Best Fungicide Timing for Pea Disease Management

By Scout Nelson

Recent research conducted in Carrington from 2023 to 2025 provided important insights into managing foliar diseases in field peas using fungicides. The study focused on two major diseases, Ascochyta blight and powdery mildew, and showed that each disease requires different treatment timing for best results.

The findings showed that farmers need to carefully choose fungicide application timing if they want to manage both diseases with a single spray. The correct timing depends on which disease is expected to cause the most damage to crop yield.

For powdery mildew, strong control was achieved with a single application of Proline when plants had 3 to 5 fully filled pods. This approach worked well when the disease appeared later in the growing season. However, in some cases, powdery mildew developed earlier. In those situations, applying fungicide when plants had only 1 to 2 filled pods provided better protection. Early application was especially important during warm and dry weather conditions with overnight moisture.

The study also showed that fungicides must be applied before disease symptoms appear to achieve the best results. Delaying application can reduce effectiveness and increase crop risk.

For Ascochyta blight, the best results were seen when Proline was applied during full bloom, when the first pods were forming and growing. This timing provided consistent disease control across different years and plant varieties.

The research also compared different fungicides. Delaro was found to be the most effective product for controlling both powdery mildew and Ascochyta blight. Proline ranked second in effectiveness. Higher application rates improved disease control, especially for Proline. Other products like Headline and Quadris were less effective in comparison.

These findings help farmers make better decisions about fungicide use and improve disease management. The study also noted that product mentions do not represent endorsements by research institutions.

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