Management of Annual Bluegrass on Golf Courses: Improved Practices for Maintenance, Pest Control, and Viable Techniques for Transition to Mo

MANAGEMENT OF ANNUAL BLUEGRASS ON GOLF COURSES: IMPROVED PRACTICES FOR MAINTENANCE, PEST CONTROL, AND VIABLE TECHNIQUES FOR TRANSITION TO MO

Sponsoring Institution

National Institute of Food and Agriculture

Project Status

COMPLETE

Funding Source

HATCH

Reporting Frequency

Annual

Accession No.

1008567

Grant No.

(N/A)

Cumulative Award Amt.

(N/A)

Proposal No.

(N/A)

Multistate No.

NE-1046

Project Start Date

Oct 16, 2015

Project End Date

Sep 30, 2016

Grant Year

(N/A)

Program Code

[(N/A)]- (N/A)

Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907

Performing Department
Horticulture and Landscape Architecture

Non Technical Summary
Overview: Turf areas including golf courses are a valuable and rapidly expanding component of urban and rural landscapes covering 12 million ha in the United States (Potter & Braman 1991). Over 16,000 golf courses in the U.S. provide green space in the urban environment; offer recreation for 36 million Americans; generate jobs, commerce, economic development, and tax revenues for communities; and contribute $62.2 billion worth of goods/services each year to the national economy (www.golf2020.com).The primary golf playing areas across the cool-humid region and transition zone regions of the USA include putting greens, fairways and the teeing ground. Although these areas are often originally planted to a number of regionally adapted species, annual bluegrass (Poa annua) is a highly invasive weed on short-mown golf course surfaces (fairways, tees, putting greens) where it often becomes the dominant species despite extensive attempts to suppress it. Golf course managers often resort to managing it instead of more pest-tolerant bentgrasses (Agrostis spp.) (Miltner et al. 2004). P. annua can provide an acceptable playing surface for putting greens and fairways when properly maintained, but this requires extensive chemical inputs (Grant & Rossi 2005; Bigelow and Tudor, 2012). It has high tiller density and tolerance of low cutting heights, shade and traffic, but is often maligned for its lack of stress (severe winter and summer months) tolerance, yellow-green color, prolific flowering habit, and susceptibility to many diseases and insect pests (Beard, 1973).Thus, the overarching purpose of this project is to study the cultural requirements of annual bluegrass as a golf turf species. In addition a number of studies will be conducted to evaluate the pests that chronically affect P. annua and how cultural programs can be modified to improve turf health and reduce chemical inputs for this species. In summary, the goal is to provide golf turf managers better data and information so that they can manage their turf in an environmentally responsible manner while providing a persistent and consistent playing surface with fewer management inputs.

Animal Health Component

90%

Research Effort Categories

Basic

10%

Applied

90%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	2130	1160	50%
102	2130	1070	50%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 216 - Integrated Pest Management Systems;

Subject Of Investigation
2130 - Turf;

Field Of Science
1070 - Ecology; 1160 - Pathology;

Keywords

integrated pest management

Goals / Objectives
Develop improved options for the management of ABR associated with P. annua on golf courses in the Northeast and Mid-Atlantic including (a) fill critical knowledge gaps in our understanding of ABR biology, ecology, and pathogenesis, (b) develop cultural, biological, chemical, and genetic control options, and (c) develop improved tools for pathogen detection and quantification. Develop cultural, chemical, biological, and genetic methods to suppress/eliminate P. annua and to transition P. annua-dominated areas to more sustainable turfgrass species. Disseminate best management practices for P. annua and major pests and for P. annua suppression/transition to more sustainable turfgrasses and assess impact thereof. Develop a better understanding of stresses that affect P. annua and the cultural, chemical, and genetic methods to mitigate these stresses.

