Dr Bruce Martin Fungicide Program #13
Non Technical Summary Disease management in putting greens is problematic in transition zone climates because of the environmental stresses encountered in both bentgrass and bermudagrass systems. It is very important to develop and evaluate tools in an integrated approach to manage the biological stress of plant diseases.
Chemical fungicides ae still the cornerstone of plant disease control on creeping bentgrass putting greens in these regions of the United States. However, loss of older products and introduction of new fungicide chemistries, new formulation, new regulations predicate the need to evaluate the potential role of these materials in disease management strategies. Increasing urbanization in the southeastern United States is predicted to occur and the region is a popular destination for tourism. Concomitantly, the demand for quality turfgrasses in golf course, parks, home lawns and commercial settings will increase. Disease management to assist in attaining and maintaining quality turfgrass is critical to continued economic developement in the region. This research will provide a scientific basis for best management practices for disease control in putting greens regionally. It will provide a basis for understanding new diseases such as rapid blight that are the result of degrading environmental components as well as increased old diseases such as Rhizoctonia leaf and sheath spot that may result from increased inputs for putting green speed and consistency.
Goals / Objectives Goals of this project are: 1)develop improved practices for fungicide use for disease control in creeping bentgrass and bermudagrass putting greens for the southeastern United States; 2) improve understanding of the pathology and ecology of Labyrinthula terrestris, the causal agent of rapid blight disease of turfgrasses; 3) identify diseases of bermudagrass and develop effective disease management practices and programs. Expected outputs of the proposed research will include development, verification and publlcation of improved disease control programs in creeping bentgrass putting greens and in bermudagrass putting greens. Results will be disseminated by oral and written reports at scientific meetings and meetings of lay clientele, through refereed journal publications, and on-line and print trade journals. Outputs will also include new information on the infection process, life cycle and pathogenicity of Labyrinthula terrestris to host grasses, with results published in appropriate professional journals. Outputs from objective 3 will include the determination of new information on Rhizoctonia zeae and related fungi as pathogens of bermudagrass, and the influence of fertility, fungicides and growth regulators on disease severity. This information will be published in appropriate professional journals as well as to augment control recommendations for end users. Project Methods Disease control products will be evaluated on creeping bentgrass and bermudagrass greens at the Pee Dee Research and Education Center and on in-play conditions on golf courses.
Target diseases include brown patch, Rhizoctonia leaf and sheath spot, dollar spot, Pythium blight and root dysfunction, anthracnose and fairy ring infestations. Experiments to determine efficacy, timing of applications, effects of fertility and other technology will be conducted. Disease control and nontarget effects will be evaluated.
Trials will be conducted in small plots using using CO2-pressurized small plot sprayers. Design will be randomized complete block designs typically. Results will be used to design disease control programs which involve the sequential preventive treatments at low fungicide label rates for a designated period of time (e.g.
Summer months). This approach seeks to more closely mimic real world disease control as it would be practiced on golf course greens. Disease severity and quality measurements will be used to construct disease progress curves and results quantified over time as area under the disease or quality progress curve.
Concerning objective 2, to study biological aspects of the causal agent of rapid blight, traditional microbiological techniques will be used including photography and microscopic measurements of life cycle stages to compare with known species of Labyrinthula. Survey will correlate soil and irrigation water properties with outbreaks of disease, confirmed by isolation onto serum-artificial seawater agar. Experiments will be conducted in greenhouse and growth chambers to evaluate the effects of salinity and influence of salinity components (chloride, sulfate and bicarbonate salts of Na, Ca, and Mg) on disease.
Rough bluegrass and perennial ryegrass will be the typical grass hosts utilized for these experiments. Mechanisms of pathogenicity will be investigated in cooperation with scientists on campus using artificial inoculation of ryegrass and rough bluegrass and study of infection and disease progress using light and electron microscopy studies. Also, as a component of objective 2, fungicides, potential tolerant grasses, and other tools for salinity management will be evaluated in field, greenhouse and growth chamber experiments to continue to develop integrated management recommendations for rapid blight.
Concerning objective 3 ultradwarf bermudagrass cultivars will be evaluated for susceptibility to major diseases and appropriate disease control programs developed. Emphasis will be placed on identification and detection of Rhizoctonia zeae and related fungi and their role in disease outbreaks in bermudagrass greens. Fertility level and components (e.g. K, Mg, Mn, Ca as well as N, P and K) may influence recent outbreaks of Rhizoctonia diseases. Use of thiophanate methyl may also have a role in promotion of recent epidemics. Isolates of these fungi will be collected from active epidemics and identified by classical mycological and molecular techniques. Pathogenicity will be evaluated, as well as the influence of fungicides nutritional components on disease severity.
