Evaluating Corn Stands
Once again mother nature has given us a challenging spring. Any crops planted May 11 or 12 have struggled to get out of the ground. Other planting dates and conditions may have also presented some problems. Some replant decisions have already been made.
To make corn stand assessments and replant decisions:
- Walk fields carefully, looking at emergence in the various soil types in the field. In general, darker, low ground has better stands than higher, clay knobs.
- Count emerged plants in 17 feet, 5 inches of row (30 inch rows). Add three zeros (or multiply by 1000) to get the estimated plants per acre.
- Where plants are missing, dig to see if the seed has germinated. What is its condition? Has the coleoptile (tip of the shoot) broken open and the seedling begun to leaf out underground? If the seedling is leafing out underground, it only has a couple of days to emerge or the seedling will die.
- How many plants is enough? In general, if you have 22,000 or more plants at the end of May, replanting will most likely not pay. If you have 20,000 -22,000 plants, it probably will not pay to replant, but you may consider replanting if plant health is not good and/or distribution is very uneven. Less than 20,000 plants per acre is a likely replant situation, assuming no more plants are likely to emerge. As we move on into June, those numbers will move downward as the growing season window shortens.
Many growers have used rotary hoes or other tools (cornplanter, vertical tillage tools, etc.) to break up crusts and hopefully aid emergence. Timing on these operations is critical. We’ll probably review the success of these operations at a later date.
If you would like assistance assessing corn stands and making replant decisions please contact one of us.
Terry Jones CPAg, Regional Agronomist @ 419.346.7786 or
or
Rod King CCA, Regional Agronomist @ 574.596.6721 or