HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shearman, R. C. Search for Related Content PubMed Articles by Shearman, R. C. Agricola Articles by Shearman, R. C.

CSSA GOLDEN ANNIVERSARY SYMPOSIUM

Fifty Years of Splendor in the Grass

Dep. of Agronomy and Horticulture, Univ. of Nebraska-Lincoln, Lincoln, NE 68583-0724

^* Corresponding author (rshearman1{at}unl.edu)

	ABSTRACT

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
Fifty years ago there were only a few states with turfgrass research programs. Today, most states have turfgrass research and education programs at their land grant institutions. In 1955, 15 research papers were presented at the annual meeting and in 2004 there were 215. Division C-5 (Turfgrass Science) has grown to more than 500 members. This manuscript addresses some of the important historical developments of Division C-5, and discusses some of the accomplishments and contributions of its members to turfgrass science. During the last 50 yr, turfgrass science has experienced a number of important milestones in turfgrass breeding, genetics, and evaluation, physiology, soil physics, soil cultivation, and environmental impacts. These milestones are discussed here. The importance and availability of turfgrass information and funding resources are discussed. The 10 most influential contributors to turfgrass science during the past 50 yr as recognized by their peers are also identified. Like our sister divisions in the Crop Science Society of America (CSSA), Division C-5 can take pride in its past contributions, and can look forward to a bright and challenging future.

Abbreviations: ASA, American Society of Agronomy • CSSA, Crop Science Society of America • ET, evapotranspiration • ITSRC, International Turfgrass Society Research Conference • NTEP, National Turfgrass Evaluation Program • NTRI, National Turfgrass Research Initiative • PVPA, Plant Variety Protection Act • TCW, total cell wall • TIC, Turfgrass Information Center • TGIF, Turfgrass Information File • ARS, Agricultural Research Service • USGA, United States Golf Association

	INTRODUCTION

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
THE TURFGRASS INDUSTRY has experienced tremendous growth and development in the last 50 yr (Watson, 1997). According to a recent report, there are more than 50 million acres of managed turfgrass in the USA (Morris, 2005). Home lawns comprise about 65% of this acreage. There are more than 775000 sports fields, 17 000 golf courses, 40 000 landscape contracting companies, and 4500 lawn care companies. Cool- and warm-season turfgrass sod production comprises nearly 400 000 acres, and there are 685 000 acres of turfgrass seed production. In fact, turfgrasses touch nearly all of our lives on a daily basis (Beard and Green, 1994).

Recent turfgrass economic impact surveys have been conducted in states such as Illinois, Iowa, New York, North Carolina, and Virginia (Missouri Valley Turfgrass Association, 1998; Phipps, 1999; Bailey, 2000, p. 1–5.; Campbell, 2001, p. 59–64; Howard, 2004, p. 3–79). The economic impact of turfgrass maintenance from these state surveys ranged from $1 billion to $5 billion annually. The entire turfgrass industry is conservatively estimated as being a $60 billion per year industry. Golf course maintenance costs are estimated at $10 billion annually and sports turf maintenance is an $11 billion per year.

While these statistics are impressive relative to the size and scope of the turfgrass industry, the evolvement of turfgrass science in the past 50 yr may be even more significant. Fifty years ago there were only a few turfgrass research programs at universities across the USA, and most of these were located in the eastern part of the country. Today, most states have active turfgrass research and education programs in their land grant institutions, and there are numerous education programs in other 4-yr institutions and community colleges around the USA (Roberts et al., 1992). There has been considerable growth internationally as well. In 1969, the First International Turfgrass Society Research Conference (ITSRC) was held in Harrogate, UK, with 78 registrants representing 12 countries (Beard, 2005). Thirty-six years later in Llandudno, Wales, UK, at the 10th ITSRC there were 262 registrants from 25 countries.

	HISTORICAL PERSPECTIVE OF DIVISION C-5

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
In 1952, Division 11, Turfgrass Management, was formed in the American Society of Agronomy (ASA). In 1955, Turfgrass Management was moved from ASA to the newly formed CSSA. The Division 11 designation was changed to C-5 in 1963, and it remained Turfgrass Management until it was changed to Turfgrass in 1973. The title was changed to Turfgrass Science in 1995, and C-5 has maintained this designation to date. Presently, Division C-5 has more than 500 members.

A historical perspective of the evolvement of turfgrass research in the USA can be obtained by studying the Division C-5 Historian Reports (Beard, 2004a, 2004b), and internationally by looking at the increased numbers of research papers represented in the International Turfgrass Society Research Journal (Beard, 2005). There were 15 turfgrass research papers presented at the first CSSA meetings in 1955, and that number grew to 215 in 2004 (Beard, 2004a, 2004b). At the first ITSRC held in 1969 there were 99 research papers presented, and at the 10th ITSRC in 2005 there were 227 papers presented (Beard, 2005).

During the past 50 yr, C-5 members have been active in the Society. Five members have served as CSSA Presidents (G.O. Mott, 1956; H.B. Sprague, 1960; R.R. Davis, 1974; J.B. Beard, 1986; and R.C. Shearman, 1995). Of these five individuals, only Beard and Shearman had full-time responsibilities in turf. Division C-5 has 46 members who were named Fellows of CSSA, ASA, or both (Beard, 2004b). Since 1955, 51 members have served as Division C-5 Chairs, and 15 members have served 3-yr terms as ASA Board Representatives since 1961(Table 1). In addition, numerous C-5 members have served the Society as editor, technical editor, associate editors, and reviewers for Crop Science, and as committee chairs, committee members, and program session chairs. The first person from Division C-5 to serve as Editor of Crop Science was K.J. Karnok, serving from 2001 to 2003. In 2002, R.C. Shearman was the first technical editor with sole responsibility for turfgrass science appointed to the Crop Science editorial board.

	MILESTONES IN TURFGRASS INFORMATION ACCESS

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
Along with the growth in the numbers of persons conducting turfgrass research, turfgrass information has increased by volumes. Beard (2004a) reviewed turfgrass literature for the past 75 yr. He observed an important transition in the literature that occurred in the 1970s, when he indicated that it moved from primarily demonstration based, trial-and-error approaches to information based on research developed with sound scientific principles. This transition was an important milestone in the development of turfgrass science.