Progress 07/01/09 to 09/30/14 Outputs Target Audience: Target audiences include golf course superintendents, owners, lawn care companies, professional consultants, students of turf diseases and other scientists studying turf disease management. Also, professionals with agricultural pharmaceutical companies involved in testing, developing and marketing products for disease and nematode management in putting greens. Studentsin plant pathology also were an audience for the research accomplished in this period. Changes/Problems:Nothing ReportedWhat opportunities for training and professional development has the project provided?
Data from each year that are relevant to the objectives in this project are presented annually to golf course managers in workshops, seminars and through personal one-on-one interactions via email, webinars, etc. Examples from the research conducted are also used to educate graduate students and undergraduate turf majors in order to keep their knowledge up to date. How have the results been disseminated to communities of interest? Primarily through seminars, webinars, and workshops as well as journal and trade articles. What do you plan to do during the next reporting period to accomplish the goals?Nothing ReportedImpacts What was accomplished under these goals?Disease management programs have been refined for bentgrass and bermudagrass putting greens. For bentgrass, targeted diseases included Pythium root dysfunction, brown patch, dollar spot, Rhizoctonia leaf and sheath spot and anthracnose.
Fungicide choice and timing have been studied in field trials of directed studies and in programs to refine practical recommendations for fungicide deployment. General program guidelines were developed for bentgrass greens summer disease control and these guidelines have been largely adopted throughout the southeastern US for bent disease control in heat stress environments.
However, the rapid change of bent greens to ultradwarf bermudagrass greens has resulted in more emphasis on bermudagrass disease management (objective 3). Targeted diseases included spring dead spot, leaf spot, dollar spot and Michrodochium patch and objectives for management were refined through field trials and trials for each of these targeted diseases. Results of trials has led to better recommendations for control in a season-long format, so that turfgrass quality is not compromised and businesses remain viable. Concerning objective 2, the infection and colonization process of Labyrinthula infection to susceptible ryegrass was studied, as well as new fungicides for management of the rapid blight disease. Although new fungicides are still limited with good efficacy for rapid blight, another product, fluazinam, was shown to be efficacious and may provide an alternative to pyraclostrobin and trifloxystrobin for potential resistance management. This is timely because mancozeb is being limited in useage on turf, and does now fulfill a purpose in improved control as well as potential resistance management. Late in this project, an additional emphasis was the role of plant parasitic nematodes in putting greens Primary accomplishments this reporting period included a modern survey of plant parasitic nematodes in golf turf, including bentgrass and bermudagrass putting greens.
Results indicated a relatively high level of infestation of these turfgrasses in North and South Carolina with species including Belonolaimus, Hoplolaimus, Meloidogyne, and Trichodorus. The survey work has placed a good scientific framework to continue studies and educate clientele on the importance of these pests. A new nematode, Trichodorus obtusus was described as a first report of infestation in South Carolina and experiments on the diversity and control of this nematode were performed. Data obtained confirm that nematodes are primary pathogens in golf greens in the southeast and deserve increased attention regarding their management. Publications. Type:Journal ArticlesStatus:PublishedYear Published:2012Citation:Taxonomy and morphology of plant-parasitic nematodes associated with turfgrasses in North and South Carolina, USAYONGSAN ZENG, WEIMIN YE2, LANE TREDWAY, SAMUEL MARTIN& MATT MARTINZootaxa 3452: 1001346 (2012)Progress 01/01/13 to 09/30/13 Outputs Target Audience: Target audiences include golf course superintendents, owners, lawn care companies, professional consultants, students of turf diseases and other scientists studying turf disease management. Also, professionals with agricultural pharmaceutical companies involved in testing, developing and marketing products for disease and nematode management in putting greens.
Changes/Problems:Nothing ReportedWhat opportunities for training and professional development has the project provided? Data from each year that are relevant to the objectives in this project are presented annually to golf course managers in workshops, seminars and through personal one-on-one interactions via email, webinars, etc. Examples from the research conducted are also used to educate graduate students and undergraduate turf majors in order to keep their knowledge up to date. How have the results been disseminated to communities of interest? Primarily through webinars, seminars, and workshops as well as refereed journal articles and popular articles. What do you plan to do during the next reporting period to accomplish the goals?
Emphasize nematode management with new products and strategies as primary stressors of greens grasses; emphasize management and control of Rhizoctonia zeae in bermudagrass greens, causing 'Rhizoctonia leaf and sheath spot' which remains as a disease with high fungicide inputs but unsatisfactory outcomes in healing or preventing this emerging disease in bermudagass greens. Finalize a project on identification and control of spring dead spot in bermudagrass in Argentina and South Carolina.
