2011 field day cover - university of missouri · 2011 turfgrass & ornamental field day july...

Faculty Dr. Brad Fresenburg – Turfgrass Research & Extension Dr. Lee Miller – Turfgrass Pathology Dr. Chris Starbuck – Woody Ornamentals Dr. David Trinklein – Floriculture Dr. Xi Xiong – Turfgrass Management & Physiology Research Specialists Daniel Earlywine – Turfgrass Pathology Dan Lloyd – Turfgrass Management & Physiology Post Doctoral Researcher Dr. Kehua Wang Graduate Research Assistants John Haguewood, Natalie Pan, Steve Song, (Derek Cottrill – August 2011)

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

Sponsors & Contributors to the 2011 Mizzou Turfgrass Research Program

Agrologics* St. Louis, Missouri MU Ag Research Center* Columbia, Missouri Agrotain* St. Louis, Missouri A.L. Gustin Golf Course* Columbia, Missouri Arysta Life Sciences** Cary, North Carolina Dave Baker*** Columbia, Missouri BASF** Waukee, Iowa Bayer Environmental Science ** Kansas City, Missouri 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* Hartsburg, MO

Gateway Chapter (STMA) ** St. Louis, Missouri Hallbrook Country Club* Leawood, KS John Deere Landscapes* Fenton, Missouri Heart of America Golf Course Superintendents Association** Kansas City, Missouri Laser Turf Leveling* St. Charles, Missouri Macon Granuband* Macon, Missouri Mid America Green Industry Council* Kansas City, Missouri Mississippi Valley Golf Course Superintendents Association** St. Charles, Missouri MoTOC * Columbia, Missouri MO-KAN Chapter (STMA) ** Kansas City, Missouri MU Intercollegiate Athletics* Columbia, 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. 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

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 Miller Extension Turfgrass Pathologist University of Missouri Division 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 endorsement 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

2011 Turfgrass & Ornamental Field Day July 26th, 2011: Schedule of Events

7:30 – 8:30 a.m. Registration, coffee/donuts and exhibitors 8:30 – 9:00 a.m. Welcome & Introduction: Dr. Lee Miller, Turfgrass Pathology Welcome & Program Update: Dr. Mike Collins, Director of Division of Plant Sciences, Dr. Marc Linit, Associate Dean for Research & Extension, CAFNR Dr. Tom Payne, Vice Chancellor and Dean, CAFNR Welcome & MOTOC Update: Melvin Waldron, MOTOC President 9:00 – 10:30 a.m. Morning Session I: Visit 3 of 4 topics Presentations last 20 minutes; 10 minute Q&A/Transit time Page # STOP 1 “Does convenience = acceptable control? Spray vs. granular fungicide

applications for control of brown patch in tall fescue.” Dr. Lee Miller, Assistant Professor: Turfgrass Pathology

1-2

STOP 2 “New & improved fungicides for dollar spot control on bentgrass.” Mr. Dan Earlywine, Research Specialist: Turfgrass Pathology

3-4

STOP 3 “Establishing seeds without weeds; chemical and cultural control options.” Mr. Dan Lloyd, Research Specialist: Turfgrass Science

5

STOP 4 “Rose Rosette Disease: cause, current status, and management options.” Dr. Chris Starbuck, Associate Professor: Woody Ornamentals

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 “How to Conduct an Irrigation Audit.” Keith Schweiger: John Deere Landscapes

7

STOP 6 “Variation of bentgrass cultivars: general performance and disease tolerance.” Dr. Xi Xiong, Assistant Professor: Turfgrass Science

8-10

STOP 7 “Synthetic surface updates - what can you expect? Are synthetics just for athletic fields anymore? What are the current facts and stats?” Dr. Brad Fresenburg, Extension Assistant Professor

11

STOP 8 “Evaluation of Annual Flower Selections for 2011.” Dr. David Trinklein, Associate Professor: Floriculture

12

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

12:45 ~ 3:30 p.m. Offsite Hort./Ornamentals Tour: Shelter Gardens 1:00 – 3:00 p.m. Afternoon Sessions: Visit all topics Presentations last 20 minutes; 10 minute Q&A/Transit time STOP 9 “The National Turfgrass Evaluation Program. What is the present situation and

what can we expect in the future? What is new and interesting in turf cultivars?” Dr. Brad Fresenburg, Extension Assistant Professor

13-19

STOP 10 “Performance of multiple fungicide programs for continuous summer disease control on creeping bentgrass.” Mr. Dan Earlywine, Research Specialist: Turfgrass Pathology

20-22

STOP 11 “Double Down: Interaction of DMI fungicides and Trimmit applications on disease control and quality of putting greens.” Dr. Lee Miller, Assistant Professor: Turfgrass Pathology

23-24

STOP 12 “Control of Poa annua on creeping bentgrass green.” Mr. John Haguewood, Ryan Sears, GCS, & Isaac Breuer, GCS

25-27

Turf & Ornamental Field Research Booklet: Table of Contents

Research Title Field Day Presentations Pg # Map # * Does Convenience = Acceptable Control? Spray vs. Granular Fungicide Applications for Control of Brown Patch in Tall Fescue

1-‐2 1

New & improved fungicides for dollar spot control on bentgrass. 3-‐4 2 Establishing Seeds Without Weeds; Chemical And Cultural Control Options. 5 3 Rose Rosette Disease 6 4 How To Conduct An Irrigation Audit 7 5 Evaluation of Creeping Bentgrass (Agrostis stolonifera L.) Variety for Golf Course Fairways

8-‐10 6

Synthetic Turf Research 11 7 Evaluating Herbaceous Ornamentals For Performance In Missouri

12 8

National Turfgrass Evaluation Program Trials 13-‐19 9 Performance Of Multiple Fungicide Programs For Continuous Summer Disease Control On Creeping Bentgrass

20-‐22 10

Double Down: Interaction of DMI fungicides and Trimmit applications on disease control and quality of putting greens

23-‐24 11

Control of Poa annua With Bispyribac-‐sodium On a Creeping Bentgrass Green 25-‐27 12

Research Trial Reports

Common Bermudagrass Control in Tall Fescue 28-‐30

Pre And Post-‐Emergent Application Timings With ‘Specticle’ For Crabgrass Control 31-‐32

Spring and Fall Pre-‐Emergent Applications of Specticle for Crabgrass Control 33-‐34

Use of PGRs on Putting Greens to Suppress Annual Bluegrass (Poa annua L.) Seedheads

35-‐36

Evaluating Dormant Herbicide Application Timings for Winter Weed Control on Zoysiagrass

37-‐38

Control of Zoysiagrass Large Patch Disease Using Mustard Seed Meal 39-‐40

Re-‐evaluating Primo Maxx Application Intervals on Creeping Bentgrass Putting Greens

41-‐42

Seeding with ‘Imprelis’ to prevent weeds 43-‐44

Evaluation of Selective Herbicides for Bermudagrass (Cynodon dactylon (L.) Pers.) Control in Zoysiagrass (Zoysia japonica Steud.) Fairways

45-‐46

Investigation of Bermudagrass (Cynodon dactylon (L.) Pers.) Tolerance to AOPP herbicide Fenoxaprop-‐p-‐ethyl 47-‐49

Tenacity for Renovation 50

Evaluation of Brown Patch Control with Fungicides on Creeping Bentgrass. 51

Evaluation Of Headway G For Control Of Dollar Spot And Brown Patch On Kentucky Bluegrass

52

Evaluation of Alternative Management Practices for Spring Dead Spot Control on Bermudagrass.

53

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

1

Plot map on next page

Does Convenience = Acceptable Control? Spray vs. Granular Fungicide Applications for Control of Brown Patch in Tall Fescue

Lee Miller & Daniel Earlywine Summary Recently, 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 towards the lawn market. It is not necessary for either homeowners or lawn care operations to purchase and operate specialized equipment, and standard fertilizer spreaders can be used for application. Earlier reports of efficacy of granular products indicate that granulars are slightly less effective than their spray counterparts. However, newer granular formulations seem to be closing this gap in efficacy in recent reports, and need to be further evaluated. Low and high label rates of three QoI or combination DMI/QoI fungicides were applied initially on May 16, and then on 14d or 28d intervals as indicated in the table below. All granular fungicides were watered-‐in with 0.2” of irrigation after application. Current Findings Nitrogen was applied as urea (46-‐0-‐0) at 1 lb N/1000 ft2 to encourage brown patch infection. Plots were inoculated on June 27th with 25 ml volume of rye grain infested with R. solani. Mild brown patch symptoms were first observed on plots on June 13, with untreated plots exhibiting severe symptoms by 5 July. No significant differences have been observed between granular treatments and spray treatments. Disarm at the higher rate tended to be more effective as a sprayable formulation than granular on 5 July, but this will need to be confirmed over the length of the study.

Brown Patch Severityy Treatment S/Gx Rate Interval 6/20/11 7/5/11 Untreated -‐ -‐ -‐ 5.0 a 12.8 a Heritage

Heritage G G 3 lb/1000 ft2 28d 1.5 a 0.3 b Heritage TL S 1 fl oz/1000 ft2 28d 1.5 a 0 b Heritage G G 4 lb/1000 ft2 28d 1.0 a 0.3 b Heritage TL S 2 fl oz/1000 ft2 28d 0.3 a 0.3 b Heritage G G 3 lb/1000 ft2 14d 1.0 a 0 b Headway Headway G G 3 lb/1000 ft2 28d 0 a 0 b Headway S 1.5 fl oz/1000 ft2 28d 0.3 a 0.3 b Headway G G 4 lb/1000 ft2 28d 0.5 a 0.3 b Headway S 3 fl oz/1000 ft2 28d 0 a 0.5 b Disarm Disarm G G 2.3 lb/1000 ft2 28d 0.5 a 1.5 b Disarm 480 SC S 0.18 fl oz/1000 ft2 28d 0.5 a 1.5 b Disarm G G 4.6 lb/1000 ft2 28d 0.5 a 2.3 b Disarm 480 SC S 0.36 fl oz/1000 ft2 28d 1.5 a 0.3 b Pillar G G 3 lb/1000 ft2 14d 0.3 a 0.3 b Pillar G G 3 lb/1000 ft2 28d 0.3 a 0.3 b Pillar F G 3 lb/1000 ft2 28d 1.0 a 2.0 b Armada WDG S 1.5 oz/1000 ft2 28d 0.3 a 0.3 b Velista S 0.5 oz/1000 ft2 28d 0.5 a 0.3 b Eagle 20 EW S 1.12 fl oz/1000 ft2 28d 0.5 a 0.3 b

X S = sprayable formulation. G = granular formulation. y Brown patch severity evaluated as mean % symptomatic area. Means followed by the same letter are not significantly different as determined by Waller-‐Duncan k-‐ratio test (k=100)

2

Plots are 5 × 10 ft.

Disarm G4.6 lb/M

28d

Heritage G3 lb/M14d

Heritage G4 lb/M28d

Headway1.5 fl oz/M

28d

Headway G3 lb/M28d

Pillar F3 lb/M28d

Disarm SC0.36 fl oz/M

28d

Pillar G3 lb/M28d

Headway G4 lb/M28d

Disarm G2.3 lb/M

28d

Armada 1.5 oz/M

28d

Eagle1.1 fl oz/M

28d


28d

Headway3 fl oz/M

28d

Pillar G3 lb/M14d

Heritage G3 lb/M28d

Heritage TL2 fl oz/M

28dUntreated

Headway G4 lb/M28d

Velista0.5 oz/M

28d

UntreatedVelista

0.5 oz/M28d


28d

Disarm G4.6 lb/M

28d

Pillar G3 lb/M14d

Disarm G2.3 lb/M

28d

Headway G4 lb/M28d

Headway G3 lb/M28d

Eagle1.1 fl oz/M

28d


28d


28d

Heritage G4 lb/M28d

Heritage G3 lb/M14d

Armada 1.5 oz/M

28d

Headway1.5 fl oz/M

28d

Pillar G3 lb/M28d


28d

Headway3 fl oz/M

28d

Heritage G3 lb/M28d

Pillar F3 lb/M28d


28d


28d

Velista0.5 oz/M

28d


28d

Disarm G2.3 lb/M

28d

Headway3 fl oz/M

28d

Pillar F3 lb/M28d

Pillar G3 lb/M14d

Disarm G4.6 lb/M

28d

Armada 1.5 oz/M

28d

Headway G3 lb/M28d


28d

Heritage G3 lb/M28d

Heritage G3 lb/M14d

Pillar G3 lb/M28d

Headway G4 lb/M28d

Eagle1.1 fl oz/M

28d

Heritage G4 lb/M28d

Headway1.5 fl oz/M

28dUntreated

UntreatedHeritage G

3 lb/M14d


28d

Heritage G3 lb/M28d

Heritage G4 lb/M28d


28d

Headway G3 lb/M28d

Headway1.5 fl oz/M

28d

Headway G4 lb/M28d

Headway3 fl oz/M

28d


28d

Disarm G2.3 lb/M

28d


28d

Disarm G4.6 lb/M

28d

Pillar G3 lb/M14d

Pillar G3 lb/M28d

Pillar F3 lb/M28d

Armada 1.5 oz/M

28d

Velista0.5 oz/M

28d

Eagle1.1 fl oz/M

28d

!"#$%&'()*&*+,&"-.&,*/0,1-.&'$0"

North

3


New & improved fungicides for dollar spot control on bentgrass.

Daniel Earlywine and Lee Miller

Summary Dollar spot is a very common and persistent disease affects many warm and cool-‐season turfgrasses throughout the world. This trial is to evaluate new fungicides for dollar spot control on a ’Penncross’ creeping bentgrass golf green. The trial focuses on differing application intervals and treatment rates for various products. Treatments include BAS 640 00F, Curalan, and Emerald applied every 14 d, Tourney every 21 days, and Interface, Chipco 26019, Iprodione Pro 2 every 28 d. Plots were inoculated on 28 May with infested rye grain to test fungicide performance under uniform and severe dollar spot pressure. Current Findings All treatments were initiated on May 6 when dollar spot symptoms first became apparent. On May 26, dollar spot severity was higher in untreated plots and fungicides applied once (21 and 28 d interval) compared to fungicide treatments applied twice (14 d interval). In June, dollar spot pressure increased in untreated plots, while fungicide treatments had significantly lower dollar spot incidence. Not surprisingly, the three fungicides applied on 14 d intervals, BAS 640 00F, Curalan EG, and Emerald, provided excellent dollar spot suppression and tended to provide better turf quality than fungicides applied at 21 or 28 d intervals. Treatments following a 28 d interval such as Interface, Chipco 26019, and Iprodione Pro 2 may need to be adjusted to 14 or 21 day intervals in order to provide acceptable dollar spot suppression on creeping bentgrass at putting green height.

