of the twelve plots (Figure 1). The collection boxes have a built in sample splitter with about one third of the runoff directed to the sample collection bins which consists of 32 gallon collection bins buried 3 ft deep and a removable five gallon bucket for runoff collection. The remaining two thirds of the runoff not collected are directed into a drain tile traversing the plot. Drainage pipe is 4 inch round drainage tile that runs down a roughly 3% slope at a 14 inch depth for about 100 feet, which then takes a 90 degree turn for another 100 feet down

38

Table 1. Phosphorus fertilizer treatments applied to the runoff plots in 2011.

Treatment Phosphorus fertilization Soil available phosphorus1.Common homeowner scenario 150 lbs P2O5/acre High (>60 lbs P2O5/acre)

2. Soil test recommendation None (as recommended by soil test) High (>60 lbs P2O5/acre)

3. Soil test recommendation 50-150 lbs P2O5/acre Low (<40 lbs P2O5/acre) (as recommended by soil test)4. Restricted use scenario None Low (<40 lbs P2O5/acre)

a 4% slope at the same depth which eventually discharges into a swale. Each collection box has been individually cali-brated to determine the precise percentage of runoff that is directed to the sample collection bins.

Figure 1. Field plots constructed.Measurements – Runoff water is collected within 12 hours of simulated rainfall event. Total volume is determined and a representative one liter sample is collected and sent to the MU Soil and Plant Testing Laboratory for determination of total phosphorus, dissolved phosphorus, and per-cent sediments. Plant tissue samples and soil samples are also taken and analyzed by the Soil and Plant Testing Laboratory for total plant and soil nutrients including phosphorus. Weekly measurements (when weath-er condition permits) include chlorophyll index (Field Scout CM1000), NDVI (GreenSeeker®), and overall turf quality on a 1-9 scale.

Project Accomplishments:Soil phosphorous concentrations at the initial estimation date (August 25) demonstrated that numerical but not statisti-cally significant differences existed between treatments (Figure 2, blue bars). However, on November 22, treatments 1 and 2 could be classified as high soil P while treatments 3 and 4 could be categorized as low soil P (Figure 2, red bars). This would indicate that we had established treatments within our intended parameters.

Based upon fertilization of treatments 1 and 3 on Day 0, there were significantly higher levels of both total P and dis-solved P collected in runoff water compared to treatments 2 and 4 (Table 2). Total P was 6.94-fold higher for treatment 1 compared to treatment 2. This suggests that for soils with high P levels, high rainfall shortly after application of P fertilizer results in a significant loss of that P. Similarly, high rainfall shortly after application of P fertilizer on soils with low P levels also results in a significant loss of P (7.04-fold) compared to treatment 4. However, P application applied on soil with high P level (treatment 1) resulted in significantly higher total runoff P loss than applied to plots with low soil P level (treatment 3). This result indicated that accumulated higher soil P level will likely increase the chance of runoff P loss. These same trends and level of significance were also measured for P dissolved in water (Table 2). In examining the sediment P levels, we observed that some differences were noted among treatments, but this was not significant. It was quite interesting to note that of the total P estimated from treatments 2 and 4 (no additional P added at day 0), 92.3% and 94.4% were represented by sediment P from treatments 2 and 4, respectively. These data suggest that some P was lost from treatments 2 and 4, but this was represented primarily by P attached to sediment. For treatments 1 and 3, only up to 34% of the P was lost in sediment. The amount of runoff was similar for the four treatments. For 5 DAT, numerical differences in total, dissolved, and sediment P were noted between treatments, but differences were not statistically significant. The impact of the P levels was influenced by the numerical differences in runoff water collected.

On a concentration basis (amount of runoff water collected taken into consideration), total P (mg/L) and total dissolved P (mg/L) were significantly higher for plots receiving P just prior to a high rainfall event (0 DAT) compared to plots that did not receive P (Figure 3A and B). At 5 DAT, levels of total P and dissolved P were quantitatively similar at both the high and low soil P levels. These data indicate that a majority of the potential P lost with high rainfall events will occur with the first event.

Mineralization of tall fescue tissue on December 9 (18 DAT) showed differences for P among treatments but not N or K (Table 3). The P (in %) in tissue samples from high P soils (treatment 1 and 2) ware significant higher than the tissue samples collected from the low soil P plots (treatment 3 and 4). This result corresponds with the soil P level presented at Figure 2.

