MANAGING SUMMER DECLINE in Creeping Bentgrass Greens
ARE FREEDOM LAWNS ENVIRONMENTALLY RESPONSIBLE?
SMOOTH CRABGRASS CONTROL in Tall Fescue with Commercial Products
Without MSMA...
the Fate of Field Paspalum Control
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CONTENTS 08
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• Summer 2011
TURF TALK Without MSMA… the Fate of Field Paspalum Control
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FEATURE STORY Are Freedom Lawns Environmentally Responsible?
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APPLIED RESEARCH Smooth Crabgrass Control in Tall Fescue with Commercial Products
DEPARTMENTS 06 PRESIDENT’S MESSAGE 25 MEMBERSHIP APPLICATION
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MTC TURF NEWS
30 UNIVERSITY OF MD TURF TEAM
30 CALENDAR OF EVENTS 30 ADVERTISERS INDEX
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GREEN LIGHT ON GOLF Managing Summer Decline in Creeping Bentgrass Greens
MARYLAND TURFGRASS COUNCIL 12 Pressie Lane | Churchville, MD 21028 (240) 413-4312 | www.mdturfcouncil.org MTC Turf News is published quarterly for the MTC by: Leading Edge Communications, LLC 206 Bridge St. Franklin, TN 37064 615-790-3718 ( phone) 615-794-4524 (fax) info@leadingedge communications.com
2011 BOARD OF DIRECTORS PRESIDENT
Bob Shumate Calvert Co. Parks & Rec. Prince Frederick, MD 410-535-1600, ext 2225 410-610-9007 (cell) shumatrr@co.cal.md.us Bill Warpinski Central Sod Farms Centreville, MD 800-866-1387 410-827-5000 billw@centralsod.com
TWO YEAR DIRECTORS
Vernon W. Cooper All States Turf Consultant St. Michaels, MD 410-745-9643 (office) 443-742-6618 (cell) vernon@allstatesturf.com
Randall Pinckney Manor Country Club Rockville, MD 301-929-1707 240-286-1989 (cell) rpinckney@mail.manorcc.org
VICE PRESIDENT
Jamie Roell Anne Arundel Co. Rec. & Parks Millersville, MD 410-222-6250 443-370-2582 (cell) rproel09@aacounty.org
Lester Dubs Pasadena, MD 443-623-1745 (cell) ldubs@verizon.net
SECRETARY/TREASURER Cheryl A. Gaultney Churchville, MD 410-836-2876 (home) 410-322-8275 (cell) sandqueen10@aol.com
PAST PRESIDENT Nick Gammill American University W. Hyattsville, MD 202-885-2340 (office) 202-498-8020 (cell) ngammill@american.edu
EXECUTIVE DIRECTOR Michelle LoConte Montgomery Village, MD 301-990-0196 (office) 240-597-1420 (fax) mdturfcouncil@verizon.net
THREE YEAR DIRECTORS Harry Kenney Agrium Advanced Technologies Ellicott City, MD 800-235-6138 410-375-6148 (cell) hkenney@agriumat.com
OPEN
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ONE-YEAR DIRECTORS Rick LaNore MRW Lawns, Inc. LaPlata, MD 301-870-3411 (office) 301-609-1852 (cell) rick127928@rocketmail.com Bill Patton, Sr. Turf Center Lawns Spencerville, MD 301-384-9300 (office) 301-980-3094 (cell) turfcenterlawns@yahoo.com Kevin Monaco Turf Equip & Supply Jessup, MD 20794 410-799-5575 (office) 443-250-1182 (cell) kevinmonaco@turfequipment.com
SUMMER 2011
5
PRESIDENT’S MESSAGE
WHAT A SPRING, and What We Accomplished! hat a spring we have had!! Back in March, the owner of a lawncare company called me to ask, “What the heck is going on? Why am I having to treat dandelions way before I am even thinking of applying pre-emergent herbicides for summer annual grass control? This certainly is not a normal spring.” Hmmm… a “normal” spring. I am not sure I remember or even know what a normal spring is anymore. I have been working in turfgrass for 37 years and cannot remember two springs being the same. We have all chosen to live and work here in the center of the “transition zone” where our climate is not fit for any grass to grow without professional help, which keeps us all in business. I still remember the first two sentences uttered at the beginning of my first turfgrass class at the University of Maryland many years ago. Dr. Jack Hall started the class by saying, “If you can professionally manage turfgrass in Maryland for five years and keep your job, you can work anywhere in the United States.” He also commented, “The best grass in Maryland is green concrete.” Thank goodness we have such a dedicated group of professionals who are determined to make turfgrass not only survive but flourish. Not only are we constantly battling Mother Nature, but we often have to battle the knuckleheads in Annapolis and the federal EPA — both think turfgrass is the root of all evil and is the cause for the ruination of the Chesapeake Bay. I am not convinced they all think turfgrass is this ultimate polluter. I think some are just lazy and think turfgrass is an easy target because it is made up of a bunch of little companies running around competing with each other. Little did they know that these little companies have a big umbrella watching over them, and that umbrella is called the MTC. This legislative year, Delegates Hubbard, Babe and Clagett and Delegates Braveboy, Frush, Penna-Melnyk, Wood and Glenn decided to sponsor The Fertilizer Use Act (HB 573). This was part of the answer to the EPA to show that Maryland was making strides to meet the EPA’s arbitrary standards for nitrogen and phosphorus loads entering the Chesapeake Bay. I say arbitrary because neither the EPA’s standards nor the proposed Maryland legislation were based upon sound scientific bases but instead were being driven mostly by politics. Fortunately, organizations like RISE and the MTC follow legislation that will affect any of our members. A special thanks must go out to Mark Schlossberg (a former MTC president), Rick LaNore (also a former MTC president and a
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MTC TURF NEWS
current board member) and others who spent hours and days testifying before legislative committees, meeting with individual state Senators and Delegates, sending emails to keep us all informed and leading letter-writing, email and phone campaigns, all in order to develop legislation with some semblance of common sense. The essence of this legislation is probably best explained by Mark Schlossberg, president of Pro-LawnPlus, Inc./M.A.G.I. (MD Assoc. of Green Industries, Inc.), in an email after the last session of the General Assembly on April 11, 2011: The Fertilizer Use Act was passed tonight in the Maryland General Assembly on the final day of the session as HB 573. Though this bill will cost our industry some money and change the way we do business somewhat, I feel like the adjustments we have to make will not jeopardize our businesses and golf courses. And the fact that we now will have fertilizer pre-emption means that we won’t have to worry about local jurisdictions making their own fertilizer laws. We were able to get the final date for fall N and P applications extended to December 1st. We’ll still be able to apply K and limestone between
December 1st and March 1st. We were able to get allowances for controlled-release nitrogen at higher rates and an exemption for organic fertilizer P applications. From my understanding of the bills, the certification/training portion will take effect in October 2012, and the date restrictions will not take place until the fall of 2013. I will get more clarification and details from the Department over the next few weeks, and I’m sure this will be discussed in the training sessions UMD puts on in the fall and winter. One final note: one of the reasons we supported this legislation was that we as an industry wanted to get the message out to some of our allies — like the farm community, soil-conservation people and the general public — that we are willing to do our part. We might not feel that the changes required in the bill will help the Bay. Now, though, we will be able to say that we are willing to contribute to the reduction of N and P output. I want to thank everyone who came to Annapolis for meetings, called and emailed legislators, acquiesced on issues that they really didn’t want to, etc. I feel our support of this legislation will help us immensely in the future when there are bills introduced that we oppose. I guess time will tell. Fortunately, the enforcement of this legislation will be the Department of Agriculture, which with the University of Maryland must develop a training and certification program for “certified applicators.” The MTC will work with the Department of Agriculture to develop and present as much information as possible at our January Turfgrass Conference. Stand by — more is to come!