Project Methods
This multi-state project will use field, greenhouse and growth chamber studies across multiple years to investigate the cultural requirements of annual bluegrass. In addition studies will also investigate some of the unique pest problems associated with this turf species. In order assess the industry's use, care and cultural challenges of annual bluegrass as well as the economic impact of culturuing this species surveys (web-based) will be periodicially distributed to key stake-holders and practicioners.Data generated by this project will be reviewed annually by the participants at an annual meeting. From this information future studies, needs and knowledge gaps will be identified.

Progress 10/16/15 to 09/30/16

Outputs
Target Audience:The target audience has primarily been golf course managers, technical consultants to those managing golf courses, as well as those allied groups associated with providing products and services to the golf course industry, which includes roughly 32,000 golf courses globally. We also have reached golfers through the United States Golf Association Green Section and other state and regional turf associations. This has been important because it helped to educated the end users (golfers) in understanding the significant environmental (e.g. winter-kill) and major pest stresses (ABW, ABR) affecting the playing surfaces and how golf course managers are utilizing all resources to manage these pests preserve and protect the environment. It has also opened the door to conversations with respect to conversion to more desireable and sustainable golf turf species that could replace annual bluegrass. Many courses have listened and have recently begun renovating to newer species and cultivars that require fewer chemical inputs compared to annual bluegrass. Changes/Problems:There have been no major changes or problems with this multistate project. In fact, there have been significant advances along the way and frequent updates to the best management practices (BMPs) for managing the two major pests affecting annual bluegrass (anthracnose and annual bluegrass weevil). The most recent BMP recommendations for anthracnose are archived on the Rutgers Center for Turfgrass Science website (https://turf.rutgers.edu/research/bmpsanthracnose2015.pdf) and have been routinely accessed by turf managers and industry consultants over the past 10 years. In addition as this project has moved toward it's termination several instutitions have begun to work and plan heavily toward the "next step" which would include BMPs and management systems that would allow for golf turf managers to better transition toward more sustainable turf species (e.g. improved creeping bentgrasses or perhaps perennial ryegrass, etc.) that have partially been under development and/or investitgation with some of the project members. What opportunities for training and professional development has the project provided?This multi-state regional research project (NE 1046) has helped improve the exchange of information about issues related to the management and annual bluegrass, two of the major pest threats 1.)anthracnose disease of annual bluegrass and 2.) annual bluegrass weevil. In addition several pilot studies to suppress annual bluegrass in more desirable and sustainable turf surfaces as well as transitioning to these more desirable species. All of which are related to the five "umbrella" NE 1046 project objectives listed below. This has occurred between turfgrass scientists throughout North America and other parts of the world (Europe, Asia and South America). Our outreach efforts to peer scientists through the Crop Science Society of America, American Phytopathological Society, Entomological Society of America, The European Turfgrass Society (Norway, Portugal) and International Turfgrass Society (Chile and China) has stimulated the refinement of our research studies and served as an effective multiplier of the dissemination of our findings to the golf course industry globally. Develop improved options for the management of ABW on golf courses in the Northeast and Mid-Atlantic including (a) fill critical knowledge gaps in our understanding of ABW biology, ecology, and impact, (b) develop cultural, biological, chemical, and genetic control options, and (c) develop improved IPM decision making tools. Develop improved options for the management of ABR associated with P. annua on golf courses in the Northeast and Mid-Atlantic including (a) fill critical knowledge gaps in our understanding of ABR biology, ecology, and pathogenesis, (b) develop cultural, biological, chemical, and genetic control options, and (c) develop improved