39

Estimates of turf health over a 25 day period following application of P and high rainfall were similar for the four treat-ments (Table 4). Among all the variables of turf health, only NDVI measured at 10 DAT showed differences between treatments. Higher NDVI values would correlate with better turf color and coverage, but differences between treat-ments could not be associated with P levels. Our data indicate that the relative P levels in the soil did not contribute to an ability to assess the tall fescue growing in plots with that treatment as healthier.

Rainfall amounts in the experimental area were low over the duration of the study (Figure 4). As a result, the soil mois-ture potential was low and high rainfall events of 4 inches were necessary to induce runoff from the plots.

In summary, our preliminary data demonstrate that improper application of P fertilization does in-crease the chance of loss P through runoff.

Figure 2. Soil phosphorus (P) concentration (lb/ac) measured by Bray I P before and after P fertil-izer treatments. Soil samples were randomly taken from 5 different locations within each plot and mixed for analysis. Bars labeled by different letters before or after P treatment are not significantly dif-ferent using Fisher’s Protected LSD (P=0.05).

Figure 3. Concentrations of total P (mg/L) and dis-solved P (mg/L) in runoff water collected at 0 (A) or 5 (B) days after the P fertilizer treatment (DAT). Bars labeled by different letters at 0 or 5 DAT are not significantly different using Fisher’s Protected LSD (P=0.05).

Figure 4. Precipitation (inches) at the South Farm during fall, 2011.

Figure 2

Figure 3

Figure 4

40Trt #

Soil

PPr

actic

e--

-Tot

al P

(mg)

---

--D

isso

lved

P (m

g) --

---

-Sed

imen

t P (m

g)* -

----

---R

unoff

(L) -

----

0DAT

5DAT

0DAT

5DAT

0DAT

5DAT

0DAT

5DAT

1H

igh

PH

ome

owne

r33

3.9a

**37

1.8

237.

9a93

.796

.027

8.0

16.4

98.1

2H

igh

PSo

il te

st48

.1c

85.3

3.7c

6.0

44.4

79.3

15.9

58.4

3Lo

w P

Soil

test

199.

9b15

7.3

132.

0b67

.867

.989

.512

.771

.24

Low

PR

estr

icte

d us

e28

.4c

106.

61.

6c2.

126

.810

4.5

14.9

97.1

Tabl

e 2.

Tot

al p

hosp

horu

s los

s in

the

runo

ff w

ater

from

the

plot

are

a af

fect

ed b

y th

e P

ferti

lizer

trea

tmen

ts a

t the

diff

eren

t day

s afte

r tre

atm

ents

(DA

T).

Dat

a in

clud

ed a

re to

tal P

(mg)

, diss

olve

d P

(mg)

, sed

imen

t P (m

g), a

nd th

e to

tal r

unof

f (L)

from

the

plot

are

a.

*Sed

imen

t P (m

g) is

indi

rect

ly p

rese

nted

by

the

diffe

renc

e be

twee

n th

e to

tal P

and

diss

olve

d P.

**M

ean

sepa

ratio

n is

cond

ucte

d on

ly w

hen

signi

fican

t diff

eren

ces w

ere

foun

d by

AN

OVA

. Mea

ns w

ithin

a co

lum

n fo

llow

ed b

y th

e sa

me

lette

r are

not

sign

ifica

ntly

diff

eren

t usin

g Fi

sher

’s Pr

otec

ted

LSD

(P=0

.05)

.

Trt #

Soil

PPr

actic

eN

%*

P%K

%1

Hig

h P

Hom

e ow

ner

2.22

0.36

a1.

702

Hig

h P

Soil

test

1.85

0.32

b1.

333

Low

PSo

il te

st1.

870.

29c

1.49

4Lo

w P

Res

tric

ted

use

2.04

0.29

c1.

56

Tabl

e 3.

Turfg

rass

tiss

ue m

iner

al c

once

ntra

tions

, per

cent

nitr

ogen

(N%

), ph

osph

orou

s (P%

), an

d p

otas

sium

(K%

) infl

uenc

ed b

y th

e P

ferti

lizer

trea

tmen

ts.