Impacts What was accomplished under these goals?Primary accomplishments this reporting period included a modern survey of plant parasitic nematodes in golf turf, including bentgrass and bermudagrass putting greens. Results indicated a relatively high level of infestation of these turfgrasses in North and South Carolina with species including Belonolaimus, Hoplolaimus, Meloidogyne, and Trichodorus. A new nematode, Trichodorus obtusus was described as a first report of infestation in South Carolina and experiments on the diversity and control of this nematode were performed.
Data obtained confirm that nematodes are primary pathogens in golf greens in the southeast and deserve increasd attention regarding their management. New fungicides, including Daconil Action, Briskway, Secure, Lexicon, Xzemplar and others were evaluated in bent and bermudagrass putting greens for disease management. These new fungicides were determined to be valuable for dollar spot, brown patch, leaf spot in bermudagrass and perhpas in other disease systems that occur in greens (e.g. Spring dead spot). Programs that were targeted for fall/winter diseases and turf quality in bermudagrass greens prevented disease in fall and carried over into the following spring. Programs with Lexicon (fluxapyroxad + pyraclostrobin) were particularly impressive with excellent disease control and turf quality.
Publications. Type:Journal ArticlesStatus:PublishedYear Published:2012Citation:Diversity and Occurrence of Plant-parasitic Nematodes Associated withGolf Course Turfgrasses in North and South Carolina, YONGSAN ZENG, WEIMIN YE, S. BRUCE MARTIN, MATT MARTIN, LANE TREDWAY.Journal of Nematology 44(4).
2012.Progress 01/01/12 to 12/31/12 Outputs OUTPUTS: Fungicide trials were conducted in Crenshaw, A4 and A1 bentgrass to evaluate new products and how to best utilize those new products with existing fungicides and mixtures in a program used during summer stress on creeping bentgrass. This work continues from previous years but is relevant now due to 'early order' programs from major manufacturers and distributors. Related experiments utilized a base program designed by Martin (termed program 13) in which specific strobilurin fungicides were compared for effectiveness for disease control and comparison of nontarget effects. Strobilurins included pyraclostrobin (Insignia), azoyxystrobin (Heritage TL) and fluoaxostrobin (Disarm).
Timing of these components were identical. These experiments were conducted in the context of record-breaking heat again reported in SC and in the midwest in 2012. Diagnostics through our commercial turf clinic provide a basis of monitoring of disease occurrence on golf courses while experiments are conducted under controlled conditions at the Pee Dee REC or on the courses themselves. Experiments were also conducted on golf courses to evaluate alternative products and approaches for plant parasitic nematode management in putting greens and fairways. Experiments were conducted with materials such as abamectin formulations as well as nematode antagonists and parasites such as Bacillus firmus (development by Bayer) and Pasteuria usgae (development by Pasteuria Biosciences). In regard to rapid blight biology and management, experiments were completed and largely published by K.K. Yadagiri, et al.
Under direction of Dr. Julia Kerrigan. Yadagiri's work emphasized the process of infection and colonization of susceptible ryegrass to Labyrinthula terrestris, the cause of rapid blight disease. Light, scanning EM and transmission EM microscopy were the main tools for elucidation of infection. In addition, Mr. Yadagiri conducted experiments on improved culturing and long-term storage of Labyrinthula terrestris isolates provided to him by Martin. Fungicide timing and programmatic approaches for disease control and turf quality were also conducted on bermudagrass greens for spring dead spot, leafspot, dollar spot and Rhizoctonia leaf and sheath spot (R.
Many of these activities were presented to audiences of golf course superintendents and industry professionals at the Clemson turf field days in April at the Pee Dee REC and on the Clemson campus in September 2012. Workshops with data generated from these activities were conducted nationally at the Golf Industry Show and through the annual Carolinas Golf Course Superintendents Association show in Myrtle Beach, SC. Advice bases on these activities was also presented through personal contact by phone, email and website communications. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period. Impacts Disease control programs have been evaluated for the past 14 years, and have resulted in a set of general guidelines for deployment of fungicides in a planned program approach.
Golf course superintendents in the Carolinas have adopted this strategy as a guideline for use in early order programs which lead to significant monetary savings while providing improved disease control and quality during summer months. In particular, a program employing DMI fungicides such as propiconazole, triadimefon, and others are best avoided in mid-summer but can be utilized with great success at the beginning and end of summer for diseases such as dollar spot and anthracnose control. New premix products and some new actives have been evaluated for efficacy and as components in programs. Strobilurin fungicides have been placed in mid-summer to provide Pythium and Rhizoctonia control primarily, but do not provide equal quality or efficacy of Pythium root dysfunction. Pyraclostrobin (Insignia) has consistently provided the best control of Pythium and turf quality, which may be the result of base fungicidal activity for Pythium but also potentially improved plant health through reduced plant physiological stress. Additionally, assistance to Bayer in evaluation of proprietary pigments and how best to deploy those in products has resulted in improvement in disease and quality in bentgrass greens fungicide programs. Programs evaluated with and without cyazofamid applied twice in mid to late summer have generally shown a benefit to incorporation of this Pythium active fungicide.