Vernon W. Cooper MTC President
SUMMER 2011
7
TURF TALK
By Peter H. Dernoeden, Ph.D., and Christopher P. Ryan, Dept. of Plant Science and Landscape Architecture, University of Maryland
ield or smooth paspalum (Paspalum laeve Michx.) is an increasing weed problem in turfgrass sites in Maryland. Field paspalum is a warm-season perennial that has a bunch-type growth habit, but plants may develop one or two short (1.5 to 2.0 cm) rhizomes. Vernation is folded, and foliage is typically grayish green or yellow green. Leaves and sheaths are hairy and have a short (1.0 to 2.0 mm) membranous ligule. Paspalum rapidly spreads by seed. Seedheads appear in late summer (usually September), and spikelets are formed opposite on the inflorescence. Seeds are distinctly disk shaped (i.e., round, with flat sides).
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MTC TURF NEWS
This species often is confused with dallisgrass (P. dilatatum Poir.), which is not as commonly found as field paspalum as far north as Maryland. The distribution of dallisgrass in Maryland has not been assessed in recent years, but it is believed to be now more commonplace than previously reported.
The new control problem Since the 1960s, monosodium and disodium methanearsonates (MSMA and DSMA) have been used on turf to control field paspalum, dallisgrass and crabgrass (Digitaria spp.). MSMA and DSMA are organic forms of arsenic that are relatively non-toxic
and are considered less toxic than aspirin. (Inorganic forms of arsenic, like calcium arsenate, are highly toxic and were banned from use on turf several decades ago.) DSMA was withdrawn from the market several years ago. On December 31, 2010, the EPA cancelled registration of MSMA use for residential, commercial and sports turf maintenance. Existing stocks of MSMA, however, may be used legally on residential, commercial and sports fields until December 31, 2013. Sale of all products containing MSMA for use on golf courses, sod farms and highway right-of-ways will end on December 31, 2012, and use of existing
stocks on golf courses after December 31, 2013, will be prohibited. The EPA also has restricted the use of MSMA to spot applications, and other restrictions apply (U.S. EPA, 2009). MSMA and DSMA were the only known effective and selective herbicides for use on many cool-season grasses for control of dallisgrass, field paspalum and other Paspalum spp. Hence, new herbicides need to be identified for controlling these turfinvading Paspalum spp.
Photo 1. Field paspalum is a warm-season perennial bunchgrass.
Our research The search for alternative herbicides for control of field paspalum began at the University of Maryland Paint Branch Turfgrass Research Facility in College Park in 2009. We conducted three separate field studies in 2009 and 2010. In 2009, we assessed Fusilade II T&O (fluazifop-P), Segment (sethoxydim) and Round-up (gylphosate) in an unimproved site of perennial ryegrass and Kentucky bluegrass. In 2010, we evaluated Fusilade II, Velocity (bispyribac-sodium), Dismiss (sulfentrazone) and Certainty (sulfosulfuron) in a mature stand of tall fescue (Festuca arundinacea). Also in 2010, we assessed Tenacity (mesotrione) and Tupersan (siduron) as preemergence treatments in springseeded stands of tall fescue, hard fescue (F. brevipilia) and perennial ryegrass (Lolium perenne). In both 2010 studies, the herbicide treatments were applied for purposes other than targeting field paspalum. Once some level of field paspalum control became evident in the 2010 sites, however, data were collected despite paspalum not being the main target. Herbicides were applied in 50 gallons of water per acre using a CO2 powered (35 psi) backpack sprayer
Photo 2. Field paspalum on a bentgrass tee.
Summary of Key Findings • Fusilade II appears to be an alternative to MSMA for postemergence control of field paspalum in tall fescue turf. • Fusilade II also is known to be safe to use in hard fescue, but more research needs to confirm if other turfgrass species are tolerant of the herbicide. • More research is needed to identify effective Fusilade II label use rates and timings. The Fusilade II label would have to be amended to include Paspalum spp. • Postemergence applications of
Certainty, Dismiss and Velocity alone were ineffective in controlling field paspalum, but a tank mix of Velocity + Dismiss showed some promise. • Preemergence applications of Tenacity and Tupersan to spring seedbeds provided significant reductions of field paspalum development from seed, but many plants did escape. • Certainty was extremely phototoxic to tall fescue and is labeled for selective tall fescue control in Kentucky bluegrass turf.
SUMMER 2011
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TURF TALK • continued
equipped with an 8004E flat fan nozzle. Fusilade II and Tenacity were tankmixed with 0.25% v/v of Activator 90 non-ionic surfactant (NIS) in 2009 and
2010. Rates and dates of application are noted below. Field paspalum cover was assessed visually using a 0% to 100% scale,
where 0 = no paspalum and 100 = entire plot area covered by paspalum. In the 2010 postemergence study, the number of field paspalum plants in each plot also were counted. In the 2010 postemergence study, turf quality was visually assessed using a 0 to 10 scale, where 0 = entire plot area brown/dead and 10 = optimum green color and turf density. Tall fescue injury was assessed once in 2010 using a 0 to 5 scale, where 0 = no injury, 2.5 = objectionable and unacceptable injury and 5 = entire plot was brown/dead.
Our 2009 results
Photo 3. Grayish-green field paspalum in a tall fescue lawn.
Table 1. Postemergence control of field paspalum in an unimproved site in College Park, MD, 2009. Cover
Rate
% field paspalum
% turf
Treatment*
(lb. ai/A)
Aug. 3
Aug. 28
Segment 1L
0.47
6 b**
27 a
Fusilade II T & O 2L
0.375
0c
48 a
Tenacity 4SC + Fusilade II
0.187 + 0.375
0c
67 a
Round-up 3L
0.18
15 b
42 a
Untreated
–
78 a
37 a
** All herbicides were applied on June 10, 2009. ** Means in a column followed by the same letter are not significantly different according to Fisher’s protected LSD, P = 0.05.
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MTC TURF NEWS
On June 10, Fusilade II (0.375 lb. ai/acre), Segment (0.47 lb. ai/A), Tenacity (0.187 lb. ai/A) + Fusilade II (0.375 lb. ai/A) and Round-up (8.0 oz. product/A) were applied to a dense stand of field paspalum growing in a low-maintenance situation. Field paspalum cover was assessed on August 3 (43 days after the herbicides were applied). At that time, no field paspalum (i.e., 100% control) was observed in plots treated with Fusilade II and Tenacity + Fusilade II. Both Segment (6% cover = 92% control) and Roundup (15% cover = 81% — paspalum control) had reduced field populations compared to the control (78% paspalum cover) (see Table 1). Turfgrass cover was estimated on August 28. Turf cover was low throughout the site due to a lack of care and the high population of field paspalum. There were no significant turf cover differences among herbicidetreated plots. It is likely that the relatively dense field paspalum canopy at the time of application intercepted most of the herbicide applied and thus may account for the similarity in turf cover percentages among herbicide and non-herbicide-treated plots.