*Clip

ping

sam

ples

wer

e co

llect

ed fr

om th

e pl

ot a

rea

and

anal

yzed

in th

e So

il an

d Pl

ant T

estin

g La

bora

tory

and

repo

rted

as p

erce

nt (%

) dry

mat

ter.

Trt #

Soil

PPr

actic

e--

----

----

-Tur

f qua

lity*

----

----

---

----

----

Chl

orop

hyll

Inde

x**-

----

---

----

----

--N

DV

I†--

----

----

1DAT

10D

AT19

DAT

25D

AT1D

AT10

DAT

19D

AT25

DAT

10D

AT19

DAT

25D

AT1

Hig

h P

Hom

e ow

ner

7.0

7.3

7.2

7.0

240.

720

5.7

234.

020

4.3

0.79

a‡0.

670.

732

Hig

h P

Soil

test

7.2

7.2

7.0

7.0

213.

019

7.0

215.

718

3.3

0.63

b0.

590.

633

Low

PSo

il te

st7.

27.

27.

07.

022

0.3

196.

721

7.0

189.

70.

69ab

0.64

0.69

4Lo

w P

Res

tric

ted

use

7.3

7.5

7.2

7.0

234.

721

0.0

235.

020

0.0

0.72

ab0.

680.

76

Tabl

e 4.

Turf

qual

ity, c

anop

y ch

loro

phyl

l ind

ex, a

nd N

orm

alize

d D

iffer

ence

Veg

etat

ion

Ind

ex (N

DV

I) af

fect

ed b

y P

ferti

lizer

trea

tmen

ts. D

ata

wer

e co

l-le

cted

at d

iffer

ent d

ays a

fter t

reat

men

ts (D

AT)

.

*Tur

f qua

lity

wer

e vi

sual

ly a

sses

sed

at 1

-9 sc

ale

whe

re 9

repr

esen

ts id

eal t

urf,

1 re

pres

ents

dea

d tu

rf, a

nd 6

repr

esen

ts m

inim

ally

acc

epta

ble

turf

qua

lity;

**C

hlor

ophy

ll in

dex

wer

e co

llect

ed b

y us

ing

a fie

ld sc

out C

M10

00 re

flect

ance

met

er (S

pect

rum

tech

nolo

gies

, Pla

infie

ld, I

L) a

nd av

erag

ed th

ree

rand

om re

adin

gs p

er p

lot;

†Nor

mal

ized

diff

eren

ce v

eget

atio

n in

dex

(ND

VI)

wer

e re

cord

ed u

sing

a G

reen

Seek

er (N

Tech

Indu

strie

s, In

c., U

klah

, CA

);‡M

eans

follo

wed

with

in a

colu

mn

follo

wed

by

the

sam

e le

tter a

re n

ot si

gnifi

cant

ly d

iffer

ent u

sing

Fish

er’s

Prot

ecte

d LS

D (P

=0.0

5).

41

Evaluating the Chilling Tolerance of Various Common Bermudagrass Cultivars

Enzhan Song and Xi Xiong

SummaryExperiments were conducted to evaluate tolerance of various common bermudagrass (Cynodon dactylon) to chilling stress. Six bermudagrass cultivars were planted and placed in a growth chamber and chilled at a constant temperature of 4 C. Untreated control plants were maintained under greenhouse conditions at a constant air temperature of 25 C. Plant cell integrity was monitored every 3 d over a 33 d period by measuring electrolyte leakage (EL); higher EL means greater loss of cell membrane integrity. Root growth conditions were estimated as percent root biomass (PRB) by com-paring the final root biomass (at 33 DAT) of treated plants to the biomass of untreated control plants.

Current FindingsChilling stress was evident at 6 DAT for all cultivars (Figure 1). By 22 DAT, all culti-vars except ‘Princess’, ‘Riviera’, and ‘Yukon’ exhibited a loss of cell integrity of 80% or greater, with the three latter cultivars showing an EL of 60 to 70%. By 33 DAT, EL approached 100% with all cultivars except ‘Riviera’ and ‘Yukon’ (~90%; Figure 1).

Root biomass for ‘Yukon’, ‘NuMex Sahara’ and ‘Quickstand’ were superior to all other cultivars after 33 days of chilling (Figure 2). The former cultivars increased root bio-mass by 20 to 45% over non-chilled control plants.

