Corn School: Fine tuning the combine to reduce DON levels


How can growers adjust their combines to reduce vomitoxin levels when harvesting the 2018 crop?

RealAgriculture agronomist Peter Johnson has some answers. In this episode of Real Agriculture’s Corn School, Johnson visits with custom combine operator David Killins, of Killins Custom work, at Dorchester, Ontario.

Johnson acknowledges that while cleaning corn does help, it’s not realistic that you’ll be able to eliminate DON entirely. It is possible to reduce DON levels by about 20 percent or more, through cleaning, but running corn over a cleaner is a logistical challenge — why not get the combine to clean the corn in the field?

Setting up the combine properly before entering the field to reduce DOn/vomitoxin is key for success, says Killins. He says that earlier in the fall, after having a load of corn test 10.4 ppm for vomitoxin, he made the combine adjustments outlined in the video below, and the following load from the same field tested from 4.5 to 5.5 ppm – about a 50 per cent reduction. Story continues after the video.

Killins’s tips for combining vomitoxin corn include:

  • The importance of perforated doors (screens) on the bottom of clean grain and return elevators, and a screen on the unload auger, if available.
  • Setting the concave properly is also critical – ensure it’s set wide and the rotor/cylinder speed is set slow. Don’t grind the corn.
  • In badly infected fields, Killins recommends to take the return elevator bottom door completely off, and just drop the tailings in the field.
  • Also consider closing the back portion of the chaffer (sieve), if possible. This will increase wind blast and force more light kernels out the returns and over the back of the sieve. You will lose some good kernels, but if you can drop DON levels to an acceptable level, the loss is generally well worth it.

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Corn School (view all)Season 7 (2018) Episode 4

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