Some things about this year are set. The threat of damage from too much water in the Eastern Corn Belt is no longer a threat – it is reality.
USDA Crop Progress 7/20: Corn, soy conditions unchanged
Whether or not it's enough threat to sustain somewhat higher market prices than once expected or the marketing year remains to be seen. If the year plays out like 1993, there may be some reason for optimism in prices, but not necessarily in yields.
That year the Western Corn Belt was hammered with too much water and flooding all year long, says Chris Hurt, Purdue University Extension ag economist. This year the hard-hit half is the Eastern Corn Belt.
The question is whether the full impact on yield is being reflected in crop reports in the states which have been too wet. In 1993, the full effects weren't felt until later.
"One factor is that we could run out of nitrogen in many fields which still look good now," Hurt says. "If so that will drop yields."
However, Bob Nielsen and Jim Camberato, Purdue Extension agronomists, aren't convinced nitrogen will be the yield-limiting factor in many cases. Yet that still doesn't mean yield potential won't deteriorate.
Here's why. More than nitrogen loss and threat of the crop running out of N is at play. There are at least two other major players – weeds and diseases.
Bill Johnson, Purdue weed control expert, has already stated he believes that in Indiana, at least, soybean yields will be hurt because of the inability to control weeds effectively early in the season. It was too wet to spray in a timely fashion. That trend has even been observed all the way into eastern Iowa.
Plant diseases revved up early. Even in otherwise "good fields," by tasseling and early pollination lesions were found as high as the ear leaf. Unless weather conditions turn around, diseases could limit yields. Other disease could factor into soybean yields too. The bottom line is a combination of factors, not just one, could drop yield potential even in fields now rated good to excellent before the season is over.