Grain market lows this year could land in November or December if the crop finishes big — or arrive much earlier if yields disappoint, according to Don Roose, president of U.S. Commodities.

Roose told Brownfield's Managing for Profit segment that harvest results, not summer weather headlines or weekly export headlines, will decide when corn and soybean prices bottom. "Harvest results will determine how this plays out," he said.

His framework rests on a seasonal pattern commodity traders have watched for decades. In a typical large-crop year, selling pressure peaks as combines roll and bins fill, pushing cash prices and futures to their harvest low between November and December. Demand then ramps up after the new year, and basis tightens as commercial users return to the market.

When yields fall short of expectations, that timeline compresses. A smaller crop means less grain to move at harvest, so the glut-driven price trough arrives earlier — and the market starts pricing rationing demand rather than storage pressure.

Why does the timing of the low matter for growers?

For producers weighing storage decisions, the answer carries direct margin consequences. If Roose's big-crop scenario holds, holding grain past the November–December window historically gives sellers better prices and stronger basis into winter and spring. The cost side — interest on operating loans, on-farm and commercial storage fees, and shrink — eats into that carry reward.

If yields disappoint instead, the low could already be near by early fall. Growers who wait for a traditional year-end bottom in that scenario risk missing the best pricing window entirely.

What should producers watch?

The deciding data will come out of the combine, not the forecast model:

• Actual harvested yields against the USDA's projected figures
• Pace of farmer selling as harvest progresses
• Basis movement at local elevators and processors
• Export demand stepping in once prices find their low

Roose's read separates condition reports and crop ratings — which describe standing crops — from harvested results, which establish the actual supply the market has to price. That distinction drives his caution: the market cannot set its low until it knows the size of the crop it is pricing.

U.S. Commodities, based in West Des Moines, Iowa, is a commodity marketing and brokerage advisory firm. Roose is a regular market commentator on grain price outlooks for Midwest row-crop producers.

The practical takeaway for the farm office: harvest progress and yield reports over the coming weeks will signal which scenario is unfolding. A steady flow of big yields points to patience and storage into year-end; yield misses argue for pricing grain sooner rather than waiting for a seasonal low that may not arrive on schedule.

Roose says the market will keep taking its cues from the combine as harvest advances.