Progress 10/01/09 to 09/30/12
Outputs
OUTPUTS: Studies within this project have focused on cultivar performance of rudbeckias and chrysanthemums relative to rust, leaf spot, powdery mildew and downy mildew diseases, as well as disease management with reduced-risk fungicides and biological controls. In a 2012 trial at the Long Island Horticultural Research and Extension Center, 15 red or bronze-flowered chrysanthemum cultivars were compared for their susceptibility to Fusarium wilt disease. Plants were inoculated 18 Sept with 10 ml of a slurry of Fusarium oxysporum f. sp. chrysanthemi poured into holes dibbled into the media just prior to transplant. There were 2 noninoculated and 8 inoculated plants for each cultivar. Symptoms were rated 21 Nov on a 1-5 scale, scoring leaf chlorosis, necrosis and wilt. Stem sections were cultured to re-isolate Fusarium at the end of the experiment. In a 2012 biocontrol trial, 11 mum cultivars were used to evaluate the performance of a Trichoderma harzianum and T. virens combination product against Fusarium oxysporum f. sp. chrysanthemi in four single-plant replications; plants were given the Trichoderma treatment as a drench one week before challenge with the pathogen. Results of studies over the life of the project were reported in presentations at the Cornell Greenhouse Conference, the Long Island Horticultural Research & Extension Center Plant Science Day, the OFA Short Course, the Society of American Florists Plant and Pest Management Conference, the Perennial Plant Association Conference, the Northeast Greenhouse Conference, at regional grower conferences in Latham, Middletown and Riverhead, NY and at the Kanuga Ornamentals Workshop and the Northeast Division Meeting of the American Phytopathological Society. PARTICIPANTS: Margery Daughtrey and George Hudler of the Cornell Department of Plant Pathology and Plant-Microbe Biology provided direction for the studies as PIs of the project. Pinewood Perennials, Grow-Link, Ball Horticultural Company, Sunny Border and Syngenta all provided plant materials and industry perspective to the trials as partners. Extension educators Nora Catlin and Alexis Alvey of Cornell University Cooperative Extension of Suffolk County collaborated, and provided opportunities for communicating to growers. Maria Tobiasz, Lynn Hyatt and Jadwiga Jedrys provided technical research support over the life of the project. Training opportunities for growers occurred at the Plant Science Days of the Long Island Horticultural Research and Extension Center, when farmers, greenhouse growers and nurserymen could view trials in progress. TARGET AUDIENCES: The target audiences for this project included greenhouse growers, nurserymen, landscapers, Master Gardeners, plant breeders, horticultural supply businesses and other academic plant pathologists and horticulturists. Dozens of presentations have been made at horticultural industry trade events, the Society of American Florists Plant and Pest Management Conference, the Kanuga Ornamentals Workshop, the regional meeting of the American Phytopathological Society, and extension conferences at the state and regional level to share the results of these studies. Open houses at the Long Island Horticultural Research and Extension Center have allowed attendees to view the relative performance of plants in the trials. These outreach efforts have allowed many in the target audience to learn directly how plant choices can make disease management less expensive and less reliant upon pesticide applications. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
When inoculated with the Fusarium wilt pathogen in a 2012 trial, the chrysanthemum cultivar Sly Jenna Red showed progressive chlorosis and necrosis beginning in lower foliage, and 50 percent of the stems of inoculated plants yielded the pathogen in culture. Although Ashley Dark Orange, Brunette Barbie and Delightful Victoria Orange did not show symptoms, the pathogen was recovered from 40 percent of the inoculated chrysanthemums of these cultivars. Aideen Red Fire, Aubrey Orange, Dazzling Stacey, Edana Red, Foxy Marjorie Red, Hannah Orange, Harmony Orange Bicolor, Jacqueline Orange Fusion, Raquel Ruby Red, Spicy Cheryl Orange and Tabitha Scarlet all appeared to be less susceptible to Fusarium infection than Sly Jenna Red, and thus could be better choices for growers seeking to avoid Fusarium wilt losses in red cultivars. Similarly, Allegra was shown to be a highly prone yellow cultivar in earlier trials. Root health evaluations following Fusarium inoculation of chrysanthemums in 2012 indicated that root vigor of cultivars varied greatly even in the absence of the pathogen. Only in the cultivar Edana Red was the difference in root quality between inoculated and noninoculated plants statistically significant, and in this cultivar the biocontrol treatment did not improve the root rating of inoculated plants. These trials add to the previous findings in earlier years of this project, assisting growers in choosing to grow chrysanthemum cultivars that are less disease-prone. Choices may still be complex: Brunette Barbie, for example, was shown to have relatively low susceptibility to Fusarium wilt in 2012, but was vulnerable to brown rust caused by Puccinia chrysanthemi in 2011. Similarly, rudbeckia cultivars identified as less susceptible to Septoria leaf spot, Rudbeckia fulgida var. deamii, R. fulgida var. fulgida, R. subtomentosa and R. subtomentosa Henry Eilers, are still much less popular than Rubeckia fulgida Goldsturm, so adoption of the less disease-prone cultivars will take continued extension education. This project has been a partnership with the horticultural industry, which supplied most of the plant material used and has benefited from the knowledge acquired. Growers are now more aware of the variability in chrysanthemum and rudbeckia cultivar performance, and have access to information that will inform their choices of which ornamentals to grow for the greatest profitability with the least pesticide input.
