Performance of Bentgrass Cultivars on Fairways in Michigan (E2917)
August 11, 2017 - Author: Suleiman Bughrara
Bentgrass species are native to western Europe. They are the most widely used coolseason grass for golf courses, putting greens, tees and closely mowed fairways in the United State. The genus Agrostis comprises more than 220 species. Four species are most commonly used as turfgrass:
Creeping bentgrass, a finetextured, stoloniferous species that is best known for its tolerance of low mowing heights. It is often maintained at a mowing height as low as 0.1 inch. Creeping bentgrass also provides an excellent turf for golf course fairways and tees when mowed between 0.375 and 0.5 inch. Its use on fairways has increased rapidly in recent years. It is used in both cooltemperate and warm, humid environments of the United States.
Velvet bentgrass is the finest textured of the bentgrasses and the most beautiful of all turfgrasses. It is primarily used on putting greens. It can tolerate very close mowing. Velvet bentgrass can be used on fairways if the fertility level is kept low; with a high N level, it forms excessive thatch. The winter hardiness of velvet bentgrass remains suspect.
Colonial bentgrass or brown top is a finetextured, bright green, bunchtype grass, that has very high shoot density. It is a weak spreading bentgrass (short stolons and rhizomes) that has better resistance to dollar spot disease than creeping bentgrass. It is very susceptible to brown patch disease, however. Identifying sources of colonial bentgrass germ plasm with improved resistance to brown patch continues to be a major objective of the turfgrass breeding program at MSU. In northern Europe and New Zealand, it has been used as a lawn grass. It is better adapted to mowing heights of 0.4 to 0.75 inch and so is better adapted to golf course fairways and tees than greens. The grass is used for turf in some northeastern and northwestern states.
Dryland bentgrass is tufted and similar in adaptation and appearance to colonial bentgrass except that it has a blue to graygreen color. There has been confusion over the taxonomic classification of this species. Some believe it to be the same species or even a subspecies of colonial bentgrass. However, lab tests conducted at MSU laboratory confirmed that dryland bentgrass has 42 chromosomes; colonial bentgrass has 28 chromosomes. It has a short rhizome and forms a dense uniform turf at mowing heights of 0.5 to 1.0 inch. It is very heat and droughttolerant.
Two National Turfgrass Evaluation Program (NTEP) trials of bentgrass cultivars and selected lines for putting green and fairway condition trials were established in September 2003 at the Hancock Turfgrass Research Center at Michigan State University. The putting green test comprised 26 commercial cultivars and selected lines of creeping and velvet bentgrass; the fairway test consisted of 28 creeping and colonial bentgrasses (see Table 1 and Table 2). All trials were mowed frequently during periods of active growth. Putting green trials were mowed five times a week with either a triplex or walkbehind reel mower, and fairway trials received three weekly mowings with the triplex mower. The test plots received between 3 and 4 pounds of nitrogen per 1,000 square feet each year split into three to four application. The tests were core aerified in the fall of each year and irrigated frequently during the summer.
The plots were visually evaluated once per month during the growing season for turfgrass quality and other parameters. “Quality” means the overall appearance of the turf plots. Components are density, texture, uniformity, color, and freedom from disease and insect damage. Quality was rated using a scale of 1 to 9, where 9 equals the highest quality. For comparison of the average turfgrass quality of creeping bentgrass grown in similar putting green soils at 10 U.S. locations (Iowa, Illinois, Indiana, Kentucky, New York, Pennsylvania, South Dakota, Virginia and Wisconsin) for 200406, see Tables 1 and 2.
Differences between two entries are statistically significant only if the numerical difference between two entries exceeds the LSD value listed in the table. For example, if cultivar ‘Declaration’ is 2.5 units higher in quality than cultivar ‘Penncross’, this difference is significant because the LSD value is smaller (0.6). If the LSD value is greater than the numerical difference between the two cultivar, then the difference is not significant. Coefficient of variation indicates the percent variation of the mean. Smaller variation indicates good data validation.
Significant differences in turfgrass quality were found among the bentgrasses in this test during 200406. In spite of the differences in growing conditions in 2004, 2005 and 2006, the average turfgrass quality of some improved cultivars varied little among seasons. The entries showing the best seasonal average quality over the threeyear test period are listed in the table. For more information, visit www.ntep.org under Michigan State University data.