Our 2010 results In the 2010 postemergence study, Velocity (0.033 and 0.066 lb. ai/A), Dismiss (0.125 lb. ai/A) and Velocity + Dismiss (0.033 + 0.125 lb. ai/A) were applied three times (on May
continued • TURF TALK
27, June 11 and June 23); Certainty (0.023 lb. ai/A) was applied twice on (May 27 and June 11); and Fusilade II (0.375 lb. ai/A) was applied once (on May 27). According to plant count data, Dismiss and the high rate of Velocity reduced the number of field paspalum plants per plot compared to the control, but the low rate of Velocity had no effect (Table 2). The most effective treatments were Fusilade II and Velocity + Dismiss, both of which reduced the field paspalum population 84% compared to the control. When plots were evaluated by estimating field paspalum cover rather than plant counts, only Fusilade II had reduced weed cover compared to the control. The low rate of Velocity (0.033 lb./A) applied three times reduced tall
Photo 4. Field paspalum in unmown hard fescue.
Table 2. Tall fescue quality and injury, and field paspalum control as influenced by herbicides in College Park, MD, 2010. Rate
Injury (0 – 5)
Turf quality (0 – 10)
Sept. 9 Paspalum
No. Applic.* June 10
June 23
July 6
July 12
Aug. 5
Sept. 9
July 6
plants/ plot
% cover
3
8.0 a**
7.6 a
5.6 c
6.0 ab
7.0 a
6.8 b
2.8 c
55.3 ab
14.0 ab
0.066
3
7.0 bc
6.1 c
4.1 d
4.8 c
5.4 b
6.6 b
3.8 b
29.5 bcd
9.0 bc
Dismiss 4F
0.125
3
7.5 ab
7.3 a
6.9 ab
6.3 ab
7.0 a
7.1 b
1.1 de
27.8 cd
9.0 bc
Velocity + Dismiss
0.033 + 0.125
3
7.5 ab
7.2 ab
5.6 c
5.7 bc
7.0 a
7.0 b
2.8 c
11.3 d
4.3 bc
Certainty 75DG
0.023
2
6.4 c
4.6 d
1.0 e
1.3 d
1.5 c
2.0 c
4.9 a
57.2 abc
20.5 a
Fusilade II T&O 2L
0.375
1
5.6 d
6.3 bc
6.5 b
6.0 ab
7.3 a
8.0 a
2.0 cd
11.0 d
1.8 c
Untreated
—
—
8.0 a
8.0 a
7.5 a
6.8 a
6.9 a
6.7 b
0.8 e
68.5 a
12.0 ab
Treatment
(lb. ai/A)
Velocity 17.6SG
0.033
Velocity 17.6SG
**Treatments were applied 3 times on May 27, June 11 and June 23; twice on May 27 and June 11; and once on May 27, 2010. **Means in a column followed by the same letter are not significantly different according to Fisher’s LSD, P ≤ 0.05.
SUMMER 2011
11
TURF TALK • continued
fescue quality on July 6, but the high rate of Velocity (0.066 lb. ai/A) reduced quality from June 23 until data collection ended on September
9 (Table 2). The single application of Fusilade II reduced tall fescue quality from June 10 to July 12. Certainty was applied twice and almost completely
Photo 5. Field paspalum spreads readily by seed.
eliminated the tall fescue, while Dismiss (applied three times) did not injure the tall fescue. Certainty is labeled for the purpose of selectively controlling tall fescue in Kentucky bluegrass. Thus, death of most of the tall fescue plants in Certaintytreated plots came as no surprise. In the preemergence 2010 study, the site was first treated with Round-up (glyphosate) on April 5, and then separate blocks were disk-seeded with tall fescue, perennial ryegrass and hard fescue on April 6. Tenacity was applied once at 0.50 lb. ai/A on April 12 or twice at 0.125, 0.156, 0.187 and 0.25 lb. ai/A on April 12 and May 12 (mixed with 0.25% v/v NIS on May 12 only). Tupersan was applied once at 12 lb. ai/A or twice at 6.0 lb. ai/A on April 12 and May 12. Data were collected on September 9, and all treatments generally provided a statistically equivalent level of field paspalum control (Table 3). For Tenacity-treated tall fescue and
Table 3. Field paspalum cover in three spring-seeded turfgrass species in College Park, MD, 2010. Rate
% field paspalum cover on Sept. 9, 2010
Herbicide*
(lb. ai/A)
TF
PRG
HF
Tenacity 4SC
0.50
11 b**
16 b
50 b
Tenacity 4SC
0.125 + 0.125
11 b
18 b
48 b
Tenacity 4SC
0.156 + 0.156
6b
17 b
45 bc
Tenacity 4SC
0.187 + 0.187
8b
16 b
26 bcd
Tenacity 4SC
0.25 + 0.25
2b
10 b
22 cd
Tupersan 50WP
12.0
<1 b
4b
5d
Tupersan 50 WP
6.0 + 6.0
1b
6b
5d
Untreated
—
54 a
66 a
79 a
** Treatments were applied on April 12, and sequentials were applied on May 12, 2010. There were three separate stands of tall fescue (TF), perennial ryegrass (PRG) and hard fescue (HF). ** Means in a column followed by the same letter are not significantly different according to Fisher’s LSD, P ≤ 0.05.
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MTC TURF NEWS
Fusilade II may be a viable alternative to MSMA for postemergence control of field paspalum in tall fescue, but it has limitations. perennial ryegrass plots, control ranged from 73% to 94%, and 91% to 98% control in the Tupersan-treated plots. The hard fescue developed more slowly and thus was more heavily colonized by field paspalum. In hard fescue, field paspalum cover ranged from 22% to 50% in Tenacitytreated plots, whereas only 5% field paspalum cover (94% control) was observed in Tupersan-treated hard fescue. This may be the first report of preemergence control of field paspalum at spring seeding in coolseason turf with any herbicide.