Turf Quality

$ Spot Incidence (# of infection centers)

Treatment Rate Interval 5/26/11 6/23/11 5/26/11 6/23/11 Untreated 3.63 e 3.75 e 96.0 a 126.3 a BAS 640 00F 3 fl oz/ 1000 ft2 14 d 5.63 a 7.88 ab 3.0 g 1.0 e BAS 640 00F 3 fl oz/1000 ft2 21 d 4.88 b 7.88 ab 34.8 def 0.8 e Curalan EG 1 oz/1000 ft2 14 d 5.75 a 7.63 ab 5.3 fg 0.0 e Curalan EG 1 oz/1000 ft2 21 d 4.50 bc 7.00 bc 38.3 cde 7.0 de Interface 3 fl oz/1000 ft2 28 d 4.38 bcd 6.25 cd 51.8 cd 35.3 cd Interface 4 fl oz/1000 ft2 28 d 4.00 cde 6.00 d 65.8 abc 50.0 c Chipco 26019 4 fl oz/1000 ft2 28 d 4.13 cde 7.00 bc 59.0 cd 21.0 cde Iprodione Pro 2 4 fl oz/1000 ft2 28 d 3.88 de 6.25 cd 67.5 abc 30.8 cde Emerald 0.13 oz/1000 ft2 14 d 4.88 b 7.88 ab 21.0 efg 0.0 e Tourney 0.275 oz/1000 ft2 21 d 4.38 bcd 7.75 ab 44.0 cde 2.8 de

4

Plots are 5 × 5 ft.

North

5

Establishing Seeds Without Weeds; Chemical And Cultural Control Options.

Dan Lloyd and Xi Xiong

Summary Establishing turfgrass from seed can be a difficult task with the inherent competition from various weed species. Most herbicides are not recommended for use until over a month after seed germination or until after the first mowing. This can be problematic because at various times of the year weeds can colonize bare ground very quickly and outcompete turfgrass seedlings. There are some newer chemical options that can be used at seeding and there are also some cultural practices that can be used to try to keep down weeds. This demonstration experiment seeks to compare these options for establishing seeds without weeds. ‘Tenacity’ (mesotrione) and Imprelis (aminocyclopyrachlor) are the two chemical control products used in this seeding trial since they have been proven to be effective and safe at seeding. The cultural practices included are straw and a seeding blanket typical of the kind found at a home improvement store. Roundup (glyphosate) was applied two weeks prior to seeding on one half of each plot to demonstrate how the use of a non-‐selective herbicide before re-‐seeding can decrease weed pressure. Since this tactic is not always desirable for renovation projects, the other half of each plot was not sprayed with Roundup prior to re-‐seeding. Five of the eight treatments were tilled before seeding while three more treatments were left untilled, but were cut low and verticut in two directions to encourage new seed germination. The differences between the tilled and untilled plots are to demonstrate advantages and disadvantages to different strategies for renovation.

Fig. 1. Plot map of renovation study; treatments on the bottom represent the product or cultural practice used. One half of the plot area was sprayed with Roundup two weeks before seeding.

6

Rose Rosette Disease

Chris Starbuck Summary Rose rosette is a fatal disease of plants in the genus Rosa which is caused by a virus-‐like pathogen, spread (vectored) by a tiny, eriophyid mite (Phyllocoptes fructiphylus). This mite is so small that it requires 30X magnification to see and is easily dispersed on wind currents. The most common host plant is the noxious weed, Rosa multiflora. However, over the past 10 years, there have been increasing reports of rose rosette infecting domesticated roses. Although there may be differences among rose species and cultivars in susceptibility to this disease, most experts believe that no cultivated roses are highly resistant. Unfortunately, this seems to be true of Knockout ® and some of the other low maintenance shrub roses popular in the landscape trade. While they show excellent resistance to black spot, death from rose rosette disease is all too common. Symptoms of rose rosette disease (RRD) are diverse and bizarre. Initially, the infected plant may have a reddish pigmentation on the leaf veins. Affected shoots may show an abnormally rapid elongation and reddening of the stem and leaves. Gradually, leaves become distorted and there is an abnormal proliferation of shoots and thorns, ultimately leading to a “witches broom” appearance. Shoots often fail to develop winter hardiness and may, consequently, be killed by freezing injury. Flowers that develop on affected shoots are small and distorted. In some cases, damage from glyphosate exposure can create symptoms that look similar to those of RRD. Unfortunately, there is no cure for RRD. Although infection may start on individual shoots after mite infestation, it becomes systemic, usually causing death of small plants within one or two years. It may be possible to reduce the probability of mite infestation by making weekly applications of pesticides such as carbaryl, horticultural oil or insecticidal soap in May, June and July. Repeated application of carbaryl often leads to outbreaks of spider mites due to elimination of mite predators. Avid is labeled for control of both eriophyid and spider mites on roses. However, the first step in management of RRD should be to remove all multiflora or other wild roses within 100 yards (especially upwind) of uninfected domestic roses. Symptoms of new infections generally start to appear in mid July. Pruning out symptomatic shoots may slow the progression of the disease. However, if there are many uninfected roses in the vicinity, the safest approach is to remove and destroy plants (including roots) that show any symptoms.

RRD symptoms: Reddish foliage and stems and excessive elongation, branching and thorns.

7

How To Conduct An Irrigation Audit

Keith Schweiger

Introduction Water efficiency is an escalating concern in regards to maintaining lawns, landscapes, and athletic turf. Irrigation design, efficiency, and maintenance are at the forefront of this issue, and trying to ensure proper scheduling, uniform distribution and delivery of irrigation water are key aspects to maintaining turf grass health while conserving water resources. Routine auditing of irrigation systems can help determine how much water should be delivered, which often correlates directly into how much money is being spent on irrigation, chemicals, and ultimately plant health or quality. Audits also can identify gaps or inefficiencies in an irrigation system that may need to be addressed. Summary The fundamental aspects of conducting an irrigation audit will be presented at this field day stop. The discussion of what you want to achieve, including site inspections, performance testing, and irrigation scheduling will be discussed. A simple and cost efficient method of performing an irrigation audit will be demonstrated, so turf managers can audit their own irrigation systems and maximize their utility and benefit.

8

Evaluation of Creeping Bentgrass (Agrostis stolonifera L.) Variety for Golf Course Fairways

Xi Xiong, Dan Lloyd and John Haguewood

Introduction Creeping bentgrass (Agrostis stolonifera L.) is the most commonly used turfgrass species in intensively managed areas, such as golf course putting greens, tees, and fairways. Dollar spot (Sclerotinia homoeocarpa F.T. Benntt) disease is the most common and costly disease for golf course superintendents who manage bentgrass fairways. The objective of this study was to evaluate various bentgrass cultivars maintained as a typical golf course fairway for their performance and susceptibility to dollar spot. Cultivar ‘Penncross’ was included as an industry standard. A total of 23 varieties were established in the field plots in spring 2009 by seeding. The experimental design was a completely randomized block design with 3 replications. Turf quality, color, and dollar spot severity were evaluated on a monthly basis. Data were analyzed by ANOVA and means are presented. Current Findings We found that the 23 cultivars exhibited significant differences in turf quality, color, and susceptibility to dollar spot. Turf quality the previous winter, as well as the spring and summer of 2011 are presented in Table 1. During the winter months (December), it was found that all of the varieties achieved similar or higher turf quality compared to the industry standard, ‘Penncross’. Cultivar ‘Declaration’, ‘SR 1150’, and ‘007’ had the highest turf quality (≥7) during the winter compared to the others cultivars. In the spring (March), most of the varieties tested had a turf quality of 6 or above, with only two exceptions, ‘Crenshaw’, and ‘Alister’, with 5.6 and 5.3 turf quality, respectively. In the early summer (June), it was found that ‘Penncross’ is one of the best quality cultivars and received a quality reading of 7. Other cultivars that had as good as or higher quality than ‘Penncross’ were ‘Kingpin’, ‘Penn links II’, ‘Memorial’, and ‘L-‐93’. The cultivars ‘Crenshaw’, ‘Century’, and ‘Alister’ were among the lowest turf quality group and had readings below an acceptable level. Spring color is also a concern for bentgrass fairways. Figure 1 shows the mean color of 23 creeping bentgrass cultivars in the spring of 2011 (March), and ranks them from lowest to highest. It was found that all cultivars evaluated in this study achieved spring color readings at 6 or above, which is similar or higher than ‘Penncross’. Examples of cultivars that resulted in darker-‐green spring colors were ‘T-‐1’, ‘Independence’, ‘Declaration’, ‘007’, and ‘LS-‐44’. Dollar spot incidence was first observed in mid-‐March, 2011 on the variety ‘Crenshaw’ and ‘Century’. Throughout the growing season, dollar spot was only treated when the entire stand was severely infested and complete stand loss was likely. Dollar spot severity was evaluated as percent plot area coverage and presented in Figure 2. It was found that ‘Crenshaw’ and ‘Century’ were the two most susceptible cultivars and more than 75% of plot areas were infested by dollar spot. ‘Penncross’, as a older variety, demonstrated relatively good tolerance to dollar spot and 25% of the plot area was infested. As a comparison, some newer varieties, such as ‘A-‐4’, did not perform well and resulted in 60% of the plot area infested by dollar spot. Among the most resistant cultivars were ‘Kingpin’, ‘Penn Links II’, ‘SR 1150’, and ‘Declaration’.

9

Table 1. Turf quality (1-9)* of 23 creeping bentgrass varieties maintained as a golf course fairway in winter, spring and summer. Entry Variety Turf Quality (1-9)

Winter (December) Spring (March) Summer (June) 1 A-4 6.00 6.67 5.33 2 Alister 6.00 5.33 5.00 3 Alpha 5.67 7.00 5.67 4 Bengal 6.33 6.67 5.33 5 Century 6.00 6.00 4.33 6 Crenshaw 5.67 5.67 4.00 7 Crystal bluelinks 5.67 7.00 6.33 8 Declaration 7.33 6.67 6.33 9 Imperial 5.67 7.00 5.67 10 Independence 6.00 7.33 6.00 11 Kingpin 7.00 6.67 7.67 12 L-93 6.67 7.00 7.33 13 LS-44 6.33 7.00 6.33 14 Mackenzie 6.33 6.67 5.67 15 Memorial 6.33 6.67 7.33 16 oo7 7.33 7.00 6.33 17 Penncross 5.00 6.67 7.00 18 Pennlinks II 5.67 6.67 7.33 19 Putter 6.00 6.67 5.33 20 Southshore 6.00 7.00 6.33 21 SR 1150 7.00 6.67 6.67 22 T-1 6.33 7.33 7.00 23 Tyee 7.00 6.67 6.67 LSD** 0.97 1.04 1.01

*Turf quality was visual assessed with 9 represents healthy ideal turf, 1 represents all turfgrass were dead, and 6 represents minimal acceptable quality. **LSD (P≤0.05) value for comparison of turf quality within the same time of the year.

In summary, creeping bentgrass varieties exhibited significant variations in terms of turf quality, spring color/green-‐up, and susceptibility to dollar spot. Golf course superintendants are recommended to refer to NTEP results and consult with a local specialist for selection of the best variety of creeping bentgrass for their location.

10

Figure 1. Spring color (March) of 23 creeping bentgrass cultivars ranked from the lowest to the highest. Color visual assessment was estimated on a 1-‐9 scale with 9 represents darker-‐green color, 1 represents brown, straw-‐looking color, and 6 represents minimal acceptable color.

Figure 2. Dollar spot percent coverage of 23 creeping bentgrasses evaluated in early summer 2011 (June). Cultivars were ranked as the most susceptible to the most resistant from left to right.

4

5

6

7

8

9

SR 1150

Imperial

Penncross

Bengal

Pennlinks II

A-‐4

Alister

Century

Crystal Bluelinks

Kingpin

L-‐93

Mem

orial

Southshore

Tyee

Creshaw

Declaration

LS-‐44

Mackenzie

OO7

Alpha

Putter

Independence

T-‐1

5.7 6.0 6.0 6.3 6.3 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7

7.0 7.0 7.0 7.0 7.0 7.3 7.3 7.7 8.0

Color (1-9)

0

10

20

30

40

50

60

70

80

90

100

Creshaw

Century

A-‐4

Imperial

Putter

Bengal

Independence

Mackenzie

Alister

Alpha

Tyee

T-‐1

Crystal Bluelinks

LS-‐44

OO7

Penncross

Declaration

Southshore

SR 1150

Mem

orial

L-‐93

Kingpin

Pennlinks II

percent (%

) dollar spot coverage

11

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 with continued work this summer on maintenance and preliminary pathological trials. This would not have been possible without contributions made by: Paul Hollis, Redexim-‐Charterhouse Mike Munie, Perfect Play Fields & Links Steve Bohlken, Capital Sand David Coleman, Macon Granuband LLC Jerry Meyer, Laser Turf Leveling

12

Evaluating Herbaceous Ornamentals For Performance In Missouri

David Trinklein

Summary Colorful beds of herbaceous ornamental plants have become an important component of the created landscape. This is true for public areas as well as the private residence. Sales of annual flowering plants increase in scope each year, with no end in sight. Many annual herbaceous plants carry the stigma of exhibiting poor performance, 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 planting such as those typical of color beds on golf courses, surrounding commercial buildings, etc. Plant improvement via introduction and breeding results in the availability of many new cultivars each year. Their ability to tolerate Missouri conditions is, in most part, unknown. The purpose of this trial was to evaluate a number of relatively new herbaceous ornamental cultivars for performance under Missouri summer conditions. Thirty-‐five cultivars representing 13 species of herbaceous ornamental plants (refer to evaluation handout) 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 the greenhouse. On May 17, 2011 the plants were established in the outdoor plots which had been amended with 3-‐18-‐20 fertilizer applied at the rate of 2 pounds per 1000 square feet. Additional nitrogen was supplied on July 5 in the form of side dressing calcium nitrate at the rate of one ounce per individual planting. Plants were supplied with one and one-‐half inches of water per week when rainfall was insufficient. Weed control was achieved through hand weeding following with an application of Preen. Data was/will be collected for early performance, mid-‐summer performance, and late season performance using a rating scale of 1 -‐ 10.

13

National Turfgrass Evaluation Program Trials

Brad Fresenburg

Summary The National Turfgrass Evaluation Program (NTEP)* has been and still is one of the most widely known sources for information on turfgrass species and 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 information 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 purchase 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.

