COOL SEASON AND WARM SEASON GRASSES OVERVIEW

By Kevin Morris

Editor’s Note: Each year, Kevin Morris provides an update on the data collected on commercial varieties and experimental turfgrasses entered into the National Turfgrass Evaluation Program (NTEP). Tis information helps turfgrass producers choose the varieties that will best perform in their particular growing area and management programs. TPI and Turf News wish to thank Mr. Morris for the significant amount of time and effort in providing this valuable overview.

At any one time, the National Turfgrass Evaluation

Program (NTEP) is evaluating over 600 cultivars and experimental selection in nationwide tests. Data collected and summarized from these trials can be obtained directly from NTEP or from our web site (www.ntep. org). Our data is also published on a CD, in exactly the same format as the NTEP web site. Te CD is read like any informational CD on your computer. Te advantages of the CD include its portability, its search features and taking up less up space on your bookshelf than hard copy reports. We still have however, printed copies of reports available on request.

Te most widely used data in NTEP reports are

the turfgrass quality (TQ) ratings. Quality ratings are collected monthly during the growing season using a 1-9 scale with 9=ideal turf. Turfgrass quality ratings are collected by evaluators considering all the factors that make good turf, i.e. good green color, density, adequate ground cover, freedom from disease and other stresses, etc. Quality ratings show a lot about the grasses, that is why they are so important. NTEP turfgrass quality tables focus on grouping by

region or management level. In addition, we have the data from each state available on our web site and CD. Hopefully, this makes the data more useful to growers within their geographical region or under their specific management level. NTEP recommends that growers first review data collected in their state or region and also under the management regime most suited to their needs. To find data for a specific state, go to www.ntep.org/states/states.htm.

NTEP Unveils Improved

Data Reporting Procedure NTEP is committed to improving its data collection,

analysis and reporting. To that end, NTEP spent ten years researching new statistical methods and is now implementing a new reporting procedure, the ’Location Performance Index’ or ‘LPI’, on its newest trials. Te LPI is based on ‘AMMI’, a more complete, accurate statistical analysis program for predicting cultivar performance across many locations. Te LPI is only used on turfgrass quality data but in

Dr. Dennis Martin shows the 2013 NTEP bermuda trial at Stillwater, OK, to advisory panel members and participants in the USDA Specialty Crop Research Initiative warm-season breeding project.

NTEP Data Presentation NTEP information includes data collected on many

descriptive and performance characteristics. Descriptive characteristics describe the entries tested, i.e. genetic color, leaf texture and density characterize a grass’ appearance. Performance characteristics document the response to various stresses, such as disease, cold and drought. For instance, the percent ground cover rating, although not necessarily affected by a single stress, reflects the grass’ ability to withstand and/or recover from a particular stress of a series of stresses.

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reading the turfgrass quality tables, you will notice that locations may not be grouped by any apparent geographical orientation. For instance, in the 2012 data from our new Kentucky bluegrass trial, ‘LPI Group 1' included Amherst, MA, W. Lafayette, IN, Urbana, IL, St. Paul, MN, Manhattan, KS and Pullman, WA. It seems that these locations have nothing in common, geographically or climatically. However, what they do have in common is a very important similar ‘interaction pattern,’ i.e. the varieties performed in a similar manner, relative to each other, at each of these locations in that year. For that reason and most appropriately, the LPI groups them together for analysis. And that ‘interaction pattern’ can, and very often will, vary from year to year. Terefore, investigate the LPI Group data containing locations that are closest to you, or your market. Te LPI is used on new trials as they are initiated. Go

to the www.ntep.com to read more about the LPI and the reasons for utilizing this new procedure.

TPI Turf News July/August 2016