Progress 09/01/24 to 08/31/25

Outputs
Target Audience:Throughout this reporting cycle, our outreach efforts were directed toward a broad spectrum of stakeholders in agriculture, including growers, industry representatives, and academic researchers. The emphasis remained on enabling practical adoption of sustainable solutions to crop disease, with particular focus on alternatives to antibiotics. 1. Farmers and Growers We continued to engage farmers at the local level, holding direct conversations with orchard operators such as Deirdre Birmingham (The Cider Farm), Rami Aburomia (Atoms to Apples), Frank Roesch (Roesch Farm), and Jeff Knudsen (Barthel Fruit Farm). These exchanges went beyond simple outreach, serving as opportunities to evaluate fire blight control measures under real farm conditions. Farmers provided candid feedback on how antibiotic-alternative products might be integrated into their management practices, and in turn, we shared data on performance and safety. This two-way dialogue helped ensure that the outcomes of our research are not only scientifically sound but also practically relevant and adaptable to everyday farm operations. 2. Industry Professionals Our participation in national and international conferences allowed us to engage professionals working at the interface of science, industry, and regulation. At the 4th International Symposium of Fire Blight on Rosaceous Plants (June 23-27, 2025, Richland, WA), Dr. Yang presented research on Pseudomonas soli T307 and its metabolites as sustainable options for apple fire blight management. Interest was especially high given the growing restrictions on antibiotics and the persistent challenge of fire blight. Graduate student Ton Nu Bao Vy Huyen further contributed by presenting mechanistic insights into the metabolite RejuAgro A, drawing attention to its unique mode of action. The discussions extended beyond academic curiosity, with apple growers, consultants, and biotech companies exploring collaborative pathways for field trials and potential commercialization. Complementing this, Dr. Yang's involvement at the Annual Biocontrol Industry Meeting (ABIM) in Basel (October 21-23, 2024) brought valuable exposure to regulatory considerations and market dynamics shaping the biocontrol industry worldwide. Likewise, invited presentations at the APS Plant Health meeting in Memphis (July 27-30, 2024) introduced RejuAgro A to both scientific and industry audiences through sessions selected by the APS Industry Committee, amplifying global visibility of our research and its application in apple disease management. 3. Collaborators in Product Development Strategic collaboration with Dunham Trimmer, LLC, has enabled us to move beyond research and position our work within the broader context of market readiness. Their expertise in technology licensing, regulatory navigation, and industry networking ensures our discoveries resonate with commercial partners. By working with Dunham Trimmer, we remain closely aligned with industry benchmarks and consumer expectations, strengthening the pathway from lab discovery to farm adoption. 4. Academic and Research Institutions International academic engagements offered another critical platform to disseminate our findings. At invited seminars hosted by Academia Sinica's Biotechnology Center (January 2, 2025) and National Cheng Kung University (January 6, 2025), Dr. Yang presented on the journey of natural metabolites from bench to marketplace. These lectures stimulated dialogue with leading researchers in agriculture, highlighting innovative approaches to plant disease control while underscoring the translational value of our work. Such outreach fosters future collaborations and helps situate our program within global scientific efforts aimed at sustainable crop protection. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project created a range of training and professional development opportunities, advancing both scientific expertise and practical knowledge transfer to the farming community. Hands-on Learning with Growers Direct engagement with orchardists such as Deirdre Birmingham (The Cider Farm), Rami Aburomia (Atoms to Apples), Frank Roesch (Roesch Farm), and Jeff Knudsen (Barthel Fruit Farm) provided an important avenue for grassroots training. These interactions allowed for two-way exchange--farmers received guidance on incorporating non-antibiotic fire blight management strategies, including Pseudomonas soli T307, while the project team gained insight into the practical challenges of orchard operations. The result was farmer-focused training tailored to real-world needs, with emphasis on integrating sustainable practices into existing management programs. Mentorship and Capacity Building for Researchers Graduate students and early-career researchers gained extensive training under Dr. Yang's mentorship. This included developing competencies in designing and executing field trials, collecting and analyzing complex data sets, and applying biocontrol strategies under orchard conditions. Students also enhanced their scientific communication skills by preparing presentations and engaging with growers, building a foundation for careers in agricultural biotechnology and plant pathology. Professional Growth through Conferences and Knowledge Exchange Participation in major conferences expanded professional development beyond the laboratory. Dr. Yang presented research findings at the Annual Biocontrol Industry Meeting (ABIM) in Basel, Switzerland, and served as an Invited Speaker at the 4th International Symposium of Fire Blight on Rosaceous Plants (June 23-27, 2025, Richland, WA). In addition, Dr. Yang was invited to present at the APS Plant Health