Tips for harvesting, handling, storing 2016's big crops

Tips for harvesting, handling, storing 2016's big crops

Wet harvest conditions and field molds are sprouting grain quality issues for corn and soybeans this fall.

The recent massive rains and flooding in northeast, north-central and parts of eastern Iowa have complicated the need to move quickly on harvesting deteriorating grain in the field this fall. The following article looks at specific impacts from wet field conditions and tips for grain handling and storage from Iowa State University specialists. Brian Lang, ISU Extension field agronomist at Decorah in northeast Iowa put together this list of information available.

FLOODED FIELDS: A deluge of rain for the month of September in northeast and north-central Iowa, draining into rivers and streams flowing into eastern Iowa, has created challenges for harvesting, handling and storage of 2016 corn and soybean crops.

Wet fall harvest & field molds: High rainfall, temperatures and humidity create challenges for crop quality. This article by Charlie Hurburgh, ISU Grain Quality specialist, discusses grain harvest and storage issues at

Rank field harvest order by lodging risk and ear mold development

Lodging risk – use the pinch test: Test stalk firmness by pinching the lower internodes with thumb and forefinger, Lang advises. Healthy stalks are firm and cannot be compressed. If a stalk can be compressed or feels soft, it is rotting and is a good candidate for lodging. Check at least 100 plants per field in different locations. Different hybrids and fields with different tillage, rotation or fertilization histories should be scouted separately.

The preferred time for this scouting is when fields are approaching black layer. Fields with greater than 15% rotting should be targeted for early harvest. “Currently, I’m walking fields about one week past black layer. I am finding fields anywhere from 5% to 70% rotting. No question as to which fields should be harvested first,” says Lang.

Scout corn for ear molds: When scouting for standability, also examine ears for signs of ear molds. A great full color Extension publication is available as a free download at “Considering there is no night-time freeze warning in sight from our weather forecasters, fields with noticeable ear mold development (10% or more of the ears with more than 10% to 20% mold), should be targeted for early harvest and the grain dried immediately to at least 15% moisture,” says Lang. Tips on dealing with harvest and storage of grain with mold concerns is provided in the last two pages of the publication above.

Testing for mycotoxins in grain or silage

·     Scouting fields before harvest is recommended for identifying any presence of ear molds. Use this publication for mold identification:

·     Finding ear mold does not provide any information about potential mycotoxins and their concentrations, says Lang. Test the grain or silage for mycotoxins. A variety of analytical methods are available. The quality and usefulness of results often parallel the investment made. Direct fluorescence using the ultraviolet lamp (black light) is useful only for tentative identification of Aspergillus. Other procedures such as thin layer chromatography, mini columns, gas chromatography, or mass spectroscopy are probably necessary if quantitation and confirmation of the mycotoxin is needed.

·     Samples for mycotoxin analysis can be sent to ISU or a private laboratory. The ISU Veterinary Diagnostic Laboratory will only analyze samples submitted through a veterinarian;

·     Private labs in the general vicinity of northeast Iowa that test for mycotoxins include:

ü  Dairyland Labs:

ü  Minnesota Valley:

·     Currently several commercial test kits using fluorescence, radioimmunoassay or ELISA techniques are available to test for mycotoxins. These kits provide rapid, convenient analysis on-site, but they are not as precise as the chromatography methods. To learn more visit

Harvesting flooded fields and exposure to mold and dust

Grain dust is always a health concern for Iowa’s farmers and those working in the grain industry, notes Lang. However, crop harvest from fields with extensive flooding this season may cause even more health concerns for both human and animal exposures due to mold and other potential contaminants. The following are answers Lang found to the most common questions about these kinds of exposures.

·     What are the most common health concerns?

  1. Grain dust contains more than just plant material and dirt. It can also contain molds and spores, insect parts and debris, bacteria, chemicals or plant toxins.
  2. Exposure to low levels of grain dust during normal working conditions often causes reactions that are a nuisance, such as a cough, sore throat, nose and eye irritation, or feeling stuffed up or congested.
  3. Exposures to moldy and dusty grain, especially large exposures, are linked to two specific medical conditions with similar symptoms

ü  Farmer’s Lung or Hypersensitivity Pneumonitis (FHP) – a fairly uncommon condition (one in 20 farmers) caused by a delayed allergic reaction to the dust. Repeated exposures can lead to permanent lung damage or limitations to work. A medical provider should be consulted.

ü  Organic Dust Toxic Syndrome (ODTS) – a more common toxic response to dust, molds, bacteria or toxins in the grain dust. Recovery is usually in a few days, but a medical provider should be consulted.

·     What are the symptoms I should watch for? Common symptoms include cough, headache, chest tightness, muscle aches, fever or generally not feeling well. If any of these symptoms are experienced, you should visit your medical provider.

·     What should I do to protect myself when destroying this crop?

  1. Avoid direct exposures to dust whenever possible.
  2. You should use a NIOSH-approved and certified “N-95” respirator that fits you properly when working in extremely dusty conditions. ONLY do so if you are healthy and do not have health concerns with your heart and lungs. Consult your medical provider before using a respirator. N-95 respirators must be used only with a clean shaven face to ensure proper fit.
  3. People with chronic respiratory health issues should avoid dust exposure.
  4. If you have been exposed to large amounts of dust and you begin to feel ill, you should contact your medical provider for a proper medical evaluation.

Flooded crops, management of flood submerged grain

Grain submerged by uncontrolled flood waters is considered adulterated under the federal Food Drug and Cosmetic Act. Adulterated material cannot be put in commercial facilities of any type where there would be a chance of entering human or animal food. The following article defines this issue, but also lists the process where it may be possible for flood submerged grain to still be used outside of a commercial facility. 

Crop insurance payments, lease contracts, planning for next year

Dr. William Edwards, retired ISU Extension economist, provides information on issues regarding this season’s flooding and crop insurance, rented acres and looking ahead to 2017. 

Flood resources website—dealing with flooding

ISU Extension has updated its Flood Resources Website. Topics include Clean Up, Private Wells, Health and Safety, Crops, Livestock, and Stress Management.

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