Current Trials Two NTEP trials are being conducted at the University of Missouri Turfgrass Research Facility. They are the 2006 Tall Fescue trial and the 2010 Perennial Ryegrass trial. We are in the final year of the tall fescue trial and NTEP has requested a dry down for this trial from June through August to evaluate drought tolerance. Hopefully mother nature will cooperate. We are in the first season of the perennial ryegrass trial and this trial is scheduled to run for 4 years. Maintenance guidelines: Tall Fescue Trial: Perennial Ryegrass Trial: Mowing height: 2.5 to 3.0” 1.5 to 2.5 “ Nitrogen rate: 0 to 0.25 lb/1000 sqft 0.3 to 0.5 lb/1000 sqft** Irrigation: 50 to 65% potential ET None, only to prevent dormancy Herbicides: Minimal to prevent stand loss Minimal to prevent stand loss Fungicides: None None Insecticides: None None **Per growing month, however not monthly applications, 2-‐4 applications annually. Attached are plot plans of these two trials. Feel free to look through the numerous cultivars on-‐site and try to pick your favorites.

14

2006 Tall Fescue NTEP S

78 94 85 114

104 107 36 57 81 19 71 17 39 110 113 100 10 11 56 34 62 92 65 70 74 61 106 15 6 87 13 88 98 41 86 63 90 72 55 33 2 105 14 16 20 73 38 95 30 67 46 54 25 99 37 101 9 51 49 29 93 76 12 77 96 111 45 102 4 62 112 109 26 23 84 79 108 32 43 47 8 83 97 24 91 82 69 68 3 58 89 31 50 28 40 53 66 35 75 5 18 64 103 22 80 59 48 1 60 21 7 44 42 27

114 43 81 89 108 105 85 97 61 80 109 98 92 113 107 50 103 101 69 88 86 112 110 83 111 104 99 102 96 70 71 49 30 29 87 94 91 90 82 74 65 84 75 27 55 100 106 25 79 95 77 72 52 66 33 73 12 48 28 78 93 40 31 41 76 17 67 42 62 2 5 21 24 46 35 47 22 19 53 64 63 60 57 1 39 36 15 14 26 18 20 59 56 51 7 9 13 3 23 45 37 54 44 4 16 10 58 32 38 68

111 112 113 114 X X X 11 6 43 8

100 101 102 103 104 105 106 107 108 109 110 89 90 91 92 93 94 95 96 97 98 99 78 79 80 81 82 83 84 85 86 87 88 67 68 69 70 71 72 73 74 75 76 77 56 57 58 59 60 61 62 63 64 65 66 45 46 47 48 49 50 51 52 53 54 55 34 35 36 37 38 39 40 41 42 43 44 23 24 25 26 27 28 29 30 31 32 33 12 13 14 15 16 17 18 19 20 21 22 1 2 3 4 5 6 7 8 9 10 11

5 X 5 plots, RCBD, 3 replications, 114 cultivars (55’ X 160’) Planted: (Sept. 13, 2006)

15 2006 NATIONAL TALL FESCUE TEST Entries and Sponsors Entry Entry Entry No. Name Sponsor No. Name Sponsor No. Name Sponsor *1 Ky-‐31 Standard Entry *41 Firecracker LS (MVS-‐MST) Mountain View Seeds 81 JT-‐36 Jacklin Seed by Simplot *2 Spyder LS (Z-‐2000) Z-‐Seeds *42 Mustang 4 (M4) Pickseed 82 JT-‐45 Jacklin Seed by Simplot 3 Braveheart(DP 50-‐9407) DLF Trifolium A/S 43 0312 Pickseed 83 JT-‐42 Jacklin Seed by Simplot 4 Umbrella (DP 50-‐9411) DLF Trifolium A/S 44 PSG-‐TTST Smith Seed Services 84 JT-‐33 Jacklin Seed by Simplot 5 Cannavaro (DP 50-‐9440) DLF Trifolium A/S 45 Col-‐1 Pickseed 85 BGR-‐TF1 Berger Seed Company 6 Greenbrooks (TG 50-‐9460) DLF Trifolium A/S 46 J-‐130 Pickseed 86 BGR-‐TF2 Berger Seed Company *7 Plato Olsen Seed Company 47 Corona (Col-‐M) Pickseed *87 Gazelle II (PST-‐5HP) Scotts Company *8 Lindbergh Olsen Seed Company 48 Crossfire 3 (Col-‐J) Pickseed *88 Wolfpack II (PST-‐5WMB) Scotts Company *9 Aristotle Olsen Seed Company *49 Hunter LESCO, Inc. *89 AST 7002 Allied Seed LLC *10 Einstein Olsen Seed Company *50 Biltmore LESCO, Inc. *90 AST 7001 Allied Seed LLC *11 Silverado Standard Entry *51 Padre LESCO, Inc. *91 Darlington (CS-‐TF1) Columbia Seeds *12 Monet (LTP-‐610 CL) Lebanon Seaboard Corp. *52 Magellan LESCO, Inc. 92 KZ-‐1 KZ Seeds *13 Cezanne Rz (LTP-‐CRL) Lebanon Seaboard Corp. 53 Catelyst (NA-‐BT-‐1) LESCO, Inc. *93 Renovate (LS-‐11) LESCO, Inc. *14 Van Gogh (LTP-‐RK2) Lebanon Seaboard Corp. 54 Stetson II (NA-‐SS) LESCO, Inc. *94 Compete (LS-‐06) LESCO, Inc. 15 Ninja 3 (ATF 1247) Ampac Seed Company 55 Finelawn Xpress (RP 2) ProSeeds Marketing *95 Hudson (DKS) Smith Seed Services 16 Cochise IV (RKCL) Ampac Seed Company 56 Falcon NG (CE 1) ProSeeds Marketing *96 Reunion (LS-‐03) LESCO, Inc. *17 RK 4 Pennington Seed Company *57 Shenandoah Elite (RK 6) ProSeeds Marketing 97 GWTF Grassland Oregon 18 RK 5 Pennington Seed Company *58 Falcon V (ATM) ProSeeds Marketing 98 KZ-‐2 KZ Seeds 19 GE-‐1 Pennington Seed Company *59 Shenandoah III (SH 3) ProSeeds Marketing *99 AST9002 (AST-‐2) Allied Seed LLC 20 LS 1200 (SC-‐1) Lewis Seed Company 60 BAR Fa 6363 Barenbrug USA *100 AST9001 (AST-‐3) Allied Seed LLC 21 ATF 1328 Lewis Seed Company 61 BAR Fa 6253 Barenbrug USA *101 RNP Pennington Seed Company *22 Skyline Burlingham Seeds *62 Talladega (RP 3) Columbia Seeds 102 AST1001 (AST-‐4) Allied Seed LLC *23 Hemi Burlingham Seeds *63 Tahoe II Columbia Seeds *103 AST7003 Allied Seed LLC *24 Turbo RZ (Burl-‐TF8) Burlingham Seeds 64 06-‐WALK Oregro Seeds *104 AST9003 (AST-‐1) Allied Seed

16 LLC *25 Turbo Burlingham Seeds *65 Escalade Oregro Seeds 105 J-‐140 Pickseed *26 Bullseye Burlingham Seeds 66 06-‐DUST Oregro Seeds *106 Pedigree (ATF-‐1199) Pennington Seed Company 27 Trio (IS-‐TF-‐152) Ampac Seed Company *67 Honky Tonk (RAD-‐TF17) Radix Research *107 Justice Standard Entry 28 Sidewinder (IS-‐TF-‐138) Ampac Seed Company 68 PSG-‐85QR Pickseed Genetics *108 Rebel IV Standard Entry 29 Rocket (IS-‐TF-‐147) DLF International Seeds 69 STR-‐8GRQR Seed Research of Oregon *109 3rd Millennium SRP Turf Merchants, Inc. 30 Jamboree (IS-‐TF-‐128) DLF International Seeds 70 PSG-‐82BR Pickseed Genetics *110 Traverse SPR (RK-‐1) Turf Merchants, Inc. *31 Toccoa (IS-‐TF-‐151) Columbia Seeds *71 Faith (K06-‐WA) The Scotts Company *111 Rhambler SRP (Rhambler Turf Merchants, Inc. 32 Terrier (IS-‐TF-‐135) DLF International Seeds 72 GO-‐1BFD Grassland Oregon *112 Firenza Integra Seeds *33 Raptor II (MVS-‐TF-‐158) Mountain View Seeds *73 SR 8650 (STR-‐8LMM) Seed Research of Oregon *113 Falcon IV Standard Entry 34 IS-‐TF-‐159 Grassland Oregon 74 STR-‐8BB5 Seed Research of Oregon 35 GARRISON (IS-‐TF-‐153) DLF International Seeds *75 Tulsa Time (Tulsa III) Seed Research of Oregon *36 Essential (IS-‐TF-‐154) DLF International Seeds 76 PSG-‐RNDR Smith Seed Services 37 Fat Cat (IS-‐TF-‐161) DLF International Seeds 77 PSG-‐TTRH Smith Seed Services 38 MVS-‐341 Mountain View Seeds *78 Speedway (STR-‐8BPDX) Seed Research of Oregon 39 MVS-‐1107 Mountain View Seeds *79 Rembrandt Standard Entry *40 Titanium LS (MVS-‐BB-‐1) Mountain View Seeds 80 JT-‐41 Jacklin Seed by Simplot * COMMERCIALLY AVAILABLE IN THE USA IN 2010

17

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

18

2010 NATIONAL PERENNIAL RYEGRASS TEST Entries and Sponsors

Entry No. Name Sponsor Entry No. Name Sponsor 1 Rinovo Semillas Fito 46 ISG-‐31 Integrated Seeds 2 CL 11601 The Scotts Company 47 A-‐35 Allied Seeds 3 PR 909 Turf Merchants, Inc. 48 CS-‐PR66 Columbia Seeds 4 CL 11701 Turf Merchants, Inc. 49 CST Columbia Seeds 5 APR 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 OR 8 DLF LGD-‐3026 DLF International Seeds 53 Pick 10401 Pickseed USA, Inc. 9 DLF LGD-‐3022 DLF International Seeds 54 Mach I Standard Entry 10 PSRX-‐S84 Pickseed USA & Seed Research of OR 55 RAD-‐PR62 Radix Research 11 SRX-‐4RHD Seed Research of Oregon 56 RAD-‐PR55R Lewis Seed 12 P02 Novel AG 57 IS-‐PR 409 Brett Young Seeds Ltd. 13 S85 Novel AG 58 IS-‐PR 463 DLF International Seeds 14 LTP-‐RAE Lebanon Turf Products 59 IS-‐PR 469 DLF International Seeds 15 Allante Ledeboer Seed/Pro-‐Turf Solutions-‐OVS 60 IS-‐PR 479 DLF International Seeds 16 Insight Ledeboer Seed/Pro-‐Turf Solutions-‐OVS 61 IS-‐PR 487 DLF International Seeds 17 Sienna Ledeboer Seed/Pro-‐Turf Solutions-‐OVS 62 IS-‐PR 488 DLF International Seeds 18 Brightstar SLT Standard Entry 63 IS-‐PR 489 DLF International Seeds 19 CL 307 Pennington Seed Company 64 IS-‐PR 491 DLF International Seeds 20 APR 2320 Pennington Seed Company 65 IS-‐PR 492 DLF International Seeds 21 APR 2038 Smith Seed Services 66 DLF LGT 4182 DLF International Seeds 22 PPG-‐PR 121 Ampac Seed Company 67 ISG-‐30 Integrated Seeds 23 PPG-‐PR 128 Integra Turf, Inc. 68 PST-‐204D Landmark Native Seeds 24 PPG-‐PR 133 Mountain View Seeds 69 PST-‐2NKM Landmark Native Seeds 25 PPG-‐PR 134 Mountain View Seeds 70 PST-‐2DR9 Pure-‐Seed Testing 26 LTP-‐PR 135 Lebanon Turf Products 71 PST-‐2MG7 Pure-‐Seed Testing 27 PPG-‐PR 136 Lewis Seed 72 PST-‐2TQL Pure-‐Seed Testing 28 PPG-‐PR 137 Columbia Seeds 73 PST-‐2AG4 Brett Young Seeds Ltd. 29 PPG-‐PR 138 Ampac Seed Company 74 PST-‐2MAGS Turf Merchants, Inc.

19

30 PPG-‐PR 140 Mountain View Seeds 75 PST-‐2K9 The Scotts Company 31 PPG-‐PR 142 Peak Plant Genetics 76 PST-‐2BNS Pure-‐Seed Testing 32 PPG-‐PR 143 Columbia Seeds 77 PST-‐2ACR Pure-‐Seed Testing 33 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 USA 80 Bonneville Burlingham Seeds 36 BAR Lp 10972 Barenbrug USA 81 PSRX-‐4CAGL Pickseed USA & Seed Research of OR 37 BAR Lp 10970 Barenbrug USA 82 GO-‐DHS Grassland Oregon 38 2NJK Barenbrug USA 83 GO-‐PR60 Grassland Oregon 39 BAR Lp 7608 Barenbrug USA 84 GM3 Landmark Native Seeds 40 Pinnacle Standard Entry 85 PRX-‐4GM1 Pickseed USA & Seed Research of OR 41 APR 2445 ProSeeds Marketing 86 SRX-‐4MSH Seed Research of Oregon 42 Fiesta 4 Standard Entry 87 Pick 4DFHM Pickseed USA, Inc. 43 GO-‐G37 Grassland Oregon 88 Palmer V Standard Entry 44 CS-‐20 Columbia Seeds 45 ISG-‐36 Integrated Seeds UPDATED 9/10/10

20

Plot map and treatment list on next two pages

Performance Of Multiple Fungicide Programs For Continuous Summer Disease Control On Creeping Bentgrass


Summary Fungicide programs are designed to control a wide variety of diseases throughout the year. Rotating fungicides with different chemistries and modes of action can provide better control of diseases, and decrease incidence of fungicide resistance. This trial is designed to evaluate different fungicide programs for managing diseases throughout the summer on a “Penn A4” creeping bentgrass putting green. Fungicide applications were initiated on 21 April for program 5 and 6, 4 May for program 7, and 18 May for program 1, 2, 3, and 4. Fungicide applications continue every 14 days until late August to early September.

Current Findings Initial dollar spot symptoms were observed by 4 May. By 18 May, reductions in dollar spot were observed in plots treated by programs 5, 6 (Initiated on 21 April) and 7 (initiated on 4 May) compared to programs 1-‐4 where no applications had been made. Although dollar spot was significantly lower than the untreated control for programs 1-‐4 from 25 May to 1 June, disease severity wouldn’t be considered acceptable on a putting green. After 1 June, no differences in disease suppression have been observed among the fungicide programs. Turf quality also showed similar trends with only minimal differences between programs on June 1. On June 22, brown patch was observed in untreated plots with no brown patch symptoms occurring in any program plots.

0

10

20

30

40

50

60

70

5/18 5/25 6/1 6/8 6/15 6/22 6/29

# $

Spo

t In

fect

ion

Cen

ters

per

Plo

t

Dates

UTC Program 1 Program 2 Program 3Program 4 Program 5 Program 6 Program 7

21

Plot Size is 5 X 5 ft.

