Progress 10/01/03 to 09/30/09
Outputs
OUTPUTS: We evaluated several fungicides to control this disease and found that mancozeb used alone or in combination with other fungicides were most efficacious in controlling this disease. We also evaluated the effects of cultural control to reduce the severity of symptoms. For instance we found that shading could reduce the severity of the disease. However, this was a "double-edged sword". Plants tended to get "leggy" and this reduced the salability of the plants. Afternoon irrigation also reduced severity. Nurseries could easily include these practices in their operations and reduce the number of fungicide applications. We also found that growing Euonymus on poly ethylene sheeting or gravel did not decrease anthracnose symptoms with or without periodic application of sodium hypochlorite. I assisted in the training of two M.S. students in the Department of Horticulture and Landscape Architecture PARTICIPANTS: Dr. Janet Cole, Cheryl Boyer M.S., Stevie Schupback-Ningen TARGET AUDIENCES: Nurseries in eastern Oklahoma. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We determined that the causal pathogen was in deed Colletotrichum gloeosporioides and not Gloeosporium frigidum as had been reported. We found that the confusion in the literature was probably caused by the conidia masses swelling up on the conidiomata and obscuring the setae characteristic of Colletotrichum. I conducted laboratory experiments on the effect of Clorox on C. gloeosporiodes and found that the inhibitory effects on this pathogen was greatest on conidial germination, but was not inhibitory of mycelial growth, in fact, all isolates were able to grow over full-strength Clorox on saturated paper discs placed on the surface of agar. We surmised that the concentration of Clorox needed for inhibition was too great for practical application to living plants. In cooperation with Dr. Janet Cole, Department of Horticulture and Landscape Architecture, we published 9 manuscripts based on our research.
Publications
- Boyer, C. R., Cole, and Conway, K. E. 2004. Effectiveness of copper Sulfate Pentahydrate, and Mancozeb in controlling anthracnose on Euonymus fortunei. (Abstr/Poster. #232) Amer. Soc. Hort. Sci.
- Ningen, S. S., Cole, J. C., and Conway, K. E. 2004 Cultivar and night temperature affect severity of anthracnose on Euonymus fortunei. HortScience. 19:230-231.
- Sherman, A. T., and Conway, K. E. 2004. Effectiveness of benomyl to inhibit mycelial growth of Colletotrichum gloeosporioides. Student Abstract and Poster presented to Biomedical infrastructure Network. BRIN. (Summer undergraduate Research Program) 30 July 2004 at the University of Oklahoma Health Science Center, Oklahoma City.
- Ningen, S. S., Cole, J C, Smith, M. W., Dunn, D. E., and Conway, K. E., 2005. Increased shade intensity and afternoon irrigation decrease anthracnose severity on three Euonymus fortunei cultivars. HortScience 40:111-113.
- Cole, J. T., Cole, J. C., and Conway, K. E. 2005. Effectiveness of selected fungicides with and without surfactant in controlling anthracnose on three cultivars of Euonymus fortunei. J. appl. Hort. 7:16-19.
- Ningen, S. S., Cole, J. C., Cole, J. T. and Conway, K. E. 2006. Chlorothalonil, trifloxystrobin, and mancozeb decrease anthracnose symptoms on three cultivars of wintercreeper Euonymus fortunei. Hort Technol. 16:211-215.
- Boyer, C. R., Cole, J. C., and Conway, K. E. 2007. Effectiveness of Copper Pentahydrate. Mancozeb, and Hydrogen dioxide in controlling anthracnose on wintercreeper Euonymus. J. Environ, Hort. 25 1): 21-26.
- Cole, J. C., Boyer, C. R., Payton, M. E., and Conway, K. E. 2009. Anthracnose symptoms are not decreased by growing Wintercreeper Euonymus on polyethylene sheeting with sodium hypochlorite application. J. Environ. Hort.27 (2):115-118.
- Cole, J. C., Schupbach-Ningen, Conway, K. E. 2009 Intensity of anthracnose symptoms on Three Wintercreeper Euonymus Cultivars as influenced by Fungicide Programs. J. Environ. Hort. 27(3): 171-175.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: An experiment utilizing sodium hypochlorite to sanitize nursery beds used for production of Euonymus failed to reduce the severity of anthracnose. Laboratory investigations were conducted on isolates of C. gloeosporioides to ascertain what effects sodium hypochlorite might have on the fungus The first test evaluated the effect of the chemical on mycelial growth. All isolates were able to grow over full-strength Clorox with no inhibition. The second test was conducted to examine its' effect on conidial germination. 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
There was a significant reduction in conidial germination compared to the water controls. Conidia in both treatments were washed with water to remove any germination inhibitors in the mucilage matrix surrounding the conidia. The concentration of Clorox needed for inhibition is too great for practical application to living plants. But still might be a useful surface sterilant for application to polyethylene mulch under the potted plants and reduce splash dispersal from infected leaf and plant debris.
Publications
- Cole, J. C., Boyer, C. R., Payton, M E., Conway, K. E. , 2009 Anthracnose Symptoms are not decreased by growing wintercreeper Euonymus on polyethylene sheeting with periodic Sodium Hypochlorite application. Submitted to J.Environ.Hort.