Conclusions Fusilade II may be a viable alternative to MSMA for postemergence control of field paspalum in tall fescue, but it has limitations. Interestingly, Dr. Jim Brosnsan (at The University of Tennessee) reported in 2010 that Fusilade II applied just one time in early spring at 0.09 lb. ai/A (5.6 fl. oz. product/A) provided 90% dallisgrass control. Conversely, when Fusilade II was applied in early summer, the level of dallisgrass control was poor. The Fusilade II label is somewhat vague on how to use this herbicide. The label simply states that Fusliade II is to be used for the suppression and/or control of common bermudagrass, hybrid bermudagrass and other grass weeds in zoysiagrass and tall fescue. It is not for use on home lawns. There is no mention of any paspalum species being a target weed on the
SUMMER 2011
13
TURF TALK • continued
It is important to note that the effectiveness of Tenacity and Tupersan in controlling field paspalum preemergence from seed in mature turfgrass stands is unknown. Fusilade II label. The label also states that the application rate for Fusilade II to tall fescue “should be” 5 to 6 oz. product/A. The label further states that tall fescue may be injured but should recover in 10 to 14 days. In these studies, Fusilade II was applied at 24 oz. product/A (i.e., 0.375 lb. ai/A), which is four times the high label use rate for tall fescue. No injury was noted in the unimproved site (mostly Kentucky bluegrass and perennial ryegrass) with Fusilade II and
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MTC TURF NEWS
other herbicides. This was attributed to the tall, dense field paspalum canopy, which likely intercepted most of the herbicide before it could reach the underlying turf. It was observed, however, that this very high rate of Fusilade II injured tall fescue in the 2010 study for a period of about 35 to 40 days, but the turf eventually recovered. The injury took the form of browning and stunting of leaves, as well as some thinning of the tall fescue stand. In unrelated UM studies, it was
found that hard fescue showed no signs of injury from the same high Fusilade II rate used in this study. Results from the 2010 study also suggest that the mix of Velocity + Dismiss is another candidate for future study. This mix also reduced tall fescue quality for about 30 days. Hence, future research needs to focus on lower use rates and perhaps more frequent applications of these herbicides to maximize their effectiveness while minimizing injury to tall fescue. Another key finding was that Tenacity and Tupersan reduced field paspalum populations significantly when applied preemergence to springseeded stands of tall fescue, perennial ryegrass and hard fescue. Many field paspalum seedlings, however, escaped and were problematic in the springseeded stands. The level of control was poorest in hard fescue. This was attributed to the slower development of hard fescue, which did not compete as effectively with field paspalum as did the more rapidly developing tall fescue and perennial ryegrass seedlings. Numerically, lowest field paspalum cover ratings were observed in Tupersan-treated plots. Regardless, it would be helpful to use either Tupersan or Tenacity in the seedbed when renovating turfs that were previously contaminated by field paspalum. It is important to note that the effectiveness of Tenacity and Tupersan in controlling field paspalum preemergence from seed in mature turfgrass stands is unknown. In unrelated UM studies, however, it is been well established that Tenacity and Tupersan generally perform poorly in controlling crabgrass (Digitaria spp) preemergence in mature turf stands, and thus, it is likely that this would be also true of field paspalum. •
APPLIED RESEARCH
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MTC TURF NEWS
Are
Freedom Lawns
Environmentally Responsible? By Erik Ervin, Ph.D., Associate Professor of Turfgrass Culture & Physiology, Crop and Soil Environmental Sciences Department, Virginia Tech
any Mid-Atlantic residents live within the Chesapeake Bay Watershed and have a home lawn. Many are also aware that Bay health remains impaired due to excess nitrogen (N) and phosphorus (P) and sediment loading from the daily activities required in our densely populated society. These pollutants come from many sources, including sewage-treatment plants, city streets, development sites, agricultural operations and deposition from the air. Do nutrient pollutants come from home lawns? Lawn fertilizer contains N and P, so it is easy to jump to the conclusion that they do. Many who value the environmental and economic health of the Bay have come to this conclusion, leading them to advocate something called the Freedom Lawn. What is a Freedom Lawn? The basic concept is to take any existing lawn and continue only one cultural practice: periodic mowing. All other practices are to be discontinued: no fertilizer, no pesticides and no irrigation. The homeowner is then free to pursue other interests, free from the added costs of these inputs and free to proclaim to interested neighbors that he or she is protecting the water quality of the Chesapeake Bay. But is that so? In what follows, I discuss and present data on how the Freedom Lawn choice may actually result in
M
more potential for degraded Bay water quality.
Let’s review the research What happens when all inputs, except periodic mowing, are removed from lawns? All around us, we see the results in our parks, lawns and school grounds: weeds and open soil areas increase. Ignoring the aesthetic drawbacks, what are the potential waterquality impacts? A recently published study at the University of Minnesota provides some answers. The researchers installed Kentucky bluegrass sod on a silt loam soil with a 5% slope to easily allow runoff collection. To simulate soil compaction resulting from home-building activities, the compaction caused by the bulldozer during laser-leveling was not relieved by tillage prior to sodding. No fertilizer was applied during the first year. In the second year, the following treatments were applied to various plots in this study and continued over years three through five: • No fertilizer • Standard N (3 lbs./1,000 ft2/yr) + no P + standard potassium (K) • Standard N (3 lbs./1,000 ft2/yr) + 1x P (as recommended by soil test) + standard K • Standard N (3 lbs./1,000 ft2/yr) + 3x P (as recommended by soil test) + standard K
SUMMER 2011
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APPLIED RESEARCH â&#x20AC;˘ continued
Fertilizer treatments were applied in 1/3 equal increments in May, September and October of each year, based on standard lawn fertilization guidelines from Minnesota Cooperative Extension. These guidelines closely match those of Virginia Cooperative Extension. No irrigation was used on these lawn plots. The initial soil test P level was 25 ppm; this level is in the sufficiency range, so the testing lab recommended little to no P for normal lawn maintenance. What happened? By year three, the no-fertilizer plots had greatly reduced turf density, greater weed density, more exposed soil and more dead grass/weed tissue than the N fertilized plots. Adding P at a 1x or 3x rate did not improve turf density relative to applying N-alone. Significantly, total P runoff from the no-fertilizer plots was greatest over the three years of mon-
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MTC TURF NEWS
itoring because of greater runoff depth. That is, more water was lost from the plots that did not receive N fertilizer because of insufficient turf cover to impede flow, especially when the soil surface was frozen. Contained within this runoff water was also a greater load of P bound to soil and leaflitter sediment. Thus, as long as enough N was applied to maintain density and retard weed invasion, less P was lost in runoff, relative to the no-fertilizer control, even when P was applied at 3 times the recommended rate. I do not make this point to justify over-application of P to lawns, but merely to highlight that the controlling factor in reducing P runoff from lawns is turf density. Researchers in New York (a Chesapeake Bay state) have reported similar results. They established an 80% Kentucky bluegrass/20% perennial
ryegrass area from seed on a sandy loam soil with an 8% slope, using various natural organic and synthetic fertilizer treatments. Once the plots were mature (year 2,) results showed that the unfertilized control plots had significantly higher P-mass losses compared to any of the fertilized plots. These losses strongly correlated with less shoot density and lower infiltration rates on the unfertilized control plots. A direct quote is that â&#x20AC;&#x153;as shoot density doubled, the infiltration rate increased, which reduced runoff by three-fold.â&#x20AC;? The highest annual rate of fertilizer N applied in this study was moderate, at 2 lbs./1,000 ft2, but it was enough to ensure adequate turf density and water infiltration. Nitrate-N runoff from the organic or synthetic fertilizer treatments did not differ from the unfertilized control, averaging between 2 to 4.5 ppm, considerably
continued • APPLIED RESEARCH
below the EPA limit for safe drinking water (10 ppm).
Interpreting the research Given these data, what does a Freedom Lawn offer for water quality in the Chesapeake Bay Watershed? The unfertilized control plots in the studies above received only periodic mowing (fitting the definition of a Freedom Lawn), and it took only two or three years for the “Freedom plots” to become greater contributors of P loading via runoff than the areas moderately fertilized with nitrogen. Eleanor Roosevelt is credited with saying that “with freedom comes responsibility.” In my analysis, Freedom Lawns do not embrace their environmental responsibility and, in fact, can fairly rapidly become irresponsible. A more responsible approach heeds the scientific data, recognizes the limitations imposed by urban soil disturbance during development and recommends that we strive for “Sustainable Lawns” by following a set of best management practices (BMPs), with the goal of maintaining lawn surfaces with minimized water-quality impacts.