Program 1 Program 6 Program 4 Program 3 Program 5 Program 2 Untreated Program 7

Program 3 Program 7 Program 2 Program 1 Untreated Program 5 Program 6 Program 4

Program 6 Program 3 Program 4 Untreated Program 5 Program 7 Program 1 Program 2

Untreated Program 1 Program 2 Program 3 Program 4 Program 5 Program 6 Program 7

Program 1 Program 2 Program 3 Program 4

Treatment Rate/M Treatment Rate/M Treatment Rate/M Treatment Rate/M Application Date

Honor 1.1 oz Headway 3.0 fl oz Disarm 480 0.36 fl oz Tartan 2.0 fl oz May 18 Insignia 0.9 fl oz Heritage 2.0 oz Eagle SC +

Disarm SC 1.45 fl oz + 0.36 fl oz

Compass 0.25 oz June 1

Spectro 90 5.75 oz Spectro 90 5.75 oz Spectro 90 5.75 oz Spectro 90 5.75 oz June 15 Signature + Daconil

4.0 oz + 3.2 oz

Signature + Daconil

4.0 oz + 3.2 oz

Signature + Daconil

4.0 oz + 3.2 oz

Signature + Daconil

4.0 oz + 3.2 oz

June 29

Insignia 0.9 fl oz Heritage 2.0 oz Disarm 0.36 fl oz Compass 0.25 oz July 13 Signature + Daconil

4.0 oz + 3.2 oz

Signature + Daconil

4.0 oz + 3.2 oz

Signature + Daconil

4.0 oz + 3.2 oz

Signature + Daconil

4.0 oz + 3.2 oz

July 27

Chipco 26 GT 4.0 fl oz Chipco 26 GT 4.0 fl oz Chipco 26 GT 4.0 fl oz Chipco 26 GT 4.0 fl oz August 10 Honor 1.1 oz Headway 3.0 fl oz Disarm M 1.0 fl oz Tartan 2.0 fl oz August 24

North

22

Program 5

Program 6 Program 7

Treatment Rate/M Treatment Rate/M Application Date

Treatment Rate/M Application Date

Bayleton Flo 1.0 fl oz Bayleton Flo 1.0 fl oz April 21 Headway 3.0 fl oz May 4 Signature +

Triton Flo 4.0 oz + 0.5 fl oz

Signature + Triton Flo

4.0oz + 0.5 fl oz

May 18 Daconil Action 3.6 fl oz May 18

Signature + Interface

4.0 oz + 4.0 fl oz


4.0 oz + 4.0 fl oz

June 1

Concert II 4.5 fl oz June 1

Reserve 4.8 + Honor

3.2 fl oz + 0.83 oz

Reserve 4.8 + Honor

3.2 fl oz + 0.83 oz

June 15

Renown Medallion +

4.5 fl oz + 0.25 oz

June 15

Signature + Daconil

4.0 oz + 3.2 oz


4.0 oz + 9.38 fl oz

June 29

Daconil Action + Subdue Maxx

3.6 fl oz 1.0 fl oz

June 29

Signature + Honor

4.0 oz + 0.83 oz

Signature + Daconil

4.0 oz + 3.2 oz

July 13

Heritage TL + Daconil Action + Subdue Maxx

2.0 fl oz 3.6 fl oz 1.0 fl oz

July 13

Signature + Daconil

4.0 oz + 3.2 oz

Signature + Honor

4.0 oz + 0.83 oz

July 27

Medallion + Daconil Action + Subdue Maxx

0.25 oz 3.6 fl oz 1.0 fl oz

July 27


4.0 oz + 4.0 fl oz


4.0 oz + 4.0 fl oz

August 10

Renown 4.5 fl oz August 10

Reserve 4.8 3.6 fl oz Reserve 4.8 3.6 fl oz August 24 Daconil Action 3.6 fl oz August 24 Tartan 2.0 fl oz Tartan 2.0 fl oz September 7 Headway 1.5 fl oz September 7

23


Double Down: Interaction of DMI fungicides and Trimmit applications on disease control and quality of putting greens

Lee Miller & Daniel Earlywine

Summary Recent research found two early spring applications of the DMI fungicides significantly suppress fairy ring on creeping bentgrass putting greens. For those that use paclobutrazol for spring suppression of Poa annua populations in their greens, this can cause a significant problem since the DMI fungicides have a similar chemistry and can also be potent growth regulators. This study was initiated to 1) evaluate the potential negative impacts of applying paclobutrazol (Trimmit) with the DMIs during the spring, 2) examine methods of scheduling paclobutrazol in coordination with DMI applications, and 3) investigate residual efficacy of spring DMI applications on diseases of creeping bentgrass. Treatments included 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. The experiment was replicated on ‘Penncross’ and ‘Penn A-‐4’ to evaluate potential cultivar differences. Current Findings Phytotoxicity (bronzing discoloration) was first noted in plots on 23 May after the second DMI fungicide application was made on 20 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. The last Trimmit application was made on 3 June, during the warmest early June period in Columbia since 1934. These plots tended to have higher phytotoxicity than other plots, indicating heat stress was a major factor in the phytotoxic response, and Trimmit applied in conjunction with the DMIs should be scheduled earlier in the season. Dollar spot incidence was first observed on both plots on 13 May. Dollar spot incidence has been significantly lower in all DMI fungicide treated plots, and was statistically lower in Bayleton FLO treated plots as opposed to the other three fungicides. Phytotoxicityx $ Spot Incidence (# of infection centers)

6/8/11 5/20/11 6/23/11 Treatment Penncross A4 Penncross A4 Penncross A4 Untreated 0.63 h 0.75 d 66.3 a 55.0 b 152 a 151 b Trimmit Alone (16 fl oz/A) 1.3 fgh 1.0 cd 65.8 a 106.0 a 160 a 182 a Torque (0.6 fl oz/1000 ft2) Alone 1.4 e-‐h 1.5 bcd 16.8 b 21.5 cde 60.3 b 68.5 de Tank-‐mixed with Trimmit 2.3 a-‐d 2.0 abc 6.5 b 11.0 de 21.5 d-‐h 52.8 d-‐g Trimmit 7 d later 1.9 c-‐g 1.5 bcd 8.3 b 16.5 cde 19 e-‐h 59.0 def Trimmit 14 d later 2.5 abc 2.25 ab 3.8 b 7.0 e 16.3 fgh 28.0 ghi Bayleton FLO (1 fl oz/1000 ft2) Alone 1.9 c-‐g 1.6 bcd 5.5 b 20.3 cde 7.0 gh 27.5 ghi Tank-‐mixed with Trimmit 2.8 ab 2.0 abc 8.3 b 6.8 e 5.3 gh 8.5 i Trimmit 7 d later 1.9 c-‐g 2.8 a 5.8 b 17.0 cde 3.8 h 22.3 hi Trimmit 14 d later 2.9 a 2.4 ab 6.0 b 9.0 e 3.5 h 11.5 i Tourney (0.28 oz/1000 ft2) Alone 1.6 d-‐g 1.5 bcd 5.3 b 40.0 bc 58.0 b 113 c Tank-‐mixed with Trimmit 1.6 d-‐g 1.6 bcd 7.3 bc 14.5 cde 59.5 b 71.8 de Trimmit 7 d later 2.0 b-‐f 2.1 ab 5.0 c 8.8 e 43.3 bcd 47.3 e-‐h Trimmit 14 d later 2.5 abc 2.1 ab 8.3 bc 15.8 cde 27.3 d-‐g 54 d-‐g Trinity (1 fl oz/1000 ft2) Alone 1.3 fgh 1.6 bcd 10.3 bc 35.5 bcd 28.0 c-‐g 79.3 d Tank-‐mixed with Trimmit 2.1 a-‐e 2.1 ab 14.5 bc 18.5 cde 54.5 b 58.5 def Trimmit 7 d later 2.3 a-‐d 2.0 abc 14.3 bc 12.8 de 40.8 b-‐e 59.8 de Trimmit 14 d later 2.0 b-‐f 1.5 bcd

33.5 b 17.0 cde 51.0 bc 60.5 de X Phytotoxicity measured on a 0-9 scale. 0 = green turf, 2-3 = significant bronzing, 9 = total turf loss

24

Plots are 5 × 5 ft and replicated on ʻPenn A-4ʼ and ʻPenncrossʼ research greens.

Bayleton (1 fl oz/M) +

Trimmit Torque

(0.6 oz/M) Torque

(0.6 oz/M) + Trimmit 7d

Torque (0.9 oz/M) +

Trimmit

Trinity (1 fl oz/M) + Trimmit 7d

Torque (0.9 oz/M) + Trimmit 7d

Torque (0.9 oz/M)

Bayleton (1 fl oz/M) + Trimmit 7d

Trimmit (16 oz/A)

Alone



Tourney (0.28 oz/M)+ Trimmit 7d

Tourney (0.28 oz/M) +

Trimmit

Torque (0.6 oz/M) +

Trimmit


Trinity (1 fl oz/M) +

Trimmit Trinity

(1 fl oz/M) Tourney

(0.28 oz/M) Tourney

(0.28 oz/M)+ Trimmit 14d

Untreated Torque


Bayleton (1 fl oz/M)


Trimmit (16 oz/A)

Alone Bayleton

(1 fl oz/M) Tourney

(0.28 oz/M) Torque



Trinity (1 fl oz/M)

Torque (0.6 oz/M) +

Trimmit


Trimmit



Torque (0.9 oz/M) +

Trimmit


Torque (0.6 oz/M)



Trimmit



Trimmit Untreated Torque

(0.9 oz/M) Trinity

(1 fl oz/M) + Trimmit 14d


Untreated Torque







Torque (0.9 oz/M) +

Trimmit


Torque (0.6 oz/M)


Trimmit

Tourney (0.28 oz/M)


Torque (0.6 oz/M) +

Trimmit

Trimmit (16 oz/A)

Alone


Trimmit


Trinity (1 fl oz/M)



Torque (0.9 oz/M)


Trimmit

Trimmit (16 oz/A)

Alone

Torque (0.6 oz/M) +

Trimmit


Torque (0.9 oz/M) +

Trimmit



Trimmit



Trimmit



Trimmit


Untreated Torque (0.6 oz/M)


Torque (0.9 oz/M)




Tourney (0.28 oz/M)


Trinity (1 fl oz/M)


North

25

Control of Poa annua With Bispyribac-sodium On a Creeping Bentgrass Green

John Haguewood, Reid J. Smeda and Xi Xiong

Background Selective control of annual bluegrass (Poa annua L.) on creeping bentgrass (Agrostis stolonifera L.) putting greens is difficult. Bispyribac-‐sodium (Velocity®) is an effective herbicide recently labeled for annual bluegrass control on creeping bentgrass fairways. However, turf tolerance to Velocity is expected to be lower as mowing heights are reduced on greens compared to fairways (3 compared to 12.5 mm). The objective of this research was to determine if Velocity applied in late spring/summer in the transition zone could reduce annual bluegrass infestations without compromising turf quality. Field studies were established on a golf course putting green in Columbia, Missouri in 2010 and 2011. Treatments were designed as a randomized complete block with four replications, with individual plots measuring 5 ft x 5 ft. In 2010, treatments began June 21st; 2011 treatments began June 1st. All applications were made using a CO2-‐presurized backpack sprayer at a spray volume of 23 gal/acre using XR8002 flat-‐fan spray tips. Turfgrass quality and phytotoxicity were assessed weekly using a 1-‐9 scale; 9 represents desirable quality or no phytotoxicity; 1 represents poor quality or high phytotoxicity; and 6 represents minimally acceptable turf quality or phytotoxicity. The extent of Poa control was also determined visually weekly after herbicide applications. Quantitative data included NDVI (normalized difference vegetation index) readings, where “greenness” was also recorded weekly. Treatments included two rates of Velocity alone (1 and 2 oz/acre). The lower rate was applied on 14 (6 total applications) and 21 day (4 total applications) intervals, while the higher rate was applied every 28 days (3 total applications). Treatments also included Velocity at the two rates above, in combination with plant growth regulators (PGRs) paclobutrazol (Trimmit®) or trinexapac-‐ethyl (Primo Maxx™) applied every 28 days (3 total applications). Results Although Velocity is not yet labeled for creeping bentgrass putting greens, our research shows promise in Missouri. Velocity effectively reduced annual bluegrass incidence to less than 10% per plot by early fall, while the untreated control plots had ~20% Poa infestation. During the application period of treatments, turf quality was not affected by the low rate of Velocity, although transient yellowing was observed on plots receiving the high rate of Velocity (Table 2). Addition of Primo to Velocity did not improve annual bluegrass control or impact creeping bentgrass turf quality. Combinations of Velocity and Trimmit resulted in the most effective control of annual bluegrass (Figure 1), reducing Poa incidence to <5%. However, higher Poa control resulted in turf phytotoxicity within 2 weeks of application (Table 2). Results suggest that optimum management of annual bluegrass with the least impact on turfgrass quality follows applications of Velocity at a rate of 1 oz/acre on 14 or 21 day intervals. It was also observed that Velocity decreased dollar spot incidence. The use of Velocity on putting greens deserves greater consideration.

26

Table 1. Descriptions of treatments

Figure 1. Amount of annual bluegrass remaining in putting green in Fall 2010. Vertical lines above bars signify the standard deviation from the mean. Means with same latter above the bar are not significantly different using Fisher’s Protected LSD (P≤ 0.05). All treatments reduced annual bluegrass 58 to 79% compared to the untreated control.

Treatment Number

Treatment Rate (g ai/ha)

Rate (oz/acre)

Application Interval (days)

PGR (28 days)

1 Control -‐-‐-‐-‐-‐ -‐-‐-‐-‐-‐ -‐-‐-‐-‐-‐ -‐-‐-‐-‐-‐ 2 Velocity 12.4 1 14 -‐-‐-‐-‐-‐ 3 Velocity 12.4 1 14 Primo1 4 Velocity 12.4 1 14 Trimmit23 5 Velocity 12.4 1 21 -‐-‐-‐-‐-‐ 6 Velocity 12.4 1 21 Primo 7 Velocity 12.4 1 21 Trimmit 8 Velocity 24.8 2 28 -‐-‐-‐-‐-‐ 9 Velocity 24.8 2 28 Primo 10 Velocity 24.8 2 28 Trimmit 1Primo (57 g ai/ha) or (5.45 fl oz/acre) 2Trimmit (224 g ai/ha) or (16 fl oz/acre) 3Trimmit applied with spray volume of 46 gal/acre

0

5

10

15

20

1 2 3 4 5 6 7 8 9 10

% Ann

ual B

luegrass

Treatment

A

BC

B

D

BC

B

D

CB

D

27

Table 2. Mean phytotoxicity of creeping bentgrass following treatments of Velocity alone or combined with Primo or Trimmit

Velocity alone resulted in acceptable levels of creeping bentgrass injury, but when applied with Trimmit or Primo injury increased up to ~34% two weeks after treatment.

