Source: OREGON STATE UNIVERSITY submitted to NRP
DEVELOPMENT OF NON-ANTIBIOTIC PROGRAMS FOR FIRE BLIGHT CONTROL IN ORGANIC APPLE AND PEAR
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
0226439
Grant No.
2011-51300-30770
Cumulative Award Amt.
$475,835.00
Proposal No.
2011-01965
Multistate No.
(N/A)
Project Start Date
Sep 1, 2011
Project End Date
Aug 31, 2015
Grant Year
2011
Program Code
[113.A]- Organic Agriculture Research & Extension Initiative
Recipient Organization
OREGON STATE UNIVERSITY
(N/A)
CORVALLIS,OR 97331
Performing Department
Botany and Plant Pathology
Non Technical Summary
Fire blight is a destructive and feared disease of apple and pear. Presently, antibiotics are the most effective materials used to prevent this tree-killing disease, but actions by the National Organic Standards Board could prohibit their use in organic agriculture beginning in 2014. Biological control of fire blight has been researched for decades, but has not been fully integrated within the context of organic production. In 2009, at stakeholder request, we initiated research on non-antibiotic control of fire blight. Stakeholders identified two objectives: 1) development of effective non-antibiotic programs based on combinations of registered products, and 2) in apple, integration of these programs with bloom thinning. In response, this project will a) characterize, under controlled conditions, the relative abilities of registered biologicals to inhibit the fire blight pathogen on floral surfaces; b) evaluate in experimental orchards integrated non-antibiotic programs for fire blight control and the effect of treatment frequency on program effectiveness; c) in apple, evaluate if early bloom thinning treatments contribute to fire blight control, and how to integrate additional non-antibiotic treatments with a bloom thinning protocol; and d) monitor commercial organic pear and apple orchards for establishment of biologicals in flowers, for the presence of the fire blight pathogen during bloom, and for the resulting severity of the disease. In this process, we will work closely with organic producers, and disseminate the data regionally and nationally via eOrganic webinars, an online course, and through traditional methods. Stakeholders will be involved continuously in on-farm research, data review, and critique of suggested recommendations.
Animal Health Component
40%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2051115116015%
2051110116020%
2121115116015%
2121110116020%
2154010107015%
2154020107015%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 215 - Biological Control of Pests Affecting Plants; 205 - Plant Management Systems;

Subject Of Investigation
1110 - Apple; 1115 - Pear; 4010 - Bacteria; 4020 - Fungi;

Field Of Science
1070 - Ecology; 1160 - Pathology;
Goals / Objectives
Fire blight is a destructive and feared disease of apple and pear. Presently, antibiotics are the most effective materials used to prevent this tree-killing disease, but actions by the National Organic Standards Board have made this unlikely after 2014. Biocontrol of fire blight has been researched for decades, but has not been fully integrated within the context of organic production. In 2009, at stakeholder request, we initiated research on non-antibiotic control of fire blight. Stakeholders identified two objectives: 1) development of effective non-antibiotic programs based on combinations of registered products, and 2) in apple, integration of these programs with bloom thinning. In response, this project will: Objective 1: Under controlled conditions, characterize the abilities of three biological products to inhibit growth of the fire blight pathogen on stigmas and on nectaries of pome fruit flowers; Objective 2: In experimental orchard trials, evaluate integrated non-antibiotic programs for fire blight control, and the degree to which the effectiveness of these programs is influenced by frequency of treatment applications; Objective 3: In apple, evaluate the degree to which the early bloom treatments of lime sulfur and fish oil contribute to fire blight control, and how to integrate additional non-antibiotic treatments with the fruit thinning protocol; Objective 4: Monitor commercial organic pear and apple orchards within Washington, California and Oregon for establishment of applied biocontrol agents in flowers, for the presence of the fire blight pathogen during bloom, and for the resulting severity of the disease; and Objective 5: Teach integrated, non-antibiotic fire blight control to the organic tree fruit Community of Practice.
