Reducing Fungicide Dependence in North Central Strawberry Production Through Improved Cultivar Selection Under Emerging Neopestalotiopsis Disease

Commodities

Practices

Strawberry production in the North Central region (Midwestern United States (U.S.)) is increasingly threatened by Neopestalotiopsis, an emerging and highly destructive fungal pathogen associated with leaf blight, crown rot, and rapid plant decline. The disease has caused severe losses across production systems, yet no fungicides are specifically registered for its control. As a result, growers rely on preventative fungicide programs developed for other pathogens, often applying multiple products without clear efficacy data. This increases production costs, ecological impact, and the risk of fungicide resistance, while not consistently preventing crop losses.

Host resistance represents the most sustainable and cost-effective first line of defense. However, current knowledge of cultivar performance is limited and often based on evaluations using a single pathogen isolate, which does not reflect the diversity of Neopestalotiopsis populations across the North Central region. This creates uncertainty for growers when selecting cultivars and increases reliance on chemical control.

This project aims to improve disease management by identifying commercially relevant strawberry cultivars with stable performance under regionally representative pathogen conditions. Fifteen cultivars (10 widely used commercial cultivars and 5 emerging cultivars) will be selected based on regional relevance, grower input, and ongoing breeding efforts focused on fruit quality, flavor, and production performance. Emerging cultivars will be identified from current research programs led by collaborating faculty in the Department of Horticulture and Crop Science, Dr. Chieri Kubota and Dr. Francis, which focus on optimizing strawberry production systems.

Representative Neopestalotiopsis sp. isolates will be obtained through collaboration with diagnostic clinics and research partners across Ohio, Indiana, Wisconsin, and Illinois to capture regional pathogen diversity. Cultivars will be evaluated using detached leaflet assays against these representative isolates, followed by whole-plant validation using a regional mixed inoculum. Disease development and marketable yield will be quantified.

Results will provide growers with actionable, regionally relevant data on disease response and production performance to guide cultivar selection. A decision-support framework will be developed, and outreach effectiveness will be evaluated through grower surveys. This project will reduce unnecessary fungicide applications, decrease production costs, and enhance sustainability in strawberry production systems.

This project is expected to generate learning and action outcomes among strawberry growers and extension stakeholders in the North Central region.

Learning outcomes will include increased grower knowledge of cultivar performance under regionally representative pathogen conditions and improved understanding of how cultivar selection influences disease risk and informs fungicide use decisions.

Action outcomes will include changes in grower decision-making, particularly in cultivar selection and disease management strategies. Growers are expected to use project results to identify and select cultivars with improved performance under Neopestalotiopsis pressure under regional conditions.

Impact outcomes will include reduced disease incidence and severity, decreased reliance on fungicide programs, and lower production costs. Improved cultivar selection is expected to enhance yield stability by reducing severe plant losses associated with Neopestalotiopsis across production stages, including early establishment. Reduced fungicide use will contribute to improved ecological sustainability by minimizing chemical inputs and supporting more resilient production systems in the North Central region.