tools for pathogen detection and quantification. Develop a better understanding of stresses that affect P. annua and the cultural, chemical, and genetic methods to mitigate these stresses. Develop cultural, chemical, biological, and genetic methods to suppress/eliminate P. annua and to transition P. annua-dominated areas to more sustainable turfgrass species. Disseminate best management practices for P. annua and major pests and for P. annua suppression/transition to more sustainable turfgrasses and assess impact thereof. How have the results been disseminated to communities of interest?In line with Objective 5 of this project: ("Disseminate best management practices for P. annua and major pests and for P. annua suppression/transition to more sustainable turfgrasses and assess impact thereof"). Findings have been disseminated to stakeholders via state, regional, national and international educational conferences, newsletters, trade and professional publications, blogs, podcasts, websites, and webcasts. The best management practices (BMPs) for suppressing anthracnose disease of annual bluegrass were published twice as a feature article in Golf Course Management (GCM) Magazine (an international trade journal published by the professional organization for golf course managers the Golf Course Superintendents Association of America with a readership of 23,000 turf managers). Additionally, our recommendations on best management practices (BMP) to control anthracnose disease on annual bluegrass turf have been distributed to the golf course industry and the public through research reports published by the United States Golf Association andthe State and local turf Associations like the Tri-State Turf Research Foundation, as well as trade journals and turf association newsletters in Australia, Canada, New Zealand,and the United States. The most recent BMP recommendations for anthracnose also are archived on the Rutgers Center for Turfgrass Science website (https://turf.rutgers.edu/research/bmpsanthracnose2015.pdf) and have been routinely accessed by turf managers and industry consultants over the past 10 years. Our outreach presentations at national and state conferences have been sponsored by the Golf Course Superintendents Association of America, Golf Course Superintendents Association of New Jersey, Metropolitan Golf Course Superintendents Association, New Jersey Turfgrass Association, Connecticut Golf Course Superintendents Association, and numerous turfgrass associations in the mid-Atlantic, Northeast, upper Midwest, such as the Inidana Green Expo, the Pacific Northwest, California, and Canada. Overall IMPACT: Further the impact of this project, originally initiated in 2002, has been significant. Over the past 10 years, we have conducted three surveys of golf course superintendents in the United States and Canada to assess project impacts: 2006 (n=346 respondents), 2012 (n=631), and 2016 (n=215). The survey in 2016 indicated that 44% of superintendents considered anthracnose the most common disease they manage(a 22% and 28% decrease from 2012 and 2006, respectively). Similarly, 85% of the superintendents in the 2016 survey reported being confident in their ability to control anthracnose after learning about the Best Management Practices (BMPs) developedby project participants (a 26% and 35% increase from 2012 and 2006, respectively). According to Rutgers Plant Diagnostic Laboratory, the number of anthracnose sample submissions from golf courses in the United States decreased 56% from the period of 2002 to 2006, 67% from the period of 2006 to 2012, and 83% from the period of 2012 to 2016. This represents an indirect yet informative measure of the tremendous positive impact that BMPs from this project have had on golf courses in the United States and Canada over the past decade. Results from the 2012 and 2016 surveys indicatingthat golf coursemanagement practices in the United States and Canada changed as a result of learning about project BMPsincluded: increased light-frequent applications of soluble nitrogen(88 and 72%, respectively), raisedmowing heights to reduce plant stress(50 and 44%, respectively), implementedlightweight rolling and/or increased mowing frequency (63 and 94%, respectively), appliedmore sand topdressing during the growing season (50 and 59%, respectively), modifiedirrigation practices to avoid wilt stress (79 and 59%, respectively), and increased potassium fertilization, a BMP developed after 2012 (36% in 2016 survey). Of those who changed their management practices, the following percentages felt that doing so significantly reduced anthracnose severity in 2012 and 2016: increasing soluble N (95 and 