Sorting through the large amount of information that has evolved in the turfgrass literature during the past 50 yr is no easy task. In 1977, Beard et al. (1977, p. 730) compiled a bibliography that indexed turfgrass literature dating from 1672 to 1972. This bibliography was extremely helpful to turfgrass researchers, but researchers were still limited by the fact that the growing literature database was not included to any extent in general indexes, like the Agriculture Index. In 1984, the United States Golf Association (USGA) provided funding to help develop the Turfgrass Information Center (TIC) at Michigan State University (Haka, 2004). The USGA funding helped provide the resources needed to produce an index and abstracting service for turfgrass literature, and to make it available to turfgrass researchers, educators, students and practitioners. The TIC houses over 100 000 accessions that cover all aspects of turfgrass science and culture (USGA, 2005). These accessions and other related turfgrass information are available by electronic access through a system called the Turfgrass Information File (TGIF).

	MILESTONES IN TURFGRASS RESEARCH FUNDING

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
In the early 1950s there were very few full-time turfgrass research positions associated with land grant universities, and most of these positions had responsibilities split among more than one crop, with many having responsibilities shared with forage crops. In the early 1960s, this trend began to change as more positions with full-time turf responsibilities started to appear in land grant institutions, particularly in the eastern and central portion of the USA (Huffine and Grau, 1969; Roberts et al., 1992). Today, most states have some combination of turfgrass research, academic or extension activities (Roberts et al., 1992). Funding for these programs is mainly a combination of federal, state, and industry support. Many turfgrass programs have state or regional turfgrass foundations or associations that further support their research and education programs, and undergraduate scholarships. Several associations and nonprofit organizations, such as the Golf Course Superintendents Association of America, National Turfgrass Evaluation Program (NTEP), Turfgrass Producers International, and USGA are also instrumental in supporting research and educational activities.

Funding from the USGA has had a major impact on turfgrass research programs since its inception in 1983. The USGA began a research initiative for the golf industry with goals and objectives to improve turfgrasses, address environmental quality issues and concerns, and improve playing conditions for the enjoyment of the game of golf (Kenna and Snow, 2002). The USGA has funded >290 projects and invested >$25 million in this research program. The USGA has funded >$8.4 million in turfgrass biotechnology, breeding and evaluation, which has led to an improved understanding of genetics and release of improved cultivars in 10 turfgrass species. In addition, USGA funding has supported $1.5 million of research that has improved understanding of chemical, physical, and microbial aspects of putting green rootzones. Perhaps even more importantly, USGA funding has supported >$5.3 million of research on nutrient and pesticide fate and transport, and other environmental quality issues. In all, this funding has provided a basis for in-depth research that goes beyond the scope of research funded by most state-supported programs.

The USGA funding has had a major impact on turfgrass science, but touches only a small portion of the overall funding needs, particularly in light of the fact that golf makes up only 3% of the turfgrass industry. There is a need for long-term research funding to address issues that will impact the future of the turfgrass industry. To date, only a few turfgrass researchers have received National Science Foundation or National Research Initiative grants. This trend may change as research programs develop a more basic emphasis, regional cooperative research projects are identified, and granting agencies recognize the quality of research conducted in the discipline.

	NATIONAL TURFGRASS RESEARCH INITIATIVE

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
In 1995, a process was initiated through the leadership of the National Turfgrass Federation to encourage the USDA Agricultural Research Service (ARS) to use its national network of scientists and laboratories to become involved in long-term research efforts that contribute to turfgrass economic and environmental sustainability (Morris et al., 2005). It was perceived that USDA-ARS research could complement work being done at land grant universities, and it would encourage cooperation among scientists within ARS and among universities. This process moved slowly until 2002, when a listening session of various turfgrass industry representatives and the USDA-ARS was held to discuss turfgrass research priorities and needs in Dallas, TX (NTEP, 2003). As a result of this meeting, a task force was developed and it drafted a National Turfgrass Research Initiative (NTRI), with goals and objectives designed to identify key research needs for the turfgrass industry. The Initiative identified a total funding need of >$32 million to meet the goals and objectives outlined. The NTRI was published in April 2003, and was immediately shared with the USDA-ARS administration, members of Congress, and the turfgrass industry. To date, supporters of the Initiative, through extensive lobbying efforts, have garnered >$2.7 million of federal support for turfgrass research in the USDA-ARS, and efforts are continuing to obtain the additional funding needed to meet the goals of the Initiative. The Initiative formulated its funding request in a manner that encourages support for scientist positions in the USDA-ARS and special cooperative agreement funding that can be used to foster cooperative research efforts with turfgrass researchers at land grant universities. The first position, a molecular geneticist at the USDA-ARS laboratory located in Beltsville, MD, was funded in 2004.

	MILESTONES IN TURFGRASS BREEDING AND GENETICS

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
Turfgrass breeders have relied on breeding methods used in cross-pollinated, self-incompatible perennial crops, with selection based primarily on progeny performance in spaced plants and turf plots (Brilman, 2005). There have been considerable improvements in warm- and cool-season turfgrasses for adaptation, pest resistance, and stress tolerance through breeding and selection in the past 50 yr. These improvements are evident in the turfgrass species, cultivar, and experimental line evaluations conducted by NTEP (2004a).

Warm-season turfgrasses have been released primarily as vegetative cultivars, but there is an increasing interest in breeding improved seeded types. Cool-season turfgrasses are marketed primarily as seeded cultivars and breeders continue to strive to improve their adaptation, seed production, pest resistance, and stress tolerance. In a review article, Brilman (2005) remarked that the passage of the Plant Variety Protection Act (PVPA) in 1970 had a profound impact on the development and release of improved turfgrass cultivars. The PVPA allowed companies and universities to protect their cultivars and obtain a greater and more consistent return on their investments in developing new cultivars, and, therefore, heightened interest in turfgrass cultivar development.