meeting (July 27-30, 2024, Memphis, Tennessee), where he highlighted RejuAgro A produced by P. soli T307 as a sustainable alternative for the management of fire blight, citrus canker, and Huanglongbing (HLB). These venues facilitated dialogue with international researchers, regulatory specialists, and industry leaders, offering valuable exposure to emerging biocontrol technologies and global perspectives on sustainable agriculture. Graduate students also benefited from presenting their own work in these forums, gaining professional visibility and networking opportunities. Collaboration with Industry Partners The project's collaboration with Dunham Trimmer, LLC, further enriched professional development by bridging research and commercialization. Through this partnership, the team gained insight into market analysis, regulatory pathways, and product licensing. This collaboration equipped the research team with practical knowledge of how biocontrol technologies move from discovery to commercial application, deepening their understanding of industry expectations and the commercialization landscape. How have the results been disseminated to communities of interest?During this reporting period, dissemination activities were designed to reach three primary groups--local growers, industry stakeholders, and the broader scientific community--ensuring that project outcomes were communicated in ways that support both practical adoption and continued research progress. Local Farmer Engagement Direct outreach to regional growers remained a cornerstone of our dissemination strategy. We met with producers including Deirdre Birmingham (The Cider Farm), Rami Aburomia (Atoms to Apples), Frank Roesch (Roesch Farm), and Jeff Knudsen (Barthel Fruit Farm) to discuss fire blight challenges and present non-antibiotic management options such as Pseudomonas soli T307. These conversations were highly interactive, providing opportunities not only to share results but also to adapt recommendations to real orchard conditions. Farmers gained a clearer understanding of how sustainable treatments can be incorporated into their existing management practices, while we received feedback that helps guide future refinements. Communication with Industry Stakeholders Our findings were also shared at high-profile industry events. At the 4th International Symposium of Fire Blight on Rosaceous Plants (June 23-27, 2025, Richland, WA), the APS Plant Health meeting (July 27-30, 2024, Memphis, Tennessee), and the Annual Biocontrol Industry Meeting (ABIM) in Basel, Switzerland, we engaged with biocontrol companies, consultants, and regulatory professionals. These platforms allowed us to showcase the commercial potential of P. soli T307, highlight advances with RejuAgro A as a sustainable solution for fire blight and citrus diseases, and exchange perspectives on both regulatory hurdles and market opportunities. In addition, our collaboration with Dunham Trimmer, LLC, extended the reach of our results by connecting us with stakeholders responsible for product development, registration, and licensing. Their market and regulatory expertise ensured that dissemination efforts were aligned with industry standards, facilitating a clearer bridge between research outcomes and commercial application. Outreach to the Scientific Community The scientific community was engaged through invited presentations and conference sessions, where Dr. Yang shared results on the effectiveness of non-antibiotic fire blight control strategies. Presentations at the Fire Blight Symposium not only connected us with local growers in Washington State but also reached a global audience of plant pathologists and agricultural scientists. These exchanges encouraged collaborative discussions, promoted the integration of our findings into broader research initiatives, and reinforced the importance of sustainable disease management strategies in orchard systems. Through these combined efforts, our results reached those who can apply them directly--growers and industry partners--as well as researchers who can build on them to advance the next generation of biocontrol technologies. What do you plan to do during the next reporting period to accomplish the goals?1. Expanded Field Evaluations Building upon the promising results from this year, we will conduct larger-scale field trials to validate the effectiveness of Pseudomonas soli T307 in combination with L-methionine, L-glutathione, and Methylated Soybean Oil (MSO). These trials will be performed across multiple apple cultivars and growing environments to assess consistency of performance under variable orchard conditions. 2. Optimization of Treatment Formulations We will refine application protocols by testing a broader range of concentrations and combinations of the enhancers. This work will help identify the most effective and practical formulations, maximizing fire blight suppression while ensuring ease of adoption by growers. 3. Strengthening Outreach and Knowledge Transfer Our next phase of outreach will extend engagement to additional apple producers and grower networks. We also plan to increase participation in industry-focused meetings and agricultural extension events to ensure our findings are widely disseminated and accessible to the farming community. 4. Progress Toward Commercialization Collaboration with industry partners will intensify as we begin to address regulatory and commercialization requirements for P. soli T307. Efforts will focus on aligning the product with market expectations, preparing the groundwork for registration, and ensuring that the technology is positioned for adoption as a sustainable, non-antibiotic solution for fire blight management.

