Just when we think we know everything about growing corn, Mother Nature teaches us new things. Read the lessons we learned from our studies in the Corn Watch ’21 field and other fields this year. You may pick up a couple of ideas you can use in 2022:
1. Watch row-to-row variation. All corn rows across a planter may not emerge on the same day.
2. Check depth row to row. Measure actual planting depth of each row. All rows may not adjust the same, even on a new planter.
3. Identify pinch rows. Pinch rows between wheel tracks may emerge earlier than the other rows.
4. Emergence can stretch over two weeks. Cool, wet soils may stretch emergence over two weeks in extreme conditions.
5. Be patient with no-till. No-till corn may emerge more slowly but wind up with a better stand than conventional corn.
6. Dig when a plant is missing. For 80% of the plants that don’t emerge, when you dig, the seed will be there. Keep this in mind when deciding on seeding rate. Plant at least 5% more seed than the desired harvest population.
7. Tile pays. Fields with drainage problems may lose nitrogen in a wet year.
8. Revisit sidedressing N. Sidedressing N may be worth another look, even if you tried it before 2021.
9. Consider higher seeding rates. If you get 29,000 ears per acre even though you seed 32,000 seeds every year, consider raising seeding rate by 2,500 seeds per acre.
10. Think about the neighbors. If several plants in an area emerge late, that area may not see the late-emerger effect to as great a degree as when single plants emerge late.
11. Multiple factors impact emergence. When planting early, the 12-hour or 24-hour emergence rule for late emergers becoming weeds may need to be modified. Other factors affect ear weight per plant besides emergence delays.
12. Apply fungicides. If you see lesions of leaf diseases before tasseling, a fungicide application may be needed.
13. Tissue testing can pay. Tissue tests conducted at V5 can be turned around quick enough to make applications of micronutrients.
14. Factor in N trade-offs. Yield may be hurt where N loss is significant due to excessive rains. Mineralization of nitrogen in the soil may partially offset these losses.
15. Rescue N-deficient corn. If deficiency symptoms appear, applying nitrogen with a high-clearance sprayer might help, but higher rates and drops may be necessary.
16. Sulfur is no longer free. Sulfur deficiency symptoms were quite common in many fields at V5 and V10, and even at tasseling stage in some fields in 2021.
17. Ears make yield. Yield is determined by ears per acre, not seeds planted or stalks per acre. If you see plants without ears, find out why and remedy those issues.
18. Dry weather hurts kernels. Late-season dry spells cause tip abortion. Corn plants discard “runts” and develop viable progeny. Late-season dry spells can also reduce kernel size and yield.
19. Soil compaction is a stealth yield stealer. Soil compaction can contribute to emergence problems even if you don’t think you planted in wet ground.
20. Control weeds. Early weed control in corn is imperative for reducing competition.
Nanda is director of genetics for Seed Genetics Direct, Jeffersonville, Ohio. Email him at [email protected] or call and leave a message at 317-910-9876.