Sweet corn is an important processing crop in the upper Midwestern United States. It can be insured for hail losses, but actuarial tables are based on field corn. The first step in developing accurate yield loss assessments is determining yield loss due to complete plant loss. To that end, we compared ear yield of sweet corn thinned to 75, 50, or 25% of a full population at three times throughout the growing season to control plots that were not thinned. We repeated this in three consecutive years at two locations, without irrigation or supplemental fertilizer. Average yield for control plots was 16.4–20.3 Mg•ha-1. Average yield losses due to thinning were generally less than currently-used actuarial estimates. For example, average yield of sweet corn when thinned to 50% of a full population at growth stage V3–V5 was 88–96% (95%CI) of full yield. The actuarial estimate is 78% of full yield, indicating greater resilience than expected. The number of tillers per plant was greater in all thinned plots, especially those thinned early in the season. Kernel recovery was unaffected by thinning treatment in one location and declined slightly at heavy thinning in the other location. Sweet corn actuarial tables should be different from actuarial tables based on field corn.