Bermudagrass (Cynodon spp.) is the most widely grown warm-season turfgrass species on an international basis. It has received considerable attention by plant breeders in the past 50 yr. In the mid 1950s, Burton released ‘Tiffine’ and ‘Tifgreen’, which were sterile, interspecific triploid-hybrids of common bermudagrass (Cynodon dactylon L.) and African bermudagrass (C. transvaalensis Burtt-Davy) (Burton, 1991; Brilman, 2005). These hybrids had finer texture and better turfgrass quality than common bermudagrass. Tifgreen formed an excellent golf course putting green surface. Burton followed the release of these cultivars with ‘Tifway’ and ‘Tifdwarf’ (Burton, 1966; Burton and Elsner, 1966). Tifdwarf was selected as a natural dwarf mutant from a Tifgreen putting green growing in South Carolina (Burton and Elsner, 1966). Tifgreen, Tifdwarf, and Tifway are still extensively used for higher quality warm-season turfs throughout the southern USA.

More recently, breeders have released common bermudagrasses with improved turfgrass quality, seed yield, and cold tolerance (Baltensperger, 1989b; Baltensperger and Klingenberg, 1994; Baltensperger et al., 1998; Taliaferro, 2003; Anderson et al., 2005). ‘NuMex’ Sahara was released by Baltensperger (1989a) as a seeded bermudagrass with improved turfgrass quality when compared with other common bermudagrasses. He followed this release in 1994 with ‘Princes’, which had even better turfgrass quality characteristics (Baltensperger and Klingenberg, 1994). Taliaferro (2003) released ‘Riviera’ and ‘Yukon’ as seeded types with improved cold tolerance, seed yield, and turfgrass quality (Brilman, 2005). The improved cold tolerance and turfgrass quality in these seeded cultivars offer turfgrass managers in the transition zone of the USA more choices of cultivars with better adaptation for the difficult growing conditions associated with the transition zone.

Other land grant institutions and private organizations are also working to improve bermudagrass through the development of vegetative and seeded cultivars with improved turfgrass characteristics. Some other traits that are receiving attention in these programs are spring dead spot resistance, salinity tolerance, drought resistance, reduced water use, shade tolerance, iron chlorosis resistance, and improved winter growth (Brilman, 2005). Taliaferro (2003) reported that 18 commercial seed companies were listed as bermudagrass entry sponsors in recent NTEP trials (NTEP, 2000). Some of these companies simply licensed cultivars from university breeding programs, but others have active bermudagrass development programs of their own.

There is an increasing interest from the turfgrass industry and the public for grasses that conserve water and require less input of fertilizer and pesticides in the turfgrass industry. In 1984, researchers at the University of Nebraska-Lincoln, under the leadership of T.P. Riordan, initiated a breeding program with support from the USGA to develop buffalograss [Buchloë dactyloides (Nutt.) Englem.] cultivars for turfgrass use (Riordan and Browning, 2003; Shearman et al., 2004). Since its initiation, the buffalograss program released seven seeded or vegetative cultivars with improved turfgrass quality (NTEP, 2004b; Shearman et al., 2004). Seashore paspalum (Paspalum vaginatum Swartz) is a salt-tolerant warm-season species with potential for turfgrass use where nonpotable or saline irrigation sources are prevalent (Duncan, 2003). Its adaptation is somewhat limited due to lack of cold tolerance. The University of Georgia, in cooperation with USGA, initiated a seashore paspalum breeding program under the leadership of R.R. Duncan. This program released ‘Sea Isle 1’ and ‘Sea Isle 2000’ as improved cultivars for the turfgrass industry. Kopec from the University of Arizona collected inland saltgrass [Distichlis spicata (L.) Greene] as a germplasm source for turfgrass use (Kopec and Marcum, 2001). In 1998, an inland saltgrass breeding program was initiated under the leadership of D. Christensen as a cooperative effort among Colorado State University, University of Arizona, and the USGA, with the goal of developing turfgrass cultivars for salt-affected soils and where nonpotable, saline irrigation sources might be used (Christensen and Qian, 2004). The introduction of new species is always a challenge both in meeting needs and expectations of the industry. Buffalograss, seashore paspalum, and inland saltgrass show excellent promise for meeting these challenges.

Kentucky bluegrass (Poa pratensis L.) is the most widely grown turfgrass species in the USA. Early improvements in Kentucky bluegrass came from selection of ecotypes growing in existing turfgrass stands and other naturalized populations. ‘Merion’ was the first Kentucky bluegrass cultivar with a turf-type growth habit and improved disease resistance (Myers, 1952). Merion was found on Merion Country Club in Ardmore, PA. It set the standard for Kentucky bluegrass cultivars well into the 1960s, but in the late 1960s researchers began to recognize potential for Kentucky bluegrass cultivar improvement through intraspecific hybridization. Researchers at Rutgers University, under the leadership of C.R. Funk, developed techniques for intraspecific hybridization of Kentucky bluegrass that led to the development of numerous successful cultivars such as Adelphi, America, Eclipse, Midnight, and Shamrock (Pepin and Funk, 1971; Funk et al., 1973; Funk, 2000; Funk and Meyer, 2001). Their research efforts with intraspecific hybridization of Kentucky bluegrass and the subsequent improvements obtained with this breeding approach had a great impact on Kentucky bluegrass turfgrass quality. These cultivars set the standard for the turfgrass industry and had a strong impact on the growth and development of commercial seed production.

‘Penncross’ creeping bentgrass (Agrostis stoloniferous L.) was released by H.B. Musser in 1955 (Hein, 1958). This cultivar raised the standard of putting green quality for seeded creeping bentgrasses, and continued to do so well into the 1990s. Penncross is the most widely used creeping bentgrass on an international basis. In the late 1980s and early 1990s, plant breeders at Pennsylvania State University with leadership from J.M. Duich, Rutgers University with leadership from W.A. Meyer, Texas A & M University with leadership from M.C. Engelke, and commercial seed company plant breeders released cultivars with superior turfgrass quality under reduced mowing heights, and abiotic and biotic stresses when compared with standard cultivars (NTEP, 2004a).