BMPs for Sustainable Lawns Below are 12 BMPs for Sustainable Lawns throughout the Chesapeake Bay Watershed.
BMP#1: Improve the soil at establishment to reduce compaction and improve infiltration. In new-housing construction, much of the topsoil is removed, and the remaining subsoil is severely compacted. Replacing a shallow topsoil layer prior to grassing is helpful in getting the lawn established, but the underlying soil compaction remains. Subsequently, long term, water infiltration is poor, greatly increasing the possibility of thin turf and off-site movement of nutrients. Thus, prior to topsoil placement, the subsoil should be cleared of all debris and rip-plowed and tilled.
Topsoil can then be distributed and a seedbed prepared. Adding a 1" to 2" layer of quality compost prior to seedbed preparation would also be very beneficial to lawn health and water infiltration over time.
BMP#2: Plant or re-plant best-adapted turfgrass species and varieties. Each year, the turfgrass programs at Virginia Tech and the University of Maryland collaborate to put out a list of recommended turf varieties, based on field evaluations (found here: http://www.pubs.ext.vt.edu/3008/30 08-1456/3008-1456.html). To make the list, each variety must have performed above average at both test sites for at least three years. Each listed variety must also be available as certified seed, ensuring genetic purity and seed quality to the buyer. With adequate establishment, odds are that these varieties will provide greater stress persistence than those not on the list.
BMP#3: Improve the soil after establishment to reduce compaction and improve infiltration. Most homeowners inherit a lawn with compacted soil. Core aeration and compost topdressing can slowly correct compaction. The rolling-drum aerators commonly used or rented, however, pull up cores from only 1% to 3% of the lawn surface area and do not go much deeper than 2". To improve water infiltration and relieve compaction, go over the lawn in two to four directions during moist (not wet) soil conditions, twice a year during periods of active turfgrass growth. If possible, hand-spread and rake in a quality compost applied at 100 lbs./1,000 ft2. The average size of home lawns across Virginia is 5,000 ft2, requiring 500 lbs. of compost for each application. Repeatedly applying organic matter via the compost will build topsoil, bind nutrients and water and promote soil aggregation for improved water infiltration and compaction resistance. Further, it will serve as a natural
organic slow-release fertilizer, providing approximately 1.5 lbs. N/1,000 ft2 each time it is applied. Two compost applications per year would, then, provide all the fertility the lawn requires to remain healthy and dense enough to greatly limit any potential P or N runoff.
BMP#4: Soil test every 1 to 3 years to determine if fertilizer P is needed; use fertilizers with 0% P (e.g., 30-010) if the soil test indicates no need. Binding readily to clay minerals and soil organic matter, phosphorus does not leach. Thus, soil-test P levels change quite slowly in most Virginia soils. With our moderate rainfall, soil pH does fall, but not fast enough to require re-liming more frequently than every two to three years. Soil testing every one to three years, therefore, is adequate to ensure sufficient P availability. If the soil test indicates no P need, then select fertilizers that contain no P.
BMP#5: Implement a moderate fertilizer N program based on Virginia Cooperative Extension and Virginia Department of Conservation and Recreation recommendations. Our research review (above) clearly indicated that not applying N-containing fertilizer is not a responsible choice for pollution prevention. A moderate amount of N per year (1 to 4 lbs. actual N/1,000 ft2) is needed to maintain enough turf cover to impede sediment-bound P loss. Refer to these online sources to guide your N fertilization practices: http://www.pubs. ext.vt.edu/452/452-717/452-717.html and http://www.dcr.virginia.gov/soil and water/documents/tipsstate.pdf. High-use lawns will need N at the 3- to 4-lb. level to push enough growth to ensure adequate cover against runoff. Adequate cover on low-use lawns can be maintained via 1- or 2lb. programs. For added insurance against N runoff or leaching losses, use fertilizers with higher proportions of slow- or
SUMMER 2011
19
APPLIED RESEARCH • continued
controlled-release N sources. Using slow-release sources, including organics, also reduces surge growth, reducing mowing requirements relative to using quick-release N sources.
BMP#6: Do not apply fertilizers to frozen soils. Several studies have noted that 60% to 90% of P-runoff occurs during winter thawing periods when the surface soil is still frozen. Such large runoff events occur because the soils are either frozen or saturated, prohibiting water infiltration and allowing soil- or leaflitter-bound P present in open soil areas to be quickly lost. Applying Pcontaining fertilizers too late (November or December) or too early (February or March) greatly increases the potential of P loading into Bay waters.
BMP#7: Do not apply fertilizer to impervious surfaces; immediately sweep or blow any granules back onto the lawn. Fertilizer, compost, grass clippings and tree leaves all contain nutrients. As such, it is irresponsible to leave any of them on impervious surfaces where they can move unimpeded into storm drains.
BMP#8: Mow high, and follow the 1/3 rule. This BMP is all about maintaining density and high biomass on your lawn: both factors increase water-flow resistance, slowing runoff and increasing infiltration. Mowing turf at the higher end of recommended ranges (3" – 4" for bluegrass and fescue; 1.5" – 2.5" for bermudagrass and zoysiagrass) will accomplish this, while also providing a deeper-rooted, more stresstolerant lawn. Mowing high also means you can mow less frequently without breaking the 1/3 rule. The 1/3 rule is to never remove more than 33% (1/3) of the grass height at one mowing. Repeatedly removing too much at each mowing (e.g., mowing a 5" lawn down to 2" = 60% removal) results in a shal-
20
MTC TURF NEWS
low root system that produces turf thinning and weed invasion. For fescue lawns, not breaking the 1/3 rule means mowing back to a 3" height each time the lawn reaches 4.5".
BMP#9: Leave clippings on the lawn, removing any that reach impervious surfaces. Grass clippings contain 2% to 5% N and about 0.5% P, and they break down quickly, re-releasing these nutrients for root uptake. Clipping return can serve as an organic fertilizer, providing more than 1 lb. N/1,000 ft2/yr. Left on the street, however, these nutrients can quickly move into storm drains to pollute the Bay. If large clipping clumps accumulate, either rake them up and compost them on-site, or mow the lawn in 2-3 directions to disperse them.
BMP#10: Mulch tree leaves into the lawn and clean up any that accumulate on impervious surfaces. Studies at Michigan State, Purdue and Cornell have documented that mulching a 2" to 5" layer of deciduous tree leaves onto cool-season lawns for three to five consecutive autumns had no significant effects on lawn health or vigor. These studies also reported no increases in thatch or undue reduction in soil pH due to this practice. Recycling tree leaves back into your lawn is safer for the environment than piling them on the street and risking the loss of N and P to stormwater runoff. Mowing when the leaves are dry
mulches them much more effectively.
BMP#11: Irrigate only if severe drought persists and threatens to significantly reduce turf cover. Adherence to the first 10 BMPs should result in a fairly deep-rooted lawn that should recover from summer droughts of two to three weeks. Droughts of more than four weeks could result in the loss of some turf cover, especially if there is any traffic on the lawn during drought-dormancy. In this case, lawn cover should be preserved by applying 0.75" to 1" of water per week until rainfall returns.
