Don’t let your drought-stressed grain get folks up in arms
You had a rough year. You survived the drought, albeit with less-than-ideal yields. Now you can put your grain in the bin, put your worries behind you and set your sights on next season. Right?
Not exactly. If you have drought-stressed grain, it will need a little TLC during its stay in the grain bin, says Charles Hurburgh, Iowa State University grain quality specialist. While the prevailing concern with drought-stressed grain is susceptibility to aflatoxin in corn, he says, it’s hard to predict when and where it will strike.
If there is a lot of aflatoxin incidence, Hurburgh predicts some rough roads ahead. "It would put a real strain on how to test and sort grain," he says. "The grain industry is not set up to handle a high volume of testing for a low concentration factor."
On the other hand, it’s not time to panic yet, he adds. "There are a lot of acceptable outcomes still on the table. The fungus that produces aflatoxin is not very vigorous, and it requires specific growth conditions to produce the toxin in the field. Once you take your corn out of the field, as long as you get air on it right away and get the temperature down, you can limit the growth [of the disease] after harvest."
Hurburgh makes another important point about aflatoxin: For crop insurance settlements that exceed 20 parts per billion, you can’t put the grain back into general commerce before doing some additional documentation. "It’s the farmer’s responsibility to notify the system so that corn can be documented to go to the appropriate livestock," he says.
Farm Journal economist Bob Utterback says conversations with crop insurance agents should begin before harvest. "You’re required to have your crop surveyed and adjusted prior to harvest. If you have any suspicions, you need to have your adjuster coming out and pulling samples." That could create a time crunch, he adds, because at-risk corn needs to be harvested as early as possible.
Corn quality is also affected by drought. For example, Hurburgh says, drought reduces kernel fill as well as test weight. Persistent drought can result in test weights of 50 lb. to 54 lb. per bushel, which is less than acceptable for No. 2 corn.
The chart below details how long grain should be stored, based on temperature and moisture content. This time should be shortened for corn yielding below 54 lb. per bushel.
Kansas State Extension has additional pointers to avoid postharvest aflatoxin and other mycotoxins:
- Harvest at 24% to 26% moisture for minimum kernel damage.
- Adjust equipment for minimum kernel damage and maximum cleaning.
- Dry shelled grain to at least 15% moisture 24 to 28 hours after harvest.
- Aerate and test for storage hot spots every one to four weeks.
- September 2012