2013 Kentucky Corn Yield Contest Deadline Delayed

Chad Lee, Extension Agronomist, University of Kentucky

The 2013 Kentucky Corn Yield Contest deadline has been delayed until November 29, 2013. We have several farmers who still need to harvest corn and want to enter the contest. Corn harvest across the state has been delayed this year and that prompted the extension of the deadline.

This Kentucky deadline does not change the NCGA Corn Contest, which has a deadline of November 22, 2013.

Kentucky Corn Contest Form
NCGA Harvest Report Form

Corn Knocked Down from High Winds

Chad Lee, Extension Agronomist, University of Kentucky

Corn downed by high winds on October 31, 2013.
Image courtesy Eric Baker

October left with a blast. High winds across the state blew in odd directions and over some corn fields. We knew this was going to be a risk this fall. The heavy ears, shallow roots and slow drydown all created a risk for downed corn. The high winds also brought rains, meaning that harvest will not resume for several days. What can we do now?

We can start by inspecting fields. Identify the fields where corn is down and fields where corn is standing. If corn is standing, check stalk strength with the grab test. (Grab the corn stalks at shoulder height, pull or push about 18 inches off center and release. If the corn stalks remain upright, stalk strength is good. If not, stalk strength is weaker.) Identify the grain moisture in all fields.

Great Corn Harvest but Compaction Nipped Some Yields

Chad Lee, Extension Agronomist, University of Kentucky

The ear on the left is on a plant with
roots limited by compaction and the
other is on a plant with no compaction.

The corn yields being reported are excellent to date for Kentucky. With the wet weather at planting, we all were very concerned about compaction problems. The continued wet weather helped a lot of corn roots break through compaction. We dodged a disaster, but corn yields were dinged by the compaction. I walked a field yesterday where we think we may have lost as much as 75 bushels per acre to compaction.

That's the bad news. The good news is that the field went about 250 bushels per acre. That's an excellent yield in most fields and especially in a field with some compaction.

Heavy Ears and Shallow Roots at Corn Harvest

Chad Lee, Extension Agronomist, University of Kentucky

The frequent and plentiful rains throughout this season have helped to produce some very large ears and rather small roots in many healthy corn fields. The frequent rains resulted in either surface compaction or sidewall compaction at planting in some fields, which greatly restricted root growth. However, the rains masked that compaction and allowed those corn plants to produce large ears. Whether healthy corn or corn with root restrictions from compaction, the combination of large ears, shallow roots and a prolonged drydown period increases the risk for corn plants to fall over. Stalk strength is good in many fields, but we have observed some late outbreaks of diseases, such as Gray Leaf Spot. Diseases like this could compromise stalk strength.

Expect a Later, Wetter Grain Harvest, Get the Driers Ready

Chad Lee, Extension Agronomist, University of Kentucky

Corn was planted late and the cool and cloudy days are slowing development. Most corn hybrids in Kentucky need about 2,700 to about 3,300 GDD’s or heat units to reach black layer (physiological maturity). Looking at the GDD calculator on the UK Ag Weather Center, corn planted April 15, 2013 in Mayfield, Kentucky won’t get to 3,000 GDD’s until Sept. 1.  Corn planted April 15 in Henderson will get to 3,000 on Sept. 3. Corn planted May 15 in Lexington will get to 3,000 GDD’s about Sept. 27.

Late Planting but Early Harvest

Chad Lee, Extension Agronomist, University of Kentucky

Farmers in Kentucky completed corn harvest and had about 95% of the soybeans harvested according to the October 31 USDA Crop Progress Report. While harvest this year seemed late, especially with a late planting schedule, both corn and soybean harvests are ahead of schedule. The five-year averages are 91% and 69% for corn and soybeans, respectively. (University research plots were not included into these numbers!)

The Midwestern states of Illinois, Iowa and Indiana are above 92% harvested for corn and above 97% harvested for soybean. Ohio is not as far along with 89% corn and 96% soybean harvested. Like Kentucky, all of these states are ahead of schedule for harvest.

Yields from the combine have been all over the board. One farmer said that he harvested his best corn ever and his worst corn ever... in the same field. Over the next few weeks, we will get a much better picture of how harvest finished. The overall shorter growing season would imply yields below trend, but the most recent estimates for yield were increased some. 

Corn stands looking weak from stress

Chad Lee, University of Kentucky

In the the Aug 17, 2010 edition of Kentucky Pest News, Dr. Vincelli warns of aflatoxins and diplodia in corn. Another concern is final stand of the corn crop. Much of the corn crop was under stress from heat and a lack of water. Those conditions usually cause the each plant to pull photosynthate from the stalks and put them in the ear in an attempt to produce seed. While this helps each overcome some yield losses, it also causes stalks to become weak.

As you prepare for this early harvest, check fields for stalk strength and, if possible, harvest weak stands first. The easiest way to check for stand strength is to grab the stalk at about your shoulder height and pull the stalk toward you. Release the stalk and if it returns to its normal upright position, the stalk strength is still good. If the stalk does not return to the upright position, the stalks are weak.

In addition to weak stalks, I have had reports and I have visited some fields where ear attachment to the plant is very weak.  In the worst situations, ears have been found on the ground. . . typically, heavier ears. There may be an interaction between environment and hybrid. So, if you have a field like this, please email me at cdlee2@uky.edu and let me know the hybrid and field conditions. Obviously, such fields need to be harvested sooner rather than later.

Those of you who have farmed for a while know that a summer of stress often brings challenges at harvest. This year appears to be no different.

Stalk Strength Reminder

Paul Vincelli, Plant Pathology

Corn fields in the many areas that experienced wet, overcast, soggy weather since the last issue of Kentucky Pest News for the most part remain unharvested. Weather conditions generally, and the widespread occurrence of southern corn rust, conspire to make this a season with increased risk for stalk rots.

Be sure to scout fields for stalk strength. Scouting will help you select fields for harvest based on how strong the stalks are. Harvest those with the weakest stalks first, before they blow down from a strong gust.

The easiest way to check for lodging potential is to walk through the field and, at about chest height, push the plants about 8-12 inches from vertical. A stalk that bends and fails to spring back is prone to lodging. If 10-15% of the stalks in a field exhibit lodging potential, the field should be scheduled for early harvest.

Harvest Wet and Dry the Grain

Harvest corn wet and plan to dry it in the bin. The delayed maturity, cooler temperatures and wet weather will make field-drying very difficult this season. In addition, ears are heavy (a good thing) but waiting a long time for field-drying increases the chances for those heavy ears to pull stalks over. The wet conditions also provide a favorable envrionment for stalk rots and progession of ear diseases. With all of these things going against field-drying, the better option is to plan to harvest the corn wet.

Corn harvest can begin when grain moisture approaches 25 percent. Corn grain should be dried to market moistures (usually 15.5% for field corn and 14.0 % for food grade corn) or to 13 percent if corn will be stored throughout the summer.

For excellent resources on grain bins, drying grain, storing grain, etc. visit the University of Kentucky Grain Storage website operated by Dr. Sam McNeill.