In summary, this preliminary study found that there is a significant variation among different bermudagrass cultivars in re-sponse to chilling stress. Further studies are ongoing to identify the mechanisms of bermudagrass growing under low tempera-ture stress.

Figure 2. Percent root biomass (PRB) of six common bermudagrass cultivars in response to the chilling stress.

Figure 1. Electrolyte Leakage (%) of six common bermudagrass cultivars in response to the chilling stress as well as their untreated controls.

42

Suppressing Seedheads of Annual Bluegrass on Creeping Bentgrass Putting Green

John Haguewood and Xi Xiong

SummaryIn Missouri, annual bluegrass (Poa annua L.) is often found growing on creeping bentgrass (Agrostis stolonifera L.) putting greens. Because of limited herbicide control options, superintendents are forced to “manage” their Poa along with the creeping bentgrass to create the ideal playing surface for golf. In the spring, Poa becomes a prolific seed pro-ducer, which drastically disrupts the playing surface. Plant growth regulators (PGR’s) such as trinexapac-ethyl (Primo Maxx®), ethephon (Proxy®), mefluidide (Embark®) and maleic-hydrazide (Royal MH-30®Xtra) have been used to sup-press seedhead formation on putting greens. This study evaluated PGR’s and their combinations as single or sequential applications for seedhead suppression of Poa. The experiment was located on the 18th green at Lake of the Woods golf course in Columbia, MO. All treatments were applied using a CO2-presurized backpack sprayer calibrated to deliver 44 gal/acre using XR8004 flat fan spray tips. Initial application was on March 13th with the sequential application two weeks later. Initial application timing was made by field scouting for seedhead development on higher mowed turf, and prior to any development at putting green heights. Using a base temperature of 50 F, growing degree days were 55 at the initial application timing. The first visual observation of seedheads in the experimental area was noted on March 22nd, 2012. Weekly visual observations that were taken include turf quality, turf phytotoxicity, number of seedheads/ft2, and percent annual bluegrass. Quantitative data on the extent of “greenness” in the plot area was generated by NDVI (normalized difference vegetation index) readings, which were also taken on a weekly basis.

Current FindingsWithin 2 weeks after initial treatment both Royal MH-30®Xtra and Embark® showed minor phytotoxicity, but only Royal MH-30®Xtra treated plots were below acceptable levels. Two applications of Proxy + Primo or Embark resulted in the greatest reduction in seedhead formation (~65%) compared to the untreated control. Visual observations of treated plots were visibly improved in both turf quality and playability compared to the untreated control. Seedhead suppres-sion of annual bluegrass not only increases turf quality in the spring, but also reduces the amount of viable seed put back into the seed bank.

Treatment # of applications Rate (fl oz/1000ft2) Avg# seed/ft2 % seedhead

suppressionUntreated 921.94 a ---

Proxy 1 5.0 512.44 bc 44.41Proxy 2 5.0 713.81 ab 22.57

Proxy + Primo 1 5.0 + 0.125 438.19 bc 52.47Proxy + Primo 2 5.0 + 0.125 313.88 c 65.95

Embark 1 0.68 404.44 bc 56.13Embark 2 0.68 290.25 c 68.51

Royal MH-30 1 1.0 454.50 bc 50.70Royal MH-30 2 1.0 474.19 bc 48.56

Table 1. Suppression of annual bluegrass seedhead formation using applications of standard plant growth regulators. Seedhead numbers and percentage suppression include averages during peak seedhead production (April 11th). Means followed by the same letter are not significantly different using Fishers Protected LSD at P=0.05.

43

Effect of Delayed Watering-In on Insecticide Efficacy against Annual White Grubs on Cool Season Turf


SummaryIn this trial, insecticides such as Meridian (thiamethoxam) and Acelepryn (chlorantraniliprole) were tested against an experimental insecticide for grub control. The effect of timing of insecticide application and “watering-in” the insec-ticide was also evaluated in this trial. “Watering-in” regimes include 0.25 inches immediately following treatment, or 0.25 inches 6 to 7 days after treatment. All treatments were applied using a CO2-pressurized backpack boom sprayer calibrated to provide 87 gal/acre using XR 8008 flat-fan spray tips. In order to provide grub pressure, ‘Spectracide’ Japanese beetle lures were placed in the center of each plot throughout the experiment. Initial application (A), shown in Table 1, was applied June 14th with application ‘B’ 30 days later.