Project Methods
In the planned research, we are hypothesizing that satisfactory, non-antibiotic suppression of fire blight can be achieved by integrating the varied properties of the registered biological control agents. We will document these varied properties by examining in a controlled environment the degree to which these agents suppress growth of the fire blight pathogen on stigmas (the pathogen's principle site of epiphytic increase) and on the floral nectary (the site of infection). Of particular interest is the location where A. pullulans, the yeast in Blossom Protect, most strongly inhibits the E. amylovora, which is poorly understood. Understanding the relative abilities of these biological agents to inhibit pathogen growth on floral stigmas and nectaries will aid in determining the need for and order of materials applied in a non-antibiotic, integrated program. In the field, variations of integrated programs will be evaluated with the goal of finding the most effective program with the least complexity and cost. In addition, in apple, we will evaluate the degree to which the early bloom thinning treatments contribute to fire blight control, and how to integrate additional non-antibiotic treatments with the bloom thinning protocol. All experiments will be replicated and the data collected on microbial populations and on fire blight disease will be subjected to analysis of variance. By the end of the project it is expected that all of the biological products used in this study will be available commercially, and thus an integrated disease control strategy can be implemented immediately by organic growers. This project also will devoted to outreach and to monitoring the fate of applied biological agents in commercial orchards. The primary purposes of this on-farm objective are to interact with advisors and growers to present and discuss approaches to non-antibiotic fire blight control, and to evaluate the performance of biocontrol products in the commercial-scale, organic environment. By sampling multiple orchards from three states, we expect to obtain data to characterize the variability in establishment of microbial agents among organic orchards employing similar practices. Variation among orchards in establishment of microbial agents in flowers will be followed up on to attempt to identify practices (e.g., time of treatment, sprayer speed, water volume, heat units after spraying, timing in relation to bloom thinning) that contribute to variation. In previous years, we have developed tools to measure if biological agents are establishing in flowers as intended, and we have also developed a molecular detection protocol to determine if and when the fire blight pathogen has become active within orchards. During these monitoring studies, we will communicate directly with growers and advisors, collect and evaluate samples of flowers from their orchards, and provide immediate feedback on our findings of biocontrol agent establishment and pathogen detection. Additional outreach will occur through eOrganic webinars and web-based publications as well as via traditional methods.

Progress 09/01/11 to 08/31/15

Outputs
Target Audience:Project goals were to develop and deliver effective non-antibiotic spray programs to control fire blight based on combinations of registered biological materials, and to integrate these programs with fruit-load thinning in organic apple orchards. In general, recommendations to make spray treatments for disease control in commercial orchards are done by state-licensed pest control advisors (PCAs). Consequently, while our initial primary target audience was the organic apple and pear growers in the region, as the project matured we found our largest audience to be the PCAs who for their business model need to deliver effective fire blight control programs to their clients (growers). This resulted in numerous small-audience workshops held specifically for PCAS. In addition, we hosted the members of the National Organic Standards Board on a one day field tour of organic pear orchards to educate them as to what was practical and what was not practical with regard to non-antibiotic fire blight control. Through our webinars on eOrganic, we reached a national audience of people (producers, advisors, fruit distributors, consumer advocates) interested in growing, marketing and consuming organic pome fruit. Changes/Problems:The integrated biological (yeast) and non-antibiotic chemical control programs that we developed are highly effective for fire blight control. These programs, however, have a drawback in that both the yeast and the chemical treatments have a potential to damage the skins of developing fruit (this damage is termed russetting), which lessens the marketability of the fruit. In semi-arid, desert environments typical of pome fruit production districts within the Pacific west region, russeting of fruit with spray treatments is not usually a major concern but can occur in some circumstances (e.g., a period of rain at end of bloom). Copper materials, which are among the most effective materials for fire blight control, have the highest potential to russet fruit. Consequently, although our non-antibiotic programs have been successfully implemented by the organic pome fruit industry, there is some dissatisfaction with degree of fruit russetting risk vis-a-vis the need to apply treatments effective for fire blight control. Research focused on identifying effective materials to replace copper in the control program is ongoing. