Thunderstorms rumbling through Indiana in recent days and weeks have sometimes dropped payloads of hail on unsuspecting corn fields. Sometimes the devastation is quite severe or, in some cases, nearly complete. The following options are available to corn growers faced with such destruction in late June or early July.
Leave the Field Alone. While the thought of looking at a hail-damaged field for the rest of the season is not palatable, this option may be the most economically viable (best of the worst?) for some. If stand loss (plant death) is not severe, yields may be greater than you might imagine. Few fields damaged by hail this year have been older than about the 15-leaf stage. Yield losses in a full stand of corn at the 15-leaf stage completely defoliated by hail may only be 50 percent. Keep in mind that the leaf defoliation may not be as bad as your eyes tell you. Most of us overestimate the actual extent of leaf defoliation caused by hail. See my accompanying article, Assessing Hail Damage in Corn .
A big unknown in hail damage assessment is the consequence of stalk bruising by the hail stones. Such bruising may structurally weaken the stalk, encourage stalk rot development later, or actually damage the developing ear shoot if it took a direct hit. Even where stalk bruising did not occur, fields with severe hail damage will suffer more incidence of stalk rot later in the season due to the photosynthetic stress placed on the plant during grain fill.
Replant to Corn. It is late enough in the growing season that this option is a risky one. Late-planted corn is subject to several insect problems, including corn rootworm beetle damage at pollination and late generation European corn borer infestation. Grain development and maturation of late-planted corn is subject to more incidences of sub-optimal temperatures than in normal plantings. The risk of a killing fall frost is also greater for late-planted corn. Attempts to manage the frost risk by planting an unusually early maturity hybrid (essentially an unadapted variety) often fail because such early maturities are often less tolerant of late-season leaf diseases in this part of the Corn Belt.
Replant to Silage Corn. For farming operations that can use silage or have neighbors that might buy silage, this option may be appealing. Adapted early maturity hybrids (no earlier than 100-105 'days') could be used when replanting for silage at this late date. Aim for early maturity hybrids that are taller than average to help maximize tonnage. While a killing fall frost may occur before the grain matures, the ability to harvest for silage lessens the consequences of the frost risk. Keep in mind, however, that the increased risks of insect or disease damage to late-planted corn still apply to fields replanted for silage.
Replant to Sorghum. Unless a grower has experience with growing grain sorghum, this option is probably not very feasible. A replant situation is not a good time to learn how to grow the crop! Beyond that, replanting dates in most of northern Indiana are too late for planting grain sorghum. Growers in southern Indiana could still replant to grain sorghum, but they should ensure they have a market for the grain before they embark in this venture. Contact your seed dealer for variety recommendations as well as management guidelines.
Replant to Soybean. Conventional wisdom says that replanting to soybean is risky (also off-label!) if atrazine or other 'soybean killing' herbicides have already been applied to the field. Experience following the Great Frost of '92, though, tells us that replanting to soybean in such fields will sometimes work. Caution should still be used, however, since replanting to soybeans would be off-label for atrazine. Just as importantly, most of northern Indiana is probably beyond the last safe date for replanting to soybeans.
Additional information is available in the publication NCH-1 , Assessing Hail Damage to Corn, Purdue University Cooperative Extension Service.