On-site testing ensures proper cultivar selection

On the surface, selecting turfgrass cultivars seems like a relatively easy task. However, to cover all the bases, it requires much more research and work to determine the best grass for a particular location.

In today’s marketplace, there are an unbelievable number of cultivars per grass species. For example, there are numerous cultivars of perennial ryegrass on the market. If planting this species for fairway turf, selecting the correct cultivar(s) for the best performance may be a challenge.

The National Turfgrass Evaluation Program (NTEP) may be the best starting point. This program evaluates all the major golf course turfgrass species. There are various sites throughout the United States (primarily universities) that conduct the testing. This is where the first major concern may be with NTEP testing.

For example, ryegrass A is the overall, top-ranked performer for a particular year. However, a testing site such as Orono, Maine, may have it ranked fairly low, while other sites have it ranked much higher. So what’s the concern? While the overall rankings are good, the real meat of the rankings should be looked at from a regional standpoint. The optimal way to decipher the rankings is to compare testing areas that match, or are similar to a course’s climatic conditions. If a superintendent plans to grow a perennial ryegrass in Springfield, N.J., then the performance of a particular cultivar in Orono, Maine, might be of less concern.

Creating a spreadsheet is the best method for evaluating course conditions. On the spreadsheet, record results from similar growing condition regions and compute the results. When computing the results, consider throwing out certain criteria that affect the rankings. An example of this could be disease severity. If you live in an area of the country where brown patch is not a concern, then maybe the ranking for this should be excluded from your spreadsheet.

Another concern with the NTEP rankings is the management inputs at various sites. For example, if you want fast bentgrass greens, then cutting heights should be looked at in the evaluation. If university A is cutting at 5/32 inch and universities B and C are cutting at 1/8 inch, then the data for university A should be taken lighter than B and C. There are also other management inputs that differ. The least significant difference (LSD) value should also be considered. The LSD is the value when numerically subtracted from the top ranking gives you a range of different cultivars that show no true difference from another. For example, if the numerical rating for the top ranked Kentucky bluegrass was 6.9 and the LSD value was 0.4, then all the grasses rated between 6.5 and 6.9 will show no true differences, and essentially can almost be ranked as a grouping.

Advertising literature can be an interesting source of information, but should be taken lightly. Many seed companies will focus on an area where their grass performed best, and use that to their advantage for advertising. For example, if a cultivar did not rank highly overall, but it performed well in a certain area such as leaf spot resistance, then this will be the focus of a companies advertising. So in most cases, it is best to look beyond the advertising.

The best method for evaluating cultivars is individual testing by a superintendent at his/her course. No data and observations can be better than testing under the exact growing conditions. For example, when Doug Anderson, superintendent at the Vintage Club in Palm Springs, Calif., was faced with the decision to select a bentgrass for his greens surfaces before reconstruction, he decided to build a test green. Anderson constructed a practice green planted with the top eight bentgrass cultivars ranked in NTEP. Over a 12- to 16-month period, he watched these bents under his management practices and climatic conditions. As a result, he was able to select the bentgrass that would ultimately perform the best. When he finally made his selection of Penn A-4, Anderson had the utmost confidence in the bentgrass cultivar and eliminated all doubts from any other selection process.

Anderson’s method is the ultimate way to evaluate what will perform best. This testing that requires forward thinking of 12 to 18 months, but even in a new construction situation this can be done. When it comes to selecting a turfgrass cultivar for your golf course, doing some homework and on-site testing will ensure a decision that will benefit your course for many years.