Publications
- Daughtrey, M., Komorowska-Jedrys, J., Hyatt, L., Elmer, W. 2012. (Abstr.) Comparison of yellow chrysanthemum cultivars for Fusarium wilt susceptibility in the Northeast. Phytopathology 102:S1.2.
- Daughtrey, M., and Hyatt, L. 2012. Evaluation of Rudbeckias for Disease Resistance. 2011 Annual Report, LI Horticultural Research and Extension Center, Cornell University, Riverhead, NY, p. 3.
- Daughtrey, M. and Hyatt, L. 2012. Management of Brown Rust in Chrysanthemums. 2011 Annual Report, LI Horticultural Research and Extension Center, Cornell University, Riverhead, NY, p. 15-16.
- Daughtrey, M. 2011. Managing Diseases. Chapter 10 (pages 121-130) In Ball Redbook, 18th ed., Vol. 2, J. Nau, ed. Ball Publishing. 785 pp.
- Cloyd, R. and Daughtrey, M. Resistance Mitigation. 2011. Chapter 12 (pages 137-142) In Ball Redbook, 18th ed., Vol. 2, J. Nau, ed. Ball Publishing. 785 pp.
- Norman, D., Daughtrey, M. and Palmateer, A. 2012. New and Newly Important Diseases on Tropical Foliage and Other Greenhouse- and Nursery-Grown Ornamentals. Pages 49-63 In Proceedings of the 24th Conference on Plant Production and Pest Management on Ornamentals. February 18, 2012, Orlando, FL. Society of American Florists, Alexandria, VA.
- FloriCAST: Mum Flower Blights. Podcast on fungi that blight mum flowers, giving the grower info on recognition as well as control advice. http://www.greenhousegrower.com/video/c:93/disease-control/670/ (July 2010)
- FloriCAST: Diseases of Mum Leaves and Stems Caused By Bacteria. Podcast on foliar diseases of mums. http://www.greenhousegrower.com/video/c:0/504/ (May 2010)
- Daughtrey, M., Komorowska-Jedrys, J., Hyatt, L. and Elmer, W. 2012. Evaluating Fusarium Wilt Susceptibility for Yellow-flowered Mums. 2011 Annual Report, LI Horticultural Research and Extension Center, Cornell University, Riverhead, NY, p. 16.
- Daughtrey, M. L., Gardner, R., Helms, M., Sanderson, J. P., Senesac, A. F., Weiler, T. C. and Mattson, N. 2012. 2012 Cornell Guide for the Integrated Management of Greenhouse Floral Crops. Cornell University Cooperative Extension, Ithaca, NY. 150 pp.
- Daughtrey, M. L., Gardner, R., Helms, M., Sanderson, J. P., Senesac, A. F. and Tsontakis-Bradley, I. 2012. 2012 Pest Management Recommendations for Production of Herbaceous Perennials. 104 pp.
- Chastagner, G., Hanks, G., Daughtrey, M., Yedidia, I., Miller, T. and Pappu, H. 2012. Sustainable production and integrated management: environmental issues. Pp. 363-420 In Ornamental Geophytes: from basic science to sustainable horticultural production. R. Kamenetsky and H. Okubo, eds.