Impacts
What was accomplished under these goals? Problem Statement Fire blight, caused by Erwinia amylovora, continues to be a major challenge for apple orchards, leading to serious yield loss and financial strain for growers. Conventional reliance on antibiotics such as streptomycin is becoming less viable due to mounting concerns over resistance development and regulatory restrictions. Our project is directed at advancing practical, non-antibiotic solutions for fire blight control, with a focus on the biocontrol bacterium Pseudomonas soli T307, tested both independently and in combination with amino acid-based enhancers. Stakeholders Benefited: Apple growers and orchard managers: especially in regions with recurring fire blight outbreaks, who require effective and sustainable disease management tools. Crop protection industry professionals: who seek alternatives that align with evolving regulations and consumer demand. Academic and research communities: who benefit from expanded knowledge of biocontrol mechanisms and field-tested validation. Major Activities, Data Collected, and Results: This reporting period emphasized multi-site field evaluations conducted at the Connecticut Agricultural Experiment Station (CAES) and Cornell University. The primary objective was to determine whether Pseudomonas soli T307, applied alone or in combination with natural enhancers, could effectively suppress blossom blight caused by Erwinia amylovora. At CAES (Hamden, CT), trials were carried out on eight-year-old 'Crimson Crisp' apple trees at the Lockwood Farm. The experiment followed a randomized complete block design with three replications, each treatment applied to individual trees bearing at least 100 flower clusters. Seven treatments were evaluated: P. soli T307 alone, or combined with L-methionine, L-glutathione, and Methylated Soybean Oil (MSO) in different combinations. Streptomycin at 100 ppm served as the antibiotic standard, while streptomycin was included as a positive control and water as the negative control. Inoculation occurred at full bloom on May 3, 2025, with E. amylovora (1×106 CFU/mL). Disease severity was assessed on May 26, 2025, by recording the percentage of infected flower clusters. Clear differences in treatment performance were observed. The untreated control had a 40.6% infection rate, while P. soli T307 alone reduced infection to 27.5%. The combination of P. soli T307 with L-methionine and MSO further lowered infection to 14.2%, statistically indistinguishable from streptomycin at 9.4%. By contrast, L-methionine alone, or paired with L-glutathione, did not enhance disease suppression beyond the effect of P. soli T307 alone. At Cornell University, field trials were conducted at Cornell AgriTech in Geneva, NY, under OMRI-certified organic production conditions. The orchard consisted of two-year-old 'Gala' trees on G.41 rootstocks. Treatments were applied using a gas-powered backpack sprayer calibrated to deliver 100 gallons per acre (0.5 gal/tree). Trees were inoculated at 80% bloom (May 7, 2025) with E. amylovora strain Ea 273 (1×106 CFU/mL) applied via a hand-pumped Solo backpack sprayer. Blossom blight incidence was measured as the proportion of blighted clusters from a standardized 20-cluster assessment on four replicate trees per treatment. Shoot blight was evaluated as the percentage of infected terminal shoots showing discoloration or ooze. Results at Cornell confirmed the robustness of P. soli T307. Whether applied alone or supplemented with enhancers, the strain provided control equivalent to streptomycin in both blossom and shoot blight evaluations. While no statistically significant differences were observed among treatments, combinations such as L-methionine + MSO and L-methionine + L-glutathione + MSO produced numerically lower incidences of disease. These findings reinforce the potential of P. soli T307 as a reliable, sustainable alternative to antibiotics for fire blight management. Key Outcomes and Accomplishments: The most significant achievement of this reporting period is the identification of an optimal formulation--P. soli T307 combined with L-methionine and MSO--that provided control levels equivalent to the antibiotic standard streptomycin. Both sites confirmed the reliability of P. soli T307 as a strong candidate for non-antibiotic fire blight management. These findings highlight the strain's potential to transition from research into applied orchard programs. Broader Impact: This work advances the broader agricultural goal of reducing antibiotic dependence in crop disease management. By validating P. soli T307 and its optimized combinations in independent field trials, the project provides growers with an environmentally sound and effective solution. Successful adoption will help preserve apple yield and quality, meet sustainability targets, and address public concerns about antibiotic resistance, ultimately benefiting farmers, consumers, and the agricultural sector as a whole.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: RejuAgro A: A Sustainable Solution for Mitigating the Flames of Fire Blight Ton Nu Bao Vy Huyen1, Jian Huang2, Shreyashi Mitra1, Ching-Hong Yang1. 1 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA. 2 T3 BioScience Inc, Lapham Hall 181, 3209 N. Maryland Ave. Milwaukee, WI, 53211, USA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: RejuAgro A: Pioneering a Sustainable Solution to Combat Fire Blight in Apple and Pear Orchards Ton Nu Bao Vy Huyen1, Jian Huang2, Ching-Hong Yang1 1 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, USA; 2 T3 BioScience, Milwaukee, USA
• Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Novel Antimicrobial RejuAgro A Demonstrates Promising Fire Blight Management Potential and Beyond Ching-Hong Yang1, Ton Nu Bao Vy Huyen1, Shreyashi Mitra1, Quan Zeng2, George W. Sundin3, Kerik D. Cox4, Helga F�rster5, James E. Adaskaveg5, Xiaochen Yuan6, and Jian Huang7 1 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA. 2 Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, 06511, USA. 3 Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA. 4 Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Cornell AgriTech, Geneva, NY, 14456, USA. 5 Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA. 6 Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA, 50011, USA. 7 T3 BioScience Inc, Lapham Hall 181, 3209 N. Maryland Ave. Milwaukee, WI, 53211, USA.
• Type: Peer Reviewed Journal Articles Status: Under Review Year Published: 2025 Citation: Huang, J., Ton Nu, B. V. H., Liu, X., Mitra, S., Yu, M., Zeng, Q., Sundin, G. W., Cox, K. D., F�rster, H., Adaskaveg, J. E., Kuo, C.-H., Yuan, Y., Yang, C.-H. RejuAgro A: A novel antimicrobial for fire blight control of pome fruits and beyond. Nat. Commun. (accepted with revision).
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: RejuArgo A: A Sustainable Alternative for Fire Blight and Citrus Disease Management Jian Huang1, Ton Nu Bao Vy Huyen2, Shreyashi Mitra2, Ching-Hong Yang2 1 T3 BioScience, Milwaukee, USA 2 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, USA
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: RejuArgo A: A Sustainable Alternative for Fire Blight, HLB, and Citrus Canker Disease Management Jian Huang1, Ton Nu Bao Vy Huyen2, Shreyashi Mitra2, Ching-Hong Yang2 1 T3 BioScience, Milwaukee, USA 2 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, USA
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: RejuAgro A: A Novel Metabolite as a Sustainable Strategy for Huanglongbing and Citrus Canker Control Shreyashi Mitra1, Jian Huang2, Manda Yu1, Ching-Hong Yang1 1Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, USA 2 T3 BioScience, Milwaukee, USA

Progress 09/01/23 to 08/31/24

Outputs
Target Audience:During this reporting period, our outreach efforts primarily targeted the farming community, specifically growers and industry professionals engaged in crop production. This focus is vital as it aligns with our objective to facilitate the practical adoption of research findings related to sustainable crop disease management, particularly the use of antibiotic alternatives. 1. Farmers and Growers We engaged directly with local farmers, such as Deirdre Birmingham of The Cider Farm and Rami Aburomia of Atoms to Apples. These interactions fostered in-depth discussions about fire blight management, emphasizing the efficacy of antibiotic alternatives developed from our research. This grassroots engagement allows us to tailor our findings to the specific needs of the farming community, ensuring that the solutions we propose are practical and implementable. 2. Industry Professionals Our participation in the Wisconsin Fresh Fruit and Vegetable Conference allowed us to engage a diverse audience of growers, agricultural consultants, and industry professionals committed to advancing sustainable practices in crop protection. Dr. Yang's presentation on innovative, non-antibiotic strategies for managing apple fire blight, particularly focusing on Pseudomonas soli T307, strongly resonated with attendees. With fire blight posing a persistent challenge in apple production and increasing concerns about the sustainability of antibiotic use in agriculture, the audience showed great interest in biocontrol solutions. The session highlighted the need for sustainable alternatives that align with both regulatory trends and consumer demand for reduced chemical inputs in agriculture. This conference provided an excellent platform for knowledge exchange and networking, leading to discussions on integrating our research into existing crop disease management programs. These conversations opened doors for potential collaboration on field trials and product development, particularly regarding P. soli T307's commercial potential. Many attendees expressed a keen interest in how biocontrol agents could help reduce reliance on antibiotics while maintaining crop yield and quality. Additionally, Dr. Yang attended the Annual Biocontrol Industry Meeting (ABIM) Conference in Basel, Switzerland. ABIM is a premier global event for professionals in the biocontrol industry, where Dr. Yang connected with biocontrol companies, regulators, and fellow researchers. At ABIM, discussions centered on the commercialization of biocontrol solutions like P. soli T307, focusing on navigating regulatory frameworks and market trends in the global agricultural sector. This engagement provided valuable insights into ensuring our biocontrol agents meet both regulatory standards and market expectations. Dr. Yang also served as an Invited Speaker at the 12th International Congress of Plant Pathology in Lyon, France, presenting "T3SS inhibitors as antibiotic alternatives in fire blight management." This invitation further expanded our outreach to a global audience of plant pathology experts, showcasing our research on innovative approaches to sustainable crop disease management. 