Three or four soybeans on the ground don't sound like much, but those beans can add up to big harvesting losses, says University of Missouri extension agronomist Bill Wiebold.
"Every three or four seeds per square foot left in the field translates into 1 bu/acre of lost yield," says Wiebold. "A few missed beans quickly add up. Producers should remember that limiting harvesting loss is an easy way to improve profitability."
Beans that never get into the combine, a common cause of loss, may be a bigger problem than usual this year. With thin stands, soybean plants may have more branching and lodging, he adds.
"Heavily branched or tumbleweed-shaped plants may detach and become difficult to combine," Wiebold says.
Combine cutter bars set too high will leave seed pods on the lower stem. "Leaving just one pod on each plant means a yield loss of more than 2 bu/acre. Combine operators often raise cutter bar height to increase speed of operation. It pays to slow down if it means gathering an extra 2-4 bu/acre."
Modern varieties are selected to reduce shattering, but it still occurs. Wet and dry cycles increase shattering because seeds swell and shrink inside the pods, fracturing pod walls.
Timely harvest also lessens shattering. Pod walls become more fragile as drying continues. Over-dry pods split when hit by the combine reel or from cutter bar vibrations.
"It's important to look for the problem," Wiebold says. "Four seeds per
square foot are hardly noticeable. But they mean lost profitability."
