The most discussed item last week was the delay in corn planting and expectations about planting progress over the next two weeks. For much of the Corn Belt, optimal corn planting dates are believed to be in late April into very early May. Research reveals that corn yields tend to decline as planting moves beyond the optimum window. The declines also tend to accelerate as planting gets later and later, he says.

"The declines in yield, however, are relative to potential yield. Yield can still be relatively high with late-planted corn if the growing season weather is very favorable, but late-planted corn would still be expected to have yields below that of corn planted in a timely fashion," he says.

Some corn is planted late every year. For 2011, the questions center on what portion of the crop will be planted late and the degree of lateness, he adds.

"It now appears that areas in the western Corn Belt will make substantial planting progress in early May. The focus will be on the wet areas in the southern and eastern Corn Belt and the cool areas of the northern belt," Good says.

Most of the intended corn crop will likely get planted, so the most important factor will become summer weather, he notes.

"In 2009, extremely favorable summer weather extended the growing season and more than compensated for planting delays. An examination of weather records, however, reveals that the uniformly favorable conditions of 2009 have been rare," he says.

Uncertainty about consumption and production prospects, along with volatile currency and energy prices, suggest a continued wide trading range for both corn and soybeans, Good says.