86%, respectively), raising the mowing height (95 and 80%, respectively), avoiding drought stress (94 and 68%, respectively), increased summer topdressing (83 and 67%, respectively), and increased rolling or mowing frequency (64 and 58%, respectively). The 2012 survey of fungicide use indicated that 91% of respondents implemented effective fungicide programs developed by the project (i.e., utilizing the most effective fungicides and alternating/tank mixing fungicides with different modes of action) to better control anthracnose and reduce to potential for fungicide resistance. Total fungicide usage for the control of this devastating disease was reduced as a result of our BMPs; 48% of superintendents lengthened the fungicide application interval (number of days between sprays to control anthracnose) and 16% reduced fungicide rates. Our research indicated that fungicide inputs can be reduced as much as 80% if all BMPs are fullyimplemented. Increasing cultural inputs (e.g., nitrogen, sand topdressing, new mowers, etc.) to reduce anthracnose severity increased management costs for 56% of superintendents, but this was more than offset by the money saved by 73% of superintendents who reported reducing or completely eliminating turf loss caused by anthracnose by adopting project BMPs ($1,000 to $20,000 in renovation costs saved each year per golf course). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? There were five major goals of this project over the past 5-years and important advancements occurred in each: #1.) Develop improved options for the management of ABW on golf courses in the Northeast and Mid-Atlantic including (a) fill critical knowledge gaps in our understanding of ABW biology, ecology, and impact, (b) develop cultural, biological, chemical, and genetic control options, and (c) develop improved IPM decision making tools. The entomologists working on this project (Rutgers, Penn State, Univ. of Massachusetts, Univ. Rhode Island) have been spending a significant amount of time and resources to fill important knowledge gaps with respect to ABW. Their efforts have been focused on the biology, behavior of the insect as well as spatial and mapping/sampling strategies to help maximize the efficacy of various synthetic and biological control products (e.g. exploring the additive effects of entomopathogenic nematodes) and understand the ecological and biological factors that may contribute to insecticide resistance. #2.) Develop improved options for the management of ABR (basal rot anthracnose) associated with P. annua on golf courses in the Northeast and Mid-Atlantic including (a) fill critical knowledge gaps in our understanding of ABR biology, ecology, and pathogenesis, (b) develop cultural, biological, chemical, and genetic control options, and (c) develop improved tools for pathogen detection and quantification. Numerous research studies have helped fill knowledge gaps with respect to the ecology and pathogenesis of the ABR fungus. Numerous Colletotrichum cerealeisolates have evaluated and analyzed at Univ. of Guelph, Connecticut, USDA-ARS (Beltsville), Univ. Massachusetts and Rutgers. A reproducible growth chamber-based inoculation protocol for Colletotrichum cereale was developed at Rutgers and greatly improved the ability to conduct basic biology experiments for the pathogen. A series of field investigations assessed how nitrogen (N)fertility impactsthe populationand diversity of soil microorganisms. Differences among soil-inhabiting microbial communities were detected throughout the growing season and showed that sampling dateshould be an important consideration when assessing the impact of management practices on soil microbial communities. The complete transcriptome of C. cerealeis being sequenced to determine if its pathogenicityincreases under low N fertility. #3.) Develop a better understanding of stresses that affect P. annua and the cultural, chemical, and genetic methods to mitigate these stresses. The most significant and potentially catastrophic environmental stresses affecting annual bluegrass are those associated with extremes in cold and heat. This has been acutely studied in the last two years after the significant annual bluegrass turf losses that occurred as a result of "The Polar Vortex" winter of 2013-2014 where widespread turf loss occurred due to cold temperatures and ice damage. Creeping bentgrass is generally not affected by winter extremes but the metabolic responses of annual bluegrass and bentgrass are now being studied more carefully and compared by research laboratories at Univ. of Massachusetts and others. In addition, ancillary studies are being conducted with respect