3. Collaborators in Product Development Our collaboration with Dunham Trimmer, LLC, has been instrumental in targeting stakeholders involved in product development, registration, and technology licensing within the crop protection industry. This partnership facilitates our engagement with market trends and consumer preferences, crucial for aligning our strategies with industry standards and expectations. Their expertise provides valuable insights into the commercialization process of our natural metabolite RAA, enhancing our ability to reach farmers effectively. 4. Academic and Research Institutions Dr. Yang's presentations at Academia Sinica and various universities, including National Chung Hsing University, the Taiwan Agricultural Research Institute, and the Agricultural Chemical Research Institute, targeted academics and researchers in the field of agriculture. These seminars focused on the transition of natural metabolites from research to commercial products and explored innovative strategies in crop disease management. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project provided multiple opportunities for training and professional development for both the research team and the farming community, fostering advanced technical skills and knowledge dissemination. Hands-on Training and Grassroots Engagement: A key aspect of our training efforts involved direct interaction with local farmers, such as Deirdre Birmingham of The Cider Farm and Rami Aburomia of Atoms to Apples. These interactions allowed us to have in-depth discussions about fire blight management, particularly focusing on the antibiotic alternatives developed in our research. Through these grassroots engagements, we were able to tailor our training and solutions to the specific needs of the farming community, ensuring that our recommendations are practical and easily implementable. Farmers gained knowledge on how to adopt sustainable, non-antibiotic treatments, such as Pseudomonas soli T307, into their operations. Mentorship and Skill Development for Researchers: Members of the research team, particularly graduate students, benefited from one-on-one mentorship provided by Dr. Yang. This included practical training in field trial management, data collection, and statistical analysis, along with guidance in biocontrol application techniques. These training activities enabled the team to develop a strong skill set in sustainable agriculture practices and advanced research methodologies. Professional Development through Conferences and Networking: Dr. Yang participated in two key conferences that provided opportunities for professional development and networking. Dr. Yang attended the Annual Biocontrol Industry Meeting (ABIM) in Basel, Switzerland, where the latest research in biocontrol, including our findings, was discussed with industry professionals. Additionally, Dr. Yang served as an Invited Speaker at the 12th International Congress of Plant Pathology in Lyon, France, where he shared our research with a global audience. These events allowed Dr. Yang to gain valuable insights into global trends in biocontrol and sustainable agriculture, build professional networks, and engage with key stakeholders in the field. How have the results been disseminated to communities of interest?Our dissemination strategy during this reporting period focused on key target audiences such as local growers, biocontrol industry professionals, and the international scientific community, ensuring that our research findings were shared with those most likely to benefit. Engagement with Local Farmers: We engaged directly with local farmers like Deirdre Birmingham of The Cider Farm and Rami Aburomia of Atoms to Apples. These grassroots interactions fostered in-depth discussions about fire blight management, with a particular emphasis on the efficacy of the antibiotic alternatives we developed, such as Pseudomonas soli T307. This personalized outreach enabled us to tailor our findings to the specific needs of the farming community, making sure that the solutions we propose are not only effective but also practical and easily adoptable by farmers. Dissemination to Industry Professionals: Results were shared with industry stakeholders during the Annual Biocontrol Industry Meeting (ABIM) in Basel, Switzerland. This event allowed us to reach biocontrol companies, regulatory professionals, and product developers, facilitating discussions on the commercialization of Pseudomonas soli T307. By engaging directly with industry professionals, we ensured that our findings could influence the development of sustainable, market-ready biocontrol products. Additionally, our collaboration with Dunham Trimmer, LLC has played a critical role in disseminating our research to stakeholders involved in product development, registration, and technology licensing within the crop protection industry. Dunham Trimmer's expertise in aligning product development with market trends and regulatory standards