Progress 06/01/03 to 05/31/06
Outputs
Progress Report 4d Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and Cornell University. This project was initiated on June 1, 2003 and terminated in 2006. The overall objective was to evaluate a commercially available biological control organism for its ability to provide long-term suppression of white mold through parasitism of its sclerotia. Please refer to parent project 5442- 21220-010-00D, Sclerotinia Diseases, for additional information. Research was conducted in 2003-04 to evaluate a commercially available biological control organism for its ability to provide long-term suppression of Sclerotinia sclerotioum in fields in New York. An no-cost time extension of the project was requested in 2005 to complete data analyses. Final results of the study are as follows: Cropping systems included in the study were potatoes (Wolcott), wax beans (Geneva), and an organic system with dry beans planted
in 2003 (Hunt). Field populations of sclerotia declined over time both in the Contans-treated areas and in the nontreated check. However, treating with Contans resulted in a more rapid decline and lower final sclerotia populations for several months following application at two locations (Geneva & Wolcott). At the third location (Hunt) the sclerotia populations were too low for valid comparisons. Disease incidence at the Wolcott locations was statistically lower in the Contans-treated versus the nontreated plots. At Geneva the trends were the same, but differences in disease incidence were not statistically significant due to extreme variability in disease occurrence in the field. The trials indicate decline in soil populations of sclerotia immediately following application of Contans, but not for subsequent years from a single application. Our data indicate Contans should probably be reapplied following field preparation to avoid mixing treated and untreated soil in any year there
is a viable resident population of sclerotia. Low levels of sclerotia (1 per liter of soil, which is equivalent to 406,807 sclerotia per acre to a 4 inch soil depth) appear to be high enough to result in measurable disease incidence under conducive environmental conditions. A decline in sclerotia population has implications for disease management, because fewer viable sclerotia in soil will result in fewer apothecia produced, and may result in reduced disease incidence. Our trials showed variability, possibly due to natural decline in sclerotia populations in soil, uneven distribution of sclerotia in soil, and the unknown survival rate of C. minitans. The research demonstrates that strategic use of C. minitans in various cropping systems may be an effective tool to reduce populations of sclerotia of S. sclerotiorum and subsequent disease incidence. In a continuation of the trial at the Geneva location, one-liter soil samples were collected from each treatment and replication. Contans
was reapplied to the appropriate treatment, and snap beans were planted to see if further reduction in population can be achieved, and if a population decline results in less disease.
Impacts
(N/A)
Publications
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Progress 10/01/04 to 09/30/05
Outputs
4d Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and Cornell University. This project was initiated on June 1, 2003, and research is ongoing. It's overall objective is to evaluate a commercially available biological control organism for its ability to provide long-term suppression of white mold through parasitism of its sclerotia. Please refer to parent project 5442- 21220-010-00D, Sclerotinia Diseases, for additional information. Research was conducted in 2003-04 to evaluate a commercially available biological control organism for its ability to provide long-term suppression of Sclerotinia sclerotioum in fields in New York. An unfunded extension of the project was requested in 2005 to complete data analyses. Final results of the study are as follows: Cropping systems included in the study were potatoes (Wolcott), wax beans (Geneva), and an organic system with dry beans planted in 2003
(Hunt). Field populations of sclerotia declined over time both in the Contans-treated areas and in the nontreated check. However, treating with Contans resulted in a more rapid decline and lower final sclerotia populations for several months following application at two locations (Geneva & Wolcott). At the third location (Hunt) the sclerotia populations were too low for valid comparisons. Disease incidence at the Wolcott locations was statistically lower (P=0.01) in the Contans-treated versus the nontreated plots. At Geneva the trends were the same, but differences in disease incidence were not statistically significant due to extreme variability in disease occurrence in the field. The trials indicate decline in soil populations of sclerotia immediately following application of Contans, but not for subsequent years from a single application. Our data indicate Contans should probably be reapplied following field preparation to avoid mixing treated and untreated soil in any year
there is a viable resident population of sclerotia. Low levels of sclerotia (1 per liter of soil, which is equivalent to 406,807 sclerotia per acre to a 4 inch soil depth) appear to be high enough to result in measurable disease incidence under conducive environmental conditions. A decline in sclerotia population has implications for disease management, because fewer viable sclerotia in soil will result in fewer apothecia produced, and may result in reduced disease incidence. Our trials showed variability, possibly due to natural decline in sclerotia populations in soil, uneven distribution of sclerotia in soil, and the unknown survival rate of C. minitans. The research demonstrates that strategic use of C. minitans in various cropping systems may be an effective tool to reduce populations of sclerotia of S. sclerotiorum and subsequent disease incidence. In a continuation of the trial at the Geneva location, one- liter soil samples were collected from each treatment and
replication. Contans was reapplied to the appropriate treatment, and snap beans were planted to see if further reduction in population can be achieved, and if a population decline results in less disease.