to various cultural practices to minimize summer stress at all research sites. Integrated Cultural Stresses: research from this project showed that the practice of increased N fertilization frequently produces the greatest reduction in anthracnose disease on golf course putting green turf. Acceptable, season-long disease suppression without fungicides occurred during years with moderate anthracnose epidemics when increased N fertilization was combined with higher mowing and greater sand topdressing. Additional best management practices for suppressing anthracnose on annual bluegrass turf also were discovered during this project. Potassium (K) fertilization that produced a K content in the mat layer (thatch mixed with sand) of 43 to 70 mg/kg (Mehlich 3 soil test method) and a leaf K concentration of 17 to 29 g/kg was needed to suppress the severity of anthracnose on annual bluegrass putting green turf. Mat and soil layers having a pH less than 6.0 intensify the severity of this disease. Soil cultivation practices (commonly used on golf courses) deployed during anthracnose outbreaks did not greatly affect (intensify) anthracnose severity and applications of a fungicide during cultivation was sufficient to avoid subtly aggravating the disease. #4.) Develop cultural, chemical, biological, and genetic methods to suppress/eliminate P. annua and to transition P. annua-dominated areas to more sustainable turfgrass species. Several researchers (e.g. Auburn research lab) have been exploring the genetic and molecular aspects of annual bluegrass to identify key strenghts and weaknesses of the species for exploitation in suppression and management efforts. Further, at Rutgers, anthracnose resistance in bentgrass was identified and incorporated into germplasm being used to develop new cultivars with enhanced resistance to multiple diseases. Newer, improved cultivars of colonial bentgrass (Agrostis capillaris) and creeping bentgrass (Agrostis stolonifera) were developed which are more competitive with annual bluegrass in mixed stands. Compaction of the soil favors the competitiveness of annual bluegrass, but the new improved cultivars of bentgrass remain more competitive in mixed stands than older cultivars of bentgrass. Thus, newer bentgrass cultivars developed in this project are a viable option for golf courses where a surfaces that is more tolerant of anthracnose with fewer pesticides. Various studies at Penn State, Purdue, Rutgers (see objective 3 above) and Connecticut have evaluated the effect of soil and fertilizer nutritional programs, focusing on soil phosphorus, potassium, iron and nitrogen sources, on the encroachment and/or suppression of annual bluegrass into mature creeping bentgrass stands. In addition, the effects of nutrition on the incidence and severity of anthracnose have been evaluated. Since these nutritional studies generally are longer term in nature, they will continue into the next iteration of this project to better assess the ecological components of these factors. Renovating to superior species? Recent pilot studies like those at the University of Connecticut have begun to investigate methods to safely and effectively transition from an existing turf to more desirable/sustainable species, like improved creeping bentgrasses using glyphosate and various soil cultivation programs. Ideally, these studies will continue in the next iteration of this project. #5.) Disseminate best management practices for P. annua and major pests and for P. annua suppression/transition to more sustainable turfgrasses and assess impact thereof. Throughout the duration of this project the fact-based recommendations (e.g. best management practices BMPs) for the management or suppression of annual bluegrass have been disseminated by all of the cooperators through numerous oral presentations (meetings, field days, seminars, etc.) as well as print and web-based publications. The information on BMPs related with respect to basal rot anthracnose have been continually updated as new research information has been published. The most recent BMPs are archived at https://turf.rutgers.edu/research/bmpsanthracnose2015.pdf and routinely accessed by turf managers and industry consultants over the past 10 years. With respect to ABW, numerous sources of information are also available and some of the research data generated in this project with respect to ABW biology, ecology and scouting techniques (Penn State, Univ. Massachusetts, Rutgers) is being utilized commercially with a web-based "WeevilTrak" http://www.greencastonline.com/weeviltrak/home.aspx which is widely utilized by managers in the areas affected by this significant insect pest.

