David S. Gardner

Low-Input Turfgrass Species for the North Central United States

Public attention is being increasingly focused on the environmental impact and management costs of turfgrass areas such as lawns for schools, parks, and homes. The objectives of this study were to: (i) identify grass species adapted to low-input environments (limited water, no fertilizer or pesticides after establishment) in the North Central Region (NCR) of the USA; and (ii) evaluate these species for turfgrass quality under mowed and non-mowed conditions. Lowinput turf trials of 12 grass species were established at eight locations and evaluated for turf quality over two years. Plots were mowed monthly at either 5.1 or 10.2 cm or not mowed. Hard fescue (Festuca brevipila Tracey), colonial bentgrass (Agrostis capillaris L.), tall fescue (Festuca arundinacea Schreb.), and sheep fescue (Festuca ovina L.) performed well at most locations at the 5.1 and 10.2-cm mowing heights. Several other species were also evaluated: tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.], hybrid bluegrass (Poa arachnifera Torr. × Poa pratensis L.), meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.], prairie junegrass [Koeleria macrantha (Ledeb.) Schult], crested wheatgrass [Agropyron cristatum (L.) Gaertn.], alkaligrass [Puccinellia distans (Jacq.) Parl.], blue grama [Bouteloua gracilis (Willd. Ex Kunth) Lag. Ex Griffiths], and crested dogstail (Cynosurus cristatus L.). Introduction At present, Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), and tall fescue are the primary species used for turf in the North Central Region (NCR). Recently-developed Kentucky bluegrass and perennial ryegrass cultivars provide high quality turf when managed with sufficient amounts of fertilizers, water, and pesticides (21). However, there has been increasing attention drawn to the negative aspects of higher input turfs (15) which has resulted in changes such as fertilizer use restrictions in Minnesota (19), cosmetic pesticide restrictions in Canada (9), and water use restrictions set by the Environmental Protection Agency (23). Current turf management options and some of the species and cultivars commonly used for turf may be inadequate for use in the USA in the future due to potential negative impacts of high-input turfgrass management on the environment. One way to reduce inputs is by identifying and planting low-input turfgrass species that require less mowing, fertilization, and irrigation in order to achieve adequate visual quality. In order to use low-input species and make them attractive to the 26 January 2011 Applied Turfgrass Science public, it is critical to properly assess low-input adaptation across multiple environments. Diesburg et al. (6) evaluated twelve grass species as low-input turf at seven sites in the NCR for three years. Overall, the best performing species, as determined by plot uniformity and cover, were tall fescue, colonial bentgrass, redtop bentgrass (Agrostis gigantea Roth), and sheep fescue. We decided to compare the performance of some species that did well in the study by Diesburg et al. (tall fescue, colonial bentgrass, sheep fescue) with other grasses that have been shown to be effective in climates similar to the NCR and with grasses that have not been extensively tested for low-input turf but have shown the potential to perform adequately in the NCR. Hard fescue is a bunch-type grass native to central Europe known to perform well in reduced-input shady environments, under full-sun conditions, and in situations where reduced mowing frequency is desirable (10,17). Tufted hairgrass is a cool-season bunch grass that can thrive in both sun and shade when moisture is not limiting (3). Prairie junegrass is native to the Great Plains and has performed adequately in low-input turf evaluations in Canada (16). Blue grama is a warm-season bunchgrass found throughout the Great Plains that has shown potential for use as a turf in low-nitrogen and arid environments (13,16). In recent years, a number of Texas bluegrass × Kentucky bluegrass hybrid cultivars have been released; these cultivars can exhibit improved heat tolerance compared to Kentucky bluegrass (20). Other species that have not been tested on a wide-scale in the NCR include alkaligrass, which can be an effective turf when grown in areas with high salt levels in the soil (21); meadow fescue, which is similar in appearance to coarse-textured tall fescue cultivars (1); crested wheatgrass, a grass that has been the focus of germplasm improvement efforts for use in arid environments (11); and crested dogstail, which has been shown to be adapted to shady environments (14). The objectives of this study were to: (i) identify grass species adapted to lowinput environments (limited water, no fertilizer or pesticides after establishment) in the NCR of the USA; and (ii) evaluate these species for turfgrass quality under mowed and non-mowed conditions. These low-input grasses could potentially be utilized on home lawns, school grounds, parks, golf course roughs, and other turf areas. Furthermore, the identification of species with potential low-input use will give plant breeders information to help focus germplasm improvement programs. Establishment and Treatments In fall 2004, 12 grass species (Table 1) were seeded at eight sites in the NCR (Table 2). The experimental design for each location was a split plot with mowing height as the main plot and species as the sub-plot. Individual subplots were 1.52 m × 0.91 m, with no border between plots, and seeded at a generally-accepted rate for each species (Table 1). Plots were established by either dormant seeding or a typical late summer seeding on bare soil (Table 2). Dormant seeding was done late-fall once soil temperatures were below 5°C to ensure that seed would not germinate until temperatures warmed in the spring. After seed was applied and lightly raked into the soil, the dormant-seeded trials were covered with Futerra blankets (Profile Products LLC, Buffalo Grove, IL). Late summer-seeded plots were seeded in late August/early September and a starter fertilizer was used at time of seeding at a rate of approximately 49 kg N/ha and 43 kg P O /ha. Plots were irrigated during the fall establishment period. Following establishment, no irrigation or fertilizer was applied. For both establishment methods, during the first spring after seeding, broadleaf weeds were controlled with a single application of an herbicide mixture of 2,4-D, MCPP, and dicamba (Trimec Classic, PBI/Gordon Corp., Kansas City, MO) at all sites with the exception of Wisconsin (no herbicide applied), North Dakota (no herbicide applied), and Ohio [single application of an herbicide mixture of 2,4D, clopyralid, and dicamba (Millennium Ultra 2, Nufarm Americas Inc., Burr Ridge, IL)]. No other pesticides were ever applied at any location. Beginning in spring 2005, three mowing treatments were applied: (i) once per month at 2 5 26 January 2011 Applied Turfgrass Science 5.1 cm; (ii) once per month at 10.2 cm; and (iii) no mowing. Plots were mowed with a rotary mower and clippings were returned. Table 1. Turfgrass entries planted at 8 locations in the North Central United States in 2004 for the low-input turfgrass study. Table 2. Seeding method, weather information, soil type, and pH for research sites. x Total precipitation from 1 April through 31 October. Data Collection and Analysis Turfgrass quality was assessed monthly during each growing season using visual ratings on a 1 to 9 scale, with 9 representing the best turfgrass quality. Persistence (plot cover) and uniformity were the two primary criteria used to determine quality for each plot. Secondary criteria included freedom from disease and insect damage, color, and turf density. A rating of 5.0 was considered to be acceptable turf. All data were subjected to analysis of variance according to the general linear models procedure of SAS (SAS Institute Inc., Cary, NC). The yearly turf quality averages for all locations and years were combined in an analysis of variance which showed that location and all year by interactions were significant at the P ≤ 0.0001 level. Therefore, yearly turfgrass quality averages at each location were analyzed separately. Species turfgrass quality means (within mowing treatment at each location) were separated by Fisher’s Least Significant Difference (LSD) test at P ≤ 0.05. The effect of species (cultivar) was highly significant at all locations while the effect of mowing and the cultivar × mowing interaction was Common name Scientific name Cultivar or selection Seeding rate (g/m2) Alkaligrass Puccinellia distans Fults 7.3 Blue grama Bouteloua gracilis Bad river 14.7 Colonial bentgrass Agrostis tenuis SR 7150 4.9 Crested dogstail Cynosurus cristatus ShadeStar 4.9 Crested wheatgrass Agropyron cristatum Roadcrest 24.4 Hard fescue Festuca trachyphylla Berkshire 29.3 Meadow fescue Schedonorus pratensis LMC-1122 34.2 Prairie junegrass Koeleria macrantha LMC-5000 9.8 Sheep fescue Festuca ovina Blacksheep 34.2 Tall fescue Festuca arundinacea Grande II 34.2 Texas bluegrass hybrid Poa arachnifera × Poa pratensis DuraBlue 9.8 Texas bluegrass hybrid Poa arachnifera × Poa pratensis HB 342 9.8 Tufted hairgrass Deschampsia cespitosa Spike 4.9 Location Establishment method Rainfall (mm) Soil Type pH 2005 2006 Ames, IA fall 566 735 loam 7.6 West Lafayette, IN fall 480 763 silt loam 7.8 East Lansing, MI fall 388 544 fine loam 7.8 St. Paul, MN dormant 832 681 silt loam 7.6 Fargo, ND fall 571 341 silty clay 7.8 Columbus, OH dormant 547 776 loam 7.4 Brookings, SD dormant 773 561 clay loam 7.7 Madison, WI dormant 390 746 silt loam 7.5 x 26 January 2011 Applied Turfgrass Science sometimes significant depending on location (Table 3). Cultivar data from each location were analyzed separately for each year at each location for each of the three mowing heights (Tables 4 to 6). Table 3. Analysis of variance (P > F) for average turfgrass quality at eight locations in the North