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Presentations by Ken Johnson: (audience size given as 'n =') 2012 Jan "Fire blight Management in 2012". OSU Extension, Hood River Winter Horticulture Meeting, Pine Grove, OR. n =60. "New (and old) technologies for fire blight control." N. Central Washington Pear Day, Wenatchee, WA. n =200. "What's new in organic fire blight control", N. Central Washington Apple Day, Wenatchee, WA. n =300. "Managing fire blight in organic orchards", Yakima Valley Organic Grower's Meeting, Prosser, WA, n =30. "New yeast product to control fire blight", Western Orchard Pest and Disease Management Conference, Portland, n =40. "Battling fire blight with the sunsetting of tetracycline" Organic session, Washington Hort Association Annual Conference, Yakima, WA, n =225. "Fire blight control product review", Pear session, Washington Hort Association Annual Conference, Yakima, WA, n =150. 2013 Jan/Feb "Fire blight management short-course", Treasure Valley Tree Fruit Growers Association, Nampa, ID n =20. "New approaches to fire blight control", N. Coast Pear Research Meeting, Ukiah, CA, February, 2013. n =25 "Progress on Fire Blight Management, With and Without Antibiotics". 67th Annual Lake Chelan Horticultural Day, Chelan, WA. n =125 "Fire blight management with and without antibiotics", N. Central Washington Apple Day, Wenatchee, WA. n =300. "New concepts in fire blight control", N. Central Washington Pear Day, Wenatchee, WA, January 2013. n =175. "Non-antibiotic control of fire blight", Wilbur-Ellis Yakima Valley Organic Grower's Meeting, Prosser, WA n =50 "Non-antibiotic control of fire blight", Western Orchard Pest and Disease Management Conference, Portland, January 2013. n =40 "Fire blight control without antibiotics", GS Long Organic Growers, Yakima, WA, January, 2013. n =50 March/April "Organic Pear Production in Hood River Valley", Field tour given to the NOSB, Hood River, OR July "Fire blight control", OSU-SOREC Field Day, Medford, OR, n =35. 2014 Jan/Feb "Non-antibiotic control of fire blight", "Western Disease Conference, Portland, OR. n =40 "Non-antibiotic Fire Blight Control: Where We Stand with a Season to Go", Wilbur-Ellis Organic Grower's Meeting, Benton City, WA, n =50. "Organic fire blight control", N. Central Washington Apple Day, Wenatchee, W. n =250. "New concepts in fire blight control", N. Central Washington Pear Day, Wenatchee, January 2014. n =200. "New Developments in Fire Blight Control", OSU Extension, Hood River Hort. Meeting, Hood River, OR. n =75 Mar/Apr "Fire blight control after a season with high disease incidence", S. OR pear growers. n =22 "Fire blight control in organic orchards". Presented to Wilbur-Ellis crop consultants, Sunnyside, WA, and to Broetje Orchards fieldmen, Pasco, WA, n = 25 and 15 Oct to Dec "Development of non-antibiotic programs for fire blight control in organic apple and pear", USDA NIFA OREI project director's meeting, Washington, D.C. n =25. "New developments in Fire blight control", Workshop presented to Wilbur-Ellis N. central pest control advisors, Chelan, WA. n =18 Updates for fire blight control programs for organic orchards", WA Hort Association, Kennewick, WA, December, 2014. 2015 Jan/Feb "Materials and strategies for non-antibiotic fire blight control", Wilbur Ellis Organic Growers, Benton City, WA, n =60. "New developments in fire blight control", Treasure Valley Tree Fruit Growers, Nampa, Idaho. n =30 "Non-antibiotic control of fire blight", Western Disease Conference, Portland. OR. "Fire blight control without antibiotics"' GS Long Organic Growers, n =60. "Biocontrol of fire blight: Why a yeast is a new paradigm in disease suppression", Organic Research Symposium, Lacrosse, WI. n =20 "Managing fire blight without antibiotics", MOSES conference, Lacrosse, WI. n = 175 March "Fire blight management in organic orchards". Workshops to Wilbur-Ellis fieldmen, Sunnyside, WA, and to Broetje Orchards fieldmen, Pasco, WA, audiences 25 and 20. "Fire blight management", S. OR pear grower's workshop, OSU-SOREC, Medford, OR. n =20 Nov/Dec "Use of Biocontrol Control in the Management of Fire Blight", BioControls Conference and Tradeshow, Fresno, CA. n =40. Presentations by Tim Smith: (audience size given as 'n =') 2013 Nov/ Dec WA Tilth Annual Conference, Yakima, WA,: "Alternatives for the control of fire blight using organic methods and materials." n =45. WA Tree Fruit Association Annual Meeting, Wenatchee, WA, "Fire Blight, promising alternative materials for control." n =350. WA Hort Association, Wenatchee, WA, "Fire Blight of Pears, promising management practices and choices of materials for control." n =300. 