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: Data was collected on disease symptoms in Rudbeckia hirta, R. subtomentosa, and R. fulgida in a replicated field trial comparing 29 different species and cultivars of these widely used landscape ornamentals for the second year of a three year study. The rudbeckias were rated in mid-August for the percent of foliage affected by Septoria leaf spot and for presence of powdery mildew. A second experiment compared the effectiveness of one contact and three systemic fungicides for control of the newly-problematic foliage disease, Puccinia chrysanthemi brown rust, in five cultivars of chrysanthemum in fall 2011. Additionally, 36 cultivars of yellow-flowered chrysanthemum from three major plant breeding companies were compared in a greenhouse trial examining susceptibility to Fusarium wilt disease caused by Fusarium oxysporum f. sp. chrysanthemi, which continues to cause major crop losses for growers. For the Fusarium wilt trial, 10 mls of a blended slurry containing one million propagules of the pathogen were added beneath each rooted cutting at transplant into a 4.5 inch pot of peat-lite growing mix on 4 May and plants were harvested on 12 July. Results of these studies have been reported during 2011 in presentations at Cornell University's Long Island Horticultural Research and Extension Center (CU-LIHREC) Plant Science Day, Riverhead, NY and in the CU-LIHREC Annual Report posted on the internet; at the Long Island Agricultural Forum in Speonk, NY; at the Cornell Floriculture Field Day in Ithaca, NY; in bedding plant schools on Long Island, in the Hudson Valley and in Western NY; in regional Master Gardener trainings in southeastern NY; at the Ohio Florist's Association Floriculture Short Course in Columbus, OH; at the Hardy Plant Society Mid-Atlantic Group meeting in Media, PA, and at the Society of American Florists Pest Management Conference in San Diego, CA. PARTICIPANTS: Margery Daughtrey and George Hudler are co-PIs on this project and work together to plan and direct the experiments. Jadwiga Komorowska-Jedrys, research support specialist, has provided data collection and laboratory culturing for the trials as well as other technical assistance. Plant materials have been provided by Syngenta, GroLink and Ball FloraPlant for the chrysanthemum trials, and by Pinewood Perennials for the rudbeckia trial. Alexis Alvey, Andrew Senesac and Nora Catlin of Cornell Cooperative Extension of Suffolk County have provided advice and assistance. TARGET AUDIENCES: The primary target audiences for this project are the commercial growers of greenhouse and outdoor grown flower crops and the plant propagation companies that provide plants for this green industry. The information is also immediately useful to landscape gardeners for public and private gardens, and individual gardeners including Master Gardeners. Garden writers will be interested in spreading the good news about plants that are less disease prone, that may be used in the landscape without fungicide inputs. Information developed in this project has been and will continue to be extended in guest lectures to Horticulture Clubs and university classes, to Master Gardeners, to other scientists at regional and national meetings, to national and regional trade conferences of greenhouse flower growers and nurserymen, and to extension audiences including greenhouse flower crop growers, nurserymen, and landscape gardeners. Knowledge is extended through podcasts, newsletters, trade journal articles, annual reports, grower guidelines, and scientific literature. As a result of these educational efforts, new information will be utilized promptly. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Comparisons of rudbeckia cultivars have shown Rudbeckia fulgida var. deamii, R. fulgida var. fulgida, R. subtomentosa, and R. subtomentosa var. Henry Eilers to be superior to Rudbeckia fulgida var. sullivantii Goldsturm in ratings of plant health: these other coneflowers did not show the high susceptibility to Septoria leaf spot typically found in the widely-used 'Goldsturm' cultivar. If this difference continues to be evident in the next year of trialing, results will be widely disseminated because landscapers are eager for dependable cultivars that will not require fungicide spray treatments. In the container trial on brown rust susceptibility and management, the chrysanthemum cultivar Golden Helga showed no susceptibility to foliage infection with rust caused by Puccinia chrysanthemi, making it an option for gardeners wishing to avoid the need for fungicide applications. The chrysanthemums Brunette Barbie, Hankie Yellow and Beth Violet were highly susceptible to brown rust, showing over 5 pustules on many leaves of each plant, while Marilyn was only slightly susceptible, showing only a few pustules on a few leaves. Treatment with mancozeb (Protect DF at 2 lbs per 100 gal) or propiconazole (BannerMAXXII at 8 fl oz per 100 gal) at a 14-day interval did not provide effective control, whereas 14-day treatments with azoxystrobin (Heritage at 4 oz per 100 gal) or pyraclostrobin plus boscalid (Pageant at 12 oz per 100 gal) gave very good plant protection. Pageant and Heritage (a reduced risk fungicide) thus appear to be strongly effective fungicides for use in rotation with materials with different modes of action in a spray program for brown rust protection. In a greenhouse experiment testing yellow-flowered chrysanthemums for Fusarium wilt susceptibility, 12 cultivars from each of three propagators were compared. The cultivar Allegra was the only one to develop severe wilting symptoms: these began to appear 3.5 weeks after inoculation and by the end of the trial over 85 percent of the inoculated plants of this cultivar had wilted. Only 1 or 2 plants of the chrysanthemums Conaco, Florina, Elena, Malmo and Golden Helga developed wilt. Although F. oxysporum was isolated from stem bases of 21 of the inoculated cultivars at the end of the trial, many of which showed no symptoms, no Fusarium was recovered from the cultivars Bernadette, Bethany, Diana, Mary, Mildred, Mouria, Novare, Castor or Sundance. Growers will find it advantageous to avoid growing chrysanthemum cultivars with high susceptibility to Fusarium wilt. Because of the possible carryover of inoculum from year to year, using less susceptible cultivars will be critically important for growers who have observed a disease outbreak in the past. This study will continue to identify chrysanthemums that may be less prone to Fusarium wilt, in order to help growers choose which cultivars to grow.
