If switching to soybean and preventative plant crop insurance are not options, farmers need to reconsider their production practices and focus on those that will generate the greatest profits in a late planting production environment.
What optimizes yield when corn is planted early doesn’t always have the same effect when corn is planted in June. Given the shorter growing season, the response of a late-planted corn crop to certain inputs may be limited compared to responses of a corn crop planted on normal planting dates.
Moreover, some management adjustments will facilitate more rapid crop establishment and thereby limit further yield losses associated with planting delays.
Consider the following management alternatives so that planting is not further delayed when favorable planting conditions occur and economic returns from various inputs are optimized:
• Avoid high-end range N rates on corn following soybean. OSU research has shown that nitrogen rates can be decreased by 10-15% with minimal impact on productivity when corn is planted in early June.
• Sidedress anhydrous N (or UAN liquid solutions) and apply a minimum of 30 lb/N broadcast or banded to stimulate early seedling growth. If you don't have the capability to apply N with your planter, a surface application of UAN as a herbicide carrier can be a way to carry your corn crop until sidedress N is applied.
• Place starter applications of P and K in bands 2 inches to the side and 2 inches below the seed. Remember application of P and K is only necessary with the starter if they are deficient in the soil, and the greatest probability of yield response from P and K starter is in a no-till situation.
• Keep time expended on tillage passes and other preparatory operations to a minimum. Such work will provide minimal benefits if it results in further planting delays. No-till offers the best option for planting on time this year. Field seedbed preparation should be limited to leveling ruts that may have been left by the previous year’s harvest - disk or field cultivate very lightly to level. Most newer planters provide relatively good seed placement in "trashy" or crusted seedbeds.
• Switch to an adapted short season hybrid. Although a full season hybrid may still have a yield advantage over shorter season hybrids planted in early June, it could have significantly higher grain moisture at maturity than earlier maturing hybrids if it dries down slowly. Moreover, recent evaluations indicate there are some 100-104 day relative maturity hybrids with excellent yield potential. However performance data for such early hybrids is limited compared to late maturities.
For more information on selecting corn hybrids for delayed planting, consult "Delayed Planting & Hybrid Maturity Decisions", a Purdue/Ohio State University Extension publication available online at: http://www.agry.purdue.edu/ext/pubs/AY-312-W.pdf (Consult Table 4. Approximate “safe” relative hybrid maturities for delayed plantings throughout Ohio)
• Reassess seeding rates. Soil temperatures are usually warmer in late planted fields, and as a result germination and emergence should be more rapid and uniform. So, as planting is delayed, seeding rates may be lowered (decreased to 3% to 5% higher than the desired harvest population) in anticipation of a higher percentage of seedlings emerging.
Past university research indicates that optimal plant populations for early (mid to late April) and late planted (late May to early June) corn are similar.
However, recent OSU studies suggest little benefit from increasing plant populations above 30,000 plants/A in June. This lack of response to final stands over 30,000 plants/A was associated with greater stalk lodging for hybrids planted during June compared to May.