Rating (WAIT)1

Treatment 1 2 3 4 5 6 7 8 9 10 11 12

1 8.8 a1 8.9 a 9.0 a 9.0 a 9.0 a 9.0 a 9.0 a 9.03 9.0 a 9.0 a 9.0 a 9.0

2 8.4 ab 8.9 a 8.5 b 9.0 a 8.9 ab 9.0 a 8.3 b 9.0 9.0 a 9.0 a 9.0 a 9.0

3 7.5 cd 7.8 cd 8.8 ab 9.0 a 8.5 c 9.0 a 8.3 b 9.0 8.3 b 8.3 ab 9.0 a 9.0

4 6.5 e 5.9 e 8.8 ab 9.0 a 8.1 d 8.0 c 8.0 b 9.0 6.5 d 7.0 cd 9.0 a 9.0

5 7.9 bc 8.5 ab 9.0 a 8.5 b 9.0 a 9.0 a 8.3 b 9.0 9.0 a 9.0 a 9.0 a 9.0

6 7.0 de 7.4 d 9.0 a 8.4 c 9.0 a 9.0 a 8.0 b 9.0 7.5 c 8.0 b 9.0 a 9.0

7 6.6 e 5.8 e 8.5 b 8.0 d 8.5 c 8.5 b 8.0 b 9.0 6.0 d 5.8 e 8.0 c 9.0

8 7.6 c 8.5 ab 9.0 a 9.0 a 8.6 bc 9.0 a 9.0 a 9.0 8.8 ab 9.0 a 9.0 a 9.0

9 7.0 de 8.1 bc 8.9 a 9.0 a 8.1 d 8.5 b 9.0 a 9.0 7.3 c 7.8 bc 8.5 b 9.0

10 6.5 e 5.6 e 8.8 ab 9.0 a 7.5 e 8.0 c 8.5 ab 9.0 6.0 d 6.5 de 8.3 bc 9.0 1Visual turfgrass phytotoxicity ratings were measured on a 1-9 scale where 1=dead, 6=acceptable, and 9= no phytotoxcity. 2Means within a column followed by the same letter are not significantly different using Fisher’s Protected LSD (P≤ 0.05) 3Means followed by no letter are statistically similar.

28

Common Bermudagrass Control in Tall Fescue

Lala Kumar and Brad Fresenburg Tall fescue is major turfgrass specie in the transition zone. Tall fescue is a perennial cool-‐season grass and it has relatively good heat and drought tolerance, as well as good disease and insect resistance. Bermudagrass is a warm-‐season perennial grass whose growth cycle overlaps that of tall fescue. In many situations bermudagrass invades tall fescue turfs due to its spreading habit and creating an unsightly contrast between turf types. Secondly, common bermudagrass grows rapidly during the summer when tall fescue growth declines from heat stress thus giving bermudagrass opportunities to grow into weak tall fescue turf. Bermudagrass is considered one of the most difficult to control grass weeds in cool–season turfgrass. Presently, control of bermudagrass in tall fescue includes multiple applications of non-‐selective herbicides, like glyphosate; followed by reseeding or re-‐sodding. This can result in the loss of desirable and usable turfgrass areas until reestablishment. One active ingredient (fluazifop) selectively controls bermudagrass in tall fescue and zoysiagrass. A few new herbicides have given positive selective control of bermudagrass in tall fescue. Johnson and Carrow (1993) reported that fenoxaprop applied at 0.20 kg ha-‐1 starting in May and repeated at 3 to 4 week intervals for a total of six applications for two consecutive years controlled 97% of common bermudagrass without injuring tall fescue. When the herbicide rate was increased to 0.56 kg ha-‐1 and repeated at 3 to 4 week intervals for a total of six applications, common bermudagrass control was ≥ 97%. Fenoxaprop treatments at 0.56 kg ha-‐1 also caused moderate to severe injury on tall fescue, but the turf recovered within weeks following the application without any stand loss. Cudney et.al. (1997) conducted studies in southern and northern California and were able to control common bermudagrass with sequential herbicide applications, allowing seedling establishment and regrowth of established cool-‐ season turfgrass species. They reported that single applications of fenoxaprop, triclopyr or their combination only suppressed common bermudagrass. However, sequential applications of fenoxaprop, triclopyr or their combination resulted in 99, 84 and 100% control of common bermudagrass, respectively over a 2 –year period. Johnson (2000) reported that sequential applications of labeled rates of fenoxaprop or fluazifop alone only temporarily controlled bermudagrass shoots. Fenoxaprop plus fluazifop applied at 0.40 kg ai ha-‐1 in three sequential applications on monthly intervals starting in May-‐June proved effective in controlling bermudagrass rhizomes and stolons. McCarty (2002) observed five monthly applications of fenoxaprop 0.57EC (2.43 to 3.06 L ha-‐1) plus ethofumesate (1.5EC at 9.35 L ha-‐1) provided between 70 and 96 % control of common bermudagrass in a single season. Tank mix applications of fenoxaprop (0.57 EC at 3.43 to 6.83 L ha-‐1) and triclopyr 4L (1.31 to 2.63 L ha-‐1) provided 88 to 97 % control with four repeat applications during a single year. Single applications provided less than 30 percent control. McCarty (2002) cited similar work by Yelverton (1997) of North Carolina State University. According to Yelverton, three applications of fenoxaprop (0.57EC at 2.04 L ha-‐1) provided 75 % bermudagrass control by the end of the growing season.

29

However, when tank mixed with ethofumesate (1.3EC at 9.35 L ha-‐1) or triclopyr 4EC at (2.45 L ha-‐1), controlled increased to 84 and 90 %, respectively. Willis et al. (2006) reported that three-‐way combinations of mesotrione, fenoxaprop, and triclopyr (applied six times) reduced bermudagrass cover by 80% one year after treatments were completed. However, the best performing treatments included mesotrione plus triclopyr, triclopur plus fenoxaprop, and Mesotrione plus triclopyr plus fenoxaprop, with 95, 91, and 98% bermudagrass cover reduction, respectively. These treatments would be more economical and less likely to cause injury when spot treated instead of broadcast applied. Methods: Treatments (see table below) were applied on May 16, 2011to an established stand of tall fescue plots (6 ft x 6 ft) in a randomized complete block design with four replications. Each plot had a 4 inch common bermudagrass plug planted in the center of each plot in June of 2010. Bermudagrass plugs were allowed to establish in 2010 with spring treatments being applied in 2011. Mowing height of fescue was maintained at 2 inches to promote bermudagrass growth.

Trt Treatment Rate Plot No. By Rep No. Name Rate Unit 1 2 3 4

1 Untreated Control 101 206 302 409

2 Isoxaflutole 0.25 lb ai/a 102 201 308 405 3 Isoxaflutole 0.13 lb ai/a 103 207 301 410

Triclopyr 32 fl oz/a 4 Isoxaflutole 0.13 lb ai/a 104 213 307 412

Triclopyr 32 fl oz/a Fenoxaprop 28 fl oz/a

5 Triclopyr 32 fl oz/a 105 210 305 401 Fenoxaprop 28 fl oz/a

6 Mesotrione 5.33 fl oz/a 106 212 306 403 Triclopyr 32 fl oz/a

7 Mesotrione 5.33 fl oz/a 107 205 303 402 Triclopyr 32 fl oz/a Fenoxaprop 28 fl oz/a

8 Fluazifop 24 fl oz/a 108 211 313 411 9 Mesotrione 5.33 fl oz/a 109 208 310 413

Fluazifop 24 fl oz/a 10 Isoxaflutole 0.13 lb ai/a 110 209 304 408

Fluazifop 24 fl oz/a 11 MAT-28 6 fl oz/a 111 204 311 404

Fluazifop 24 fl oz/a 12 MAT-28 6 fl oz/a 112 203 312 406

Triclopyr 32 fl oz/a 13 MAT-28 6 fl oz/a 113 202 309 407

Triclopyr 32 fl oz/a Fenoxaprop 28 fl oz/a

Evaluations included bermudagrass spread from a 4 inch plug prior to treatment and twice following treatment (28 and 50 days after treatment). Phytotoxicity on tall fescue was taken on a scale of 0 to 9 with 9 being equal to dead grass at 8 hours, 1 day, 3 days, 7 days, 14 days, 21 days, 28 days, and 50 days after treatment. Initial bermudagrass burn was evaluated 10 days after treatment on a scale of 0 to 9 with 9 being equal to complete burn down. Percent control of bermudagrass was taken at 21 and 28 days after treatment on a scale of 0 to 100 with 100 being complete control. Treatments were applied with a CO2 backpack sprayer delivering 22 gallons per acre.

30

Results from a single spring application indicated some set back of common bermudagrass and some moderate injury to tall fescue. The decision to fore go the second and third applications this spring was due to the amount of injury being seen from fluazifop. We wanted to determine the length of time required to recover from this injury since injury still existed three weeks after treatment (timing of second application). The following is a quick summary of this data. Phytotoxicity on tall fescue was restricted to all treatments containing fluazifop (Treatments 8, 9, 10, 11) and began to show slight discoloration (3 on a scale of 0 to 9) 7 days after treatment (DAT). Injury from these treatments increased to 6 by 18 DAT and 7 by 25 DAT. Phyto injury decreased to 3 by 50 DAT. This was considered unacceptable injury from this active ingredient. All treatments did hold bermudagrass growth and spread up to 25 DAT, however all treatments had bermudagrass recovery by 50 DAT with one exception, Treatment 8 – fluazifop alone. This therefore confirms the need for multiple applications. Where the greatest phyto injury was observed with fluazifop, so was the greatest effect on bermudagrass growth. Fluazifop alone reduced the spread of bermudagrass by 2 inches while all other treatments increased by 3 to 10 inches after 50 days. While leaf burn was observed on bermudagrass and some stolons were abscessing, sequential applications by 21 DAT could have turned this single, suppression application into control. Fall applications will begin in late August. REFERENCES: Cudney, D. W., C. L. Elmore, V. A. Gibeault and J. S. Reints. 1997. Common Bermudagrass (Cynodon dactylon) Management in Cool-‐Season Turf. Weed Technology, Vol. 11; No.3: 478-‐483. Johnson, B. J. and R. N. Carrow. 1993. Common Bermudagrass Control in Tall Fescue with Fenoxaprop. International Turfgrass Society Research Journal 7. Johnson, M. D. 2000. The Control of Various Bermudagrass cultivars in Tall Fescue Utilizing Fenoxaprop & Fluazifop, Master of Science, Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University, Virginia. McCarty, B. 2002. Putting the brakes on bermudagrass. Ground Maintenance, June37, 6. Willis, J.W., D. B. Ricker and S. D. Askew. 2006. Selective Bermudagrass Control in Cool-‐ Season Turfgrass. Turf Weeds at Virginia Tech.

31

Pre And Post-Emergent Application Timings With ʻSpecticleʼ For Crabgrass Control


Summary This trial evaluates different application timings of the newly released ‘Specticle’ (indaziflam) pre-‐emergent herbicide for crabgrass (Digitaria spp.) control in bermudagrass (Cynodon dactylon) turf. Rates and timings are in the treatment table below (Table 1). One objective of this study was to determine how well ‘Specticle’ works as an early post-‐emergent product in addition to various pre-‐emergent timings. In total, five application timings are being evaluated: early pre-‐emergent (March 24th), typical pre-‐emergent (April 14th), late pre-‐emergent (May 5th), early post-‐emergent (May 26th – 2-‐3 leaf stage), and late post-‐emergent (June 24th – 2-‐3 tiller stage). Post-‐emergent treatments were applied with and without a surfactant and were not watered in.

Current Findings The trial location has significant crabgrass pressure and plots that did not receive a pre-‐emergent application became heavily infested with crabgrass. Early post-‐emergent applications showed definite signs of injury on the crabgrass but the crabgrass was not completely controlled. Addition of non-‐ionic surfactant appeared to improve the control, although the differences were not statistically significant. Late post-‐emergent applications also resulted in crabgrass injury but the crabgrass was able to rebound. At no point did the post-‐emergent applications provide significantly better control compared to the untreated plots (Table 2). All pre-‐emergent timings were effective at controlling crabgrass throughout the spring and early summer and often provided significantly better control compared to post-‐emergent and untreated treatments. However, toward the end of June, crabgrass began to break through in all pre-‐emergent treatment timings also and differences in control were no longer consistently significant. This suggests that during a favorable year for crabgrass, as 2011 has been, none of these application timings will always provide 100% control. Perhaps a higher rate or multiple applications could be evaluated in future research. None of the application timings caused injury on the ‘Quickstand’ bermudagrass.

32

Table 1. Treatments include five different application timings of ‘Specticle’ applied in 2011. Treatment Product Rate Transformed

Dosage App. Code

Timing

1 Untreated -- -- 2 Specticle 6.5 oz/A 35 g ai/ha A Early Pre (March 24th) 3 Specticle 6.5 oz/A 35 g ai/ha B Normal Pre (April 14th) 4 Specticle 6.5 oz/A 35 g ai/ha C Late Pre (May 5th) 5 Specticle 6.5 oz/A 35 g ai/ha D Early Post ( May 26th) 6 Specticle 6.5 oz/A 35 g ai/ha E Late Post (June 24th) 7 Specticle + NIS* 6.5 oz/A 35 g ai/ha D Early Post ( May 26th) 8 Specticle + NIS 6.5 oz/A 35 g ai/ha E Late Post (June 24th) * NIS -Non-ionic surfactant applied at 0.25 % V/V Table 2. Percent crabgrass infestation over time as influenced by Specticle application timing.

% Crabgrass # Treatment Rate Unit App 5/4/2011 5/18/2011 6/1/2011 6/15/2011 6/30/2011

1 Untreated 0 a* 0.5 c 4.5 a 7.3 abc 35 ab 2 Specticle 6.5 OZ/A A 0 a 0 c 0 b 0 c 5.8 c 3 Specticle 6.5 OZ/A B 0 a 0 c 0 b 0 c 12.5 bc 4 Specticle 6.5 OZ/A C 0 a 0 c 0 b 0 c 12.5 bc 5 Specticle 6.5 OZ/A D 0 a** 4.3 a 7.3 a 9.3 ab 23.5 abc 6 Specticle 6.5 OZ/A E 0 a 2 b 6 a 13.8 a 40.3 a 7 Specticle 6.5 OZ/A D 0 a 1.3 bc 3.5 ab 5.3 bc 9 bc

NIS 0.25 % v/v D 8 Specticle 6.5 OZ/A E 0 a 1 bc 5.5 a 12 ab 50 a

NIS 0.25 % v/v E LSD (P=.05) 0 1.3 4.3 8.1 26.88 Standard Deviation 0 0.9 2.93 5.51 18.27 * 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 yet occurred.

