Probably the biggest reason is because of new diseases and pests that keep cropping up in soybeans.

In the last 10 to 15 years we've seen SDS, White Mold, Aphids, and Cyst Nematode affecting soybean yields. These are all recent diseases that did not influence bean yields in the 60's and 70's - or if they did, they were confined to small areas of the country. The

Contrast this with corn, where we have had no new diseases or insects pressuring yields - although you could count 1st year corn rootworm but with the advent of rootworm corn, this pest is easily managed.

Until we see some big advances in bean technology, beans will continue to lag corn.