New knowledge has been obtained in the elucidation of the infection processes by Labyrinthula terrestris, causing Rapid Blight disease in cool season turfgrasses. It appears the extracellular matrix exuded by the organism during growth provides support and anchoring to stomates and leaf trichomes during penetration by the infective cells. There is some evidence of enzymatic degradation of host plant cell walls as well, and clear evidence of penetration through natural (stomata) or wound (mowing) openings in leaves.
Yadagiri has developed an improved media to culture Labyrinthula utilizing ryegrass extracts in a basal medium. This will result in better methodology to study this organism and related organisms in the future. Management of nematodes is a significant challenge in the context of loss of cheap and relatively effective but dangerous chemical nematicides. Experiments with abamectin provided a basis for a 24c label in NC and SC, which was expanded over most of the southeast. Experiments with Bacillus firmus have consistently shown effects on slightly reducing nematode reproduction but more importantly, improved host plant growth and quality during summer stress. It is now registered as Nortica through Bayer. Publications.
Fouly, H., Henning, S., Radwan, O., Martin, B., and Wilkinson, H. The role of melanin production in Gaeumannomyces graminis infection of cereal plants. IN: Melanin: Biosynthesis, function and health effects. Xiao-peng Ma and Xiao-Xiao Sun, ed. Martin, S.B.
EC 699 2012 Pest Control Guidelines for Professional Turfgrass Managers. Chapters for disease control and nematode control. McCarty, L.B. And Martin, S.B. Management of creeping bentgrass greens in heat stress environments. Golf Course Superintendents Association of America.
Lawrence, KS, CD format. Park, D. Soil surfactant and fungicide influence on soil moisture, disease presence and quality of Champion ultradwarf bermudagrass grown on a USGA specified constructed rootzone in South Carolina, U.S.A.; Abstract. Bouyoucos Conference: Constructed Rootzones. Philadelphia, PA. Kerrigan, J.L., M.W. Olsen, and S.B.
Rapid Blight of Turfgrass. The Plant Health Instructor. DOI: 10.1094/PHI-I-2012-0621-01. Yadagiri, K. K., Kerrigan, J. Improved methods for axenic culture of Labyrinthula terrestris, causal agent of rapid blight disease on turfgrasses.
Canadian Journal of Microbiology 58:1230-1235. Weimin Ye, Yongsan Zeng, Lane Tredway, Bruce Martin, and Matt Martin.
Plant parasitic nematodes in Carolina turfgrass. Carolinas Green, March-April. 24-26.Progress 01/01/11 to 12/31/11 Outputs OUTPUTS: Fungicide trials were conducted in Crenshaw and A4 bentgrass to evaluate new products and how to best utilize those new products with existing fungicides and mixtures in a summer program used during summer stress on creeping bentgrass.
There has been a trend in the industry to place fungicide premixtures on the market containing at least 2 active ingredients and these were incorporated when appropriate, continuing work from last year. Related experiments utilized a base program designed by Martin (termed program 13) in which specific strobilurin fungicides were compared for effectiveness for disease control and comparison of nontarget effects. Strobilurins included pyraclostrobin (Insignia), azoyxystrobin (Heritage TL) and fluoaxostrobin (Disarm) as well as trifloxystrobin (Compass). Timing of these components were identical. Also, diseases were diagnosed as needed from samples submitted through our commercial turf diagnostic clinic to identify stress-related changes in disease occurrence. These diagnoses provide a basis of monitoring of disease occurrence on golf courses while experimentation is conducted under controlled conditions at the Pee Dee REC or on the courses themselves.
Experiments were also conducted on golf courses to evaluate alternative products and approaches for plant parasitic nematode management in putting greens and fairways. Additionally, a survey of plant parasitic nematodes was conducted in cooperation with NC State and the NC Department of Agriculture through a grant from the Carolinas Golf Course Superintendents Association. Experiments were conducted with formulations of abamectin, which resulted in successfully obtaining a 24C registration for Avid 0.15EC in SC. In regard to rapid blight biology and management, experiments were conducted by a Ph.D. Candidate, K.K. Yadagiri, on campus under the primary direction of Dr.
