Extension News

Producers Face Mixed Bag of Late Harvest Issues

Giberrella ear rot

10/28/2008

The rain and winds of the past week, mixed with a few snowflakes in some parts of the state, continue the crazy weather patterns that grain producers have battled this growing season. With the majority of the corn and a good deal of soybeans still in the field, producers are facing several grain quality issues as they get back into the fields.

“In Eastern and Southwestern Iowa, a good share of the soybeans are still in the fields,” said Charles Hurburgh, Iowa State University Extension agricultural engineering specialist . “These beans in will not dry any more. In fact, they will go up in moisture to 18 or 20 percent if left in the field. Plus, we are beginning the freeze/thaw cycle which will split the pods and drop the grain.”

Hurburgh recommends that producers get the soybeans harvested as quickly as possible and dry any beans over 15 percent moisture. “It isn’t very often that we need to dry beans, but it may be necessary for those beans that are still standing,” said Hurburgh. “Typical dryers, either high or low temperature, can be used effectively. Soybeans respond quickly, so moisture monitoring will be needed to avoid overshooting market targets.”

If Hurburgh had one bit of advice for grain producers right now, it would be to “run wide open and don’t lift,” because the field drydown period and any improvements to quality has ended. He recommends getting the corn and beans out of field – then managing the moisture.

“There are corn test weight problems this fall because the crop didn’t have time to completely mature or ran out of nitrogen – influenced by hybrid and planting date,” he said. “Low test weight grain doesn’t store well and it’s harder to dry. If producers have the choice, they should sort and sell corn by test weight; selling the lightest corn first, knowing that the heaviest will carry safely through spring.”

To hold low test weight corn (below 54 pounds per bushel after drying), producers should plan to have it gone by Feb. 15 when storage conditions become less favorable.

The cool, wet weather is also contributing to development of fusarium fungi – which in turn can produce several toxins harmful to people and livestock. Scouting corn fields will help determine the extent of ear and stalk rot fungi – important information to have before harvesting the field. It is recommended that producers harvest problem fields (greater than 10 to 15 percent incidence of ear rot) as soon as possible. The longer the corn remains in the field, the greater the chance of toxin production.

“If producers have grain that has shown mold in the field and they are going to feed it to livestock – they must get it tested either with the help of their veterinarian or by a local USDA grain inspection service provider,” Hurburgh said. “This is especially important if grain is being fed to sensitive animals which are poultry, pregnant sows and dairy.”

Hurburgh recommends producers contact their crop insurance agent and then leave check strips if they have corn like the ear in the picture. He also advises against mixing moldy corn with corn from other fields, as elevators will begin checking for mold if  they start seeing loads with mold come into their facility. Ethanol plants will be particularly diligent about mold, which means elevators and producers selling to them will become more sensitive to the mold.

The USDA October corn yield estimate for Iowa of 172 bushels per acre in this wetter than normal year has the potential to create another problem – not enough immediate storage capacity and inability to dry grain as quickly as it comes from the field. Hurburgh says that producers have three options to buy some time without letting grain spoil.

The first option he outlines is to dry down the corn to intermediate moisture (17 or 18 percent), then put it in storage with air flow and cool it in the bin. Corn will end up at 14 to 15 percent moisture.
The second option is to stop the drying process at 20 percent and cool it. It won’t be dry, but can be held if aerated and kept cold. However, it will need to be dried come spring. “It’s possible to hold corn at 17 to 18 percent through the winter if it is aerated. But by March, it will need to be dried.”

Double pass drying is the third option that Hurburgh says producers have for this year’s wet corn. “This is an option for producers that have drying capacity without high aeration. Start by drying corn to 20 percent, then cool the grain, and turn around and immediately dry again. Costs and labor will be more, but it is an option for buying some time and extending capacity.”

While sections of Iowa have normal moisture rates for this time of year, producers east of Interstate 35, where some corn is over 22 percent moisture, are not so fortunate. “The plus side of all this, if those folks can find a plus side, is that stalk strength is pretty good and the corn is standing up fairly well,” Hurburgh said.

Additional details on the corn quality issues in 2008 can be found in recent Integrated Crop Management News articles authored by Hurburgh and Extension colleagues at www.extension.iastate.edu/cropnews


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Contacts :

Charles Hurburgh , Ag and Biosystems Engineering, (515) 294-8629, tatry@iastate.edu

Roger Elmore , Agronomy, (515) 294-6655, relmore@iastate.edu

Willy Klein, Communications and External Relations, (515) 294-0662, wklein@iastate.edu

 A high resolution version of the thumbnail photo above is available for use with this article: 1023Giberrella.JPG [3.1 MB]