BMP#12: Use pesticides only when weed, insect or disease levels threaten to significantly thin the lawn; strictly follow label directions. Careful application of the preceding BMPs to ensure a dense, healthy lawn should greatly minimize the need for pesticides. For homeowners who wish to have lawns that are environmentally friendly or more sustainable than what current suburban development gives them, there are two primary choices: take what you are given and improve it by following these 12 BMPs, or start over by improving the soil and establishing a no-mow prairie and herbaceous/woody perennial landscape. Simply stopping all management inputs and calling it a “Freedom Lawn” is easy and cheap, but it may ultimately be irresponsible. •
APPLIED RESEARCH
Controlling Smooth Crabgrass in Tall Fescue with Pre- and Postemergence Commercial Products
By Peter H. Dernoeden, Ph.D., and C. P. Ryan, Dept. of Plant Science and Landscape Architecture, University of Maryland
his field study, which was conducted at the University of Maryland Paint Branch Turfgrass Research Facility in College Park, compared all of the commonly used preemergence herbicides that target smooth crabgrass (Digitaria ischaemum). In addition, corn gluten meal (Espoma Corn Gluten 9-0-0) was assessed and compared to the commercial products. Finally, three postemergence herbicides were applied in late June and compared to the preemergence herbicides and corn gluten meal (CGM).
T
Our research methods The turf was a mature stand of Titan II tall fescue (Festuca arundinacea) and was mowed two times weekly to a height of 2.5 inches. Soil was a Keyport silt loam with a pH of 5.7 and 2.2% organic matter. Rates and dates of product applications are noted in Table 1. The site received rainfall or irrigation within 24 hours of each application. The
22
MTC TURF NEWS
study site was irrigated thereafter to avoid drought stress. Turf color and quality were rated once on May 13 using a 0 to 10 scale, where 0 = entire plot area brown or dead, and 10 = optimum green color and density. Percent of the plot areas covered with smooth crabgrass was assessed visually on a 0% to 100% scale, where 0% = no crabgrass, and 100% = entire plot area covered with smooth crabgrass. Crabgrass ratings less than 5% of plot area covered (subjectively) were considered to have provided commercially acceptable control. Smooth crabgrass pressure was uniform and severe across the site.
About CGM Corn gluten meal, the protein fraction of corn, is a natural herbicide that is used to control crabgrass and other weeds in â&#x20AC;&#x153;organic lawncare programs.â&#x20AC;? Corn gluten was evaluated previously by the University of Maryland (Dernoeden, 2001). In those studies, CGM applied twice per season
reduced crabgrass populations significantly, but it did not provide commercially acceptable control. Single applications of CGM typically provided poor control. The product contains 9% to 10% nitrogen (N) and, as such, also serves as an N fertilizer. The recommended use rate of CGM is 20 lbs. product per 1,000 ft2. Hence, at this rate, a manager is delivering 1.8 to 2.0 lbs. N/1,000 ft2 with a single application. A single spring application of 2.0 lbs. N/1,000 ft2, however, is considered agronomically excessive and wasteful. The sewage sludge Oceangro 5-5-0 fertilizer was entered into the study to determine if this high rate of N (i.e., 2.0 lbs. N/1,000 ft2) from a natural organic fertilizer would impact crabgrass levels at the site. That is, the Oceangro served as a standard for comparing the potential influence of organic N on crabgrass invasiveness in the study site. The levels of N delivered via CGM and Oceangro resulted in excellent turf color and quality (8.8
to 9.4) on May 13 (Table 1). Echelon 0.3G + Fertilizer (about 0.65 lb. N/1,000 ft2) improved color and quality compared to all other treatments, except CGM or Oceangro.
Our research results Due to unusually high temperatures in late March and early April, crabgrass seedlings were observed on April 7, 2010, which was about 8 to 12 days earlier than the usual emergence time. Most germination, however, occurred in June, but some new germination continued to be stimulated by thunderstorms in July and August. Since the site was not allowed to enter a state
of drought dormancy, crabgrass populations were kept in abeyance by the presence of a fairly dense and competitive turf. Smooth crabgrass cover was assessed on July 12 and August 13. In general, crabgrass populations as low as 0.5% (i.e., one half of one percent of the plot area) in early July invariably indicate that the level of crabgrass control will be unacceptable by early August (i.e., ≥120 days since the treatment was initially applied). Only data collected on August 13 will be discussed, but you can make your own judgment of each herbicide’s loss of residual effectiveness (i.e., through
dissipation) based on the July 12 evaluation. Crabgrass cover (i.e., tillering) increases exponentially in late summer in College Park, MD, and mid-August ratings are more likely to identify significant treatment differences. By early September, however, even a single multi-tillered plant can cover 5% of the plot area, which is above the threshold. Crabgrass pressure was considered to be severe compared to most commercial lawn or golf course rough situations. All treatments, including Oceangro, reduced crabgrass levels significantly compared to the untreated control (Table 1). However, the
Table 1. Pre- and postemergence smooth crabgrass control with commercial herbicides, College Park, MD, 2010. Quality
Color
% Crabgrass Cover
Herbicide*
Rate (lb. ai/A)
Timing
May 13
May 13
July 12
Aug. 13
Dimension 2 EW
0.38
Pre
6.8 c***
6.6 e
0.3 c
4.8 d
Dimension 0.21G
0.38
Pre
6.9 c
7.3 d
0.5 c
5.3 d
Echelon 4SC
0.75
Pre
6.9 c
7.4 d
0.0 c
5.5 d
Echelon 0.3G + Fert
0.75
Pre
8.1 b
8.4 c
0.0 c
1.3 d
Barricade 4F
0.75
Pre
6.9 c
7.1 de
0.0 c
0.3 d
Pendulum Aquacap 3.8ME
1.5 + 1.5
Pre
6.6 c
7.1 de
0.0 c
0.6 d
Pendulum Aquacap 3.8ME
3.0
Pre
6.8 c
6.9 de
0.1 c
5.0 d
Team Pro 2G (1992 product)
3.0
Pre
6.8 c
7.1 de
0.0 c
0.9 d
Tenacity 4SC
0.187 + 0.187
Pre
6.5 c
6.9 de
4.9 bc
37.8 b
Corn Glutten
20 lbs./M
Pre
9.4 a
9.4 a
2.6 bc
24.5 bc
Corn Glutten
15 + 15 lbs./M
Pre
9.3 a
9.1 ab
7.0 b
26.5 b
Oceangro 5-5-0
2.0 lbs. N/M
Pre
9.3 a
8.8 bc
7.5 b
39.3 b
**Drive XLRB 1.5SC + MSO
0.75
Post
7.3 bc
6.9 de
0.1 c
9.8 cd
**Acclaim Extra 0.57EW
0.110
Post
7.1 c
7.4 d
0.0 c
5.0 d
**Tenacity 4SC + Activator
0.187 + 0.187
Post
7.4 bc
7.1 de
0.0 c
0.6 d
Untreated
—
—
7.1 c
7.0 de
12.8 a
63.5 a
*** Preemergence (Pre) treatments were applied April 2, and sequential treatments were applied May 18, 2010. *** Postemergence (Post) treatments were applied June 29 (2 to 4 tiller crabgrass); the Tenacity sequential treatment was applied July 13, 2010. *** Means in a column followed by the same letter are not significantly different according to Fisher’s LSD, P ≤ 0.05.