Impacts
(N/A)
Publications
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Progress 10/01/03 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? A. Single Most Significant Accomplishment during FY 2003: NA. B. Other Significant Accomplishment(s), if any. NA C. Significant Activities that Support Special Target Populations. NA. D. Progress Report This report serves to document research conducted under a specific cooperative agreement between ARS and Cornell University. This project was initiated on June 1, 2003 and research is ongoing. Its overall objective is to evaluate a commercially available biological control organism for its ability to provide long-term suppression of white mold through parasitism of its sclerotia. Please refer to parent project 5442- 21220-010-00D, Sclerotinia Diseases, for additional information. Research was conducted in 2003-04 to evaluate a commercially available biological control organism for its ability to provide long-term suppression of Sclerotinia sclerotioum in fields in New York. The cropping systems
included potatoes (Wolcott), wax beans (Geneva), and an organic system with dry beans planted in 2003 (Hunt). Field populations of sclerotia declined over time both in the Contans-treated areas and in the nontreated check. However, treating with Contans resulted in a more rapid decline and lower final sclerotia populations for several months following application at two locations (Geneva & Wolcott). At the third location (Hunt) the sclerotia populations were too low for valid comparisons. Disease incidence at the Wolcott locations was statistically lower (P=0.01) in the Contans-treated versus the nontreated plots. At Geneva the trends were the same, but differences in disease incidence were not statistically significant due to extreme variability in disease occurrence in the field. The trials indicate decline in soil populations of sclerotia immediately following application of Contans, but not for subsequent years from a single application. Our data indicate Contans should
probably be reapplied following field preparation to avoid mixing treated and untreated soil in any year there is a viable resident population of sclerotia. Low levels of sclerotia (1 per liter of soil, which is equivalent to 406,807 sclerotia per acre to a 4 inch soil depth) appear to be high enough to result in measurable disease incidence under conducive environemental conditions. A decline in sclerotia population has implications for disease management, because fewer viable sclerotia in soil will result in fewer apothecia produced, and may result in reduced disease incidence. Our trials showed variability, possibly due to natural decline in sclerotia populations in soil, uneven distribution of sclerotia in soil, and the unknown survival rate of C. minitans. The research demonstrates that strategic use of C. minitans in various cropping systems may be an effective tool to reduce populations of sclerotia of S. sclerotiorum and subsequent disease incidence. In a continuation of
the trial at the Geneva location, one- liter soil samples were collected on June 14, 2004, from each treatment and replication. Contans was reapplied to the appropriate treatment, and snap beans were planted to see if further reduction in population can be achieved, and if a population decline results in less disease. Non-ARS Publications: Cobb, A., and H. Dillard, 2004. Disease control update. 2004 Mid- Atlantic Fruit and Vegetable Convention, Proc. For the Vegetable, Potato, Flower, Small Fruit, and General Session, vol. 1, pages 42-44.
Impacts
(N/A)
Publications
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