33 Spring and Fall Pre-Emergent Applications of Specticle for Crabgrass Control

Xi Xiong & Dan Lloyd

Summary The objective of this trial is to determine the most effective timings to use ‘Specticle’ (indaziflam) for pre-‐emergent crabgrass (Digitaria spp.) control in ‘Quickstand’ bermudagrass (Cynodon dactylon) (Table 1). Additionally, this trial evaluates the integration of ‘Ronstar’ (oxidiazon) and ‘Specticle’ in a program for season-‐long weed control. This trial includes fall application timings for ‘Specticle’ in addition to traditional spring applications. If the fall timing proves to be effective for control of summer annual grasses, this timing could have an added benefit for turf managers since winter annuals would also be suppressed. This trial is located on ‘Quickstand’ bermudagrass with a history of both smooth and large crabgrass infestation. Treatments began on November 22nd, 2010 with ratings starting in April of 2011.

Current Findings Crabgrass is abundant outside the plot area but inside the trial there is substantially less pressure. All ‘Specticle’ treated plots have provided good crabgrass control for both Fall 2010 (November 22nd) and Spring 2011 (April 14th) application timings (Table 2). There have been minor breakthroughs of smooth crabgrass in some of the plots but no significant differences have been observed among treatments. Fall applications of ‘Specticle’ noticeably limited winter annual weeds while the bermudagrass was dormant although data was not collected on winter annuals. No goosegrass (Eleusine indica) has been observed and none of the treatments have caused any phytotoxicity. Treatments are listed in Table 1 and the pattern of crabgrass emergence is represented by Table 2.

34 Table 1. Treatments included in this multi-year pre-emergent crabgrass trial.

Treatment Product Rate Transformed dosage

App code

Application Timing

1 Untreated --- -- --- 2 Specticle 3.75 oz/A 52.5 g ai/ha A Fall 2010 3 Specticle 3.75 oz/A 52.5 g ai/ha B Spring 2011 4 Specticle 3.75 oz/A 52.5 g ai/ha AC Fall 2010/2011 5 Specticle 3.75 oz/A 52.5 g ai/ha BD Spring 2010/2011 6

Specticle 3.75 oz/A 52.5 g ai/ha ABC

D Spring + Fall 2010/2011 7 Specticle 3.75 oz/A

+ 2.5 oz/A 52.5 g ai/ha + 35 g ai/ha

AC BD

Fall 2010 + Fall 2011

8 Specticle + Ronstar

3.75 oz/A + 3 lb ai / A

52.5 g ai/ha + 3366 g ai/ha

AC BD

Fall 2010/2011 + Spring 2010/2011

9 Ronstar 3 lb ai / A 3366 g ai/ha BD Spring 2011 10 Ronstar 3 lb ai / A 3366 g ai/ha BD Spring 2010/2011 11 Barricade 0.75 lb/ A 546 g ai/ha BD Spring 2010/2011 Table 2. Percent crabgrass at individual rating dates as influenced by various treatments applied in fall 2010 and/or spring 2011. Trt Treatment Rate Appl % Crabgrass No. Name Rate Unit Code 4/13/2011 5/13/2011 6/16/2011 7/4/2011 1 Untreated 0 a* 0.3 a 1 a 2 a 2 Specticle 3.75 oz/a A 0 a 0 a 0 a 0 a 3 Specticle 3.75 oz/a B 0 a** 0 a 0 a 0.3 a 4 Specticle 3.75 oz/a AC*** 0 a 0 a 0 a 0 a 5 Specticle 3.75 oz/a BD 0 a 0 a 0.3 a 2 a 6 Specticle 3.75 oz/a ABCD 0 a 0 a 0 a 0 a 7 Specticle 3.75 oz/a AC 0 a 0 a 0 a 0 a Specticle 2.5 oz/a BD 8 Specticle 3.75 oz/a AC 0 a 0 a 0 a 0 a Ronstar 3 lb ai/a BD 9 Ronstar 3 lb ai/a B 0 a 0 a 0.3 a 2.7 a 10 Ronstar 3 lb ai/a BD 0 a 0.7 a 2 a 4.3 a 11 Barricade 0.75 lb/a BD 0 a 0 a 0.7 a 1 a

LSD (P=.05) 0 0.68 1.4 3.61 Standard Deviation 0 0.4 0.82 2.12 * Means followed by the same letters within a column are not significantly different based on LSD

test at p=0.05 level. ** Numbers grayed out indicate readings that are not relevant because treatment had not occurred. *** Letters grayed out indicates application timings that have not taken place

35 Use of PGRs on Putting Greens to Suppress Annual Bluegrass (Poa annua L.) Seedheads

John Haguewood, Steve Song, Reid J. Smeda and Xi Xiong

Summary

Annual bluegrass (Poa annua L.) is a serious weed problem on creeping bentgrass (Agrostis stolonifera L.) putting greens. In addition to color and texture differences compared to creeping bentgrass, Poa is also a prolific seed producer. Individual plants can produce up to 2,200 seeds in one growing season. Seedheads on a putting surface disrupt ball roll, affect green speed, reduce green aesthetics, and add viable seeds to the seed bank. Plant growth regulators (PGRs) such as trinexapac- ethyl (Primo Maxx®), ethephon (Proxy®) and mefluidide (Embark®), have been used to suppress the seedheads on putting greens. However, there is limited data available on the comparison of single versus sequential applications of single PGRs or mixtures for season-long suppression of Poa seedheads. This study evaluated different PGRs and their combinations as single or sequential applications for seedhead suppression at two golf courses. The locations included Columbia and Moberly, MO with the Columbia location on a “Cato/Crenshaw”, and the Moberly location on “Penncross” creeping bentgrass putting green. Both locations had soil-based style greens with sand incorporation through aerification and topdressing. The experimental design at each location was a completely randomized block with four replications. Plots measured 5 ft x 10 ft with 1-ft borders. Initial PGR application was on March 21st using a CO2-pressurized backpack sprayer that delivered 44 gal/acre at ~40 psi using XR8004 flat-fan spray tips. The second application was made to half (5ft x 5 ft) of the plot 2 weeks later. Initial timing was determined by field scouting, and treatments were applied prior to visualization of annual bluegrass seedheads. Using a base temperature of 50 F, growing degree days were 50 at the initial application timing. The first seedheads in the plots were observed on April 11th. Turf quality and phytotoxicity was recorded weekly by visual assessment on a 1-9 scale. With this scale, 9 represents healthy turf with no phytotoxicity, while 1 represents brown turf in the entire plot area; 6 represents minimally acceptable turf quality and phytotoxicity. Phytotoxicity caused by PGR applications, is the stunting and yellowing to the creeping bentgrass. Quantitative data on the extent of “greenness” in the plot area was generated by NDVI (normalized difference vegetation index) readings, which were recorded on a weekly basis. Percent coverage of annual bluegrass in each plot was estimated weekly; seedhead suppression was evaluated by counting seedheads in three, random 1×1 ft2 grids in each plot. The three ratings were averaged for each plot and total of 12 weeks’ ratings were collected up to this point in spring of 2011.

Results None of the treatments resulted in unacceptable creeping bentgrass quality (rating below 6),

although minor turf injury was noted 1 to 2 weeks following applications (Table 1). For Poa, PGR treatments significantly reduced seedhead formation compared to the untreated control by May 10 (Table 1). Proxy alone reduced seedheads by ~67% and ̴78% compared to the untreated control when applied one or two times, respectively. When Proxy was combined with Primo, seedhead suppression for single or sequential applications improved to ~85% and ~79%. Embark suppression of Poa seedheads was the poorest, about 53 and ~66% after one or two applications compared to the untreated control, respectively. Additional data on seedhead formation are being collected through the fall.

36 Table 1. Seedhead suppression data include means from two locations at the peak of Poa seedhead production (May 10th). Turf phytotoxicity data are means from two locations, two weeks after the 2nd application. Means followed by the same letter are not significantly different using Fishers Protected LSD (p≤0.05) (Duncan’s multiple range test). Treatment # of

Apps Rate (fl oz/1000 ft2)

Rate (kg ai/ha-1)

Avg # seed/ft2

% seedhead suppression

Turf phytotoxicity

Untreated ----- ----- ----- 97.89 a ----- 9.00 a

Proxy 1 5 3.8 32.59 b 66.7 9.00 a

Proxy 2 5 3.8 21.31 b 78.2 8.87 ab

Proxy + Primo 1 5 + 0.125 3.8 + 0.05

14.28 b 85.4 8.75 ab

Proxy + Primo 2 5 + 0.125 3.8 + 0.05

20.50 b 79.1 8.50 b

Embark 1 .68 .07 46.06 b 52.9 8.75 ab

Embark 2 .68 .07 33.38 b 65.9 7.50 c

37 Evaluating Dormant Herbicide Application Timings for Winter Weed Control on Zoysiagrass

Dan Lloyd and Xi Xiong Summary Treating winter-‐dormant zoysiagrass (Zoysia spp.) with non-‐selective herbicides is common practice in the transition zone to eradicate winter annual weeds prior to spring green-‐up. Timing for this application is important to effectively remove weeds without causing phytotoxicity or delaying zoysiagrass spring green-‐up. Repeated applications of glyphosate over multiple seasons have resulted in selection of glyphosate-‐resistant weed populations, for example annual bluegrass (Poa annua L.). Therefore, this study was conducted to determine the ideal timing for dormant applications on zoysiagrass turf by using ‘Roundup’ (glyphosate) at the 16 oz/A rate and ‘Finale’ (glufosinate), another non-‐selective herbicide, at two rates (3 and 6 QT/A). Field plots were established in both Columbia, MO and Carbondale, IL. Application timing of application and herbicides were arranged randomly with four replications and repeated over two years. Application timings are described as early dormant (soil temperature ≤ 42oF), late dormant (soil temperature ≤ 48 oF), stolon green-‐up (soil temperature ≤ 60 oF), and 50% leaf green-‐up (soil temperature ≤ 66 oF). Results Results indicate that once zoysiagrass stolons began to green-‐up and soil temperatures reached 60 oF, applications caused substantial injury and delayed green-‐up up to four weeks (Fig. 2). Zoysia injury was minimal when treatments were applied at soil temperatures less than 50 oF (Fig.1). Glufosinate caused less damage to zoysia than glyphosate approaching 50 oF. Weed control was less effective at the early dormant stage when soil temperatures were below 45 oF, since only 58% of weed populations were existed at that time. The best timing for both herbicides was at late dormant stage, when the four inch soil temperatures were at 48 degrees F. No significant differences were found in weed control by using glyphosate or glufosinate. Table 1. Treatments included in this trial, only non-‐selective herbicides are included in data. Trt # Treatment Rate Rate Unit Transformed Unit Code Description

1 Untreated 2 Finale 3 qt/a 842 g ai/ha A dormant 3 Finale 6 qt/a 1684 g ai/ha A dormant 4 Finale 3 qt/a 842 g ai/ha B later dormant 5 Finale 6 qt/a 1684 g ai/ha B later dormant 6 Finale 3 qt/a 842 g ai/ha B later dormant Celcius 4.9 oz wt/a 233.4 g ai/ha B later dormant

7 Celcius 4.9 oz/a 233.4 g ai/ha B later dormant 8 Finale 3 qt/a 842 g ai/ha C stolon greenup 9 Finale 6 qt/a 1684 g ai/ha C stolon greenup

10 Roundup 16 oz/a 561 g ai/ha A dormant 11 Roundup 16 oz/a 561 g ai/ha B later dornmant 12 Roundup 16 oz/a 561 g ai/ha C stolon greenup 13 Roundup 16 oz/a 561 g ai/ha D 50 % leaf greenup 14 Finale 3 qt/a 842 g ai/ha D 50 % leaf greenup 15 Finale 6 qt/a 1684 g ai/ha D 50 % leaf greenup

38

Figure 1. Zoysia green-up as related to the early application timings (A= completely dormant, 42 oF soil temperature; B= later dormant, 48 oF soil temperature)

Figure 2. Zoysia green-up as related to the later application timings (C= stolon green-up 60 oF soil temperature; D= 50 % leaf green up, 66 oF soil temperature)

0

10

20

30

40

50

60

70

80

90

100

% Zoysia Green up

Rating Date

Zoysia Green-up - Timing A and B 1 -‐ Untreated

2-‐ Finale low A

3-‐ Finale high A

4-‐ Finale low B

5-‐ Finale high B

0

10

20

30

40

50

60

70

80

90

100

% Zoysia Green up

Rating Date

Zoysia Green-up - Timing C and D 1 -‐ Untreated

8-‐ Finale low C

9-‐ Finale high C

12-‐ Roundup C

39

Control of Zoysiagrass Large Patch Disease Using Mustard Seed Meal

Kehua Wang, James English, Carl Sams, and Xi Xiong

Summary Zoysiagrass (Zoysia japonica) is widely used on golf course fairways and tees in Missouri. Large patch, caused by Rhizoctonia solani AG-‐2, is a major and destructive disease for zoysiagrass in the state and worldwide. Multiple applications of fungicide in the fall and spring are often required to minimize damage caused by this disease. Such repeated applications are not only costly, but they increase the risk of selecting fungicide-‐resistant populations. Alternatively, mustard (Brassica spp) seed meal (MSM), a byproduct of mustard seed oil extraction process, has been reported to provide suppression of several soil borne pathogens, including some Rhizoctonia species. MSM contains glucosinolates, which are converted by the enzyme myrosinase into toxic or biocidal isothiocyanates in the presence of water. The objective of the study was to examine the effectiveness of MSM on R. solani isolated from infested zoysiagrass via laboratory in vitro experiments and a greenhouse trial. Current Findings In laboratory experiments, addition of MSM powder to the surface of V8 juice agar growth medium suppressed the growth of R. solani for 5 and 8( to match table?) days at rates of 210 and 1680 kg ha-‐1, respectively (Table 1). By comparison, R. solani resumed growth 1 or 2 days after inoculation in non-‐amended control plates and plates amended with Heritage® fungicide (azoxystrobin) at label rate. Residual MSM effects were evaluated by inoculating plates with R. solani 4 days after addition of powdered material. In these experiments, fungal mycelial growth at 840 kg ha-‐1 was less than 50% of growth of non-‐treated control growth medium. Fungal mycelia inoculated to growth medium amended with 1680 kg ha-‐1 MSM never resumed growth. In greenhouse studies, MSM at all application rates provided significant control of large patch. Optimal control of tiller death from R. solani inoculation at 3 weeks occurred on plants treated with75% autoclaved MSM powder at 1680 kg ha-‐1 applied biweekly (Table 2). These initial experiments suggest that MSM is a promising material for control of large patch disease of zoysiagrass. Further studies under field conditions are being conducted. Table1. Relationship of MSM application rate to suppression of R. solani growth onset and subsequent mycelial growth. Suppression period Mycelial growth rates (mm)ζ Treatment (days) Day0 Day1 Day2 Day3 Day4 Control 1 a 0 2.4 a 8.1 b 18.2 ab 31.1 b§ MSM 210 5 b 0 2.9 a 12.1 a 22.5 a 36.0 a MSM 420 5 b 0 1.5 b 8.0 b 17.1 b 29.8 b MSM 840 6 b 0 0.3 c 2.2 c 6.1 c 12.9 c MSM 1680 8 c 0 0.0 c 0.0 c 0.0 d 0.0 d Heritage® 2 a N/A N/A N/A N/A N/A ζ Inoculum was added to the growing medium 4 days after the mustard seed meal (MSM) treatments were added

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

40 Table 2. Influence of of MSM on tiller death of zoysiagrass inoculated in the greeenhouse with R. solani and plant growth parameters.