Julia Kerrigan. The basis of Mr. Yadagiri's research is the process of infection and colonization of susceptible ryegrass to Labyrinthula terrestris, the cause of rapid blight disease. Light, scanning EM and transmission EM microscopy were the main tools for elucidation of infection. In addition, Mr. Yadagiri conducted experiments on improved culturing and long-term storage of Labyrinthula terrestris isolates provided to him by Martin.
Fungicide timing and programmatic approaches for disease control and turf quality were also conducted on bermudagrass greens for spring dead spot, leafspot, dollar spot and Rhizoctonia leaf and sheath spot (R. Many of these activities were presented to audiences of golf course superintendents and industry professionals at the Clemson turf field days in April 2011 at the Pee Dee REC and at an industry field day in August 2011 at the Pee Dee Research and Education Center.
Workshops with data generated from these activities were conducted nationally at the Golf Industry Show and through the annual Carolinas Golf Course Superintendents Association show in Myrtle Beach, SC. Advice bases on these activities was also presented through personal contact by phone, email and website communications. PARTICIPANTS: Dr. Julia Kerrigan, Assistant Professor, School of Agricultural, Forest and Environmental Sciences serves as major professor to KK. Yadagiri and directs the rapid blight project Dr.
Hanafy Fouly, Extension Associate, Pee Dee Research and Education Center, is chief diagnostician for commercial turf disease and nematode samples, and began research on suspected bacteria that may be pathogenic to bentgrass during this period. Cooperation continues with educational programs conducted through the Carolinas Golf Course Superintendents Association and the Golf Course Superintendents Association of America, through which seminars on current research are presented. Dara Park, Assistant Professor,School of Agricultural, Forest and Environmental Sciences cooperated on evaluation of organic fertilizers for nematode suppression and evaluation of surfactants to improve control of rapid blight of cool season grasses. TARGET AUDIENCES: Golf course superintendents in the southeastern United States who deal with chronic pest problems, including diseases and nematode infestations. This audience is excellent at adopting new technology or transfer of modified technology that improves pest control in turf.
Typically workshops at the Carolinas GCSA or GCSAA are filled to capacity, providing evidence of the effectiveness and relevance of this research. PROJECT MODIFICATIONS: Not relevant to this project. Impacts Disease control programs have been evaluated for the past 13 years, and have resulted in a set of general guidelines for deployment of fungicides in a program approach. Golf course superintendents in the Carolinas have adopted this strategy as a guideline and it has resulted in improved disease control and quality during summer months. In particular, a program employing DMI fungicides such as propiconazole, triadimefon, and others are best avoided in mid-summer but can be utilized with great success at the beginning and end of summer for diseases such as dollar spot and anthracnose control.
Some fungicides in the DMI class, such as metconazole or tebuconazole have shown improved safety to bentgrass while providing excellent control of dollar spot, anthracnose and brown patch. Strobilurin fungicides have been placed in mid-summer to provide Pythium and Rhizoctonia control primarily, but do not provide equal quality or efficacy tof Pythium root dysfunction or Pythium root rot. Pyraclostrobin (Insignia) has provided the best control of Pythium and turf quality, which may be the result of base fungicidal activity for Pythium but also potentially improved plant health through reduced plant physiological stress. Additionally, assistance to Bayer in evaluation of proprietary pigments and how best to deploy those in products has resulted in improvement in disease and quality in bentgrass and bermudagrass greens fungicide programs. Improvement was seen in the base program in 2011 in bent by including cyazofamid (Segway) in mid- to late summer for additional control of Pythium root rot and root dysfunction. New knowledge has been obtained in the elucidation of the infection processes by Labyrinthula terrestris, causing Rapid Blight disease in cool season turfgrasses. Yadagiri has developed an improved media to culture Labyrinthula utilizing ryegrass extracts in a basal medium and clearly showed superior results in culturing this difficult organism.
This will result in better methodology to study this organism and related organisms in the future. Management of nematodes is a significant challenge in the context of loss of cheap and relatively effective but dangerous chemical nematicides. Experiments with coactyl H and fertiactyl have not proven efficacious for nematode suppression or sustained host plant quality improvements; however, experiments with Bacillus firmus and abamectin derivatives have consistently shown effects on slightly reducing nematode reproduction but more importantly, improved host plant growth and quality during summer stress.
A product called 'Nortica' was introduced last year by Bayer with the active ingredient Bacillus firmus. Publications.
Marvin, J., L.B. McCarty, and S.B. Nitrogen Source and Fungicide Interaction Efficacy on Sclerotinia homoeocarpa Causal Agent of Dollar Spot on Creeping Bentgrass (Agrostis stolonifera). ASA/CSSA/SSSA International Annual Meeting, Long Beach, CA. 74-8.