Advances in turfgrass molecular genetics have been slower than those occurring in many other crops. However, progress in genome mapping of bermudagrass and creeping bentgrass has been made, and other species such as buffalograss and Kentucky bluegrass are being studied. To date, herbicide-resistant transgenic lines of creeping bentgrass and bermudagrass have been developed (Li and Qu, 2004; Brilman, 2005). In creeping bentgrass, stable transformation has been obtained through protoplast and particle bombardment (Zhong et al., 1993; Asano and Ugaki, 1994; Dalton et al., 1998; Asano et al., 2000). In a review of creeping bentgrass breeding and genetics research, Warnke (2003) indicated that a commercial company had developed a glyphosate-resistant line. This line has several hurdles to overcome since it would be the first perennial grass plant released with glyphosate resistance. Concerns have been expressed regarding the potential for this glyphosate-resistant line to outcross with wild-type Agrostis spp. and nontransgenic cultivars in commercial production. Regardless of what happens with this release, it is apparent that molecular genetics will play a major role in the future of turfgrass science and management.

	MILESTONES IN TURFGRASS EVALUATION

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
With the growing emphasis on turfgrass improvement by university and industry plant breeders, there has been a sharp increase in the numbers of cultivars and experimental lines available for cool- and warm-season turfgrass species. Recent national cultivar trials for Kentucky bluegrass, perennial ryegrass (Lolium perenne L.), and tall fescue (Festuca arundinacea Schreb.) had 110, 120, and 160 entries, respectively. The increased numbers of cultivars are a boon to the turfgrass industry, but are also a bane to turfgrass managers, who need to select from multiple options for the best cultivars for their turf sites.

In 1968, turfgrass researchers from the Northeastern Regional Turfgrass Research Committee (NE-57) conducted a cooperative Kentucky bluegrass cultivar evaluation at 19 locations across the northeastern and central USA (Morris, 1999). They evaluated 43 entries that were comprised of experimental lines and commercially available cultivars. Before this cooperative trial, turfgrass researchers interested in species and cultivar evaluations had to contact each private and public source of cultivars and experimental lines to obtain entries for trials. This process was difficult, time consuming, and often resulted in trials that were incomplete or even out-of-date by the time a study was initiated.

With these concerns in mind, the NTEP evolved as a coordinated effort to conduct turfgrass evaluation trials under diverse environments and management conditions. The NTEP was the brainchild of J.J. Murray, who was a scientist at the USDA-ARS Agricultural Research Center in Beltsville, MD (Anonymous, 1994; Morris, 1999). Murray coordinated several cooperative cultivar evaluation trials in the 1970s with researchers in the northeastern and southern USA. The success of these trials led to interest in conducting a nationwide trial with Kentucky bluegrass in 1980. The 1980 Kentucky bluegrass trial had 84 entries and was evaluated at 50 locations. No entry fees were collected for the cultivars and experimental lines evaluated, and evaluators volunteered their time and facilities to conduct the trial. Murray coordinated the trial, provided staff and facilities to collect and disseminate trial entries, and provided data analysis and clerical support.

The 1980 Kentucky bluegrass trial was a great success, and it served as the inauguration of NTEP trials. In 1982, a perennial ryegrass trial was conducted. Fees were charged for the cultivars and experimental lines entered in this trial, and the funds collected were used to hire a full-time technical coordinator for the program. In subsequent years, trials have been initiated for the most commonly used cool- and warm-season turfgrass species. These trials have continued with new species evaluation trials initiated on a 5-yr cycle, allowing plant breeders to anticipate trial initiation and have entries ready for evaluation.

During 25 yr of conducting NTEP trials, entry fees have increased, and funds from these fees have grown to support NTEP infrastructure, data analysis and reporting, and the trial evaluation sites. Trial information is readily available to interested persons on the NTEP website (http://www.ntep.org, verified 19 June 2006). The NTEP trials are widely used in the turfgrass industry by practicing turfgrass professionals, extension educators, public and private plant breeders and researchers, and commercial companies. Turfgrass researchers and extension educators value the trials for the species and cultivar adaptation and potential use information, and for staying abreast of new developments in cultivar improvements. Public and private plant breeders and commercial seed producers value the trials for the information they can glean regarding the adaptation and performance of their entries under diverse conditions and management. Certainly, there is a marketing potential that commercial entities can apply from data obtained in these studies. The NTEP Advisory Committee has developed criteria to guide the potential use of trial data in commercial advertising.

	MILESTONES IN TURFGRASS PHYSIOLOGY

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
Turfgrass science has benefited from plant physiology research conducted by researchers working with other plants and crops, as well as excellent research with turfgrasses during the past 50 yr. Beard (1985a), DiPaola and Beard (1992), and Hull (1992) reported extensive reviews covering many of these contributions. Only a few of the important turfgrass physiology milestones can be mentioned here. An emphasis will be placed on accomplishments contributing to our improved understanding of turfgrass high temperature stress, water use rates, and drought resistance, shade adaptation, and traffic stress tolerance mechanisms during the past 50 yr.

One of the limiting factors in maintaining quality cool-season turfgrasses is their susceptibility to supraoptimal temperature stress. Beard and Daniel (1965, 1966) described high temperature stress blockage of new root initiation from meristematic tissues and its effects on creeping bentgrass root maturation and death. Their findings helped turfgrass managers understand high temperature stress and to better manage its effects on turfgrasses. Lehman and Engelke (1993) studied narrow sense heritabilities for heat stress tolerance and drought resistance in creeping bentgrass. Their work identified a strong genetic component for shoot water content and this component may be important for improving heat stress tolerance in creeping bentgrass, which is an issue of importance to expanding the range of adaptability for cool-season turfgrasses into southern climates.

Summer decline of cool-season turfgrass quality under supraoptimal temperature stress is likely associated with reduced availability of carbohydrates, decreased photosynthesis, and increased respiration rates (Hull, 1992; Huang and Gao, 2000; Liu and Huang, 2000; Xiaozhong and Huang, 2001; Xu et al., 2004; Wang et al., 2004; He et al., 2005). A positive balance of carbohydrate production, consumption, and accumulation would assist plants in tolerating an abiotic stress such as high temperature. Cultivar selection and modification of cultural practices could be used to alleviate summer decline and high temperature stress in cool-season turfgrasses (Beard, 1985a, 1990; DiPaola and Beard, 1992).