Publications

Type: Journal Articles Status: Published Year Published: 2016 Citation: Inguagiato, J. C., and K. Guillard. 2016. Foliar N concentration and reflectance meters to guide N fertilization for anthracnose management of annual bluegrass putting green turf. Crop Sci. 56(6):p. 3328-3337.
Type: Journal Articles Status: Published Year Published: 2016 Citation: Schmid, C. J., J. A. Murphy, B. B. Clarke, M. DaCosta, and J. S. Ebdon. 2016. Observations on the effect of potassium on winter injury of annual bluegrass in New Jersey in 2015. Crop, Forage and Turfgrass Management. 2(1):p. 1-4.
Type: Journal Articles Status: Published Year Published: 2016 Citation: Chen, S., J. S. McElroy, M. L. Flessner, and F. Dane. 2015. Utilizing next-generation sequencing to study homeologous polymorphisms and herbicide-resistance-endowing mutations in Poa annua acetolactate synthase genes. Pest Management Science. 71(8):p. 1141-1148.
Type: Journal Articles Status: Published Year Published: 2015 Citation: Hempfling, J. W., B. B. Clarke, and J. A. Murphy. 2015. Anthracnose disease on annual bluegrass as influenced by spring and summer topdressing. Crop Sci. 55(1):p. 437-443.
Type: Journal Articles Status: Published Year Published: 2015 Citation: Hoffman, L., M. DaCosta, A. Bertrand, Y. Castonguay, and J. S. Ebdon. 2014. Comparative assessment of metabolic responses to cold acclimation and deacclimation in annual bluegrass and creeping bentgrass. Environ. Exp. Bot. 106:p. 197-206.
Type: Journal Articles Status: Published Year Published: 2015 Citation: Clarke, B. B., L. A. Beirn, and J. A. Crouch. 2014. Influence of host and geographic locale on the distribution of Colletotrichum cereale lineages. PloS ONE. 9(5):p. e97706 [1-10].
Type: Journal Articles Status: Published Year Published: 2015 Citation: Hoffman, L., M. DaCosta, and J. S. Ebdon. 2014. Examination of cold deacclimation sensitivity of annual bluegrass and creeping bentgrass. Crop Sci. 54(1):p. 413-420.
Type: Journal Articles Status: Published Year Published: 2015 Citation: Flessner, M. L., J. S. McElroy, and G. R. Wehtje. 2014. Annual bluegrass (Poa annua) control in glyphosate-resistant perennial ryegrass overseeding. Weed Technol. 28(1):p. 213-224.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Park, B. S., C. Mansue, and J. A. Murphy. 2016. Using herbicides to renovate turf dominated by annual bluegrass. p. 148-149. In Proceedings of the First Annual Meeting of the Northeastern Plant, Pest, and Soils Conference. Philadelphia, Pennsylvania: January 3-7, 2016.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Schmid, C. J., J. A. Murphy, and B. B. Clarke. 2016. Annual bluegrass response to potassium and calcium fertilization and soil pH. Agron. Abr. p. 99639.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Song, E., and X. Xiong. 2016. Influences of plant growth regulators on seedhead development of annual bluegrass (Poa annua L.). Agron. Abr. p. 99825.
Type: Journal Articles Status: Published Year Published: 2015 Citation: McGraw, B. A., and A. M. Koppenhofer. 2015. Spatial analysis of Listronotus maculicollis immature stages demonstrates strong associations with conspecifics and turfgrass damage but not with optimal hosts on golf course fairways. Entomologia Experimentalis et Applicata. 157(3):p. 307-316.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Hempfling, J. W., B. B. Clarke, and J. A. Murphy. 2016. Best management practices for anthracnose on annual bluegrass. Agron. Abr. p. 100384.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Kaminski, J. E., T. T. Lulis, and C. Stephens. 2016. Influence of nitrogen, plant growth regulators and iron sulfate on annual bluegrass populations. Agron. Abr. p. 101974
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: McGraw, B. 2016. The Rutgers model: A cultural approach to minimizing annual bluegrass weevil insecticide applications on putting greens. Proc. Rutgers Turfgrass Symp. 25:p. 14.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Schmid, C. J., J. A. Murphy, and B. B. Clarke. 2016. Anthracnose of annual bluegrass: How our understanding of soil fertility requirements has changed over the past five years. Proc. Rutgers Turfgrass Symp. 25:p. 21.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Kostromytska, O. S., S. Wu, and A. M. Koppenh�fer. 2016. Sustainable management of the annual bluegrass weevil. Proc. Rutgers Turfgrass Symp. 25:p. 59-61.
Type: Other Status: Published Year Published: 2016 Citation: Koppenh�fer, A., O. Kostromytska, and S. Wu. 2016. Optimal management programs for annual bluegrass weevil populations with different insecticide resistance levels. Golf Course Manage. 84(11):p. 77-78.
Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Kostromytska, O. S., S. Wu, C. Rodriguez-Saona, and A. M. Koppenh�fer. 2015. Towards sustainable management of the annual bluegrass weevil. Proc. Rutgers Turfgrass Symp. p. 30-32