Marvin, J.W., L.B. McCarty, S.B. Toler, and H.
Dr Bruce Martin San Antonio
Dollar Spot (Sclerotinia homoeocarpa) Control Using Organic and Synthetic Fungicide Combinations. Annual Clemson University Turfgrass Field Day Abstract. P12.
Menchyk, N.A., F.G. Bethea Jr., H.
Luo, and D.G. 'Diamond' Zoysiagrass Putting Green Management in the Transition Zone with Primo and Nitrogen. Annual Clemson University Turfgrass Field Day Abstract.
P11. Menchyk, N.A., F.G. Bethea Jr., H. Luo, and D.G. 'Diamond' Zoysiagrass Putting Green Management in the Transition Zone with Primo and Nitrogen.
Annual Clemson University Turfgrass Field Day Abstract. P11. Marvin, J.W., L.B. McCarty, S.B. Toler, and H. Dollar Spot (Sclerotinia homoeocarpa) Control Using Organic and Synthetic Fungicide Combinations.
Annual Clemson University Turfgrass Field Day Abstract. P12. McCarty, L.B. Advanced Management of Ultradwarf bermudagrass golf greens. Golf Course Superintendents Association of America.
Lawrence, KS, CD format. McCarty, L.B. Management of Creeping Bentgrass Golf Greens in Heat-stress Environments.
Golf Course Superintendents Association of America. Lawrence, KS, CD format. Hanafy Fouly, B Martin, H. Wilkinson (2011). Bacteria associated with bentgrass disease syndrome in the southeast USA.
Phytopathology 101: accepted. Sokol, M., D.M. Park, and S.B. Labyrinthula terrestris Control by Managing Soil Salinity Using Soil Conditioners. ASa-CSSA-SSSA Annual Meetings.
Long Beach CA. (abstract).
Hanafy Fouly, O Radwan, B Martin, H. Wilkinson (2011). Phylogentic analysis of Gaeumannomyces graminis varieties based on sequence insertions in the small subunit rDNA. Australina J of Plant Pathology: DOI: 10.1007/s13313-011-0067-5. Park, D.M., S.B. Martin, and M.
Manging Soil Salinity with Soil Conditioners for Rapid Blight Control. 9th International Symposium on Adjuvants for Agrochemicals.
(abstract). Martin, B and Clarke, B. Cutting Edge Disease ID and Management for Cool Season Grasses. Golf Course Superintendents Assocation of America, Lawrence, KS, CD format.Progress 01/01/10 to 12/31/10 Outputs OUTPUTS: Fungicide trials were conducted in Crenshaw and A4 bentgrass to evaluate new products and how to best utilize those new products with existing fungicides and mixtures in a program used during summer stress on creeping bentgrass. There has been a trend in the industry to place fungicide premixtures on the market containing at least two active ingredients and these were incorporated when appropriate. Related experiments utilized a base program designed by Martin (termed program 13) in which specific strobilurin fungicides were compared for effectiveness for disease control and comparison of nontarget effects. Strobilurins included pyraclostrobin (Insignia), azoyxystrobin (Heritage TL) and fluoaxostrobin (Disarm).
Timing of these components were identical. These experiments were conducted in the context of record-breaking heat throughout much of the eastern United States.
Also, diseases were diagnosed as needed from samples submitted through our commercial turf diagnostic clinic to identify stress-related changes in disease occurrence. These diagnoses provide a basis of monitoring of disease occurrence on golf courses while experimentation is conducted under controlled conditions at the Pee Dee REC or on the courses themselves. Experiments were also conducted on golf courses to evaluate alternative products and approaches for plant parasitic nematode management in putting greens and fairways. Experiments were conducted with materials such as co-actyl H and fertiactyl products as well as with known nematode antagonists and parasites such as Bacillus firmus (development by Bayer) and Pasteuria usgae (development by Pasteuria biosciences). In regard to rapid blight biology and management, experiments were conducted by a Ph.D. Candidate, K.K. Yadagiri, on campus under the direction of Dr.
Julia Kerrigan. The basis of Mr. Yadagiri's research is the process of infection and colonization of susceptible ryegrass to Labyrinthula terrestris, the cause of rapid blight disease. Light, scanning EM and transmission EM microscopy were the main tools for elucidation of infection.
In addition, Mr. Yadagiri conducted experiments on improved culturing and long-term storage of Labyrinthula terrestris isolates provided to him by Martin. Fungicide timing and programmatic approaches for disease control and turf quality were also conducted on bermudagrass greens for spring dead spot, leafspot, dollar spot and Rhizoctonia leaf and sheath spot (R. Many of these activities were presented to audiences of golf course superintendents and industry professionals at the Clemson turf field days in April at the Pee Dee REC and on campus in September 2010. Workshops with data generated from these activities were conducted nationally at the Golf Industry Show and through the annual Carolinas Golf Course Superintendents Association show in Myrtle Beach, SC. Advice based on these activities was also presented through personal contact by phone, email and website communications.
PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: golf course superintendents, golf course professionals, and industry professionals PROJECT MODIFICATIONS: Nothing significant to report during this reporting period. Impacts Disease control programs have been evaluated for the past 12 years, and have resulted in a set of general guidelines for deployment of fungicides in a program approach. Golf course superintendents in the Carolinas have adopted this strategy as a guideline and it has resulted in improved disease control and quality during summer months.
In particular, a program employing DMI fungicides such as propiconazole, triadimefon, and others are best avoided in mid-summer but can be utilized with great success at the beginning and end of summer for diseases such as dollar spot and anthracnose control. A relatively new fungicide in the DMI class is metconazole, developed by Valent, which has shown improved safety to bentgrass while providing excellent control of dollar spot, anthracnose and brown patch. Strobilurin fungicides have been placed in mid-summer to provide Pythium and Rhizoctonia control primarily, but do not provide equal quality or efficacy of Pythium root dysfunction. Pyraclostrobin (Insignia) has provided the best control of Pythium and turf quality, which may be the result of base fungicidal activity for Pythium but also potentially improved plant health through reduced plant physiological stress.
Assistance to Bayer in evaluation of proprietary pigments and how best to deploy those in products has resulted in improvement in disease and quality in bentgrass greens fungicide programs. Improvement can also result in particularly stressful summers, such as the summer of 2010, by including cyazofamid (Segway) in mid- to late summer for additional control of Pythium root rot and root dysfunction.
New knowledge has been obtained in the elucidation of the infection processes by Labyrinthula terrestris, causing Rapid Blight disease in cool season turfgrasses. It appears the extracellular matrix exuded by the organism during growth provides support and anchoring to stomates and leaf trichomes during penetration by the infective cells. There is some evidence of enzymatic degradation of host plant cell walls as well, and clear evidence of penetration through natural (stomata) or wound (mowing) openings in leaves.
Yadagiri has developed an improved media to culture Labyrinthula utilizing ryegrass extracts in a basal medium. This will result in better methodology to study this organism and related organisms in the future. Management of nematodes is a significant challenge in the context of loss of cheap and relatively effective but dangerous chemical nematicides. Experiments with coactyl H and fertiactyl have not proven efficacious for nematode suppression or sustained host plant quality improvements; however, experiments with Bacillus firmus have consistently shown effects on slightly reducing nematode reproduction but more importantly, improved host plant growth and quality during summer stress. It is anticipated that this product will become registered in 2011 for turf nematode control.
Publications. Park, J., Radwan, O., Martin, B., Wilkinson, H. And Fouly, H. (2011), Transformation of Gaeumannomyces graminis with β-Glucuronidase Reporter and Hygromycin Resistance Genes.
Journal of Phytopathology, 159: 317-320. Martin, B., Management of leaf and sheath spot of ultradwarf bermudagrasses Phytopathology Phytopathology.
Jun 2010.Progress 01/01/09 to 12/31/09 Outputs OUTPUTS: Experiments were conducted to determine field performance of disease control programs with fungicides for the major diseases of creeping bentgrass and bermudagrass putting greens. Experiments were also conducted on the infection process of Labyrinthula terrestris to perennial ryegrass as part of a Ph.D. Student project, and experiments on the influence of soil amendments potentially affecting sodium concentration and rapid blight were performed.
Research on occurence and identity of Rhizoctonia species associated with leaf and sheath spot in bermudagrass and on control of the disease was conducted on golf courses with naturally occurring diseases. Experiments aimed at evaluation of alternative methods for control of plant parasitic nematodes were conducted in 2009 in field trials on golf courses. Reports have been disseminated by personal contacts with clientele by emails, telephone and personal conversations. Results have also been provided by seminars in South Carolina through the Carolinas Golf Course Superintenents Association, the Golf Course Superintendents Association of America and by other industry sponsored events. Results were provided during 2 field days at the Pee Dee Research and Education Center during April 2009 and August 2009.
On-going research results and experience gained from work in these areas is communicated to undergraduate students directly through classwork (Plant Pathology 406/606 at Clemson University). PARTICIPANTS: Julia Kerrigan, Ph.D., Assistant Professor, Entomology, Soils and Plant Sciences Department,Clemson University served as major advisor to Kirthi Yadagiri, a Ph.D. Student working on rapid blight and infection processes. Hanafy Fouly, Ph.D., Extension Associate and Adjunct Assistant Professor, Entomology, Soils and Plant Sciences Department, Clemson University worked with S.B. Martin in disease control experiments and more specifically in molecular identification of Rhizoctonia species associated with diseased bentgrass, bermudagrass and overseeded cool season turfgrasses.
