Project Overview
Commodities
- Fruits: berries (strawberries)
Practices
- Pest Management: biological control, chemical control, integrated pest management
- Production Systems: organic agriculture
Proposal summary:
The proposed solution is to run an on-farm field trial that tests five practical, organic-approved methods for reducing Neopestalotiopsis (neo-p) in field-grown organic strawberries. I hope to figure out which approaches give real, measurable control under the conditions growers actually face in the Southern region-weather swings, heavy dew, high humidity, and tight spray windows. The project focuses on treatments that farmers can afford, apply with regular farm equipment, and repeat season after season without harming soil biology or the farm ecosystem.
The five treatment categories are: (1) surfactant-based sprays, (2) copper-based sprays, (3) beneficial-organism displacement sprays, (4) redox-environment shifting sprays, and (5) oregano-oil-based sprays.
All work will be conducted on my farm, with replicated field plots, untreated controls, and clear data collection on disease levels, canopy health, plant vigor, and total yield.
1. Surfactant-Based Treatments
Surfactants help water sheet off the leaves faster and may interfere with spore germination. Because neo-p loves sitting moisture, reducing leaf wetness could slow infection. Surfactants also help improve spray coverage with other organic materials. This project will test whether a simple, low-cost surfactant can make a noticeable difference in disease pressure. Success will be measured through reduced lesion counts, healthier leaves, and improvements in yield compared to untreated rows.
2. Copper-Based Treatments
Copper remains one of the very few effective organic fungicides for a wide range of diseases. In a previous SARE-funded study by Dan Egel at Purdue, copper was the most effective of the three OMRI-listed fungicides tested for neo-p control. Because copper can impact soil biology when overused, this project will rely on careful timing and dosing to minimize excess, combined with pre- and post-season soil sampling to make sure copper isn't accumulating.
3. Beneficial-Organism Displacement Treatments
This approach uses beneficial microbes to occupy the same leaf-surface "real estate" that neo-p needs to infect. Serenade Opti is the most common example of a displacement product, but it depends on a patented strain that can be costly and hard to source for smaller farms. For this project, I will test a non-patented, more accessible microbe (Bacillus cereus), so that if the results are good, the practice can be adopted easily by organic growers of all sizes.
4. Redox-Environment Treatments
Some organic fungicides work by shifting the oxidation-reduction balance on the leaf surface. Neo-p seems to prefer certain surface conditions, especially under humid, still-air environments. By decreasing the oxidative environment around the leaf microsurface, these sprays may make it harder for the fungus to establish. These materials are affordable, easy to apply, and should have minimal impact on soil health.
5. Oregano-Oil-Based Treatments
Oregano oil has shown strong antifungal properties against other Neopestalotiopsis species and related genera, but it has not yet been tested against neo-p strains in field-grown strawberries, as far as current literature shows. Because oregano oil is organic-approved, plant-derived, and relatively safe for soil biology, it may offer a natural alternative to copper or synthetic fungicides. This project will test realistic, field-safe rates to see whether oregano oil provides measurable suppression of neo-p without burning leaves or stunting growth.
How This Solution Supports Agricultural Sustainability
Farmer Profitability
Neo-p can wipe out most or all of a field. Organic strawberry growers have very few effective tools. This project aims to identify affordable, replicable strategies that protect yield and keep farms financially stable. Even modest disease reduction could save thousands of dollars per acre.
Environmental Conservation
All treatments are organic-approved and selected with soil biology in mind. Copper levels will be monitored to keep applications safe. Displacement, redox, surfactant, and oregano-oil treatments all provide lower-impact alternatives that could help farmers reduce or rotate away from heavier-use materials. This aligns directly with the Farm Bill's emphasis on protecting soil, water, and ecological health.
Community Quality of Life
Local organic strawberries are an important crop for CSAs, U-pick farms, and direct-to-market growers. When neo-p wipes out fields, both growers and communities lose access to fresh, locally grown fruit. A practical organic solution supports local food availability, keeps small farms viable, and strengthens rural economies.
Why This Approach Is Achievable
This is a single-farm, farmer-led trial with materials that are already legal, affordable, and widely available. The project avoids specialized greenhouse or lab work. Nothing requires expensive technology, or complicated application systems.
The end result will be a simple, clear set of findings showing which treatments help, how much they help, what they cost, and whether they offer a realistic path toward long-term sustainability for organic strawberry growers in the South.
Project objectives from proposal:
Experimental Layout
Project Site and Experimental Design
This on-farm field trial will be conducted at Ecosystem Farm in Atlanta, GA, during the 2026 and 2027 growing seasons. The study will utilize a randomized complete block design with three replications to test five organic management strategies against Neopestalotiopsis (neo-p) in field-grown strawberries, compared to an untreated control.
The experimental design incorporates two strawberry cultivars-'Chandler' and 'Sequoia'-to account for potential varietal differences in disease susceptibility and treatment response. If there's a significant difference between cultivars and the Ember variety is available in 2027, I may swap out the underperforming cultivar for Ember, which was just released from UF and is supposed to have good neo-p resistance.