has enhanced our ability to target a broader audience, including those responsible for bringing biocontrol products like Pseudomonas soli T307 to market. Their support has also helped ensure that our research findings are aligned with industry expectations, making it easier to reach farmers with effective, commercially viable solutions. Outreach to the Scientific Community: Dr. Yang's presentation at the 12th International Congress of Plant Pathology in Lyon, France, provided an additional platform to share our research with a global network of scientists and researchers. By focusing on antibiotic alternatives in fire blight management, we disseminated our findings to those working in sustainable crop disease management, fostering further advancements and collaborations in this field. Through these targeted efforts, we ensured that the research outcomes were communicated effectively to those who can directly benefit from or contribute to further developments in sustainable fire blight management and biocontrol technologies. What do you plan to do during the next reporting period to accomplish the goals? Further Field Trials: Building on this year's results, we plan to conduct additional field trials to confirm the efficacy of P. soli T307 with L-methionine and L-glutathione on a larger scale. We will explore different apple cultivars and environmental conditions to ensure the robustness of the treatment. Refinement of Treatment Combinations: We will test additional concentrations of L-methionine and L-glutathione to fine-tune the treatment for optimal fire blight suppression. Expansion of Outreach Efforts: We plan to broaden our outreach efforts to include more apple growers and expand our participation in industry conferences. Additionally, we aim to disseminate knowledge to a broader farming community. Commercial Development: Further collaboration with industry partners will be prioritized to facilitate the commercialization of P. soli T307 as a sustainable, non-antibiotic alternative for fire blight management. We will focus on addressing regulatory requirements and market demands to bring the product to market.

Impacts
What was accomplished under these goals? The primary issue our project seeks to address is the control of fire blight, a devastating bacterial disease caused by Erwinia amylovora, particularly in apple orchards. Fire blight poses a significant threat to commercial fruit production, resulting in substantial economic losses. The use of antibiotic-based treatments, such as streptomycin, is increasingly scrutinized due to concerns about antibiotic resistance and sustainability. Therefore, this project aims to develop effective, sustainable, and non-antibiotic alternatives for managing fire blight, utilizing the biocontrol strain Pseudomonas soli T307 with amino acid enhancers. Audience Impacted: The audience most immediately helped by this work includes apple farmers and growers, particularly those in regions prone to fire blight outbreaks. Additionally, industry professionals in crop protection and agricultural researchers have benefited from the knowledge dissemination. The results of this project provide these stakeholders with viable alternatives to antibiotic treatments, promoting sustainable agricultural practices. Major Activities, Data Collected, and Results: During this reporting period, we focused on field trials conducted on 8-year-old 'Pink Lady' apple trees at the Lockwood Farm of the Connecticut Agricultural Experiment Station. The trials evaluated the efficacy of Pseudomonas soli T307, both with and without the addition of L-methionine and L-glutathione, in controlling blossom blight caused by Erwinia amylovora. The treatments were arranged in a randomized, complete block design with three replicates. Streptomycin (FireWall 17) served as the antibiotic standard, and a water-treated control was used as the negative control. Seven different treatments were tested, each spray-inoculated at 80% and 90% bloom. All trees were inoculated with Erwinia amylovora on May 3rd, 2024. Disease severity was assessed by calculating the percentage of infected flower clusters on May 28th, 2024. Statistical analysis revealed that P. soli T307 alone reduced blossom blight infection from 92% (control) to 65%. The addition of L-methionine (0.12%) and L-glutathione (0.06%) further reduced infection rates to 25%, indicating that this combination has the most significant impact on disease suppression. However, higher concentrations of L-methionine (0.24%) and L-glutathione (0.06%) did not yield further improvements. Key Outcomes and Accomplishments: The key outcome of this reporting period is the identification of an optimal combination of P. soli T307 with L-methionine (0.12%) and L-glutathione (0.06%), which significantly reduced fire blight infection in apple orchards. This finding presents a promising alternative to traditional antibiotic treatments, offering farmers a more sustainable option for disease management. The project's broader impact lies in its contribution to the ongoing efforts to reduce antibiotic use in agriculture, addressing both environmental and health-related concerns. This solution supports sustainable farming practices while safeguarding apple yields, ultimately benefiting farmers and consumers.

Publications