Publications
- Chase, A.R., and Daughtrey, M.L. 2011. This month in diseases: chrysanthemum. Greenhouse Product News 21(10):12. http://www.gpnmag.com/This-Month-in-Diseases-Chrysanthemum-article130 78.
- Daughtrey, Margery. 2011. Perennial Crop Diseases. Greenhouse Management. Aug. pp. 32-35.
- Daughtrey, M. 2011. Chrysanthemum white rust. Pp. 104-111 in Proceedings, 27th Annual SAF Pest and Production Management Conference, San Diego, CA. February 24-26, 2011.
- Daughtrey, M. L., Gardner, R., Helms, M., Sanderson, J. P., Senesac, A. F., Weiler, T. C. and Mattson, N. 2011. Cornell Guide for the Integrated Management of Greenhouse Floral Crops. Cornell University Cooperative Extension, Ithaca, NY. 152 pp.
- Daughtrey, M. L., Gardner, R., Helms, M., Sanderson, J. P., Senesac, A. F. and Tsontakis-Bradley, I. 2011. Pest Management Recommendations for Production of Herbaceous Perennials. 108 pp.
- Daughtrey, M. 2010. Avoiding Mum Brown Rust. FLORIcast podcast on control of brown rust of chrysanthemum. http://www.greenhousegrower.com/ggtv/vid=325
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: One replicated field trial was established for comparing disease susceptibility for 23 cultivars of Rudbeckia hirta. A second trial focused on chemical control of Septoria leaf spot of container- grown rudbeckia cv. Goldsturm. Initial observations and results on disease problems of rudbeckia and chrysanthemum were communicated in presentations to growers at the Capital District Bedding Plant School in Latham, NY; the Hudson Valley Greenhouse and Nursery Conference in New Paltz, NY; the Long Island Floriculture Conference; the Professional Turf, Plant and Tree Conference, Uniondale, NY; the 2010 Professional Turf and Landscape Conference and Trade Show, White Plains, NY; the Long Island Mum School; the Long Island Horticultural Research and Extension Center Plant Science Day; the Society of American Florists Pest and Production Management Conference in Orlando, FL; the Ohio Florists Association Short Course in Columbus, OH; New England Grows in Boston, MA; and the Canadian Greenhouse Conference. PARTICIPANTS: 1) Principal investigators: Margery Daughtrey and George Hudler, Department of Plant Pathology and Plant-Pathogen Biology, Cornell University have planned and directed the work and presented results 2) Research Technician Maria Tobiasz has propagated plants, set up experiments, made treatments and analyzed data. Partner organizations: The Fred C. Gloeckner Company provided seed for the rudbeckia trial; Ivy Acres, Inc. provided rudbeckia cv. Goldsturm; Sunny Border Nursery provided rudbeckia plants for cultivar comparisons; and Syngenta, Inc. will be supplying chrysanthemum cuttings. Collaborators: Nora Catlin and Alexis Alvey of Cornell Cooperative Extension of Suffolk County and Jim Glover of Glover Perennials have assisted with experiment planning. There have been multiple opportunities for training greenhouse growers and nurserymen in disease management of rudbeckias and chrysanthemums at Cooperative Extension meetings and national conferences for persons who maintain or produce ornamental plants. TARGET AUDIENCES: Audience includes greenhouse growers, nurserymen, botanical gardens, professional landscape gardeners, Master gardeners, plant propagation companies, chemical companies, biological control companies, horticultural societies and the gardening public. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Eight cultivars of Rudbeckia hirta appeared to have very low susceptibility to powdery mildew in our trial, as did Rudbeckia cv. Goldsturm. In contrast, 16 other cultivars showed nearly 70 percent of the foliage covered with the white growth of the fungus. Growers and landscape gardeners have been provided with information on the variation in rudbeckia cultivar susceptibility to powdery mildew. This new knowledge will help them to choose crops that will not require fungicide applications for powdery mildew management.
Publications
- Daughtrey, M. 2010. Managing Persnickety Diseases. Pages 68-79 in Proc. 26th Annual Pest and Production Management Conference, Society of American Florists and Meister Media Worldwide, Orlando, FL
- Bennett, K. C., Gardener, R., Helms, M., Smith, W., Sanderson, J., Daughtrey, M., Senesac, A. and Tsontakis-Bradley, I. 2010. 2009 Pest Management Guide for the Production and Maintenance of Herbaceous Perennials, Cornell University, Ithaca, NY.
- Daughtrey, M. 2010. Avoiding Stem and Root Rot on Mums. FloriCast. http://www.greenhousegrower.com/ggtv/vid=258
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