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 website (www.ntep.org). Our data is also published on a CD, in exactly the same format as the NTEP website. 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 space on your bookshelf than hard copy reports. We still have however, printed copies of reports available on request.

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 or a series of stresses.

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 website 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 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.

Te NTEP Low Input Cool-Season trial at Logan, UT, planted in fall 2015. Tis photo was taken in September of 2016. Note the clover that was included in some mixtures.

36 TPI Turf News July/August 2017