Red Clover Grower Tool (Beta)
Published:
The Red Clover Economic Threshold Calculator is an interactive decision-support tool designed for red clover seed growers managing the lesser clover leaf weevil (Hypera nigrirostris).
It allows growers to estimate:
- Economic Injury Levels (EILs)
- Economic Thresholds (ETs)
This tool is based on multi-year field trials and laboratory studies conducted in Saskatchewan, and is tailored specifically for Western Canadian red clover seed systems.
What this tool does
- Calculates economic injury level using real agronomic inputs
- Generates economic threshold values recommended for scouting and spray timing
- Incorporates dynamic cost, market price, and expected injury parameters
- Helps reduce unnecessary insecticide applications
Why this tool matters
Lesser clover leaf weevil larvae can substantially reduce seed yield and growers often face uncertainty about whether damage levels justify treatment.
This calculator turns field scouting information into a practical recommendation by combining:
- Observed larval densities
- Cost of control
- Market value of seed
- Expected injury per larva
It provides a transparent, research-supported threshold to guide decision-making.
This tool is based on results from:
Irvine & Prager (2025)
Economic Thresholds for Hypera nigrirostris in Red Clover Seed Production from On-Farm Trials. Journal of Economic Entomology. https://doi.org/10.1093/jee/toaf290
Additional supporting data from sequential sampling and dispersion analyses will be incorporated in future updates.
Features Planned for Future Updates
- Sequential sampling plan integration
- Larval dispersion visualization tool
- Yield-loss forecasting module
For Growers & Agronomists
This tool was developed to support evidence-based pest management and reduce unnecessary insecticide use in red clover seed production.
If you have any questions, please contact:
Jeremy R. Irvine
Department of Plant Sciences, University of Saskatchewan @JeremyIrvine jeremy.irvine@usask.ca jeremy@entomologist.ca