With another week of rain some Ohio farmers face the prospect of replanting. Several factors must be considered before growers can make the best decision on whether or not to replant, says Peter Thomison, an Ohio State University Extension agronomist.

Many growers might be weighing this decision now that heavy rains have caused soil crusting leading to reduced emergence, Thomison says.

The issue is of concern to growers statewide, particularly in areas with poorly drained soils or in river bottoms, which are more prone to flooding conditions.

Continued Rains Raise Questions About Replanting

"Before growers replant, they need to have strong evidence that the returns from replanting will cover both the replanting costs and net enough of a profit to make replanting worth the time, costs, energy and effort," Thomison says. "The complicating factor is the quality of the stand.

"Corn may now look pretty mediocre or questionable. But more often than not, the quality of the stand improves as crops warm up and nitrogen becomes available to the stand. That helps to make replanting decisions difficult for growers."

If growers decide, after completing a crop damage assessment, that they need to replant, they should consider the following:
•Original target plant population/intended plant stand.
•Plant stand after damage.
•Uniformity of plant stand after damage.
•Original planting date.
•Possible replanting date.
•Likely replanting pest control and seed costs.

Other key considerations include herbicide and insecticide programs under late-planting conditions; the cost of replanting, which will vary depending on the need for tillage and chemical application; and the cost and availability of acceptable seed.

"These factors must be weighed against expected replanting yield gains," Thomison says. "If after considering all the factors there is still doubt as to whether or not a field should be replanted, you will perhaps be correct more often if the field is left as is.

"Sometimes it becomes a trade-off between a poor stand with early planting or a good stand with late planting. Some growers may achieve a higher yield with a late-planted stand."

Historically, the optimal time to get corn planted in southern Ohio is between April 10 and May 10 and in northern Ohio between April 15 and May 10. Growers who follow those planting dates generally see optimal yields, Thomison says. Planting later than these times historically has resulted in yield loss - in some cases, a 30-bushel-per-acre reduction in yield.

Source: OSU Extension