SUMMER 2011
23
APPLIED RESEARCH â&#x20AC;˘ continued
crabgrass populations in plots treated with CGM, Oceangro and Tenacity applied as preemergents was excessive and ranged from 24% to 39% of plot area infested. All other treatments provided a statistically equivalent level of crabgrass control, and most products had provided commercially acceptable control (i.e., less than 5.0% crabgrass cover). This included Team Pro, which was a product that was received in 1992 and stored dry in an open-bag condition for 18 years. The single postemergence application of Drive XLR8 on June 29 was judged to have provided unacceptable control, but data were statistically equivalent to the level of control provided by Acclaim Extra and Tenacity. Good control was provided by Dimension (both formulations) and Echelon (both formulations). Exceptional crabgrass control (i.e., less than
24
MTC TURF NEWS
1.0 crabgrass cover; > 98% control) was provided by Barricade, Pendulum AquaCap (1.5 + 1.5 lbs./A) and Team
Pro applied preemergence, and by Tenacity applied twice postemergence (June 20 and July 13). â&#x20AC;˘
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SUMMER 2011
25
GREEN LIGHT ON GOLF
Managing Summer in a Creeping Decline Bentgrass Green By Peter H. Dernoeden, Ph.D., and C. P. Ryan, Dept. of Plant Science and Landscape Architecture, University of Maryland
revious studies have documented improved summer performance of creeping bentgrass (Agrostis stolonifera) putting greens treated with selected fungicides even in the absence of disease. Chipco Signature, especially when tank-mixed with either Daconil or Fore Rainshield, has been associated with color enhancement and improved cover and quality. Mancozeb was shown to mitigate scalping in “puffy” putting green turf in summer (Dernoeden and Fu, 2008). Other studies have demonstrated the superior ability of spoonfeeding with urea to improve summer quality of putting greens, when compared to biostimulants, chelated iron and micronutrient products (Settle and Dernoeden, 2009). The non-disease-related benefits provided by some fungicides and urea are said to reduce summer decline. Summer decline of creeping bentgrass greens normally occurs in response to high-temperature stress combined with mechanical injury and sometimes
P
26
MTC TURF NEWS
diseases. Additional information regarding summer decline management with other products is warranted. The objective of this study was to assess various fungicides, as well as Super Stimulant (organic peat humates; 6% humic acid) and Nano Argentum (elemental silver in osmotized water applied at 41 ml/acre), applied alone and/or tank-mixed with another compound, for their ability to improve the summer quality of a creeping bentgrass putting green turf. Urea was applied in a spoonfeeding program and served as the standard for comparison.
Our research methods This field study at the University of Maryland Paint Branch Turfgrass Research Facility in College Park was conducted on an 80/20 sand/ sphagnum peat moss (v/v) creeping bentgrass putting green constructed to USGA specifications. The area was a mature stand of ‘Declaration’ creeping bentgrass. The study area was fertilized
with 2.5 lbs. N/1,000 ft2 from mostly 20-20-20 between September 20 and November 11, 2009. The bentgrass received an additional 0.5 lb. N/1,000 ft2 from 20-20-20 in April and May 2010. Thereafter, the study area received no additional nitrogen, except for that provided by the urea spoonfeeding treatment. The turf was mowed five times weekly to a height of 0.150 inches and otherwise was maintained as a putting green. To induce mechanical stress, lower mowing heights were imposed on three dates in July, as described below. During the study period, daytime high temperatures generally exceeded 90ºF, and nighttime temperatures seldom fell below 68ºF. The site was irrigated to prevent drought stress and was syringed as needed. Treatments were applied three times on a two-week interval on June 15, June 29 and July 13, 2010. Turfgrass quality was rated visually on a 0 to 10 scale, where 0 = brown or dead
turf, 8.0 = minimal acceptable quality for a creeping bentgrass putting green, and 10 = optimum greenness, uniformity and density. Color was rated visually on a 0 to 10 scale, where 0 = brown or dead turf, 8 = minimum acceptable color, and 10 = dark green turf. Yellow spot became pronounced the week of July 24 (the cause was unknown, but blue-green algae have been implicated) and was evaluated by counting the number of spots in each plot. Rings caused by Rhizoctonia zeae were counted, and blighting by R. solani was visually assessed on a 0 to 100 scale. The entire site was treated with Insignia (0.9 oz./1,000 ft2) to control the Rhizoctonia diseases on June 29.
Our results — summer quality Treatments were initiated on June 15, 2010. As noted previously, the site was treated with Insignia, which effectively controlled the Rhizoctonia diseases
present in June. Hence, these quality ratings reflect color and uniformity and generally were not impacted by disease. Any residual disease in plots was disregarded in the quality ratings. During the period between June 23 and July 12, the study area was mown to a height of 0.150 inches. Unlike in previous years, the Declaration did not become “puffy,” and there was little mechanical stress during this period. At this time of minimal stress, Fore Rainshield and Signature + Fore Rainshield improved quality compared to the control on all three rating dates (see Table 1). Urea, Chipco Signature alone and Super Stimulant + urea showed improved quality compared to the control by July 12 (i.e., 13 days following the second application of treatments). On July 16, the mowing height was reduced to 0.135 inches and then to 0.125 inches on July 19 and July 20. Plots were double cut on July 19 and July 20, at which time daily air temperatures were in excess of 95ºF.
Table 1. Color and quality of a ‘Declaration’ creeping bentgrass green in summer decline, 2010. Overall quality++
Rate
Color
Fungicide+
(Product/1,000 ft2)
June 23
June 29
July 12
July 20
July 26
July 12
Chipco Signature 80WG
4.0 oz.
7.9 ab‡
6.8 bcd
8.0 bc
6.7 b
5.8 d
7.9 de
Fore Rainshield 80WP
6.0 oz.
8.7 a
7.8 ab
8.4 ab
7.9 a
7.3 bc
8.2 cd
Torque 3.6SC
0.6 oz.
7.4 b
7.4 abc
7.7 cd
6.2 bc
6.4 d
7.5 ef
Urea 46-0-0
0.15 lb. N
8.0 ab
7.1 a-d
8.8 a
8.3 a
8.1 a
8.7 ab
Super Stimulant
6.0 fl. oz.
7.2 b
6.6 cd
7.5 d
5.9 c
5.6 d
7.4 ef
Signature + Fore
4.0 + 6.0 oz.
8.6 a
7.7 ab
8.6 a
7.7 a
7.3 c
8.4 bc
Signature + Torque
4.0 + 3.2 oz.
8.1 ab
8.0 a
7.9 bcd
6.5 bc
5.9 d
7.7 ef
Super Stimulant + Urea
6.0 oz. + 0.15 lb. N
8.1 ab
7.4 abc
8.7 a
6.5 bc
8.1 ab
8.8 a
Nano Argentum
0.032 oz.
7.3 b
6.1 d
7.6 cd
5.9 c
5.8 d
7.7 ef
Untreated
—
7.2 b
6.7 cd
7.5 d
5.9 c
5.7 d
7.5 ef
++
Treatments were applied on June 15, June 29 and July 13, 2010. were mowed to a height of 0.150 inches; mowing height was reduced to 0.135 inches on July 16 and to 0.125 inches on July 19 and July 20, and increased to 0.150 inches on July 22 and thereafter. ‡ Means in a column followed by the same letter are not significantly different according to Fisher’s LSD, 5%.