The availability of irrigation water and water conservation are major concerns for the turfgrass industry, particularly in the arid and semiarid regions of the USA (Carrow et al., 1990; Beard, 1993; Green, 2005). In the 1980s, a considerable amount of research was initiated on factors that influence turfgrass evapotranspiration (ET) rates, such as species, cultivar, and cultural practices, and physiological and morphological aspects (Beard, 1985b; Shearman, 1985, 1986, 1989a; Carrow, 1985; Kopec et al., 1988; Carrow et al., 1990; Salaiz et al., 1991). Johns et al. (1983) and Shearman (1986, 1989a, 1989b) demonstrated the importance of canopy resistance on turfgrass ET. Their research results and those of Kim (1983, 1987) indicated that germplasm with reduced vertical elongation rate, horizontal leaf orientation, greater shoot density, and more extensive verdure production had reduced ET rates. Turfgrass breeding programs could use these characteristics as selection criteria to develop cultivars with reduced water use rates. In addition, cultural practices such as mowing height, plant growth regulators, and N nutrition influence vertical elongation rates, shoot density, verdure, and canopy resistance (Shearman and Beard, 1973; Biran et al., 1981; Johns and Beard, 1982; Feldhake et al., 1983; Doyle and Shearman, 1985; Fry and Butler, 1989). Shearman et al. (2005) reported significant interactions between irrigation and K nutrition treatments for soil and leaf tissue K content, turfgrass quality, and water conservation. Their results support the potential to manipulate irrigation rate and K nutrition level to maintain desirable turfgrass quality and reduce water consumption under fairway management conditions. More research addressing systems approaches to water conservation is needed as the turfgrass industry deals with increasing demand for water by all users.

Soil compaction influences a number of soil–turfgrass water relations and drought stress responses. Soil compaction decreases soil water infiltration rates, decreases soil aeration, increases soil strength, alters water retention capabilities, and impacts soil temperatures (Carrow, 1986). Agnew and Carrow (1985a, 1985b) studied Kentucky bluegrass growing in compacted soils and found that plants with high root porosity were more efficient in extracting soil moisture under low oxygen levels than those with low porosity, and plants with shallow rooting were less effective in extracting soil moisture from deep in the profile. They also reported higher stomatal resistance and lower leaf water potential in plants exposed to soil compaction and moisture stress. Their results support the importance of the role of root system plasticity and soil conditions on turfgrass water conservation and drought resistance.

Shade stress is a problem for cool- and warm-season turfgrasses. It is estimated that 25% of turfs in the USA are grown under some tree or structural shade that limits turfgrass growth and development (Beard, 1997). Reduced photosynthetic irradiance limits turfgrass growth and development, assuming all other factors are nonlimiting (Dudeck and Peacock, 1992). Only a few turfgrass species are well adapted for growth in reduced-light environments (Wood, 1969; Wilkinson et al., 1975). In general, warm-season turfgrasses are less shade tolerant than cool-season species (Winstead and Ward, 1974; Dudeck and Peacock, 1992). Hybrid bermudagrasses can be limited in turfgrass quality and performance by prolonged periods of cloud cover and low light intensity.

Wilkinson and Beard (1974) described changes in anatomical, morphological, and physiological responses of ‘Pennlawn’ creeping red fescue (Festuca rubra L.), a shade tolerant species, and ‘Merion’ Kentucky bluegrass, a shade intolerant species. They reported similarities between creeping red fescue and Kentucky blue-grass for stomatal density and pore size, and chloroplast density and distribution, when grown in the shade. Pennlawn had greater cuticle thickness, more-developed vascular and support tissue, and more prostrate growth in shade than Merion. They hypothesized that creeping red fescue was more shade tolerant than Kentucky bluegrass due to its slower vertical elongation rate, which meant less tissue was removed by mowing, and reduced disease incidence, which was associated with the thicker cuticle and increased support tissues.

Beard (1965) found that shade resulted in a microenvironment with higher relative humidity and prolonged periods of dew, which produced more succulent turfgrass growth and encouraged disease development. Research with Kentucky bluegrass cultivars grown in shade and nonshade conditions revealed cultivars that were not susceptible to Bipolaris sorokiniana (Sacc.) Shoemaker, or Blumeria graminis (DC.) Speer in full sunlight became highly susceptible to these pathogens under shade stress conditions (Vargas and Beard, 1981). Whitcomb (1972) demonstrated that tree roots can reduce turfgrass root growth and plant vigor even when water and nutrients are not limiting. He reported that Kentucky bluegrass was more sensitive to tree root competition than creeping red fescue, rough bluegrass (Poa trivialis L.), and perennial ryegrass.

Most turfgrass areas are exposed to some degree of traffic stress, and intensively used sports fields and golf course turfs are particularly subject to foot and vehicular traffic stress conditions (Shearman, 1989b). Carrow and Petrovic (1992) reported a review of turfgrass literature concerning the impacts of traffic stress on turfgrasses. Turfgrass traffic stress can be broken into components of wear injury and soil compaction stress. Soil compaction results in the pressing together of soil particles, which brings about higher soil bulk density with reduced macropore space and lower soil oxygen levels (Carrow and Petrovic, 1992). Wear injury results from direct pressure, scuffing and tearing of the plant tissues (Shearman and Beard, 1975a). Turfgrass wear injury occurs immediately on applying traffic and is accentuated by repeated trafficking events (Youngner, 1961; Shearman et al., 1980, 2001; Shearman and Beard, 2002). Soil compaction stress is chronic and is accentuated on soils with high clay content (Carrow et al., 2001). While wear injury and soil compaction stress likely occur simultaneously on turfgrass sites, one of these stresses will likely dominate (Carrow and Petrovic, 1992). On sand rootzones, wear injury will be dominate, while on fine-textured soils maintained at field capacity, compaction stress will be the dominate factor (Carrow et al., 2001). Canaway (1981) reviewed literature in an attempt to identify characteristics that contribute to turfgrass wear tolerance. He found very few areas of agreement among the research studies reported. Canaway (1981) concluded that the lack of agreement among these studies was most likely due to researchers combining both wear injury and compaction stress rather than separating the components.