2014 Jan/Feb Western Disease Conference, Portland, OR, "Fire Blight of Pears, promising management practices and choices of materials for control." n =30. Lake Chelan Horticulture Day, Chelan, WA, "Fire Blight, promising management practices and choices of materials for control." n =150. Pear Day, Wenatchee, WA, "Fire Blight of pear, promising management practices and choices of materials for control." n =220. Apple Day, Wenatchee, WA, "Fire Blight of apples, promising management practices and choices of materials for control." n =200. NW Wholesale Annual Meeting, Wenatchee, WA, "Fire Blight of apples and pears, promising management practices and choices of materials for control." 1 n =130. Apple Crop Protection Research Review, Yakima, WA, "Final Report: Management of Two Critical Diseases of Apple and Pear." n =90. Okanogan Co Horticultural Assoc., Omak, WA, "Fire Blight of apples and pears, promising management practices and choices of materials for control." n =120. NW Wholesale Organic Growers Meeting, Chelan, WA, "Alternatives for the control of fire blight using OMRI approved materials." n =65. NW Wholesale Annual Growers Meeting, Oroville, Washington, "Fire Blight of apples and pears, promising management practices and choices of materials for control." " 30 minutes to 65 tree fruit growers and orchard advisors in the audience. Manson Fruit Growers, "Fire Blight of apples and pears, promising management practices and choices of materials for control." n =35. Apr Greenbluff Fruit Growers, Spokane, WA, "Fire Blight of apples and pears, promising management practices and choices of materials for control." n =25 . Oct/Nov/Dec Certis Fire blight research review, "Fire Blight of apples and pears, promising management practices and choices of materials for control." n =40. Washington Tree Fruit Association, Kennewick, WA, "Fire Blight, more progress towards promising alternative materials for control." n =400. 2015 Jan/Feb Western DiseaseConference, Portland, OR, "Fire Blight of Pears, promising management practices and choices of materials for control." n =40. Lake Chelan Hort Day, Chelan, WA, "Fire Blight, more progress benefitting management practices and choices of non-antibiotic materials for control." n =160. Pear Day, Wenatchee, WA, "Modern fire blight control materials- product choices and timing. n =190. Apple Day, Wenatchee, WA, "Fire Blight of apples, promising management practices and more new choices of non-antibiotic spray materials for control." n =180. NW Wholesale Growers Meeting, Oroville, WA, "Fire Blight of apples and pears, promising management practices and choices of non-antibiotic materials for spray control." " n =55. February, Okanogan Co. Hort. Assoc., Omak, WA "Fire Blight of apples and pears, promising management practices and non-antibiotic choices of spray materials for control." n =110. NW Wholesale Organic Growers, Chelan, WA, "Alternatives for the control of fire blight using OMRI approved materials." n =70. Manson Fruit Growers, "Fire Blight of apples and pears, promising management practices and choices of materials for control." n =38. G.S. Long Fieldmen, Yakima, WA. "Fire Blight of apples and pears, promising management practices and choices of materials for control."n = 10. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? All objectives were completed. Under obj. 1, the yeast biocontrol agent, Aureobasidium pullulans (product Blossom Protect) was shown to be an excellent colonist of flowers. This organism inhibits growth of the fire blight pathogen on both stigmata and the nectary (where pathogen infects the flower), whereas bacterial biocontrol agents inhibit pathogen growth on stigmata only. Obj. 2: Integrated biological and non-antibiotic chemical control provided fire blight suppression that was equivalent to antibiotics. These integrated programs began with a treatment of A. pullulans (Blossom Protect)followed by two treatments of a Bacillus-fermentation product (Serenade Opti) and/or a soluble copper product (Cueva or Previsto). Under obj. 3, in apple orchards, fruit thinning with 2% lime sulfur plus 2% fish oil (LS+FO) at 30 and 70% bloom reduced significantly the proportion of blighted flower clusters. Furthermore, lime sulfur suppressed epiphytic pathogen