Dara Park, Ph.D., Assistant Professor, Horticulture, Clemson University worked with projects on nematode control in golf course turf and in experiments with surfactants and soil amendments and their effect on rapid blight severity in perennial ryegrass. TARGET AUDIENCES: Target audiences are graduate students, undergraduate students and professional turfgrass managers, especially golf cours superintendents in the southeastern United States that encounter potentially devastating diseases and profit by increased knowledge of disease processes and in how to control the diseases most efficiently, at reduced cost, and with minimal impact on the environment. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period. Impacts A specific disease control program for creeping bentgrass greens was shown to be highly efficacious over a 3 year period of varying weather conditions and disease severities. This particular program associated with Clemson research ('program 13')has been adopted in whole or in part as a guideline for development of site-specific disease control programs resulting in improved control of summer diseases in bentgrass, resulting in high quality surfaces.
As new technology is developed for disease control, it is evaluated under real world conditions to determine its potential in program deployment. Thus, this work is an on-going process although definite guidelines have been developed. Although not as defined as in bentgrass, fungicide use guidelines for bermudagrass greens have been tested in field experiments and adopted by area superintendents as well.
Some DMI fungicides were shown to be unacceptably phytotoxic to bermudagrass during summer months, but some DMI fungicides in combination with others has been safe and showen to provide needed control for diseases such as fairy ring or Rhizctonia leaf and sheath spot. Labyrinthula infection of ryegrass, resulting in rapid blight disease, appears to be accomplished by passive as well as active means, penetrating leaf surfaces through leaf stomata as well as penetrating cells by presumed enzymatic activity, shown by light and electron microscopy experiments. Potential causal agents of Rhizoctonia leaf and sheath spot were identified as R. Oryzae and less frequently by R.
Circinata var. Circinata and partial control achieved with several labeled fungicides.
Publications. Martin, S. B., and McCarty, L. Turfgrass Diseases. In: Best Golf Course Management Practices, 3rd edition. Prentice Hall. 720 pages.
Martin, Bruce. Disease Control. In: Pest control recommendations for professional turfgrass managers.
McCarty (ed.). EC 699. Martin, Bruce. 2009 Nematode Control. In: Pest control recommendations for professional turfgrass L.
McCarty (ed.).
Using Appear II as part of an agronomic program enhances disease control and improves turf quality throughout the season. In this trial, the Appear II program had an average turf rating of 6.54 and the Signature™ XTRA Stressgard ® program had an average of 6.06. Lee Miller, University of Missouri, 2018. Phosphonate comparison study on creeping bentgrass greens. The only program variable was the inclusion of Appear II or Signature XTRA Stressgard. Data indicates turf quality scoring each month to show the progression of overall turf quality during a season-long agronomic program.
Applications were made on 14-day intervals. “Appear II fungicide is fantastic, especially when tank-mixed with Daconil Action or Secure Action. When you add Appear II to Daconil Action or Secure Action, it really improves disease control and turf quality. It had a fantastic, natural green color and maintained turf density throughout the season. It’s a really, really good product, and it showed an overall increase in turf quality compared to standard treatments and showed 99 percent disease control in my trials. If I was a superintendent, I would use Appear II plus Daconil Action every other week. It provides four different modes of action for disease control, so it should be about as broad spectrum as it’s going to get.
It’s the best fungicide combination I’ve ever used.”- Travis Teuton, Ph.D., research director, Southeastern Turfgrass Research CenterAnthony, Florida. “Appear II fungicide lasted longer than comparative products used in the trial.
Dr Bruce Martin Texas
It showed significantly better turf quality and overall plant health. And when tank-mixed with products like Secure Action and Daconil Action, Appear II provided better turf quality than when the products were used alone. Based on my experience with Appear II, I wouldn’t hesitate to recommend it to a customer.
I think it’s a good product that will sell itself.”- William L. Berndt, Ph.D., independent researcherNorth Fort Myers, Florida. ©2019 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements.
Dr Bruce Martin Euless
Please check with your local extension service to ensure registration status and proper use.Action™, Appear ®, Daconil ®, GreenCast ®, GreenTrust ®, Heritage ®, Posterity ® and the Syngenta logo are trademarks of a Syngenta Group Company. Secure ® is a registered trademark of Ishihara Sangyo Kaisha, LTD. All other trademarks are the property of their respective owners.Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.1Always consult the product label for complete use and application information.