Those who aren’t dealing with floodwater are out looking at fields this afternoon to figure out how quickly we can get the planters back in the field.  This article is written for those who intend to continue planting corn to fill contracts or to attempt to stay in their planned rotations.  We have to assume some yield reduction now compared to what “might have been” but yield penalty will depend so much on our weather this summer it is difficult to predict an amount.  I do think there is benefit to planting as much corn as quickly as possible over the next week.  Some field work and experience also tells us that managing late planted corn will be slightly different compared to a March or April planted crop.     

•  Where practical, place corn in fields with some ability to supply moisture during the summer.  After mid-May consider switching to soybeans on upland ground with known history of low yields (<100 bushels) in past dry years like 2007, 2008 or 2010. 
• Check your hybrid tech sheet.  May planted hybrids should have good heat tolerance (check out those hybrids that yielded well in 2010!!), standability, and dry down scores where possible.  Some research indicates full season hybrids planted late dry down slowest of all maturities, but part of the problem can be found in the inherent dry down potential of the hybrid itself.  Plant as much Bt corn as your refuge restriction allows.  With limited aerial application options, hybrid resistance to Gray Leaf spot and rust is particularly important in late planted corn.   
• Reduce seeding rates slightly.  We typically plant 10% above our target population in March and April to allow for more seed loss under less than ideal conditions.  May planted corn can emerge quicker with less seed loss, therefore seeding rates can be adjusted back to the target population or slightly above. 
• Seed depth should be at least 1.5 inches deep.  Deep planting isn’t necessary in moist soils but shallow planting would hinder root development as these seedlings develop during hot weather. 
• Be timely with inputs.  Corn will develop at a more rapid pace when planted in May.  The time between planting and need for side dress fertilizer, herbicides and at-tassel treatments can be cut by a third.
• Foliar fungicide may be needed depending on disease environment.  Hybrid response to foliar fungicide can vary tremendously.   2010 data on foliar fungicide response of more than 50 early and medium season hybrids can be found at utcrops.com under corn disease information. 
• Expect slower dry down in September the later you plant in May.  Hybrids develop at a quicker rate due to hotter temperatures compared to April planted corn but typically face cooler temperatures near maturity in September.  Extreme stress environments during July and August can also affect ‘normal’ plant development.  Foliar fungicide use delays plant dry down and can lead to wetter corn at harvest.