populations after its establishment on flowers. Over four trials, treatment with Blossom Protect after LS+FO suppressed fire blight by an average of 92% compared with water only; this level of control was similar to streptomycin. Spray treatments of biocontrol agents after the 70% bloom LS+FO treatment established the agents on a significantly higher proportion of flowers than a spray of the biocontrol agents before LS+FO. Consequently, in apple, biological treatments are not advised until after lime sulfur treatments for fruit thinning are completed. Under obj. 4, WA, OR, and CA orchards monitored for establishment of the biocontrol agent, A. pullulans, demonstrated that the yeast colonizes nearly all flowers on a tree (> 99%), even those closed at the time of treatment. Ongoing research is examining the question of how many flowers become colonized by an applied strain of A. pullulans (i.e., those in the product) compared to becoming colonized by a strain from the orchard. We also monitored commercial pear orchards in CA to ascertain the likelihood of detecting the pathogen as a function of bloom stage. In conjunction with these monitoring experiments, we re-evaluated the practice of prebloom, copper-based sanitation treatments to slow to pathogen colonization of flowers. We found that copper sanitation may add value to fire blight managementby delaying the increase of epiphytic pathogen populations to the late stages of the bloom period, at which time the number of susceptible flowers declines rapidly. Obj. 5 was accomplished by webinars (described under other products) and by >50 regional presentations made to the pome fruit community (listed under dissemination). In spring 2015, non-antibiotic fire blight control programs were implemented in certified-organic orchards with apparent success. We documented project impact through stakeholder 'clicker' surveys, which to date have shownthat the pome fruit community is optimistic about the future of organic apple and pear production. They are using integrated programs of non-antibiotic materials for fire blight control as well as adjusting nutrition, irrigation, insect control, tree canopy, which are known to influence the disease.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Johnson, K. B., and Temple, T. N. 2013. Evaluation of strategies for fire blight control in organic pome fruit without antibiotics. Plant Dis. 97:402-409.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Elkins, R. B., Temple, T. N., Shaffer, C. A., Ingels, C. A., Lindow, S. B, Zoller, B. G., and Johnson, K. B. 2015. Evaluation of dormant-stage inoculum sanitation as a component of a fire blight management program for fresh market Bartlett pear. Plant Dis. 99:1147-1152.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Johnson, K. B., Temple, T. N., Elkins, R. B., and Smith, T. J. 2014. Strategy for non-antibiotic fire blight control in U.S.-grown organic fruit. Acta Hort. (ISHS) 1056:93-100.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Johnson, K., Temple, T., Elkins, R. and Smith, T. Systems approach to fire blight control in organic pear and apple without antibiotics. 2nd International Organic Fruit Research Symposium, Leavenworth, WA, June 2012. Archived on YouTube.


Progress 09/01/11 to 08/31/12

Outputs
Target Audience: Currently, National Organic Program standard organic pome fruits can be treated with antibiotics for fire blight, but recent actions by the standards board indicate these materials will likely be unavailable to organic growers after 2014. The project's goal is to develop, within the context of organic production practices, effective non-antibiotic programs for fire blight suppression in apple and pear. The target audinece is primarily producers of organic pome fruit, and secondarily comsumers of organic pome fruit. Non--antibiotic methods of fire blight must be developed by 2014 to ensure that organic pome fruit will be available for opurchase in the marketplace.. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? In addtion to the webinars and scientic meetings listed above, we make regional talks and workshops in areas where orgain apple and pear growers and advisers are located. Examples for 2010 to 2014: "2015: Updates for fire blight control programs for organic and conventional orchards", Washington Hort Association Annual Conference, Kennewick, WA, December, 2014. "New developments in Fire blight control", Workshop presented to Wilbur-Ellis N. central region pest control advisors, Chelan, WA, November, 2014 "Development of non-antibiotic programs for fire blight control in organic apple and pear", USDA NIFA Organic Agriculture project director's meeting, Washington, D.C., October, 2014. "Fire blight control in organic orchards". Two workshops presented to Wilbur-Ellis crop