Hail Damage to Late Vegetative to Silking Corn and Options

Hail-damaged fields
Hail damage to corn in the North Platte Valley area in the Panhandle of Nebraska after a late June hailstorm in 2023. (Photos by Gary Stone)

Hail Damage to Late Vegetative to Silking Corn and Options

REVISED: July 3, 2024 (originally published July 14, 2023 by authors Jenny Rees, Justin McMechan, Nicolas Cafaro La Menza and Daren Redfearn)

Several severe hailstorms have hit portions of Nebraska recently. The timing of the storms, development stage of the crop, individual field damage, subsoil moisture and crop insurance are important factors in decision-making. For general information and crop recovery assessments tips, visit Hail Know.

Much of the corn in Nebraska prior to hailstorms the past two weeks was in the late vegetative stages through silking stages of development. Damage assessment in the late vegetative stages is based on leaf loss and stand reduction.

To determine yield losses due to defoliation, you will need to determine the stage of the plant at the time of the hail event. Defoliation should be estimated based on missing leaf area and tissue that is no longer green. Assess defoliation on plants at three places in the field to get an accurate estimate.

To estimate yield losses based on these defoliation averages, see Table III of the EC126 Evaluating Hail Damage to Corn. It indicates corn at the 13th leaf stage with 50% defoliation could have a production loss of 10%; 100% defoliation would lead to a 34% loss in production. Complete yield losses can occur if all leaf area is destroyed in corn at the VT (tassel stage).

Yield losses from plant stand reductions are still accounted for in corn through the 17th leaf stage. It’s important to note that the Corn Loss Adjustment Standards Handbook has two tables — one for corn prior to 10th leaf and another from the 11th to 17th leaf stage.

Depending on the hail damage and how close the plant was to tassels shooting and silking, you may observe hailstone bruising to tassels and ears. You can pull out a few whorls and carefully unroll the leaves around the tassels to assess this. You can also pull the primary ear shoot and carefully unroll the husk to assess bruising to the ears. From experience, bruising on the ears leads to grain molds developing in those areas (fungicides will not help with this).

Also watch for timing of pollen shed vs. silking and any impacts to resulting pollination. Be aware that hailstone bruising to the stem can allow for stalk rot to set in. Fungicide can help with stalk strength.

Figure 1. Carefully peel back leaves and husks to examine tassels and ears for hailstone damage. (Photos by Jenny Rees)

Options with Additional Considerations

These options are dependent upon the corn development stage prior to hail damage and resulting damage after hail. They’re also dependent on soil moisture, as parts of Nebraska are seriously short on subsoil moisture. Perhaps the biggest concern is weed control with these open canopies.