Current FindingsVisual evaluations indicated that none of the treatments resulted in a decline in turfgrass quality or caused phytotoxicity within one week after treatment, regardless of delayed “watering-in”. As of the writing of this report, there are no data on grub control, but grub pressure is expected to be high. Grub count evaluations will be taken in the fall.

Treatment # Treatment Name Rate ( g ai/ha) Transformed Rate

Application code

Watering-in Schedule

1 Untreated --- --- --- ---2 Experimental 220 223 g/a AB 24 hours3 Experimental 220 223 g/a AB 6-7 days4 Experimental 298 300 g/a AB 24 hours5 Experimental 298 300 g/a AB 6-7 days6 Meridian 25 WG 224 363 g/a A 24 hours7 Meridian 25 WG 224 363 g/a A 6-7 days8 Acelepryn 1.67 SC 98 6.7 fl oz/a A 24 hours9 Acelepryn 1.67 SC 98 6.7 fl oz/a A 6-7 days

Table 1. Insecticide and ‘watering-in’ treatments for grub control at the Turfgrass Research Center.

44

‘Tribute Total’ on Dicot Weed Control


SummaryThe objective of this trial was to investigate the efficacy of ‘Tribute Total’ (thiencarbazone-methyl, foramsulfuron, and halosulfuron-methyl) for control of common broadleaf weeds. Tribute Total is a mixture of ALS-inhibiting herbicides and is labeled for post-emergence control of more than 50 broadleaf, grass and sedge weeds. This trial was placed on an extremely ‘weedy’ location in order to provide information on multiple weed species. A single application of ‘Tribute Total’ (variable rates), ‘Trimec Classic’ and ‘Drive XLR8’ was evaluated for weed control. Treatments were applied at a spray volume of 44 gal/acre using a CO2-presurized backpack boom sprayer equipped with XR 8004 spray tips.

Current FindingsPrior to application, the research plot was highly infested with many annual and perennial broadleaf weeds including; corn speedwell, prostrate knotweed, lespedeza, clover, and dandelion. For this report, prostrate knotweed and lespe-deza control will be reported (Table 1) approximately 1 month after application. All rates of ‘Tribute Total’ significantly decreased the incidence of lespedeza compared to the untreated control. Prostrate knotweed control was improved with ‘Tribute Total’ when compared to the untreated control, but was not statistically significant. ‘Drive XLR8’ resulted in the greatest control of lespedeza among all treatments, but poor control of prostrate knotweed allowed this weed to dominate the plots. Effective weed control must consider the dominant species present; control of a narrow spectrum can allow other weeds to be released.

Treatment # Treatment Name Rate Rate Unit % Prostrate Knotweed (Average)

% Lespedeza (Average)

5/5/2012 6/1/2012 5/5/2012 6/1/20121 Untreated --- --- 9.3 a 5.5 b 40.0 a 71.3 a2 Tribute Total* 1.0 oz/A 7.5 a 1.3 b 38.8 a 47.5 b3 Tribute Total* 2.0 oz/A 10.5 a 2.3 b 33.8 a 36.3 bc4 Tribute Total* 3.0 oz/A 11.3 a 2.5 b 32.5 a 32.5 c5 Tribute Total* 3.2 oz/A 13.0 a 2.3 b 33.8 a 27.5 c6 Trimec Classic 3.75 pt/A 10.0 a 1.8 b 36.3 a 30.0 c7 Drive XLR8** 1.5 fl oz/A 6.8 a 26.3 a 35.0 a 8.0 d

Table 1. Weed control prior to treatment and approximately one month after application

*Nonionic surfactant added at 0.25% v/v.**Methylated seed oil added at 1.5 pt/A.Averages followed by the same letter within a column are not significantly different based on a LSD test at p=0.05.

45

Crabgrass Prevention on Bermudagrass Turf in the Transition Zone


SummaryThis trial evaluated the herbicide ‘Specticle’ (indaziflam) for preemergence control of crabgrass (Digitaria spp.) in ber-mudagrass (Cynodon dactylon) turf. Treatments included a liquid form of ‘Specticle’ as well as the industry standard ‘Ronstar 2G’ (Oxadiazon). In addition, ‘Specticle’ was evaluated at a “full-rate” single application vs. a “half-rate” split application, as well as ‘Ronstar 2G’ followed by ‘Specticle’ (Table 1). Granular treatments were applied using shaker jars to evenly distribute the product over the plot, and liquid formulations were applied using a CO2-pressurized backpack sprayer calibrated to deliver 44 gal/acre and equipped with XR 8004 flat fan spray tips.