- Boyer, C. R., Cole,J. C., and Conway, K. E. 2007, effectiveness of Copper Sulfate Pentahydrate and /hydrogen dioxide in controlling Anthracnose on wintercreeper Euonymus, J. Environ. Hort. 25:91):21-26.
- Cole, J. C., Schupbach, S. and Conway, K. E. 2007. Mancozeb, propiconazole and Thiophanate Methyl decrease anthracnose symptoms on three Euonymus fortunei cultivars. Submitted to HortSci.
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Progress 10/01/06 to 09/30/07
Outputs
Nurseries in eastern Oklahoma Continued to suffer great losses due to Anthracnose, but have begun to achieve better control by following our fungicide recommendations and by using cultural control that we have developed
Impacts
Nurseries in eastern Oklahoma continue to claim a savings of from $400,000.00 to $600,000.00/yr from reduced lost of saleable plants.
Publications
- No publications reported this period
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Progress 10/01/05 to 09/30/06
Outputs
Progress has continued in our evaluations of fungicides for control of anthracnose. An additional year of data has been generated on field evaluation of selected fungicides. This data can now be added to those collected by a Master's graduate student (Mrs. C.R. Boyer) which will give two years data and expedite the publication of these studies. Additional isolates of C. gloeosporiodes have been obtained from diseased plants and are now available for further cultural studies.
Impacts
Nurseries in eastern Oklahoma continue to claim a savings of from $400,000.00 to $600,000.00/yr from reduced lost of saleable plants.
Publications
- Schupbach-Ningen, S. L., Cole, J. C., Cole, J. T., Conway, K. E. 2006. Chlorothalnonil, trifloxystrobin, and mancozeb decrease anthracnose symptoms on three cultivars of wintercreeper Euonymus. HortTechnology 16:211-215.
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Progress 10/01/04 to 09/30/05
Outputs
Significant progress has been made in understanding this host- pathogen interaction. Stress appears to be the predisposing factor in this relationship. Cultural factors that reduce disease included; cooler night-time temperatures (75 degrees F vs. 65 degrees F) during propagation, afternoon irrigation (vs., morning), and deep shade (80% vs. full sun) during the day. There are inherent differences in cultivar repose to anthracnose (Emerald gaiety vs. either Emerald n Gold or Emerald Surprise). In addition, Mancozeb is the most efficacious fungicide used either by itself or in mixtures or rotations. Combinations of all factors; irrigation, cultivar selection, shading and fungicide can provide a disease-free, and salable plant.
Impacts
This research will control anthracnose disease on Euonymus spp. in nurseries in Oklahoma and save $400,000.00 to $600,000.00 per year normally spent on fungicide applications. When fungicides are needed, the most efficacious fungicide or combinations can now be selected and applied at the correct rates and timing. Cultural controls have also been identified that can reduce the severity of anthracnose throughout the production cycle. This information is applicable to all Nurseries producing Euonymus plants for sale.
Publications
- Cole, J. T., Cole, J.C., and Conway, K. E. 2005. Effectiveness of selected fungicides with and without surfactant in controlling anthracnose on three cultivars of Euonymus fortunei. J. Appl. Hort. 7: 16 -19.
- Ningen, S. S., Cole, J. C., and Conway, K. E. 2004. Cultivar and night temperature affect severity of anthracnose on Euonymus fortunei. HortScience 39: 230-231.
- Ningen, S.S., Cole, J. C., Smith, M., Dunn, D.E. and Conway, K.E. 2005. Increased shade intensity and afternoon irrigation decrease anthracnose severity on three Euonymus fortunei cultivars. HortScience 40: 111 - 113.
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Progress 10/01/03 to 09/30/04
Outputs
Two presumed strains,#415 and #423 of C. gloeosporioides (Cg) from Euonymus fortunei were compared in poison-agar tests using logarithmic concentrations of the fungicide benomyl (Benlate 50 WP) and radial growth of the fungus was recorded for 6 da. Percent inhibition was calculated and Ec50 values were determined from linear regression of growth. The experiment ws conducted 3 times and Benomyl consistently inhibited mycelial growth . The response of each isolate was similar indicating that they did not represent two different strains and that benomyl should be an effective fungicide to use in rotation with other fungicides. In other experiments, copper pentahydrate did not inhibit mycelial growth of Cg in culture. In nursery experiments, Mancozeb was more effective than copper pentahydrate in controlling Cg on Euonymus. Also, lower night-time temperatures reduced the severity of Cg on Euonymus fortunei.
Impacts
Nothing to report this period.
Publications
- NINGEN, S. S, COLE, J. C, AND CONWAY, K. E., 2004. Lower night temperatures decrease severity of anthracnose on Euonymus fortunei. HortScience 39:230-231.
- BOYER, C.R., COLE, J. C.,AND CONWAY, K.E., 2004. Effectiveness of copper pentahydrate and mancozeb in controlling anthracnose on Euonymus fortunei. (Abstract) American Society for Horticultural Science Poster #232.
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Progress 10/01/02 to 09/30/03
Outputs
New in October. No progress to report this period.
Impacts
Nothing to report this period.
Publications
- No publications reported this period
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