Turfgrass Water Conservation Alliance
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  • GRASSES
    • Qualified
      • Seed
      • Sod
    • Cool-season
      • Fine Fescues
      • Kentucky Bluegrasses
      • Perennial Ryegrasses
      • Tall Fescues
    • Warm-season
      • Bermudagrasses
  • PARTNERS
    • Cooperators
    • Members
      • Industry
      • Producers
        • BrettYoung
        • Pennington
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        • Scotts Miracle-Gro
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        • Vista
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[email protected]

TRIALS

Trialing
TWCA uses peer review of objective data collected through multi-year, multi-site trialing to qualify the most drought tolerant cultivars of each turfgrass species. 
TWCA Qualified cultivars meet or exceed the standard for drought tolerance at all locations across at least two years of trialing. TWCA Qualified products must contain at least seventy percent (70%) TWCA Qualified material to carry the TWCA seal.
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SEED
SOD
members
PRODUCERS

​Perennial Ryegrass Trial

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The 2024 Perennial Ryegrass Trial (24WCLP) is established at all five (5) locations across North America. The final rainout shelter (ROS) is positioned thanks to a herculean effort by Dr. Mike Fidanza, University of Pennsylvania, and Dr. Tyler Carr, The University of Ohio. 
  • Seven hundred twenty (720) sample packets
  • One hundred twenty (120) samples per location
  • One hundred thirteen (113 lb.) pounds seed
  • Sixty-three (63 lb.) pounds entry seed
  • Fifty (50 lb.) pounds border seed
  • Thirty-four (34) experimental entries (85%)
  •  Eighteen (18) named cultivars (45%)
  • Fourteen (14) packages (17.5%)
  • Seven (7) TWCA qualified cultivars seeking re-qualification (17.5%)
  • Six (6) independent breeding programs
  • Six (6) standard entries (15%)
  •  Five (5) independent producers
  •  Four (4) independent research reviewers
  •  Two (2) proposed trialing regimes
  •  One (1) species evaluated
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    120 samples per location

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    5 Independent Locations

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    3 Years of data collection

DOWNLOAD THE 24WCLPnn FAQS

TWCA Partners download pdfs of the trial talking points.
DOWNLOAD
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RESOURCES

Trial Cooperators

TWCA Code
Cooperator
Location
Most Recent Trial
1
Derr
​Virginia Tech
20WCFAnn
2
Hignight
NexGen Plant Science Center
20WCFAnn
3
Bigelow
Purdue University
20WCFAnn
4
Langlois
​NexGen Plant Science Center, New Jersey
18WCPPnn
5
Richardson
University of Arkansas
20WCFAnn
6
Dodson
Olds
15WCPPnn
7
Lyons
​University of Guelph
20WCFAnn
8
Gregoire
Laval
15WCPPnn
9
Fricker
​Pure Seed Testing
​20WCFAnn
10
Kopp
Utah State
​20WCFAnn
11
Richardson
University of Arkansas 
​LOW MAINTENANCE
16WCFA
12
Frazer
​Pure Seed Testing East
20WCFAnn
13
Hignight
NexGen Plant Science Center
​LOW MAINTENANCE
16WCFA
14
Baird
​​UC Riverside
​18WCPPnn
15
Sorochan
University of Tennessee
16WCFAnn
16
Hignight
NexGen Plant Science Center
​CHRONIC

18WCPPnn
19
Raymer
University of Georgia
​​20WCFAnn
22
Goatley
Virginia Tech, Blacksburg
18WCPPnn
24
Fidanza
Penn State, Berks
​​20WCFAnn
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Trialing

