Hail Damaged Sorghum – Now What?
Hail Damaged Sorghum – Now What?
Brent Bean, Sorghum Checkoff Director of Agronomy
Few things are more discouraging for a grower than watching a healthy sorghum crop get devastated by a hailstorm in a matter of minutes. The extent of the yield loss depends on both the growth stage of the sorghum at the time of the storm and the severity of the hail. While small hailstones may cause minimal leaf shredding, larger stones can bruise stalks or severely damage panicles. Damage is rarely uniform across a field, making it essential to evaluate multiple areas when assessing the impact.
Immediately after a hailstorm, the crop may appear heavily damaged—and this often looks even worse 48 to 72 hours later as injured tissue dies. Fortunately, grain sorghum is remarkably resilient, especially when damage occurs early in the growing season. With favorable conditions, plants may begin showing new growth within 72 hours, and much of the crop’s original yield potential can still be realized. Ideally, wait at least seven days before conducting a full damage assessment to allow for both visible tissue death and the emergence of new growth.
The crop’s ability to recover is largely tied to its growth stage. Until about the sixth or seventh leaf stage (roughly the first 28 days), the growing point of sorghum remains below or just above the soil surface. At this early stage, even severe above-ground damage can be overcome as the primary stem produces new growth. If the stalk is severely damaged below the growing point, to the point that it will not recover, new tillers will be produced, largely compensating for the loss of the main stalk. Potential yield loss gradually increases as the plant approaches the heading stage.
When evaluating hail damage, consider three key factors:
- Leaf Defoliation
Leaf damage is often visually overestimated. Even partially shredded leaves can still photosynthesize if the tissue is green. Yield loss from defoliation varies based on the crop’s stage. For instance, 50% leaf loss at the 10-leaf stage may reduce yield by less than 5%, while the same damage at the boot stage could cause up to 30% yield loss. - Stand Loss from Stalk Damage
Assess stalk bruising based on both its location and severity. Deep bruises reaching the stalk’s center usually lead to plant death, while minor bruises may not affect the plant initially, but may increase lodging or stalk rot infection. Although it looks bad, superficial scars on the leaf sheath that surround the stalk have little effect on the health of the plant. When evaluating stand loss, consider all plants with deep bruises as lost, and count half of the plants with minor bruises as potentially non-viable. If stand loss occurs early, sorghum’s ability to tiller and adjust kernel count can help compensate. - Panicle Damage
Panicle injury can occur from the boot stage through grain fill. Estimate what portion of the panicle is damaged—this loss is typically a direct 1:1 impact on yield.
Before making any decision to terminate the crop, always consult your crop insurance agent.
For additional guidance, watch the 15-minute video “Assessing Hail Damaged Sorghum” on the United Sorghum Checkoff Program website.
