Rain-Delayed Wheat in North Dakota: When Is an Aerodynamic Grain Cleaner Worth Testing?

If rain has delayed your wheat harvest, a cleaning trial is worth considering when a sample contains material the machine can separate, such as chaff or light foreign material. First establish what is wrong with the lot. The METRA ADS aerodynamic grain cleaner can separate lighter affected kernels where their behaviour in airflow differs from the grain being retained. Cleaning does not reverse sprouting inside an individual kernel or replace drying; the retained lot still needs assessment against buyer requirements.

NDSU Extension's September 10, 2026 Crop & Pest Report described rain-delayed harvest, sprouting concerns and strong weed growth in northeastern North Dakota. For growers facing similar conditions, a representative grain sample helps identify the next step: cleaning, further quality testing or moisture management. See the report's Northeast ND section, pages 30-32. NDSU report

Start with the buyer's concern

Keep separately harvested lots identifiable while you investigate. Ask the intended buyer which characteristics determine acceptance and which sample or laboratory tests they require. Share the lot's harvest conditions and sample results with the buyer.

For the cleaning decision, write down three things: the buyer's stated problem, what you can identify in the sample, and what remains untested. Moisture, suspected sprouting and foreign material belong on separate lines. If the issue is grain condition rather than a removable fraction, discuss the relevant testing, drying or storage decision with the appropriate service provider before ordering cleaning equipment.

If weed seeds or other foreign material are a concern, inspect a representative sample to establish what is present. A grain specialist can help identify unfamiliar material before you select a separation method.

Match the trial to the material

The aerodynamic grain cleaner uses airflow to separate fractions according to weight and aerodynamic behaviour. Adjustable airflow and outlet baffles allow the operator to collect different fractions, with dust, chaff and other light impurities following the air stream. A trial shows which material can be removed from your lot and how much acceptable wheat remains. METRA ADS operating manual, sections 4.1 and 5

Bring photographs and a sample description to the equipment discussion. If large pieces of straw or other material dominate the sample, ask whether the proposed setup can handle that feed or whether a separate preparation step is needed. The feed condition determines which preparation steps are needed.

Light damaged kernels and DON

A damaged kernel may keep a normal external size while losing mass. METRA's operating experience includes separating such lighter kernels with its airflow cleaners. Size alone therefore does not decide whether the unwanted fraction can be separated in air.

NDSU describes removing lightweight Fusarium-damaged wheat kernels during harvest and by post-harvest gravity separation. For your lot, a cleaning trial can show whether a useful lighter fraction separates from the wheat you want to retain. NDSU: Fusarium Head Blight of Small Grains, Harvest section

Deoxynivalenol (DON), also called vomitoxin, is a toxin associated with Fusarium head blight. METRA reports using air separation to remove affected grain and lower DON concentration in retained grain. Where a more contaminated fraction is successfully removed, this can reduce the concentration in the remaining lot. Confirm the actual change with representative before-and-after DON tests reported in the same units, and record how much grain was retained. DON concentration requires testing; it cannot be determined from kernel appearance.

Compare the whole trial, not just the cleanest outlet

Before processing, agree on the sampling procedure and the acceptance criteria. Keep an untreated reference sample. Record the starting mass and the machine settings, then weigh and label every collected fraction. Note any material that was not collected; the trial record should make clear whether all of the input has been accounted for.

Have the retained grain assessed against the same criteria used for the original sample. Inspect the rejected fractions too: losing saleable wheat may change the decision even when the retained sample looks better. Repeat the comparison if a setting is changed; do not compare a new output against an unrelated starting sample.

A useful trial record answers four questions: what was removed, how much grain remained, whether the retained fraction met the buyer's requirements, and what the processing and handling would cost. Use the assessed grade and buyer's actual offer in that comparison.

Make the next step specific

If the trial addresses a measured problem, discuss the complete setup and handling requirements for that lot. If sprouting, moisture or another quality issue still prevents acceptance, the retained grain needs further assessment before a sale or storage decision.

Contact METRA with the crop, location, lot condition, identified foreign material and buyer requirements to discuss whether a sample cleaning trial is appropriate.