Plot Layout and Randomization
The field layout consists of 17 rows total, arranged as follows: six rows dedicated to 'Chandler' (arranged in three blocks of two rows each), six rows for 'Sequoia' (similarly arranged), and five buffer rows of 'Eclair' variety positioned between experimental blocks. Each experimental block contains two treatment rows, with three treatment plots per row, allowing for six treatments total per block. Buffer rows prevent cross-contamination between treatments and provide realistic field conditions.
Treatments will be randomly assigned within each block to eliminate positional bias. The three replications ensure statistical validity while maintaining practical farm-scale plot sizes. Each treatment plot will be clearly marked for consistent data collection throughout the season.
Treatment Protocols
All plots will receive identical baseline cultural practices, including soil amendments (compost and AEA soil primer), and nutrient applications based on sap analysis results during the season. All plants will be grown on landscape fabric with drip irrigation. This standardized foundation ensures that treatment effects can be attributed to the specific neo-p management strategies rather than nutritional differences.
Control: Baseline practices only, with no additional disease management inputs.
Treatment 2 (Redox Environment): Baseline practices plus applications designed to alter leaf surface oxidation-reduction conditions. Applications will be timed based on weather conditions favoring neo-p development, particularly during periods of high humidity and leaf wetness.
Treatment 3 (Surfactant): Baseline practices plus organic-approved surfactant applications to reduce leaf surface tension and accelerate drying. Timing will coincide with periods of prolonged leaf wetness, typically after rain events or heavy dew.
Treatment 4 (Copper): Baseline practices plus low-rate copper applications, timed preventively before anticipated disease pressure periods. Rates will be optimized to provide disease suppression while minimizing phytotoxicity and soil accumulation.
Treatment 5 (Bacillus cereus): Baseline practices plus beneficial microorganism applications intended to displace neo-p through competitive colonization of leaf and crown surfaces. Applications will be scheduled to establish beneficial populations before peak disease pressure.
Treatment 6 (Oregano Oil): Baseline practices plus oregano oil applications at rates determined through small-scale phytotoxicity trials conducted prior to field implementation.
Application Methodology
All treatments will be applied using separate backpack sprayers to ensure no cross contamination between treatments. Application timing will be based on treatment type, environmental conditions, plant growth stage, and neo-p disease pressure indicators. Weather conditions will be recorded at each application, including temperature, humidity, wind speed, and recent precipitation. A minimum 24-hour period without precipitation will be required post-application to ensure treatment efficacy.
Data Collection Methods
Disease Assessment: Visual disease ratings will be conducted on every plant within each plot using a standardized 1-5 scale, where 1 = no visible symptoms, 2 = minimal leaf spotting (<5% leaf area affected), 3 = moderate symptoms (5-25% leaf area affected), 4 = severe symptoms (25-50% leaf area affected), and 5 = very severe symptoms (>50% leaf area affected or plant death). Assessments will occur weekly throughout the growing season. In addition, three plants from each treatment block will be submitted to the University of Florida plant pathogen laboratory to determine whether neo-p is present at the start and end of the season.
Yield Measurements: Despite the challenge of u-pick operations, yield will be estimated through systematic sampling. Representative subplots within each treatment plot will be harvested completely at regular intervals, with fruit counted and weighed. These samples will be extrapolated to estimate total plot yields. Additionally, visual estimates of fruit load and plant vigor will be recorded weekly during peak production periods.
Plant Health Monitoring: Overall plant vigor, canopy density, and runner production will be assessed monthly using standardized rating scales. Photographic documentation will supplement numerical ratings to provide visual records of treatment effects.
Environmental Data: On-site weather monitoring will track temperature, humidity, rainfall, and leaf wetness duration. This data will be correlated with disease development patterns and treatment efficacy to identify critical application windows.
Soil Health Assessment
To ensure treatments do not negatively impact soil biology, particularly with copper applications, soil samples will be collected pre-season and post-season from each treatment area. Samples will be analyzed using the Haney test from Regen Ag labs, which includes copper levels and incorporates measurements of biological activity. This monitoring ensures sustainable practices while documenting any treatment effects on soil health.
Materials and Equipment
Required materials include: organic-approved surfactant, copper fungicide, Bacillus cereus formulation, redox-modifying compounds and oregano oil. The farm will purchase additional backpack sprayers to avoid using SARE funds on equipment that will last beyond the study period. The remainder of the funds will go towards testing and labor.
Statistical Analysis
Data will be analyzed using analysis of variance (ANOVA) appropriate for randomized complete block designs. Treatment means will be compared using Tukey's HSD test to identify significant differences. Disease severity data may require transformation to meet normality assumptions. Correlation analyses will examine relationships between environmental factors and disease development. Economic analysis will compare treatment costs with yield benefits to determine practical return on investment.
Quality Assurance
Standardized protocols will be maintained throughout the study. All personnel conducting assessments will be trained to ensure consistency in disease rating applications. Data will be recorded electronically with built-in validation checks. Regular calibration of equipment and cross-checking of visual ratings will maintain data quality and reproducibility.
This comprehensive approach will generate practical, statistically valid results that organic strawberry growers can immediately implement to manage neo-p effectively while maintaining sustainable farming practices.