Current FindingsThe trial was located in an area with significant crabgrass pressure, with untreated plots becoming heavily infested with crabgrass. No crabgrass was present at the initiation of treatments (Table 2). All treatments reduced crabgrass germination compared to the untreated control, especially at later evaluation timings (Table 2). ‘Specticle’ applied alone resulted in equivalent suppression of crabgrass compared to ‘Ronstar 2G’ at individual evaluation timings. However, at the latest evaluation timing (10 weeks), ‘Specticle’ suppression of crabgrass is numerically superior to ‘Ronstar 2G’. At the present time, there is no difference between a single, “full-rate” compared to a “half-rate” split application of ‘Spec-ticle’ for the control of crabgrass. With very favorable temperatures for crabgrass germination this year, we noticed some emergence of crabgrass in all treatments at the June 7 evaluation timing. None of the treatments have shown phytotoxicity to bermudagrass, but an increase in turf quality compared to the untreated control was obvious due to the suppression of crabgrass.

Table 1. Herbicide treatments and application timings for preemergence control of crabgrass are listed below.

Treatment # Treatment Name Rate Rate Unit Application Code1 Untreated --- --- ---2 Ronstar 2G 150 lb/a A (single application, March 24th)3 Specticle 9 oz/a A (single application, March 24th)4 Specticle 4.5 oz/a AB (March 24th, May 18th)

5 Ronstar 2GSpecticle

1004.5

lb/aoz/a

A (March 24th)B (May 18th)

46

Figure 1. Plot Map of trial located on bermudagrass

Ronstar 2GApp: A

Ronstar 2G App:A

SpecticleApp:B

Specticle4 oz/a

App: ABUntreated

Specticle9 oz/aApp: A


Untreated

Ronstar 2G App:A

SpecticleApp:B

Ronstar 2GApp: A

Specticle4 oz/a

App: AB

Untreated Ronstar 2GApp: A


Specticle4 oz/a

App: AB

Ronstar 2G App:A

SpecticleApp:B

% Crabgrass

# Treatment App Code 3/24/2012 4/9/2012 4/24/2012 5/8/2012 5/22/2012 6/7/2012

1 Untreated --- 0.0 a* 2.7 a 4.3 a 7.3 a 9.0 a 12.3 a2 Ronstar 2G A 0.0 a 0.0 b 0.0 b 0.7 b 1.0 b 1.3 a3 Specticle A 0.0 a 0.0 b 0.0 b 0.0 b 0.0 b 0.3 a4 Specticle AB 0.0 a 0.0 b 0.0 b 0.0 b 0.0 b 0.3 a

5 Ronstar 2GSpecticle

AB

0.0 a 0.0 b 0.0 b 1.0 b 1.7 b 3.0 a

LSD (P=0.05) 0.0 0.97 1.29 2.20 4.38 9.73Standard Deviation 0.0 0.52 0.68 1.17 2.33 5.17

Table 2. Percent crabgrass infestation is described over time for all treatments.

*Means followed by the same letters within a column are not significantly different based on LSD test at p=0.05 level

47

The Residue Effect of Mustard (Brassica juncea L. Czern.) Seed Meal for Suppression of Dollar Spot (Sclerotinia homoeocarpa)