Shearman and Beard (1975a, 1975b, 1975c) reported on wear injury differences among seven cool-season turfgrass species, and the effects of various anatomical, physiological, and morphological plant characteristics contributing to observed wear injury among the species. Their research was the first to report the importance of total cell wall (TCW), cellulose, and lignin content contributing to turfgrass wear tolerance. They also demonstrated that leaf tensile strength, leaf width, percentage sclerenchyma fibers, and lignified cells were closely associated with turfgrass wear injury tolerance. The combination of TCW, cellulose, and lignin accounted for 96% of the observed wear tolerance variation among the species studied. These factors could be used as selection criteria in a breeding program designed to develop wear-tolerant cultivars.

Madison (1971) indicated that soil compaction is the foremost turfgrass problem on intensively used recreational turf sites, causing an overall decline in turfgrass vigor, growth, persistence, and quality. Carrow (1980) noted that total nonstructural carbohydrates declined by as much as 50% during midsummer for turfgrasses exposed to soil compaction stress. Turfgrass root morphology, physiology, growth, and depth and distribution have been reported to be modified by soil compaction stress (Carrow, 1980; O'Neil and Carrow, 1983; Agnew and Carrow, 1985a; Carrow and Petrovic, 1992). Under soil compaction stress, surface rooting increases and the volume of soil occupied by roots decreases. Therefore, turfgrasses growing on compacted soils exhibit reduced shoot growth and verdure due to the turfgrasses lacking the ability to effectively extract nutrients and water from the soil.

Shearman and Watkins (1985) reported intraspecific differences in lateral spread of Kentucky bluegrass cultivars growing in compacted and noncompacted soil conditions. Their results support the potential to select cultivars with improved tolerance of soil compaction stress. In Michigan, mixtures of Kentucky bluegrass and supina bluegrass (Poa supina Schrad.) were evaluated under traffic (Sorochan et al., 2001). After 2 yr of traffic stress, original mixtures containing 5 and 10% supina bluegrass had turfgrass covers of 99 and 96%, respectively. Their results support the competitive advantage of supina bluegrass over Kentucky bluegrass under soil compaction stress conditions.

	MILESTONES IN TURFGRASS SOIL PHYSICS AND CULTIVATION

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
Until the early 1960s, most putting greens and sports fields were constructed with high soil clay content. The clay gave stability, and good nutrient and water holding characteristics, but increased compaction stress potential (Kunze et al., 1957; Bloodworth et al., 1993). High sand content rootzones are currently the trend for intensively used sports fields and golf course putting greens. These rootzones offer improved soil aeration and drainage, enhanced playing conditions, and better turfgrass quality compared with high clay content rootzones that are more prone to soil compaction under intensive use.

Davis (1952) was the first to relate putting green soil physical condition to their performance. He found that better performing putting greens had greater macropore space than ones that performed poorly. He hypothesized that this response was likely due to differences in soil compaction. The first high sand content rootzone system based on scientific principles and extensive research was the USGA rootzone. It was developed at Texas A&M University under the leadership of M.E. Bloodworth and J.B. Page with support from the USGA (Kunze et al., 1957; USGA Green Section Staff, 1960; Ferguson et al., 1960; Bloodworth et al., 1993). Some of the physical characteristics of the USGA rootzone include improved infiltration rates, total pore space volumes of 40 to 50%, and enhanced water retention capacity. The USGA rootzone construction uses a two- or three-tier profile. The presence of the multiple tiers develops the hanging water column or perched water principle, which allows the rootzone to be drier near the surface and wetter in the mid and lower portions of the rootzone. Miller and Bunger (1963) explained that a saturated water reservoir is retained in the lower rootzone area due to the unsaturated conductivity characteristics of the coarse material and the desorption characteristics of the overlying rootzone.

The USGA specification rootzone is the most widely used construction method in the turfgrass industry. It revolutionized the golf course industry and has withstood the test of time (Duble, 1974; Snow, 1993). The specification criteria were refined in 1973, 1982, 1993, and 2004 (Brown and Duble, 1975; Hummel, 1993; Moore, 2004). When built to specification criteria and maintained properly, the USGA rootzone provides consistent playing conditions and turfgrass quality.

Many intensively used turfgrass sites are comprised of native soils that are prone to soil compaction (Carrow and Petrovic, 1992). In the late 1970s, an increased interest in soil cultivation was emerging as a cultural practice to improve turfgrass performance on intensively used turfgrass sites. At the same time, researchers were initiating studies to evaluate soil cultivation effects (Rieke and Murphy, 1989). These research efforts demonstrated benefits from soil cultivation such as enhanced root depth and density, increased infiltration rates, improved gas exchange between the soil and atmosphere, and more resilient playing surfaces (Murphy and Rieke, 1990; Wiecko et al., 1993). Though the benefits from soil cultivation are substantial, there are also negative aspects, like turfgrass injury, disruption of the playing surface, potential weed encroachment, and soil compaction in localized areas that need to be considered as well (Rieke and Murphy, 1989; Murphy and Rieke, 1990; Murphy et al., 1993). The turfgrass industry continues to develop new technologies in soil cultivation. Solid-tine, shatter coring, high pressure water injection and deep-tine are among these innovations that offer turfgrass managers greater opportunities to deal with soil compaction stress. The advent of site-specific management approaches may offer turfgrass managers even more specific approaches to limiting soil compaction stress in the future.

	MILESTONES IN ENVIRONMENTAL IMPACTS

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
Beard and Green (1994) described the role of turfgrasses in environmental protection and their benefits to humans. They divided the benefits into functional, recreational, and aesthetic components. Functional benefits of turfgrasses include: soil erosion control, dust stabilization, improved recharge and quality protection of groundwater, runoff and flood control, biodegradation of synthetic organic compounds, heat dissipation–temperature moderation, reduced noise, decreased glare, safety along roadsides, reduced fire hazard and green firebreaks, and improved security provided by high visibility zones. Despite these benefits, turfgrasses often receive criticism by those who believe turfgrass management practices have deleterious effects on water quality, and other environmental concerns.

