Progress 07/01/03 to 06/30/08
Outputs
4d Progress report. The Canker portion of the project was established by an interagency grant from USDA/APHIS to examine the spatial spread of Citrus Canker under the parent project, 6618-22000-026-00D, Domestic, Exotic and Emerging Diseases of Citrus, Vegetables and Ornamentals (DEED). The National Program is 303, Plant Diseases. Citrus canker continues to be a legal issue for Florida and USDA, APHIS, making eradication problematic. Further epidemiological analysis of distances of spread and spatial distributions were conducted on data from 320 orchards in Brazil. Results confirmed that the distances of spread determined in Brazil are within the same range as distances of spread in South Florida. Spatial analyses indicated that spread of citrus canker is different since the introduction of the Asian leaf miner and has resulted in one draft manuscript. The data and analysis has been used in Brazil to adjust the eradication protocol for citrus canker and improve
disease suppression/eradication. In a second project on citrus canker in Brazil during 2003-2004, 14 1- hectare plots were established in Brazil under endemic citrus canker conditions to examine the spread of citrus canker from known sources of inoculum under various control strategies, i.e., chemical control of the synergistic leaf miner, wind breaks to reduce inoculum spread and infection, and combinations versus untreated control plots. Plots will be inoculated later this year and disease will be followed and assessed weekly for 12-18 months. Results will provide results of various control strategies under large field plots conditions and should provide valuable information for the control of citrus canker in the US if eradication cannot be accomplished. The duration and capacity of citrus canker lesions to produce inoculum and the dynamics of spread under various environmental conditions is not completely understood. Experiments to determine the duration of inoculum production
for canker lesions under filed conditions were conducted at a remote quarantine location and a wind tunnel capable of generating hurricane velocity winds and rain was designed and is in the final stages of construction to explore the dynamics of canker bacterial dispersal. Citrus canker lesions were found to begin dispersing inoculum within a few minutes of exposure to wind and rain and inoculum production was found to continue for multiple days. Information generated has produced two manuscripts to date and are the basis of weather related models to predict canker dispersal for regulatory and eradication purposes. This project comes under the parent project, 6618-22000-026-00D, Domestic, Exotic and Emerging Diseases of Citrus, Vegetables and Ornamentals (DEED). A mobile containment greenhouse was designed, prototyped and built at the Orlando USHRL over the last few years. The greenhouse was deployed and has been used for citrus canker research at two remote locations in south
Florida and has proved to be invaluable for conducting containment research at the site of disease outbreaks. The technology transferred to USDA APHIS who saw the advantage of such a remote facility and decided to invest in the development of a second generation to be used to address new exotic pathogen/pest outbreaks in remote areas. APHIS provided grant funding for design and construction of a second generation mobile containment greenhouse. The USDA, APHIS lab in Mission, Texas in collaboration with Tim Gottwald in Fort Pierce finalized construction of a new second generation mobile greenhouse lab, and deployed it to south Florida for Citrus Canker research to test its feasibility for use with other invasive plant pathogen emergency programs in the US. This project is in collaboration with USDA, APHIS on remote sensing to detect citrus canker and falls under the parent project is 6618-22000-026- 00D, Domestic, Exotic and Emerging Diseases of Citrus, Vegetables and Ornamentals
(DEED). Experiments using hyperspectral radiometry methods were conducted under containment in Miami. Data on the spectral signature of citrus canker infected versus non-infected leaves and whole plants was collected and analysis indicated that the spectral signature of citrus canker was unique but could not always be differentiated from that of other diseases and maladies and in the case of whole plants, from healthy trees. Additional experiments continue on the sensitivity of detection, that is, the proportion of the foliage that must be infected for reliable detection to occur.
Impacts
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Publications
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Progress 10/01/03 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report Citrus canker continues to be a legal issue for Florida and USDA, APHIS, making eradication problematic. Further epidemiological analysis of distances of spread were conducted on data from 100 groves provided by the Brazilian citrus canker eradication program. Results confirmed that the distances of spread determined in Brazil are within the same range as distances of spread in South Florida. This validated the protocol used by the joint state/federal eradication program and provides documentation to support the legal status of the eradication program. The data and analysis have been used in Brazil to adjust the eradication protocol for citrus canker and improve disease suppression/eradication. The duration and capacity of citrus canker lesions to produce inoculum and the dynamics of spread under various environmental conditions is not completely understood. Experiments to
determine the duration of inoculum production for canker lesions under filed conditions were conducted at a remote quarantine location and a wind tunnel capable of generating hurricane velocity winds and rain was designed and is in the final stages of construction to explore the dynamics of canker bacterial dispersal. Citrus canker lesions were found to begin dispersing inoculum within a few minutes of exposure to wind and rain and inoculum production was found to continue for multiple days. Information generated will be the basis of weather related models to predict canker dispersal for regulatory and eradication purposes. This project comes under the parent CRIS, 6618-22000-026-00D, Domestic, Exotic and Emerging Diseases of Citrus, Vegetables and Ornamentals (DEED). A mobile containment greenhouse was designed, prototyped and built at the Orlando USHRL over the last few years. The greenhouse was deployed and has been used for citrus canker research at two remote locations in south
Florida and has proved to be invaluable for conducting containment research at the site of disease outbreaks. The technology transferred to USDA APHIS who saw the advantage of such a remote facility and decided to invest in the development of a second generation to be used to address new exotic pathogen/pest outbreaks in remote areas. APHIS has provided grant funding for design and construction of a second generation mobile containment greenhouse. The USDA, APHIS lab in Mission, Texas in collaboration with Tim Gottwald in Fort Pierce is in the final stages of constructing the new second generation which should be completed within the next two months and deployed to south Florida for Citrus Canker research as a program to test its feasibility. This project is in collaboration with USDA, APHIS on remote sensing to detect citrus canker and falls under the parent CRIS is 6618-22000-026- 00D, Domestic, Exotic and Emerging Diseases of Citrus, Vegetables and Ornamentals (DEED).
Experiments using hyperspectral radiometry methods were conducted under containment in Miami. Data on the spectral signature of citrus canker infected versus non-infected leaves and whole plants was collected and analysis indicated that the spectral signature of citrus canker was unique but could not always be differentiated from that of other diseases and maladies and in the case of whole plants, from healthy trees. Additional experiments continue on the sensitivity of detection, that is, the proportion of the foliage that must be infected for reliable detection to occur.
Impacts
(N/A)
Publications
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