++ Plots
SUMMER 2011
27
GREEN LIGHT ON GOLF • continued
quality of these plots was acceptable (>8.0) on only one date (July 12). Torque alone, Superstimulant alone and Nano Argentum did not improve quality compared to the untreated control on any rating date. Plots treated with these products exhibited unacceptable quality on July 20 and July 26.
Our results — diseases
This mowing stress resulted in a rapid decline in the quality of plots treated with Signature alone, Torque alone, Signature + Torque, Super Stimulant alone, Nano Argentum and the untreated control. Urea alone had provided good quality (> 8.0) between July 12 and July 26. Fair quality (> 7.0) was provided by Fore Rainshield alone and by Signature + Fore Rainshield in that same time period.
On July 26 (i.e., 4 days after 0.150" mowing was resumed), plots treated with Super Stimulant + urea improved to a rating of 8.1. Only Fore Rainshield alone or tank-mixed with Signature had improved quality on all rating dates. The benefits of urea were not evident until following the second application. Chipco Signature alone improved quality compared to the control on July 12 and July 20, but the
Disease data appear in Table 2. Due to variability in the distribution of R. zeae, R. solani and yellow spot across the study area, there were no significant treatment effects. There was a trend for reduced Rhizoctonia disease with Torque, Signature + Torque, and Fore Rainshield. Yellow spot was enhanced by SuperStimulant applied alone, when compared to the control.
Conclusion This study supports previous investigations demonstrating that urea and Fore Rainshield are powerful tools in improving the summer quality of creeping bentgrass greens. •
Table 2. Rhizoctonia spp. and yellow spot diseases in a ‘Declaration’ creeping bentgrass green with summer decline, 2010. Rate
++
‡
28
Number of R. zeae rings/plot
% R. solani
# of Yellow spots/plot
Fungicide+
(Product/1,000 ft2)
June 23
June 29
June 29
July 12
Chipco Signature 80WG
4.0 oz.
2.8 a‡
6.0 a
3.8 a
3.3 b
Fore Rainshield 80WP
6.0 oz.
0.0 a
2.3 a
0.8 b
2.5 b
Torque 3.6SC
0.6 oz.
0.0 a
1.0 a
0.3 b
4.8 ab
Urea 46-0-0
0.15 lb. N
3.3 a
4.8 a
9.8 a
4.8 ab
Super Stimulant
6.0 fl. oz.
1.5 a
6.0 a
5.5 ab
8.5 a
Signature + Fore
4.0 + 6.0 oz.
0.5 a
4.0 a
3.8 ab
3.8 b
Signature + Torque
4.0 + 3.2 oz.
0.0 a
0.5 a
0.0 b
6.0 ab
Super Stimulant + Urea
6.0 oz. + 0.15 lb. N
1.8 a
3.5 a
6.5 ab
3.5 b
Nano Argentum
0.032 oz. (41 ml/A)
3.5 a
4.5 a
10.8 a
5.3 ab
Untreated
—
2.8 a
7.0 a
4.8 ab
2.3 b
Treatments were applied June 15, June 29 and July 13, 2010. Means in a column followed by the same letter are not significantly different according to Fisher’s LSD, 5%.
MTC TURF NEWS
TURF INDUSTRY CALENDAR OF EVENTS
INDEX OF ADVERTISERS
July 18–22
January 11–13, 2012
TPI Summer Convention & Field Days (Turfgrass Producers International)
Mid-Atlantic Nursery Trade Show
Grand Sierra Resort Reno, NV
Baltimore Convention Center Baltimore, MD
Agrium Advanced Technologies Direct Solutions.......................Inside Front Cover www.agriumat.com
All States Turfgrass Consultants, LLC .............13 BASF .......................................Inside Back Cover www.basf.com
July 19, 2011
January 2012
Buy Sod ............................................................5
MNLA — CPH Specialist Tests (Herbaceous Perennials and Integrated Pest Management)
35th Annual MTC Turfgrass Conference & Trade Show
Capitol Sports Fields ......................................24
Adele H. Stamp Student Union University of Maryland College Park, MD
Collins Wharf Sod Farm.....................................7
Contact: www.mnlaonline.org or 410-823-8684
www.buysod.com www.capitolsportsfields.com www.collinswharfsod.com
CoverSports USA...............................................7 www.coversports.com
East Coast Sod & Seed ...................................29
October 27–29 Green Industry & Equipment Expo
February 10–11, 2012
Kentucky Exposition Center Louisville, KY
Chesapeake Green 2011 — A Horticulture Symposium
January 10–14, 2012
MD Institute of Technology Linthicum, MD
www.eastcoastsod.com
Mid Atlantic Association of Turf Equipment Managers (MAATEM).........................................7 Mid-Atlantic Turf Equipment, LLC ...................14 www.midatlanticturfequipment.com
Oakwood Sod Farm, Inc. .................................13 www.oakwoodsod.com
STMA Annual Conference & Exhibition
Quali-Pro ........................................................21 www.quali-pro.com
Long Beach Convention Center Long Beach, CA
Summit Hall Turf, Inc. ........................Back Cover www.summithall.com
Syngenta Professional Products .....................25 www.syngentaprofessionalproducts.com
The Turfgrass Group....................................3, 15 www.theturfgrassgroup.com
WinField Solutions, LLC...................................13 www.winfieldsolutionsllc.com
Wood Bay Enterprises Inc. ..............................18 www.woodbayturftech.com
UNIVERSITY OF MARYLAND TURFGRASS TEAM Pete Dernoeden, Ph.D.
Tom Turner, Ph.D.
Mark Carroll, Ph.D.
Kevin Mathias, Ph.D.
Dave Funk
Dept. of Agronomy University of Maryland College Park, MD 301-405-1337 pd@umd.edu
Paint Branch Turfgrass Research Facility University of Maryland College Park, MD 301-403-4431 tturner@umd.edu
Dept. of Agronomy University of Maryland College Park, MD 301-405-1339 mcarroll@umd.edu
Institute of Applied Ag. University of Maryland College Park, MD 301-405-4692 jkm@umd.edu
Paint Branch Turfgrass Research Facility University of Maryland College Park, MD 301-403-8195 dfunk@umd.edu
MTC Turf News is the Maryland Turfgrass Council magazine. Subscriptions are complimentary to MTC members. The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, its board of directors, MTC Turf News, or its editors. Likewise, the appearance of advertisers, or their identification as MTC members, does not constitute an endorsement of the products or services featured in any issue of MTC Turf News. Copyright ©2011 by the Maryland Turfgrass Council. MTC Turf News is published quarterly. POSTMASTER: Send change of address notification to Maryland Turfgrass Council: 12 Pressie Lane, Churchville, MD 21028. Postage guaranteed. Presorted standard postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: MTC allows reprinting of material published here. Permission requests should be directed to MTC. We are not responsible for unsolicited freelance manuscripts and photographs. Contact the managing editor for contribution information. Advertising: For display and classified advertising rates and insertions, please contact Leading Edge Communications, LLC, 206 Bridge Street, Franklin, TN 37064, (615) 790-3718, Fax (615) 794-4524.
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