Corn Replant Considerations
When corn stand loss occurs, replanting should be considered if the resulting yield increase will more than cover the cost.
Factors to Consider in Replant Decision-Making
- Plant density of the current stand
- Uniformity and health of the current stand
- Date of original planting and potential replanting
- Costs associated with replanting
- Crop insurance provisions
- In situations such as flooding damage, only a portion of the field may need to be considered for replant
- Frost or hail can damage a wide area. In this case plant density and health should be assessed across the entire field
Replant Yield Potential
- The expected yield from the current stand should be compared to expected replant yield.
- The table below shows yield potential for a range of planting dates and final plant populations.*
|Planting Date||Plant Population (1,000 plants/acre)|
|———- % of maximum yield ———-|
Replanted areas in a field that experienced severe flooding damage in 2008.
Profitability of Replant
Even if replanting will increase yield, the yield increase must be sufficient to pay for all of the costs associated with replant such as:
- Extra herbicide or tillage costs
- Planting costs
- Increased grain drying costs
Also consider these factors when making a replant decision:
- Probability of an autumn freeze prior to physiological maturity of replanted corn
- Increased susceptibility of late-planted corn to summer drought or disease and insect pests such as gray leaf spot and European corn borer
Hybrid Maturity for Replant
- The chart below shows the relative profitability of full-season, mid-maturity, and early maturity hybrids in 29 north-central Corn Belt environments over 17 years of DuPont Pioneer research.
- Results indicate that a grower may consider using a mid-maturity hybrid if replanting after May 17 and an early maturity hybrid if replanting after June 5.
Replanting to soybeans may be preferable after mid-June, but this will depend on soil-applied corn herbicides that were used.
Carter, P.R., E.D. Nafziger, and J.G. Lauer. Uneven Emergence in Corn. North Central Regional Extension Publication No. 344
Hicks, D.R., S.L. Naeve, J.M. Bennett, and N.B. Bennett. The Corn Growers Field Guide for Evaluating Crop Damage and Replant Options. Univ. of Minnesota.
Lauer, J.G. 1997. Corn Replant/Late-Plant Decisions in Wisconsin (A3353). Univ. of Wisconsin-Extension.
* Replant yield data was interpolated from University of Illinois population response data (E. Nafziger, E. Adee, and L. Paul) and University of Minnesota planting date response data (Hicks et al.).