NOVEL FIRE BLIGHT BIOPESTICIDE FIELD TESTING AND EVALUATION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1031023
• Grant No.: 2023-70006-40595
• Cumulative Award Amt.: $185,490.00
• Proposal No.: 2023-02954
• Project Start Date: Sep 1, 2023
• Project End Date: Aug 31, 2026
• Grant Year: 2023
• Program Code: [ARDP]- Applied Research and Development Program

Project Director
McNellis, T. W.

Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505

Performing Department
(N/A)

Non Technical Summary
Fire blight disease is one of the most important bacterial diseases affecting apple and pear production in the United States and worldwide. The disease costs US fruit growers about $160 million annually in crop losses and expenditures on management tools, and the disease limits commercial pear production to mainly the western part of the US. Fire blight can be managed quite effectively using antibiotic sprays such as streptomycin or oxytetracycline at bloom time to prevent infection through the flowers. However, this practice is leading to antibiotic resistance development in Erwinia amylovora, the fire blight causal bacterium. There is a need for fire blight management tools that do not rely on antibiotics. This project will help to validate a novel fire blight biopesticide. Previously, we discovered that certain non-pathogenic, auxotrophic strains of E. amylovora can effectively reduce fire blight disease incidence in both apples and pears in Washington and Pennsylvania during two years of orchard tests. In this proposed study, the novel biopesticide will be tested in New York and Michigan using commercial research service provider facilities to allow a larger number of tests to be performed than could be done at academic test sites. These tests will reveal the concentrations of active ingredient and amino acid inactive ingredient needed for optimal activity under natural infection and inoculated plant conditions over two seasons. These results will position the novel biopesticide for development into a commercial product that will provide an effective new fire blight management tool to apple and pear growers.

Animal Health Component

20%

Research Effort Categories

Basic

(N/A)

Applied

20%

Developmental

80%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	1110	1100	90%
216	1115	1100	10%

Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1110 - Apple; 1115 - Pear;

Field Of Science
1100 - Bacteriology;

Keywords

fire blight

apple

pear

biopesticide

erwinia amylovora

biological control

Goals / Objectives
This project has a single objective: to determine an effective formulation of a newly discovered fire blight disease preventative treatment. This will invove testing about a dozen formulas to determine minimum doses of active ingredient that provide suitable disease mitigation and concentrations of inactive ingredients that are most potent for boosting active ingredient efficacy. These candidate formulations will be tested at two different sites - one in Michigan and one in New York. These are major apple growing states where fire blight disease is a chronic challenge to the tree fruit industry. Tests will be replicated at both sites for two years to provide robust data.

Project Methods
The test material will be produced at a large-scale pilot plant fermentation facility at Penn State under the direction of the Project Director. This includes freeze-drying of the material for stable, long-term storage and shipping to test locations. At two test locations (one in Michigan, one in New York), the material will be tested for proective effects on apple trees from fire blight disease. The trees will be pre-treated with the test material and subsequently inoculated with the fire blight pathogen bacteria, Erwinia amylovora. These tests will be completed at bloom time, when most flowers are open. This is the time when the trees are most vulnerable to infection, which occurs primarily through the flowers. Symptom development, fruit quality, and fruit yield will be measured throughout the growing season up until fruit harvest. Symptom development is measured as disease incidence per flower cluster, and expressed as a percentage of flower clusters that become blighted. Control treatments include water spray and antibiotic sprays. Antibiotics are the standard fire blight preventative treatment used by growers and are the standard against which alternative preventative treatments are measured.

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

Outputs
Target Audience:The target audience of this research is apple and pear growers who are managing fire blight disease in their orchards. Fire blight disease affects apple and pear producers throughout the United States, including especially the states producing the largest quantities of these fruits, such as Washington, New York, Michigan, Oregon, Pennsylvania, Virginia, West Virginina, and California. Currently, conventional growers of apples and pears rely heavily on antibiotic sprays at bloom time to head off infections by the fire blight pathogen, the bacterium Erwinia amylovora. However, antibiotic resistance is developing in the target bacterium, raising the need for new modes of fire blight disease management that do not rely on antibiotics. While some biological controls exist, these often have limited efficacy. This project aims to test and optimize a novel active ingredient for fire blight disease suppression. This material is not an antibiotic and does not carry the risks of antibiotic resistance development. Growers will be interested in this technology, which has some advantages over existing fire blight biological control agents. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project does not include a training component. How have the results been disseminated to communities of interest?PI McNellis presented the project to around 50 growers in at Soergel Orchards in Wexford PA, on May 15th, during a "twilight grower meeting" organized by the Penn State Fruit Research and Extension Center. McNellis was among several faculty presenting project and practical findings to the growers. What do you plan to do during the next reporting period to accomplish the goals?We will repeat field testing of our material in New York and Michigan in the 2025 season as planned in the proposal. The exact treatments will be informed by results obtained from this year's tests, with the goal of optimizing the application rates and timing of the material and documenting the efficacy of the material for fire blight disease mitigation. PI McNellis is scheduled to present the project in a 30-minute presentation to stakeholders at the Mid-Atlantic Fruit and Vegetable Convention on January 28, 2025, where hundreds of fruit and vegetable growers, processors, and other interested parties will meet. McNellis also plans to present the project at additional twilight grower meetings to be organized by the Fruit Research and Extension Center in May of 2025.

Impacts
What was accomplished under these goals? We peformed tests of the efficacy of our fire blight mitigation materials in Michigan and New York. Material was produced at Penn State, freeze-dried, formulated, and shipped to testing sites. We tested a range of material concentrations for efficacy to determine minimum quantities of the biopesticide that are effective. These materials were sprayed on blooming apple trees during April - June of 2024 at both locations. In New York, material was applied to the trees three times, and the trees were inoculated with the fire blight pathogen Erwinia amylovora by spray application as well during this period. In Michigan, the material was applied up to 8 times, starting at bloom and going into the summer, over the course of 4-7 weeks. In Michigan, the trees were not incoculated with E. amylovora because natural disease pressures are very high. Water and antibiotic controls (streptomycin or kasumin) were also included. Fire blight disease incidence and severity data are still being collected as of this report, and final assessment of material efficacy is made in September and October following harvest. Since these tests are still ongoing, we do not have efficacy results to report yet. We expect to be receive and analyze 2024 season efficacy data during fall of 2024.

Publications