2024 QualificationsTWCA Qualification relies on independent peer review of objective data. Data is collected by vetted cooperators using standardized trialing manual. Qualification employs cultivar plant factor (CPF) analysis for consistent comparable evaluation.
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TWCA Qualification
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.
Qualification in TWCA is time limited and progressive; meaning each cultivar must either re-qualify against a new, higher standard of drought tolerance or lose its use of the seal.
Qualified products must contain a minimum of 70% TWCA Qualified cultivars.
Qualification in TWCA is time limited and progressive; meaning each cultivar must either re-qualify against a new, higher standard of drought tolerance or lose its use of the seal.
Qualified products must contain a minimum of 70% TWCA Qualified cultivars.
QualificationTurfgrass 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. 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.
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.