Kenna and Snow (2002) summarized turfgrass environmental research on the fate of nutrients and pesticides, water quality and quantity issues, and efforts to address public concerns about turfgrasses. In 1989, the USGA initiated grant support for research focused on turfgrass environmental issues and concerns. Research results show that under most conditions only small amounts of nutrients move through the turfgrass–soil complex and those levels were far below the health and safety standards established by the USEPA (Wesely et al., 1987; Branham et al., 1995; Petrovic, 1995; Smith, 1995; Cisar and Snyder, 1996; Miltner et al., 1996; Shuman et al., 2000). Research indicated that turfgrass leaves, shoot, thatch, and roots act as an effective filter with most pesticides and nutrients remaining on plants, or in the thatch and upper few centimeters of soil (Wesely et al., 1985; Stahnke et al., 1991; Lickfeldt and Branham, 1995; Carroll and Hill, 1997). Research in Georgia, Pennsylvania, and Oklahoma demonstrated that pesticide and nutrient runoff from turfgrass sites may pose a greater threat to water quality than leaching (Linde et al., 1995; Cole et al., 1997; Shuman et al., 2000). However, low runoff volumes, antecedent soil moisture, effective attenuation of chemicals, and use of best management practices indicate that the likelihood of runoff being a major concern for nutrient and pesticide movement from turfgrass sites is minimal (Harrison,1993; Cole et al., 1997; Baird, 1998; Petrovic and Easton, 2005).

Despite the apparent decline of water quality and quantity in urban and suburban areas, there is very little research attempting to identify the actual causes. It may simply be the growing overall development in these areas that leads to these issues or other factors may be involved as well. Regardless, more research is needed to determine the sources of urban and suburban pollution impacting water quality. The NTRI is ideally suited to address these concerns. Since most of this research requires long-term efforts and is national in its scope of interest. Increased funding for this Initiative is imperative for maintaining a viable turfgrass and green industry in the future.

	OTHER IMPORTANT IMPACTS

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
In the past 50 yr, there have been numerous advances in areas like turfgrass pest management, pesticide chemistry, fertilizer technology, and plant growth regulators (Watson, 1997; Beard, 2004a). The introduction of 2,4-D [(2,4-dichlorophenoxy) acetic acid], although before the 50 yr covered in this manuscript, was instrumental in providing specific and highly effective postemergence herbicide control of many broadleaf weeds, which led to the process that has evolved even more effective herbicides, with greater specificity for turfgrass managers to use today. The subsequent development of preemergence herbicides in the late 1950s and early 1960s assisted turfgrass managers in maintaining even higher quality turfs than ever before that were free from warm-season, annual grass weeds (Watson et al., 1992). In addition, the development of fungicides and insecticides with specific activity for targeted pests improved turfgrass managers' capabilities of maintaining high-quality turfs. Coated fertilizers provided slow release of nutrients and improved opportunities for nutrient management in turfgrass fertilizer programs. Equipment manufacturers have responded to the needs of the industry with improved and more efficient mowing, fertilizer and pesticide application, and soil cultivation equipment, as well as more sophisticated irrigation systems. Recently, researchers in the public and private sectors have succeeded in relating remote sensing to various turfgrass abiotic and biotic stresses (Green et al., 1998; Guertal et al., 1999; Hamilton and Gibb, 2000; Carrow et al., 2002). Developing remote sensing as a tool for site-specific management of turfgrass biotic and abiotic stresses is of considerable interest to the turfgrass industry, particularly as it faces concerns regarding cost effectiveness and environmental sustainability. However, more research with this potential management tool is needed before it becomes widely accepted and cost effective in the industry.

	TOP 10 CONTRIBUTORS TO TURFGRASS SCIENCE SINCE 1955

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 
As previously mentioned, there have been a myriad of accomplishments in the discipline of turfgrass science in the past 50 yr. Many individual scientists and teams of scientists have made significant contributions in this regard. As a part of the CSSA 50th Anniversary celebration, Division C-5 members were surveyed to determine the 10 most influential persons contributing to turfgrass science during the past 50 yr. Approximately 10% of the current 504 members of C-5 were surveyed, and respondents represented the current demographics of the division. Responses were tabulated and 10 individuals who were identified most frequently by the respondents were listed alphabetically (Table 2). Most respondents indicated that the task of identifying just 10 individuals was more difficult then they first anticipated. Certainly, there are many individuals who are well deserving of this recognition, and hopeful those who were not included on this list will not feel slighted by this exercise.

There were a number of other individuals who received mention and were likely worthy of making this list. They included L.A. Brilman, R.N. Carrow, N.E. Christians, H.B. Couch, W.H. Daniel, J.M. Duich, M.H. Ferguson, R.E. Gaussoin, B. Huang, B.J. Johnson, K.J. Karnok, M.P. Kenna, W.A. Meyer, O.J. Noer, P.E. Rieke, R.W. Smiley, G.H. Snyder, J.M. Vargas, and D.V. Waddington. Their contributions are noteworthy and can be easily recognized when one reads the turfgrass literature.

The past 50 yr have been significant in the growth and development of the turfgrass industry, but they will pale in what the potential of the next 50 yr have to offer. Our discipline has many challenges and opportunities that need to be addressed, if the future of the turfgrass industry is to be fully realized. This said, we have many excellent turfgrass scientists and educators who appear willing to meet these challenges, and the future looks bright for Division C-5 (Turfgrass Science).

Received for publication December 10, 2005.

