November 26, 2012

5 Min Read

Whether the farm is in Georgia or Tennessee, or from the Carolinas to Louisiana, high grain prices have made corn a thriving cash crop for many Southern growers who know the value of efficient corn production in their rotations.

With a little help from Mother Nature, high yields of quality grain can be expected. And a timely harvest, fined-tuned combine and solid storage system can make those rewards even stronger for farmers and their families.

Southern growers can sometimes take advantage of stronger corn markets by getting into the field earlier than those in the Corn Belt. The supply and demand theory could mean an extra 50 cents a bushel or more. That’s why it’s vital to have combines in top condition and adjusted for every field before harvest gets under way.

Setting the combine to minimize loss is extremely important, especially in years when drought dries many fields earlier than normal.

“It may mean constant adjustments to match the conditions in each field,” says Angela McClure, University of Tennessee Extension corn and soybean specialist.

“Finding an average of two kernels per square foot or a full sized ear on the ground is equivalent to 1 bushel of corn lost per acre. Try and figure out where the loss is coming from: header, thrasher, etc., and make one single adjustment at a time on the equipment until you seem to be going in the right direction.”

McClure says that in fields with a lot of variability in ear size, “doing a really efficient job thrashing the larger sized ears makes more sense than giving up some of the better grain in order to try to capture the tiniest of nubbins.”

There is no definite moisture percentage rate for when harvest should begin. But according to Mississippi State University Extension, initial corn harvest should begin at about 18 percent to 20 percent moisture. Growers in the Midwest sometimes fire up combines when corn hits 25 percent. It all depends on potential harvest weather and machinery.

Summers hotter and drier than normal, as in 2012, can cause corn to ripen faster and put pressure on growers to get it out of the field. MSU and Louisiana data show the field-drying rate of corn at maturity occurs at 0.6 percent per day when it reaches 15 percent. MSU says a combine will shell corn at 30 percent moisture, with minimal kernel damage.

“Axial-flow combines will shell corn at moisture contents as high as 35 percent and ease of shelling at higher moisture contents depends on the hybrid,” says Erick Larson, MSU Extension corn specialist.

For example, a corn hybrid that matures on Aug. 1 at 33 percent moisture would likely be ready to harvest in 8 to 13 days at a 25 percent to 28 percent moisture content. MSU says harvest could begin Aug. 9 with farm drying or accepting elevator dockage for excess moisture. Field drying to 15 percent would push the harvest date toward Sept. 1.

Due to the high costs of storage facilities, drying equipment and energy needed to steadily move thousands of bushels of corn in the drying process, efficiency is a must when drying and storing corn or other grain.

To lower the moisture count from 25 percent  to 15 percent at the bin requires removing about 7.47 pounds of water per bushel. MSU says that in the South, it requires about 2,000 Btu to remove 1 pound of water from 1 bushel of corn.

Other estimates indicate it can range from 1,400 Btu for a continuous-flow dryer to 2,100 Btu for a bin-batch drying system.  That all equates to about 1 gallon of LP gas (about 95,000 Btu) to remove 10 percent moisture from six bushels of corn, MSU says. With a cost of LP gas at $2 per gallon, it will cost close to 30 cents or more a bushel to dry.

On-farm storage provides growers with an opportunity to make later sales when corn prices or the basis improves. However, storage bins should be prepared for safe long-term storage, Larson says.

Even though growers are encouraged to get grain out of the field early, they should work to avoid aflatoxin contamination. “Due to the region’s hot, humid climate, the threat of aflatoxin is a worry for Southern growers,” Larson says. “Fungal growth escalates with higher temperatures and higher humidity. Anything above 15 percent moisture can cause aflatoxin to escalate quickly.

“You can minimize the likelihood of developing an aflatoxin problem by using sound agronomic practices, properly storing and drying grain, maintaining grain quality, and sanitizing grain-handling equipment,” Larson says.

According to MSU, here are some key steps that should be taken to assure grain is safe:

  • Clean and disinfect bins before placing grain in them.

  • Treat bins for insects as the bin is filled.

  • Keep corn moisture content below 13 percent.

  • Aerate when ambient and grain temperature differ by 10 degrees F and relative humidity is less than 65 percent.

  • Avoid re-wetting grain without operating a stirring device (to help prevent swelling of grain that can cause bin walls to fail).

  • Regularly inspect the grain for potential problems.

Larson points out that heavy duty plastic storage bag systems offer growers an option for temporary corn and other grain storage. Normally situated near a field, corn can be placed in them alongside the field. This can help speed harvest. Some systems can hold 300,000 bushels or more.

Again, with the continued high prices for corn, more growers will keep the golden grain in their crop rotations, along with their white food grade production. And growers should use proven methods of harvesting and storing yellow, white and other types of corn to help maintain its highest quality.

Larson and McClure encourage producers to consult with their Extension agronomists or their seed company specialists on how to take advantage of their region’s growing conditions. With that, and help from the weather, they should be rewarded for their corn production.

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