Extension Education: Perennial Grass Cultivars Show Promise as Turf

Turf grass species require large amounts of irrigation water to produce good-quality turf. In the semi-arid Central Great Plains (CGP) of Wyoming where average annual precipitation is less than 14 inches, water availability for turf grass irrigation is limited. Identifying drought-tolerant, low-maintenance turf grass is of prime interest to landowners and turf managers. 

Kentucky bluegrass and tall fescue are the most widely planted cool-season turf grass species for high and low-maintenance turf systems. Recent reports suggest that several cultivars of Kentucky bluegrass and tall fescue provided high visual quality under reduced inputs, such as irrigation and fertilization.

Although tall fescue has been reported to produce high-quality turf under low-maintenance conditions across several regions in the Midwest, information on the performance of recently released cool-season turf grasses under drought conditions is limited in the semi-arid CGP. Selecting grasses that have the ability to maintain green cover for long periods without supplemental irrigation could have a significant impact on seasonal water use.

Warm-season species

Blue grama and buffalograss are native grass species found in the North American Great Plains. These warm-season grasses are tolerant to drought, adapted to semi-arid regions and are being used as low-maintenance turf grass species across the Great Plains. Efforts have been made to breed native grass species particularly buffalograss for their suitability as turf grass in the CGP. 

“Bowie” and “Cody” are turf-type buffalograss cultivars released recently by the University of Nebraska with superior turf quality and drought tolerance. In Manitoba, Canada, blue grama cultivar “Bad River” has been reported to produce good-quality turf with excellent drought tolerance with great potential as a low-maintenance turf.

These newly released cultivars are reported to have wider geographic adaptability, but their performances in the CGP have not been widely evaluated. 

Researching species

Scientists in the Department of Plant Sciences conducted a recent evaluation of several turf grass cultivars at the James C. Hageman Sustainable Agriculture Research and Extension Center (SAREC) near Lingle during 2009–2011. Two treatments were imposed: cultivars/species and irrigation management.

Three cultivars of Kentucky bluegrass (“Bandera,” “Common 85/80” and “Midnight”), tall fescue (“Blackwatch,” “Tar Heel II” and “Watchdog”), buffalograss (“Bison,” “Bowie,” and “Cody”) and blue grama (“Alma,” “Bad River” and “Hachita”) were evaluated. Cultivar selection for each species was based on reported drought tolerance. Irrigation management included irrigated versus rain-fed. The study was planted in May 2009. Seeds were broadcast onto a clean, firm and smooth seedbed then softly raked-in and rolled into the soil. Sowing rates of pure live seed were 175, 436, 87 and 131 pounds per acre for Kentucky bluegrass, tall fescue, buffalograss and blue grama, respectively.

During the establishment year of 2009, rain-fed plots received irrigation water as needed to ensure good emergence. Good precipitation conditions following sowing in 2009 aided rapid plant establishment. Plot establishment in the autumn of 2009 was identical among all treatments. The supplemental amounts of water added to the irrigated turf grass plots were nine, 9.5 and 10.5 inches in 2009, 2010 and 2011, respectively. On average, the irrigated plots received 67 percent more water than the rain-fed plots.

All plots were mowed bi-weekly to control weeds and stimulate growth. Plots were fertilized based on soil test results with 50 pounds per acre of nitrogen as urea, phosphorus as mono-ammonium phosphate and 20 pounds per acre of sulfur as elemental sulfur in mid-September in the second and third year of the establishment.

Results

Turf grass establishment was successful, and plant performance was similar among irrigated and rain-fed treatments in the establishment year in 2009. However, differences occurred over time. Coverage of turf grasses was similar in both irrigated and rain-fed conditions for the entire evaluation period. In general, better performance and turf quality in terms of vigor and color were obtained in irrigated plots. Plant vigor and color rankings were tall fescue, Kentucky bluegrass, buffalograss, blue grama under irrigated conditions. However, under limited water supply, plant vigor and color were superior for the warm-season turf grass species buffalograss and blue grama.

Tall fescue cultivars “Tar Heel II” and “Watchdog” performed very well under rain-fed conditions showing their superior drought tolerance and low water requirements comparable to “Cody” (buffalograss) and “Bad river” (blue grama). There was little-to-no weed invasion in tall fescue turf grass plots over the three-year evaluation period indicating its superior competitiveness to weed infestation compared to other turf grass species tested.

Based on three-year results from the evaluation, tall fescue cultivars “Tar Heel II” and “Watchdog,” blue grama cultivar “Bad River” and buffalograss cultivar “Cody” are the most promising drought-tolerant cultivars and have potential for use in the CGP of Wyoming, and perhaps beyond, under limited irrigation. Specific cultivar information can be obtained by contacting the author.

Anowar Islam is an assistant professor and the University of Wyoming Extension Forage Agroecologist in the Department of Plant Sciences in the College of Agriculture and Natural Resources. He can be reached at 307-766-4151 or mislam@uwyo.edu.