Turfgrass Water Conservation Alliance (TWCA) is a 501c3 non-profit dedicated to water conservation and committed to preserving the ecological benefits of turfgrass in the managed environment.  TWCA relies on third party peer review of objective data to qualify the most drought tolerant turf available today. 
Using strong research TWCA advocates for the responsible use of drought tolerant turf in landscapes to preserve the livability and viability of communities around the world.​
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TWCA Cooperator demonstrates DIA data collection with a lightbox at NexGen.
Technology
TWCA and its cooperators pioneered the use of Digital Image Analysis (DIA) to collect and evaluate stress related data in turfgrass.  This includes NexGen Turf Research and University of Arkansas developing the lightbox technology widely considered industry standard and developing the Turf Analyzer tool.
These revolutionary technologies, coupled with the use of Rainout Shelters (ROS)s allow effective and accurate evaluation of multi-year multi-site trialing.

Trialing Types
During the single species evaluation process, TWCA utilizes both Drought and Low Maintenance trialing.  Drought trialing gives an accurate accounting of cultivar performance under drought stress.  Low Maintenance trialing, on the other hand, looks at turf performance under a decreased inputs regime.
TWCA evaluates two types of droughts stress: chronic and acute.  Chronic stress is a low water scenario where the turf is brought to uniform green before being watered at a decreased evapotranspiration (ET) rate.  Chronic stress is excellent at simulating water requirements in a decreased water scenario like a daily or weekly watering restriction.  However, it is fairly labor intensive.  TWCA research cooperators have shown through repeated trialing, a high correlation between drought tolerance performance in chronic and acute conditions.  For these reasons, this is a less common approach in the program.  Acute stress, on the other hand, is a zero-water evaluation, where established turf is brought to uniform green and field capacity before the water is entirely shut off.  This is a prolonged drought, no water scenario and provides a smooth uniform performance curve for evaluation.  Drought trialing is governed by the TWCA's Turfgrass Water Conservation protocol.
Low Maintenance trialing presents a unique evaluation challenge.  Unlike TWCA drought trialing with one variability (drought) low-maintenance functions with a broad spectrum of variables.  The trialing regime bans herbicides and pesticides completely and restricts fertility to between 1 and three pounds per one thousand square feet.   Moreover, the low-maintenance regime also imposes acute drought stress.  A key requirement for any cultivars coming out of the low-maintenance regime is qualification through the TWCA Drought process.
Regardless of the trialing regime imposed, all TWCA trials are standardized using the TWCA Cooperators Manual.  This manual lays out expectations for ROS construction, trialing conditions including, establishment, mowing height and fertility.  
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​Qualification
TWCA Qualification relies on third party peer review of the objective data collected at all the locations.  The TWCA Research Review Committee selects the final qualifications.  Comprised of University Researchers with no vested interest in any cultivar being evaluated, the RRC meets to review and evaluate the data before making the final qualifications.  As qualified cultivars approach expiration, they must either requalify against a new, higher standard of drought tolerance or lose their qualified status.

TRIALING TIMELINE

2010
Individual submissions permitted.
2011
Individual submissions permitted.
2012
Individual submissions permitted.
2013
Individual submissions permitted.
2014
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14WCLP
2015
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15WCPP
2016
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16WCFA
2018
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18WCPP
 2020
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20WCFA
​2024
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24WCLP
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2026
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26WCFR
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26WCCD
 Copyright © 2022 Turfgrass Water Conservation Alliance. All rights reserved.​
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  • GRASSES
    • Qualified
      • Seed
      • Sod
    • Cool-season
      • Fine Fescues
      • Kentucky Bluegrasses
      • Perennial Ryegrasses
      • Tall Fescues
    • Warm-season
      • Bermudagrasses
  • PARTNERS
    • Cooperators
    • Members
      • Industry
      • Producers
        • BrettYoung
        • Pennington
        • PureSeed
        • SiteOne
        • Scotts Miracle-Gro
        • TMI
        • Vista
      • Resources
        • Logos
        • Rosters
        • Records
  • Programs
    • Outreach
      • NGBS
      • Turf Trade
      • Water Budgets
        • Budgeting Resources
        • MWELO
        • Run Timer
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