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

Protective treatments: MSM at 1680 kg/ha original powder (1680P), 1680 kg/ha 75% autoclaved powder (1680P-75%), 840 kg/ha original powder (840P), 1680 kg/ha liquid extract of 75% autoclaved powder (1680L-75%), and 840 kg/ha liquid extract of 75% autoclaved powder (840L-75%)

Number of Died-back Tillers Protective Treatment

week1 week3 week4 week5 week6 week7 week8 No MSM 0 48.4 a§ 17 a 10 a 3.2 a 1.4 0.8 Heritage® .4oz/M 0 6.6 c 2.6 de 1.4 de 0.4 b 0 0 1680P -biweekly 0 6.8 c 7.6 bc 3.6 cd 1.4 b 1.2 1 1680P-75% biweekly 0 4.6 cd 4.8 cd 2.6 cde 1.4 b 0.4 0.8 840P weekly 0 8.6 c 9.2 b 4.2 bc 1 b 1 0.2 1680L -75% biweekly 0 8.2 c 16.8 a 6.4 b 1.4 b 1 0.8 840L-75% biweekly 0 24.4 b 15.2 a 5.2 bc 1.2 b 1.2 0.2 Control 0 0 d 0 e 0 e 0 b 0 0 Clipping (g) Biomass (g) week1 week3 week5 week7 week8 No MSM 0.45 0.16 d 0.20 de 0.21 c 2.54 c Heritage® .4oz/M 0.45 0.33 b 0.44 b 0.38 ab 4.15 a 1680P -biweekly 0.41 0.24 c 0.33 cd 0.27 c 2.45 c 1680P-75% biweekly 0.41 0.27 c 0.43 b 0.43 a 2.93 bc 840P weekly 0.46 0.28 bc 0.38 bc 0.38 ab 3.11 b 1680L -75% biweekly 0.45 0.28 bc 0.25 de 0.29 c 2.66 bc 840L-75% biweekly 0.45 0.25 c 0.27 de 0.27 bc 2.72 bc Control 0.40 0.41 a 0.55 a 0.46 a 4.06 a

41

Re-evaluating Primo Maxx Application Intervals on Creeping Bentgrass Putting Greens

Dan Lloyd

Summary The Primo Maxx (Trinexapec Ethyl) label states that turfgrass growth will be suppressed by 50% and results will last roughly four weeks applied at the label rate. Although this is accurate in most instances, on creeping bentgrass (agrostis stolonifera) putting greens most superintendents that use Primo Maxx do not expect four weeks growth suppression and generally reapply after two weeks. Previous research recently performed at the University of Wisconsin suggests using a growing degree day model to determine the ideal application interval since the rate of primo metabolism in the plant is temperature dependent. Growing degree days accumulate over time based on daily average temperatures until a certain number is reached, which in this case will signal that it is time for another application. After each application the model resets and growing degree days start accumulating from zero. Wisconsin researchers, Soldat and Kreuser, found that by reapplying every 200 growing degree days on their Celsius based scale (0 degree base temperature), suppression is maintained near 15-‐20% without the undesirable growth surge during the rebound phase. They also found that color and quality were improved when the 2x rate of primo (0.250 oz/1000 ft2) was applied every 200 GDD, although growth suppression was the same at the higher rate. Their research also suggests that poa annua is suppressed at a greater magnitude compared to creeping bentgrass from consistent 200 GDD applications of Primo Maxx, but then if allowed to enter the rebound phase (>250 GDD), it grows at an even faster rate compared to creeping bentgrass.

We are following up on this research at the University of Missouri with the following

objectives: 1) How does a two week interval compare to a 200 GDD interval in terms of growth

suppression and color/quality? 2) How is lateral growth / recovery influenced by consistent growth suppression? 3) What is the growth response of a Missouri biotype of poa annua and how does it

compete with bentgrass? 4) When temperatures get consistently above 90 degrees F in mid-‐summer, is it

better to continue on with reapplications or to give the greens a break from Primo Maxx.

To answer these questions we are collecting clippings 2-‐3 times per week, rating color and quality weekly, measuring growth of poa annua by inserting a 6 inch plug in the center of each plot, and determining recovery rate by cutting cup cutter size holes and filling them with sand and measuring how quickly they are filled in. Treatments and ratings began on June 3rd and will continue throughout the season. At the time of writing there is limited data to present although the creeping bentgrass is clearly maintaining a high quality standard while the poa annua appears to be slightly discolored and stunted. These same results have been observed in multiple golf courses in mid-‐Missouri that are also following the 200 GDD model. Our treatment list is as follows:

42

Table 1. Two rates and four application intervals of Primo Maxx are included in the treatment list for this trial. Treatment Product Rate Reapplication Interval 1 Primo Maxx 0.125 oz/1000

ft2 200 Growing Degree Days (GDD)

2 Primo Maxx 0.250 oz/1000 ft2

200 GDD


2 weeks


2 weeks


800 GDD


800 GDD


200 GDD (Then stop treatments in mid-‐July)


200 GDD (Then stop treatments in mid-‐July)

9 Untreated

43

Seeding with ʻImprelisʼ to prevent weeds

Dan Lloyd and Xi Xiong Summary Imprelis (aminocyclopyrachlor) is a newly released herbicide with several advantages over other products, one of which is its safety on seedlings. Imprelis is one of the few products available for use during seeding. This trial was set up to compare weed control efficacy, turf quality, and seedling density among several herbicides including Imprelis, Tenacity (mesotrione), and Trimec (2,4-‐D, dicamba, MCPP). Instead of tilling the area, Finale (glufosinate) was sprayed on the plot area two weeks prior to seeding to kill the existing vegetation, and then the plots were mowed at one inch and verticut in two directions to simulate a no-‐till renovation project. Tall fescue (Festuca arundinacea) seed was broadcast at the rate of 8 lbs/1000 ft2 on June 2nd and raked into the slits left by the verticutter. All treatments were applied at three timings: a) prior to seedling emergence, b) 7 days after emergence (DAE), and c) 14 DAE. Another group of treatments were also included on an adjacent plot that had not been sprayed with the non-‐selective Finale, these treatments included Roundup (glyphosate) and Imprelis mixed and were applied at the same three timings.

Observations Summer annual and perennial weeds quickly established themselves in the plot area including smooth crabgrass (Digitaria Spp.), yellow nutsedge (Cyperus esculentus), and Virginia buttonweed (Diodia virginiana). All treatments provided significantly greater control on broadleaf weed species compared to the untreated control (Table 2). None of the treatments caused phytotoxicity on the fescue seedlings. Imprelis stunted existing crabgrass and had some pre-‐emergent efficacy, although it did not provide complete control. Averaged across timings, Imprelis provided 47% control on smooth crabgrass, compared to 50% and 0% control from Tenacity and Trimec Classic averaged across timings, respectively. Tenacity applied 0 DAE was the most effective treatment, providing 90% control of crabgrass and 98% control of Virginia buttonweed. During this trial, applications made 7 and 14 DAE allowed to weed species too much time before treatment and they quickly crowded out the seedlings. Even once the weeds were eventually eradicated in some plots, the competition early on was enough to diminish the stand of tall fescue. Trimec Classic and granular Imprelis did not provide acceptable weed control for a summer seeding, although ratings are still being collected. Future research will evaluate these same treatments in fall and spring to determine if results change with different species of weeds. Table 1. Products and rates applied at three different timings; 0, 7, and 14 days after seedling emergence.

Treatment Product Rate Rate Unit Application Timing 1 Imprelis™ 0.103 fl oz/1000 ft2 0 DAE 2 Imprelis™ + 0.103 fl oz/1000 ft2 0 DAE

Roundup 11 fl oz/a 0 DAE 3 Granular Imprelis 200 lb/a 0 DAE 4 Trimec Classic 1.47 fl oz/1000 ft2 0 DAE 5 Tenacity 5 fl oz/a 0 DAE 6 Imprelis™ 0.103 fl oz/1000 ft2 7 DAE 7 Imprelis™ + 0.103 fl oz/1000 ft2 7 DAE

Roundup 11 fl oz/a 7 DAE 8 Granular Imprelis 200 lb/a 7 DAE 9 Trimec Classic 1.47 fl oz/1000 ft2 7 DAE

44

10 Tenacity 5 fl oz/a 7 DAE 11 Imprelis™ 0.103 fl oz/1000 ft2 14 DAE 12 Imprelis™ + 0.103 fl oz/1000 ft2 14 DAE

Roundup 11 fl oz/a 14 DAE 13 Granular Imprelis 200 lb/a 14 DAE 14 Trimec Classic 1.47 fl oz/1000 ft2 14 DAE 15 Tenacity 5 fl oz/a 14 DAE 16 Untreated -- -- --

Table 2. Percent crabgrass, Virginia buttonweed, and turf cover 30 days after seeding as influenced by treatment.

Trt. No Treatment name Rate Unit

app code

Crabgrass Va. Buttonweed Turf cover ---------------- (%) 30 DAS ----------------

1 Imprelis™ 0.103 fl oz/1000 ft2 A 30 cd* 0 c 60 bc

2 Imprelis™ + 0.103 fl oz/1000 ft2 A 3.8 e 0 c 55 bc

Roundup 11 fl oz/a A 3 Granular Imprelis 200 lb/a A 60 ab 2.5 c 30 def

4 Trimec Classic 1.47 fl oz/1000 ft2 A 75 a 3.8 c 21.3 ef

5 Tenacity 5 fl oz/a A 4.3 e 0.5 c 95.5 a

6 Imprelis™ 0.103 fl oz/1000 ft2 B 30 cd 2 c 51.3 bcd

7 Imprelis™ + 0.103 fl oz/1000 ft2 B 1.3 e 0 c 50 bcd

Roundup 11 fl oz/a B 8 Granular Imprelis 200 lb/a B 61.3 ab 6.3 c 17.5 f

9 Trimec Classic 1.47 fl oz/1000 ft2 B 48.8 bc 0 c 41.3 cde

10 Tenacity 5 fl oz/a B 35 cd 2.5 c 55 bc

11 Imprelis™ 0.103 fl oz/1000 ft2 C 20 de 0 c 70 b

12 Imprelis™ + 0.103 fl oz/1000 ft2 C 0 e 0 c 42.5 cde

Roundup 11 fl oz/a C 13 Granular Imprelis 200 lb/a C 60 ab 16.3 b 26.3 ef

14 Trimec Classic 1.47 fl oz/1000 ft2 C 45 bc 0 c 52.5 bc

15 Tenacity 5 fl oz/a C 36.3 cd 0 c 57.5 bc 16 Untreated 50 bc 26.3 a 23.8 ef

LSD (P=.05) 23.36 7.3 22.06

Standard Deviation 16.34 5.11 15.44 * Means followed by the same letters within a column are not significantly different based on LSD test at p=0.05 level

45

Evaluation of Selective Herbicides for Bermudagrass (Cynodon dactylon (L.) Pers.) Control in Zoysiagrass (Zoysia japonica Steud.) Fairways

Enzhan Song, Dan Lloyd and Xi Xiong Summary Bermudagrass and zoysiagrass are important warm-‐season grasses in tropic, sub-‐tropic and transition areas. In Missouri, the majority of golf course fairways are populated with zoysiagrass due to its superior cold tolerance and an ability to support the golf ball above the grass canopy. However, when zoysia turf is weakened by disease or open areas are created by divots, bermudagrass (primarily common bermudagrass) may encroach. Mixed stands of bermudagrass and zoysiagrass often result in unacceptable turf quality, due to the texture and color differences between the two species. When growing out of place, bermudagrass is considered the world’s second worst weed. It is difficult to control with herbicides; glyphosate alone at 5 quarts/A often requires repeated application. Therefore, when bermudagrass infests zoysiagrass, total renovation is often necessary to eliminate bermudagrass completely. Greenhouse studies conducted in 2010 have selected few promising herbicides. The objectives of this multi-‐year project are to evaluate the promising herbicides under field conditions. This study was conducted on the 9th. fairway of The Falls Golf Club in O’ Fallon, MO, 2010. Treatments were designed in a Randomized Complete Block arrangement with 4 replications, and each plot was measured with 5 by 10 feet. Re-‐application was conducted when bermudagrass in the treated area reached 30% or greater regrowth on average. Turf quality were rated using a 1 to 9 scale, where 1 means total death and 9 means best turf quality. All plots received a consistent turf quality rating of 7.5 initially. Percentage of bermudagrass encroachment and zoysiagrass injury were measured using a 0 to 100% reading scale, where 0% means no bermudagrass exist or no injury on zoysiagrass was evident, and 100% means total bermudagrass occupation or death of all zoysiagrass. Chlorophyll index was also measured by a GreenSeeker®, with NDVI readings ranging from 0 to 1, where a higher number represents healthier turf.

Current findings After 5 applications in 2010, our results showed that treatments with fluazifop + triclopyr (Fusilade® II+Turflon® Ester) or fenoxaprop + triclopyr (Acclaim® Extra+Turflon® Ester) resulted in greater than 90% of bermudagrass control. Acclaim® Extra+Turflon® Ester treatments showed a rapid effect by yellowing and stunting the bermudagrass within 7 days after the first application. However, Fusilade II + Turflon Ester achieved the same suppression following the second application. For the two treatments, no phytotoxicity was observed on zoysiagrass, and the treatment with Fusilade II also consistently produced the highest turf quality at 7.5 throughout the entire growing season. After the year-‐long study, treatments with Fusilade and Acclaim maintained 90% or greater bermudagrass suppression (Figure 1). Although treatments with mesotrione (Tenacity®) achieved up to 80% Bermudagrass control following the first 2 or 3 applications in 2010, bermudagrass regrowth was significantly higher at the beginning of 2011, compared to other treatments. In the plots that received a tank mixture of Tenacity and Fusilade, more than 100% regrowth of bermudagrass was observed. Additionally, treatments containing Tenacity showed unacceptable injury to zoysiagrass and 20 to 50% of zoysiagrass in the treated area exhibited yellowing and stunting for approximately 4 weeks. Currently, this research is ongoing at The Falls Golf Club and the MU turf research center.