consultants, Sunnyside, WA, and to Broetje Orchards Fieldmen, Pasco, WA, April 2014. "Fire blight control after a season with high disease incidence", S. OR pear growers. March 2014 "New Developments in Fire Blight Control", OSU Extension, Hood River Winter Horticulture Meeting, Hood River, OR, February, 2014. "Non-antibiotic Fire Blight Control: Where We Stand with a Season to Go", Wilbur-Ellis Yakima Valley Organic Grower's Meeting, Benton City, WA, January, 2014. "Organic fire blight control", N. Central Washington Apple Day, Wenatchee, WA, January 2014. "New concepts in fire blight control", N. Central Washington Pear Day, Wenatchee, January 2014. Updates on current research efforts: "Non-antibiotic control of fire blight", "New coppers for fire blight control", Western Orchard Pest and Disease Management Conference, Portland, January 2014. "Fire blight control", SOAREC Field Day, Medford, OR, July, 2013. "Organic Pear Production in Hood River Valley", Field tour given to the National Organic Standards Board, Hood River, April 2013 "Research update on non-antibiotic control of fire blight", eOrganic webinar, March, 2013. "Fire blight management short-course", Treasure Valley Tree Fruit Growers Association, Nampa, ID, February, 2013. "New approaches to fire blight control", N. Coast Pear Research Meeting, Ukiah, CA, February, 2013. "Progress on Fire Blight Management, With and Without Antibiotics". 67th Annual Lake Chelan Horticultural Day, Chelan, WA January 2013 "Fire blight management with and without antibiotics", N. Central Washington Apple Day, Wenatchee, WA, January 2013. "New concepts in fire blight control", N. Central Washington Pear Day, Wenatchee, WA, January 2013. "Products for fire blight Control", Wilbur-Ellis Yakima Valley Grower's Meeting, Yakima, WA, January, 2013. "Non-antibiotic control of fire blight", Wilbur-Ellis Yakima Valley Organic Grower's Meeting, Prosser, WA, January, 2013. Updates on current research efforts: "Non-antibiotic control of fire blight", "New coppers for fire blight control", Western Orchard Pest and Disease Management Conference, Portland, January 2013. "Fire blight control without antibiotics", GS Long Yakima Valley Organic Grower's Meeting, Yakima, WA, January, 2013. "Battling fire blight with the sunsetting of tetracycline" Organic session, Washington Hort Association Annual Conference, Yakima, WA, December, 2012. "Fire blight control product review", Pear session, Washington Hort Association Annual Conference, Yakima, WA, December, 2012. "A new technology for fire blight control", Technology session, Washington Hort Association Annual Conference, Yakima, WA, December, 2012. "Fire blight Management in 2012". OSU Extension, Hood River Winter Horticulture Meeting, Pine Grove, OR, January, 2012. "New (and old) technologies for fire blight control." N. Central Washington Pear Day, Wenatchee, WA, January 2012. "What's new in conventional and organic fire blight control", N. Central Washington Apple Day, Wenatchee, WA, January 2012. "Managing fire blight in organic orchards", Yakima Valley Organic Grower's Meeting, Prosser, WA, January, 2012. Updates on current research efforts: "New yeast product to control fire blight", Western Orchard Pest and Disease Management Conference, Portland, January 2012. "Life without antibiotics: Non-antibiotic systems approach to fire blight control", Washington Hort Association Annual Conference, Wenatchee, WA, December, 2011. "Organic Fire Blight Management", Tilth Producers of Washington Research Symposium, Yakima, November 2011. "Fire blight management in organic apples" Yakima Valley Organic Grower's Meeting, Prosser, WA, February, 2011. What do you plan to do during the next reporting period to accomplish the goals? The research objectives are open-ended. We have developed effective non-antibiotic programs for fire blight control. Nonetheless, the programs carry with them some risk that fruit quality can be impacted by the non-antibiotic materials after they are sprayed onto the trees. We are working to understand and mitigate these risks without reducing the effectiveness of the disease control program,.

Impacts
What was accomplished under these goals? We acomplished most aspects of each of the goals/objectives. We are still planning additional outreach publications to commicate the research finding of this project.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Johnson, K. B., Temple, T. N., Elkins, R. B., and Smith, T. J. 2014. Strategy for non-antibiotic fire blight control in U.S.-grown organic fruit. Acta Hort. (ISHS) 1056:93-100.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Johnson, K. B., and Temple, T. N. 2013. Evaluation of strategies for fire blight control in organic pome fruit without antibiotics. Plant Dis. 97:402-409. doi: 10.1094/PDIS-07-12-0638-RE