Xiaowei Pan, James T. English, and Xi Xiong

SummaryDollar spot (Sclerotinia homoeocarpa F.T. Bennett) is the most serious turf disease on golf courses in the United States. Early reports have found that the formation of volatile isothiocyanates from mustard (Brassica juncea L. Czern.) seed meal (MSM) effectively suppresses dollar spot under field conditions. Few published papers have focused on dosage ef-fects whereby MSM powder and water have been mixed for complete release of the fungicidal compounds in vitro. How-ever, the dosage effect of isothiocyanates was unclear when the original MSM was applied as a powder on the surface of the medium used to determine dollar spot response. The objective of this in vitro study was to investigate the dosage effect of MSM for control of S. homoeocarpa. ‘Study 1’ was designed to distribute original MSM powder on the surface of Potato Dextrose Agar (PDA) medium in a petri dish at rates equivalent to 0, 100, 200, 400, 800 and 1600 kg/ha. In addition the PDA was amended with the fungicide Daconil Weather Stik (chlorothalonil) at 6.88 kg/ha a.i. for compari-son. Isolated dollar spot pathogen (S. homoeocarpa) was introduced at the center of each plate. Treatment effects on fungal mycelium growth was recorded and compared to the untreated control daily over a 14 d period. The inoculum that showed no hyphal growth for 14 days was transferred onto a control PDA plate to observe the hyphal growth and colony development for another 3 days. Based on the results of ‘study 1’, ‘study 2’ was initiated by using lower rates of MSM including: 0, 5, 10, 15, 20, 40, 60, 80 and 100 kg/ha. In addition, Heritage fungicide was also used as a treatment for comparison. ‘Study 1’ was comprised of 7 treatments with 10 replications for each treatment. ‘Study 2’ contained 10 treatments with 8 replications for each treatment. The PDA medium was amended with 100 ppm ampicillin and 100 ppm streptomycin sulfate to preclude bacteria. All petri dishes in the two studies were incubated at 24 C in the dark.

Current FindingsFor ‘study 1’, no mycelial growth was observed in any MSM treatments with the exception of 3 plates for the 400 kg/ha MSM treatment. The reason for the mycelial growth in those 3 plates is not certain. The treatment of 0 kg/ha MSM (control) was covered entirely with mycelia in three days, while the fungicide Daconil Weather Stik treatment resulted in slow mycelial growth and changed the morphology of the mycelia. The mycelia stopped growing and formed a resting structure without covering the entire plate, 12 days after initial inoculation. At 14 d after inoculation and no observa-tion of growth on MSM plates, the original fungal plugs were transferred to new PDA plates for an additional 3 days. However, no hyphal growth was observed in any petri dish. Our results suggest that MSM at 100 kg/ha or higher can totally kill the fungus, while the fungicide Daconil Weather Stik can only slow the rate of fungal development.

For ‘study 2’, no mycelial growth was observed in plates containing MSM treatments at 60 kg/ha or above by 11 d after inoculation, except one plate. The treatment of MSM at 5 kg/ha resulted in faster mycelial growth than the control plates, and the mycelia covered the whole plate in three days. Treatment of MSM at 10 and 15 kg/ha had slower mycelial growth compared to the control at the first day and exhibited faster growth after the second day. Treatments of MSM at 20 and 40 kg/ha had slower mycelial growth than control, but plates for all three treatments had mycelia cover the entire plates on the fourth day. Daconil Weather Stik resulted in slower mycelial growth than MSM treatments of 40 kg/ha or below, which was similar to results in ‘study 1’. In conclusion, MSM treatments at 60 kg/ha or above can effectively kill the fungus, while MSM treatments at 20 and 40 kg/ha suppress fungal development better than the control, but not as good as the fungicide Daconil Weather Stik. The 5 kg/ha MSM treatment resulted in faster fungal growth than that of the control, which may be due to the nitrogen source and other nutrients released by the MSM.

48

mycelial growth than the control plates, and the mycelia covered the whole plate in three days. Treatment of MSM at 10 and 15 kg/ha had slower mycelial growth compared to the control at the first day and exhibited faster growth after the second day. Treatments of MSM at 20 and 40 kg/ha had slower mycelial growth than control, but plates for all three treatments had mycelia cover the entire plates on the fourth day. Daconil Weather Stik resulted in slower mycelial growth than MSM treatments of 40 kg/ha or below, which was similar to results in ‘study 1’. In conclusion, MSM treatments at 60 kg/ha or above can effectively kill the fungus, while MSM treatments at 20 and 40 kg/ha suppress fungal development better than the control, but not as good as the fungicide Daconil Weather Stik. The 5 kg/ha MSM treatment resulted in faster fungal growth than that of the control, which may be due to the nitrogen source and other nutrients released by the MSM.

Figure 1. Growth response of Sclerotina homoeocarpa to higher rates of mustard seed meal (MSM).

Figure 2. Growth response of Sclerotina homoeocarpa to lower rates of mustard seed meal (MSM).

0

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Figure 1. Growth response of Sclerotina homoeocarpa to higher rates of mustard seed meal (MSM).

