Indiana's corn planting progress stalled significantly for the week ending May 21. Only 48 % of the state's corn crop was reported to be in the ground, compared to the past five years' average of 80 %. The 1995 planting season is on its way to being the latest in recent memory. What are the consequences of a late planting season for Indiana corn growers? As usual, the answer depends greatly on the weather conditions between now and harvest in the fall.
Stand Establishment. Late-planted fields should germinate and emerge somewhat sooner than fields planted in late April because of relatively warmer soils. That's good news. As nodal (permanent) roots begin to elongate from the plant's crown area (beginning at about 1-leaf stage), the relatively warmer soils should also encourage faster and deeper root growth. That's also good news. If the surface one to two inches of soil dry rapidly before or at the time of nodal root elongation, some stunting of initial nodal root development can occur. That's bad news. Prolonged stunting of nodal root development due to excessively dry soils can result in the dreaded 'floppy' corn syndrome, whereby plants fall over because of insufficient rooting.
Soil Compaction. Fields that were worked wet and/or planted on the wet side may come back to haunt you if the weather turns off dry later on. Soil compaction from equipment traffic, tillage implements, and planter disc openers can severely restrict root elongation. Subsequent effects on plant growth and development will be especially severe if unusually dry conditions occur prior to pollination (think back to 1983). One of the tell-tale symptoms of soil compaction effects is uneven corn growth across the field, otherwise known as the 'Tall Corn - Short Corn' syndrome.
Pollination. The critical pollination period for late-planted fields will likely occur later in July and into early August. The good news is that you can enjoy the 4th of July weekend without worrying about the progress of pollination in your fields. The bad news is that pollination will likely occur when the chances for hotter, drier conditions are greater. Severe drought stress during pollination, aggravated by high temperatures, can cause poor or uneven kernel set due to pollination failure or kernel abortion early in the grain fill period.
Stalk Lodging. Later-planted corn will usually be taller than early-planted corn. Where you have hybrids with less than desired stalk strength anyway or that are tall hybrids to begin with, be sure to monitor those fields in early to mid-September for the development of stalk lodging.
Grain Drying Considerations. Grain of later-planted corn will usually be wetter than early planted corn for any given day in the fall. If you don't want to wait longer to allow the grain to dry down in the field to acceptable moisture levels, be prepared to spend more on grain drying. If you harvest the grain at wetter than usual moisture levels, don't be surprised at lower than desired test weights. Test weight in corn grain increases as grain moisture decreases, so wetter than usual grain tested direct from the field will be lighter weight than usual.
Insect Problems. Extremely early or extremely late-planted fields of corn can be quite attractive to a range of pests, including corn rootworm beetles at pollination time and European corn borer moths. Make a concerted effort this year to pay attention to the potential development of these and other insect pests, especially if your field(s) is among the earliest or latest in the neighborhood.