	REFERENCES

TOP ABSTRACT INTRODUCTION HISTORICAL PERSPECTIVE OF... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS RESEARCH... NATIONAL TURFGRASS RESEARCH... MILESTONES IN TURFGRASS BREEDING... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS... MILESTONES IN TURFGRASS SOIL... MILESTONES IN ENVIRONMENTAL... OTHER IMPORTANT IMPACTS TOP 10 CONTRIBUTORS TO... REFERENCES

 

• Agnew, M.L., and R.N. Carrow. 1985a. Soil compaction and moisture stress preconditioning in Kentucky bluegrass. I. Soil aeration, water use, and root responses. Agron. J. 77(6):872–878.[Abstract/Free Full Text]
• Agnew, M.L., and R.N. Carrow. 1985b. Soil compaction and moisture stress preconditioning in Kentucky bluegrass. II. Stomatal resistance, leaf water potential, and canopy temperature. Agron. J. 77(6):878–884.[Abstract/Free Full Text]
• Anderson, J., M. Anderson, A. Guenzi, C. Taliaferro, and D. Martin. 2005. Freeze tolerance and low temperature-induced genes in bermudagrass plants [Online]. Available at http://usgatero.msu.edu/v04/n01.pdf [verified 16 June 2006]. USGA Turfgrass Environ. Res. Online 4(1):1–7.
• Anonymous. 1994. James "Jack" Murray. Golf Course Manage. 62(7):72.
• Asano, Y., and M. Ugaki. 1994. Transgenic plants of Agrostis alba obtained by electroporation-mediated direct gene transfer to protoplasts. Plant Cell Rep. 13:243–246.
• Asano, Y., M. Ugaki, Y. Ito, M. Fukami, and A. Fujiie. 2000. Transgenic bentgrass (Agrostis spp.). p. 127–138. In Y.P.S. Bajaj (ed.) Biotechnology in agriculture and forestry, Transgenic Crops. Springer-Verlag, Berlin.
• Bailey, A. 2000. Virginia turfgrass industry. Virginia Agricultural Statistics Service, Richmond, VA.
• Baird, J.H. 1998. Evaluation of best management practices to protect surface water quality from pesticides and fertilizers applied to bermudagrass fairways. p. 56–59. In M.P. Kenna and J.T. Snow (ed.) USGA turfgrass and environmental research summary. USGA, Far Hills, NJ.
• Baltensperger, A.A. 1989a. Registration of ‘NuMex Sahara’. Bermudagrass. Crop Sci. 29:1326.[Free Full Text]
• Baltensperger, A.A. 1989b. NuMex Sahara—A new seed-propagated bermudagrass. USGA Green Sec. Rec. 27(1):5–6.
• Baltensperger, A.A., and J.P. Klingenberg. 1994. Introducing a new seed-propagated F1-hybrid (2-clone synthetic) bermudagrass. USGA Green Sect. Rec. 32:14–19.
• Baltensperger, A., C. Taliaferro, and C. Rodgers. 1998. Seeded bermudagrasses gain respect, quality. Golf Course Manage. 66(10):59–64.
• Beard, J.B. 1965. Factors in the adaptation of turfgrasses to shade. Agron. J. 57(5):457–459.[Abstract/Free Full Text]
• Beard, J.B. 1985a. Turfgrass physiology research: 1981–85. p. 81–104. In F. Lemaire (ed.) Proc. 5th Int. Turf. Res. Conf. Int. Turfgrass Soc., Blacksburg, VA.
• Beard, J.B. 1985b. An assessment of water use by turfgrasses. p. 45–60. In V.B. Gibeault and S.T. Cockerham (ed.) Turfgrass water conservation. Div. of Agriculture and Natural Resources Publ. 21405. Univ. of California, Riverside.
• Beard, J.B. 1990. Turfgrass color: When green is bad. Grounds Maint. 25(9):28–32.
• Beard, J.B. 1993. The xeriscaping concept: What about turfgrasses. Int. Turfgrass Soc. Res. J. 7:87–98.
• Beard, J.B. 1997. Shade stresses and adaptation mechanisms of turfgrasses. Int. Turfgrass Soc. Res. J. 8(Part 2):1186–1195.
• Beard, J.B. 2004a. Evolution of turfgrass research contributions and future research potentials in the 21st century. Int. Turfgrass Bull. 226:51–56.
• Beard, J.B. 2004b. Historian report Division C-5 Turfgrass Science. Presented at the C-5 annual business meeting. Seattle, WA. p. 1–10.
• Beard, J.B. 2005. 1965 to 2005 historian report for the International Turfgrass Society. Presented at the 10th Int. Turf. Res. Conf. Business Mtg., Wales, UK.
• Beard, J.B., H.J. Beard, and D.P. Martin. 1977. Turfgrass bibliography from 1672 to 1972. Michigan State Univ. Press, East Lansing, MI.
• Beard, J.B., and W.H. Daniel. 1965. Effect of temperature and cutting on the growth of creeping bentgrass (Agrostis palustris Huds.) roots. Agron. J. 57:249–250.[Abstract/Free Full Text]
• Beard, J.B., and W.H. Daniel. 1966. Relationship of creeping bentgrass (Agrostis palustris Huds.) root growth to environmental factors in the field. Agron. J. 58:337–339.[Abstract/Free Full Text]
• Beard, J.B., and R.L. Green. 1994. The role of turfgrasses in environmental protection and their benefits to humans. J. Environ. Qual. 23(3):452–460.[Abstract/Free Full Text]
• Biran, I., B. Brando, I. Bushkin-Harav, and E. Rawitz. 1981. Water consumption and growth rate of 11 turfgrasses as affected by mowing height, irrigation frequency, and soil moisture. Agron. J. 73:85–90.[Abstract/Free Full Text]
• Bloodworth, M.E., K.W. Brown, J.B. Beard, and S.I. Sifers. 1993. A new look at the Texas-USGA specifications for root-zone modification. Grounds Maint. 28(1):13–14.
• Branham, B.E., E.E. Miltner, and P.E. Rieke. 1995. Potential groundwater contamination from pesticides and fertilizers used on golf courses. USGA Green Sect. Rec. 33(1):33–37.
• Brilman, L.A. 2005. Turfgrass breeding in the United States: Public and private, cool and warm season. Int. Turf. Soc. Res. J. 10:508–514.
• Brown, K.W., and R.L. Duble. 1975. Physical characteristics of soil mixtures used for golf green construction. Agron. J. 67:647–652.[Abstract/Free Full Text]
• Burton, G.W. 1966. Tifway bermudagrass. Crop Sci. 6(1):93–94.
• Burton, G.W., and J.E. Elsner. 1966. Tifdwarf bermudagrass. Crop Sci. 6(1):94.
• Burton, G.W. 1991. A history of turf research at Tifton. USGA Green Sec. Rec. 29(3):12–14.
• Canaway, P.M. 1981. Wear tolerance of turfgrass species. J. Sports Turf Res.