Figure 2A. Corn in late vegetative stages that was stripped due to hailstorm in early July and has since produced a healthy whorl. (Photos by Jenny Rees)
Figure 2B. Field mostly reduced to stumps.
Figure 2C. Field mowed off at just above the ear.
  1. Leave it alone: If the corn had mostly stripped-up leaves and new growth is occurring in the whorl (Figure 2A). For those with a large portion of stalks with tassels above the ear removed in the field, yet there’s also tassels that remain in the field, you may also need to leave the field or at least strips for crop insurance final decisions at harvest.
  2. Replant corn: The field must be released by crop insurance. Because it’s past June 14, the corn crop would not be insured by federal crop insurance. In 2023, no producers chose this option. Using the U2U model can help you assess the probability of different hybrid maturities making it to physiological maturity before the average frost for your area of the State.
  3. Plant soybean: For those with only stem bases remaining (Figure 2B), some have considered planting soybeans (either by directly planting/drilling the soybean remaining residue or shredding then drilling/planting beans). The field must be released by crop insurance. Considerations here include seed cost for at least 150,000 seeds/ac, seeding cost, seed treatment fungicide cost and herbicide cost. One also needs to consider any replant restrictions for the corn herbicide used in 2024; one assumes the risk if planting soybeans prior to this interval. We also recommend at least a 0.5-unit reduction in maturity group for better probability of reaching physiological maturity prior to a killing frost. Please see Hail Damage to Soybeans in the Reproductive Stages and Options and for more information.
  4. Plant a forage crop: For those with only stem bases remaining and considering a forage crop, the field must be released by crop insurance. It is important to check if there are any replant restrictions for seeding a particular cover crop. If one chooses to seed a cover crop before the replant restriction listed on the label, the risk is on that individual for cover crop germination and growth. Opportunities exist for warm-season annual forages planted in July or warm-/cool-season forages planted in August. The following BeefWatch article shares annual forage options for July or August plantings. The following forage options after hail damage to crops video shares additional information.
  5. Graze the corn: For the fields where the stalks were mowed off at the ear or lower (Figure 2C), and for those needing forage, some have considered grazing the cornstalks. In talking with producers, some want to graze the stalks first and then plant a cool-season forage this fall after grazing. Others are planning to fly in turnips/radishes to graze with the cornstalks. The corn must be released by crop insurance to consider grazing. One also needs to consider any grazing restrictions from chemicals applied to the corn crop. If choosing to seed a cover crop, consider any replant restrictions; the risk is yours if you plant before that interval is up. Regarding nitrates, we consider this situation similar to cattle grazing drought-stressed corn prior to ear development. Nitrates most likely will be present. For best practices, do not turn the cattle into cornstalks empty — have a source of fresh water, and allow them to openly graze the field. Consider supplementation of hay/energy. It is important to avoid grazing the lower eight inches of the stalk.

Figures 3A-3D. These fields east of Gothenburg, Nebraska experienced hailstorm damage in 2024. Recovery is less likely for the fields in photos A and B than the fields in C and D (click to expand). (Photos by Nicolas Cafaro La Menza)

What We Learned in 2023

The following are things we learned from the York and Seward County hailstorms that occurred in July 2023.

  • For fields with stalks mostly broken off at the ear, if there were up to 1/3 tassels in the field, crop insurance typically delayed a decision until pollination occurred.
  • There is some time to make decisions, especially if you’re not planning on replanting corn. Producers were already exhausted and stressed from irrigating due to drought, thus, there was less desire to make a quick decision in totaled fields.
  • Some producers chose to graze the remaining corn/soy plants and resulting weeds with cattle or sheep, then followed with a small grain cover crop in the fall.
  • Many crop producers chose to plant a forage like pearl millet. There was an opportunity during drought to sell forage and there wasn’t the risk of prussic acid poisoning with pearl millet vs. the sorghum species. Much of the state isn’t in drought this year, but there are often opportunities to sell forage. Producers are often pressured to plant longer-maturity soybeans in July. We don’t recommend this due to the risk of 30-year average freeze and soybeans reaching maturity. The following article shares what we learned by following five replant fields in the Waco, Nebraska area during the 2023 growing season.
  • It’s hard to lose beautiful-looking crops any time of the year. Stress and anxiety in addition to grief are real. Please reach out to others to talk and check out the following resources: Resources to Support Farmers and Ranchers Dealing with Stress.

Resources

Drewnoski, Mary and Daren Redfearn. July 1, 2023. Annual Forage Options for July or August Planting.

McMechan, Justin, Roger Elmore, Robert Klein, and Jenny Rees. June 25, 2021. Mid-Season Hail Damage Assessments in Corn and Soybeans. UNL CropWatch article.

McMechan, Justin. Video: Hail Damage Evaluation and Management in Corn. https://cropwatch.unl.edu/hail-know/video-hail-damage-evaluation-and-management-corn

Redfearn, Daren. Video: Forage, Livestock Options and Cover Crops Following Hail Damage in Corn or Soybean. https://cropwatch.unl.edu/hail-know/video-forage-livestock-options-and-cover-crops-following-hail-damage-corn-or-soybean

Rees, Jenny and Jim Specht. June 20, 2024. Follow-up from July 2023 Hailstorms to Soybean. UNL CropWatch article.

Resources for dealing with stress: https://ruralwellness.unl.edu/

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