Figure 2. Growth response of Sclerotina homoeocarpa to lower rates of mustard seed meal (MSM).

49

Evaluation of Solitare for Postemergent Crabgrass Control in Cool-Season Turf


SummaryLarge Crabgrass (Digitaria sanguinalis) can be a difficult weed to control post emergently. This trial evaluates the per-formance of the herbicide ‘Solitare’ (with active ingredients of sulfentrazone and quinclorac) for its effectiveness at post emergence control of large crabgrass in tall fescue (Festuca arundinacea) turf. Treatment were applied at three appli-cation timings based on crabgrass growing stages at 1-4 leaf stage (May 10th), 1-2 tiller (June 14th), or 5+ tillers stage (early to mid-July). In addition, two rates of ‘Solitaire’ were evaluated against the industry standard ‘Drive’ (quinclorac) (Figure 1). All applications were made using a CO2-presurized backpack sprayer calibrated to deliver 44 gal/acre with XR 8004 flat fan spray tips.

Current FindingsThe location of this trial has good crabgrass pressure. Prior to applications, the mowing height of the turf was reduced to two inches. Plots were verticut, and seeded with large crabgrass to ensure consistent weed pressure. After the crab-grass seeding, the plots received adequate irrigation to promote crabgrass germination. The initial application made on May 10th at the 1-4 leaf stage showed a significant reduction in crabgrass percentage compared to the untreated control, despite the application rate (Table 1.). This is an on-going study and it is still under evaluation.

Table 1. Treatment list and Application Timings

% Large CrabgrassTreatment

NumberTreatment

Name Rate (lbs ai/a) Transformed Rate Application Code 5/10/2012 6/7/2012

1 Solitare .75 16 oz/a A (1-4 leaf May 10th) 2.5 a** 1.0 de2 Solitare 1.0 21.3 oz/a A (1-4 leaf May 10th) 2.0 a 1.3 de3 Drive XLR8* .75 64 fl oz/a A (1-4 leaf May 10th) 1.8 a 0.8 e4 Solitare .75 16 oz/a B (1-2 tiller June 14th) 3.0 a 6.0 ab*** 5 Solitare 1.0 21.3 oz/a B (1-2 tiller June 14th) 3.5 a 6.6 bcde6 Drive XLR8 .75 64 fl oz/a B (1-2 tiller June 14th) 4.3 a 2.5 cde7 Solitare .75 16 oz/a C (5+ tillers TBA) 3.0 a 4.0 abcd8 Solitare 1.0 21.3 oz/a C (5+ tillers TBA) 3.5 a 4.5 abc9 Drive XLR8 .75 64 fl oz/a C (5+ tillers TBA) 4.5 a 5.5 abc

10 Untreated --- --- --- 5.5 a 6.8 a* methylated seed oil added at 1.5 pt/a.** Means followed by the same letters within a column are not significantly different based on LSD test at p=0.05 level.***Numbers and Letters grayed out indicate that ratings do not reflect control because treatments had not been applied.

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Evaluation of Experimental Insecticide for Control of Turfgrass Pest Insects


SummaryThe objective of this trial is to demonstrate the effectiveness of sequential applications of an experimental insecticide compared to two industry standards for control of key turfgrass insect pests. Research plots (5 ft X 5 ft) were estab-lished on a tall fescue/Kentucky bluegrass site with adequate irrigation. A ‘Spectracide’ Japanese beetle lure was placed in the center of each plot to promote insect pressure. All treatments (Table 1) were applied using a CO2-presurized backpack sprayer equipped with XR 8008 flat fan spray tips calibrated to deliver 87 gal/acre. All treatments were imme-diately incorporated using 0.25 inches of irrigation. The initial application (A) was applied June 14th and a sequential application (B) will be applied 30 days later.

Current FindingsOne week after initial treatment, no treatments caused a decline in turfgrass quality or showed any phytotoxicity. Grub pressure on this site is expected to be high. Further evaluations are on-going, and grub count data will be taken in the fall.

Table 1. Treatment list included for this trial

Treatment # Treatment Name Rate (g ai/ha) Transformed Rate Application Code

1 Untreated --- --- ---2 A16901B 220 223 g/A AB3 A16901B 298 300 g/A AB4 Meridian 25 WG 298 480 g/A A5 Acelepryn 1.67 SC 117 8.0 fl oz/A A

N

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