46

Table 1. Treatments list Trts #

Common name

Brand name Rates (fl oz/a or oz/a)

Active ingredient rates(kg a.i./ha)

Application dates (2010)

1 Fenoxaprop+ Triclopyr

Acclaim® Extra+ Turflon® Ester(low)

28 + 6.5 0.14+0.23 6/9, 6/30, 7/21, 8/5, 8/18

2 Fenoxaprop+ Triclopyr

Acclaim® Extra+ Turflon® Ester(high)

24 + 24 0.12+0.85 6/9, 6/30, 7/21, 8/5, 8/18

3 Fluazifop+ Triclopyr

Fusilade® II + Turflon® Ester

5.1 + 28.5 0.09+1.0 6/9, 6/30, 7/21, 8/5, 8/18

4 Mesotrione+ Fluazifop

Tenacity® + Fusilade® II

5 + 5.1 0.175+0.09 6/9, 6/30, 7/21, 8/5, 8/18

5 Mesotrione+ Fenoxaprop

Tenacity® + Acclaim® Extra

5 + 28 0.175+0.14 6/9, 6/30, 7/21, 8/5, 8/18

Figure 1. Comparison of changes in bermudagrass coverage (%) prior to initial application of treatments in 2010 and 2011.

Note: Negative percentage means an increase of bermudagrass coverage, where bermudagrass reduction percentage represents positive results. Mean bars titled by the same letters are not significantly different at P ≤ 0.05.

a

ab ab

bc

d

cd

-120

-100

-80

-60

-40

-20

0

20

40

60

80

Acclaim Extra + Tur8lon

Ester(low)

Acclaim Extra + Tur8lon

Ester(high)

Fusilade II + Tur8lon Ester

Tenacity + Fusilade II

Tenacity + Acclaim Extra

Untreated

Perc

enta

ge o

f Ber

mud

agra

ss R

educ

tion

47

Investigation of Bermudagrass (Cynodon dactylon (L.) Pers.) Tolerance to AOPP herbicide Fenoxaprop-p-ethyl

Enzhan Song, Dan Lloyd and Xi Xiong

Summary Fenoxaprop-‐p-‐ethyl (Acclaim Extra®) is a promising herbicide for selective control of bermudagrass in zoysiagrass (Zoysia japonica Steud.) turf. Acclaim Extra belongs to the aryloxyphenoxypropionic herbicide group (AOPP), which inhibits a crucial enzyme (acetyl coenzyme A carboxylase) in the fatty acid biosynthetic pathway of sensitive species, and consequently stop the building of membrane systems required for cell growth. However, the bermudagrass control effects varied between different studies, and the tolerance of different bermudagrass varieties is unclear. The objective of this research was to investigate chemical tolerance of six commonly used bermudagrass cultivars to the AOPP herbicide Acclaim Extra. Six bermudagrass cultivars, Princess 77, Celebration, NuMexSahara, Quickstand, Riviera and Yukon, were established in the greenhouse by plugs or seeds in 6 inch diameter pots, and were treated after plants reached full coverage. Research was conducted in greenhouses at the University of Missouri in 2010 with a Randomized Complete Block design and 4 replications. Treatments included an untreated control and Acclaim Extra at 40.1 fl oz/a (0.2 kg a.i./ha). Turf quality was rated using a 1 to 9 scale, where 1 means total death and 9 means best turf quality. Percentage of bermudagrass injury was measured using a 0 to 100% reading scale, where 0 means no injury, and 100 means total death. Chlorophyll index was also measured by GreenSeeker®, with NDVI readings ranging from 0 to 1, where a higher number represents healthier turf.

Current Findings Current results show that Quickstand had the lowest initial injury (30%) at 9 days after treatment (DAT), with recovery starting 2 weeks after treatments (WAT). Also, the final injury was lower than 10% by 8 WAT (Figure 1). Yukon and Riviera appeared to be the second most tolerant cultivars. Although they received up to 50% injury 9 DAT, recovery started around 17 DAT and injury was reduced to 20% 5 weeks later (Figure 1). Celebration and Princess 77 had the lowest tolerance, with up to 80 and 60% injury, respectively in the first 4 and 3 weeks following treatment. Injury remained above 40% through 8 WAT for both cultivars. NuMex Sahara also displayed greater than 70% injury by 3 WAT, and the injury remained greater than 30% by 8 WAT (Figure 1). Weekly clipping biomass also correlated with plant injury results. Yukon, Quickstand and Riviera had significantly higher shoot growth rates compared to the other three cultivars in the first 4 weeks (Table 1). Although NuMexSahara, Princess 77 and Celebration started to produce significantly more clippings in the later stages (5 to 8 WAT), their average weekly clipping production were still significantly lower than Yukon, Quickstand and Riviera (Table 1). Root biomass harvested at the end of this research also showed that Quickstand, Riviera and Yukon exhibited the greatest root growth, where Princess 77 root growth was significantly lower (Figure 2).

48

In summary, Quickstand, Riviera and Yukon appeared to be the most tolerant cultivars to fenoxaprop-‐p-‐ethyl in this research. Celebration, NuMexSahara and Princess 77 were the most sensitive to fenoxaprop-‐p-‐ethyl. This research may improve the ability of golf course superintendants to determine the selective removal of bermudagrass using fenoxaprop-‐p-‐ethyl.

Table 1. Weekly clipping dry mass of six bermudagrass varieties expressed as a percentage (%) over the untreated control after treatment with fenoxaprop-p-ethyl applied at 0.2 kg a.i. ha-1 rate.

†0%–100% score, where 100 = equal shoot biomass production to the untreated control group, 0 = no biomass. ‡Means should be compared separately for early and late stages. Means followed by the same letters or numbers within the same column or row for each data set are not significantly different at P ≤ 0.05.

Clipping percentage production† per week

-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐Early Stage-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐Late Stage-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐

Cultivars 1 wat 2 wat 3 wat 4 wat 5 wat 6 wat 7 wat 8 wat

-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐100% -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ Celebration 0a1‡ 0a1 14.35a1 11.93a1 39.19a1 32.1a1 41.67a1 39.66a1

Princess 77 0a1 4.12a1 16.68a1 10.84a1 48.99ab12 35.72a1 59.43ac2 76.62b3

Sahara 0a1 3.7a1 27.37a2 13.86a12 43.56ab1 60.05bc1 62.26ab1 58.45ab1

Riviera 5.39ab1 18.05ab1 64.12b2 63.33c2 66.36b1 78.5bc1 69.78b1 76.46b1

Yukon 19.89b1 6.03a1 52.73b2 50.3bc2 41.46a1 97.73c2 152.35d3 165.05c3

Quickstand 70.69c1 36.6b2 50.21b2 34.61b2 37.42a1 78.68bc2 115.48c3 121.12c3

49

Figure 1. Percent injury (%) of six bermudagrass cultivars in response to fenoxaprop application within 8 WAT.

Figure 2. Root biomass dry weight (g) 8 weeks after treatment.

0

10

20

30

40

50

60

70

80

90 Bermuda Cultivar Injury%

Celebration

Princess 77

Quickstand

Riviera

Sahara

Yukon

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

1

Root biomass

Celebration Princess 77 Quickstand Riviera Sahara Yukon

50

Tenacity for Renovation


Summary This trial demonstrates the use of Tenacity (mesotrione) for newly seeded tall fescue (Festuca arundinacea) at the rate of 8 lbs/1000 ft2. Tenacity is one of few available herbicides safe for use while seeding. Tenacity, Drive XLR8 (quinclorac), and Tupersan (siduron) are included in this trial to control weed contamination in newly seeded areas. Three seeding timings are planned for this study, the first run was seeded May 20th, the second run was seeded July 6th, and the third run will be seeded in August. Tenacity and Tupersan were applied at the time of seeding and reapplied 28 days after emergence on only half of each plot. Drive is applied only once per run 28 days after emergence.

Current Findings Plots that did not get an application with seeding quickly became dominated by summer weeds including yellow nutsedge (Cyperus esculentus), smooth crabgrass (Digitaria spp.), and Virginia buttonweed (Diodia virginiana). Both Tupersan and Tenacity were effective controlling Virginia buttonweed and smooth crabgrass but only Tenacity controlled yellow nutsedge. Tenacity provided 100%, 98% and 85% control of Viginia buttonweed, yellow nutsedge and smooth crabgrass, respectively. Tupersan provided 100% and 65% control of Virginia buttonweed and crabgrass, respectively, but did not prevent yellow nutsedge from quickly dominating localized patches of the plot area. Neither Tupersan nor Tenacity inhibited tall fescue seed germination. Drive XLR8 worked well after application but by 28 days after seed emergence, the seedlings had been severely out competed by the weeds thus producing a week stand of tall fescue. Tenacity at seeding with a second application 28 days after emergence is the best option included in this trial for the May 20th seeding. The post-‐emergent split application of Tupersan was ineffective and is only effectively used as a pre-‐emergent product. Data is still being collected and will likely provide data for different weeds that are more prominent later in the summer. Table 1. Treatments included in this trial, 28 DAE treatments of Tenacity and Tupersan are applied as a split plot application to only half of each plot.

Trt Treatment Rate Appl Appl Adjuvant No. Name Rate Unit Code Description

1 Tenacity 5 fl oz/a AB May 20th + 28d 2 Tenacity 5 fl oz/a CD July 6th + 28d 3 Tenacity 5 fl oz/a EF August + 28d 4 Tupersan 4 lb/a AB May 20th + 28d 5 Tupersan 4 lb/a CD July 6th + 28d 6 Tupersan 4 lb/a EF August+ 28d 7 Drive XLR8 64 fl oz/a B 28 DAE –run 1 +MSO 8 Drive XLR8 64 fl oz/a D 28 DAE –run 2 +MSO 9 Drive XLR8 64 fl oz/a F 28 DAE –run 3 +MSO

10 Untreated May 20th seeding 11 Untreated July 6th seeding 12 Untreated August seeding

51

Evaluation of Brown Patch Control with Fungicides on Creeping Bentgrass.


Summary Brown patch is caused by the pathogen Rhizoctonia solani, which can infect many cool-‐ season grasses during the hot summer months and continue into early September. Brown patch symptoms appear as a foliar blight affecting circular or irregularly shaped patches, and may appear different depending on turfgrass species and mowing heights. When the pathogen is active during hot and humid weather, a dark purplish or gray border of mycelium called a “smoke ring” may surround affected areas. In this trial an array of fungicides were evaluated on a preventative basis to control brown patch throughout the summer. Treatments include Velista (penthiopyrad), Insignia (pyraclostrobin), and Daconil Ultrex (chlorothalonil) applied on 14-‐day intervals.

Current Findings All treatments were initiated and applied preventatively on May 16. Brown patch pressure wasn’t observed until July 5, where (<10 %) disease incidence was observed. Due to low disease pressure thus far in the study, no statistical differences have been found compared to the untreated control. Although brown patch is the main disease focus in this study, a large infestation of dollar spot was observed within all plots. Plots treated with Velista and Insignia showed an increase in turf quality compared to the untreated control and Daconil Ultrex. Dollar spot severity was also reduced by June 20 for all treated plots compared to the untreated control. All treatments in this trial provided acceptable control of dollar spot, however Velista at (0.5 oz/1000 ft2) tended to provide better dollar spot suppression. Ratings are ongoing and will continue throughout the season.

Treatment Rate Application Interval Application Dates For all Treatments

Untreated

Velista 0.3 oz/1000 ft2 14 days

Velista 0.5 oz/1000 ft2 14 days Insignia 0.54 fl oz/1000 ft2 14 days

Daconil Ultrex 3.25 oz/1000 ft2 14 days

May 16 May 30 June 13 June 27 July 11 July 25

52

Evaluation Of Headway G For Control Of Dollar Spot And Brown Patch On Kentucky Bluegrass


Summary The focus of this trial is the evaluation of a granular fungicide for controlling dollar spot and brown patch in Kentucky bluegrass lawns. Dollar spot is a common and persistent disease caused by Sclerotinia homoeocarpa that can infest many warm and cool–season grasses from early spring to fall. Brown patch, caused by Rhizoctonia solani, is also a common disease that damages many cool-‐season grasses during the summer months when there is extended periods of hot weather and high humidity. Additional research is also evaluating Headway G (azoxystrobin +propoconizole) for control of brown patch in tall fescue. This study focuses on Kentucky bluegrass, which is susceptible to both dollar spot and brown patch throughout the season.

Current Findings A preventative application of Headway G was applied on May 11 before the onset of disease. Dollar spot and brown patch inoculum were applied to each plot on May 31 and June 29, respectively. Dollar spot and brown patch symptoms were first noted in plots on 6 July. Plots treated with Headway G showed significant increases in turf quality compared to the untreated control plots. Disease pressure is currently moderate, and weekly ratings will continue to evaluate Headway G for disease control throughout the rest of the season.

Treatments Rate Application Interval Application Date 1. Untreated 2. Headway G 4 lbs/1000 ft2 28 days May 11

June 8 July 6

53

Evaluation of Alternative Management Practices for Spring Dead Spot Control on Bermudagrass.

Derek Cottrill & Lee Miller Research Summary Spring dead spot is a major disease limiting bermudagrass performance on sports fields and golf course fairways in Missouri. Spring dead spot is difficult to control because the pathogen is located in the soil, and infection occurs in the fall before symptoms are observed in the spring. Past research in the SE United States has demonstrated different nitrogen sources suppress spring dead spot development. The mechanism is unknown, but in other pathosystems lowering rhizosphere pH has a suppressive effect on soil borne turfgrass pathogens. This study will investigate the impact of summer applications of different nitrogen sources and sulfur, and fall preventative fungicide applications on curative spring dead spot control. Each treatment will be evaluated individually as well as in combination. Fertilizer treatments will be applied once a month in June, July, and August and include urea (46-‐0-‐0), UMaxx (47-‐0-‐0), UFlexx (46-‐0-‐0), ammonium sulfate (21-‐0-‐0), and calcium nitrate (15.5-‐0-‐0) at 1 lb N/1000 sq ft2. Sulfur treatments will be applied at 2 lb/1000 sq ft2 in the summer to “heavy-‐handedly” attempt to lower bulk soil pH. Two applications of Rubigan along with another to-‐be-‐determined fungicide will be applied in the fall. All applications will be watered-‐in with 0.25” of irrigation to deliver materials to the root zone and lessen any potential phytotoxic side effects. Evaluation of disease control will begin in the spring of 2012. Digital image analysis will be utilized to determine the curative efficacy of each treatment.

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No Sulfur

No Fungicide

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CaNO3 (15.5-0-0) TBD

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2011 field day cover - university of missouri · 2011 turfgrass & ornamental field day july...

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