Lateral Spread of Glyphosate-Resistant Transgenic Creeping Bentgrass (Agrostis stolonifera) Lines in Established Turfgrass Swards

Genetically engineered varieties of creeping bentgrass, resistant to glyphosate, have been developed. Studies were initiated in 2000 and 2001 to examine the relative competitive lateral spread of several transformed lines of creeping bentgrass, nontransformed controls, and cultivar standards. Five-centimeter-diameter vegetative plugs of creeping bentgrass were transplanted into a 1-yr-old stand of perennial ryegrass in Columbus, OH, and 10-yr-old bermudagrass or 10-yr-old St. Augustinegrass in Loxley, AL. Plots were watered to prevent moisture stress to either the bentgrass plugs or surrounding turf swards. Monthly average diameter of the creeping bentgrass was determined by measuring the longest spread and shortest spread. At the end of the experiment, no differences (P = 0.05) in lateral spread were observed between individual lines of transgenic bentgrass, standard cultivars, and nontransformed control lines. Lateral spread of transgenic lines was similar to or less than their nontransformed parent and the standard cultivars tested. Results indicate that glyphosate-resistant creeping bentgrass lines do not spread laterally more than nontransgenic lines. Therefore, if the glyphosate-resistant creeping bentgrass escaped into surrounding turfgrass swards, the potential for spread would not be greater than other creeping bentgrass cultivars currently in use. Nomenclature: Glyphosate; bermudagrass, Cynodon dactylon L.; creeping bentgrass, Agrostis stolonifera L. syn. Agrostis palustris Huds.; perennial ryegrass, Lolium perenne L.; St. Augustinegrass, Stenotaphrum secondatum S. (Walt.) Kuntze. Additional index words: Competition, genetically modified organism, GMO.