A Publication of WTVP

The 2004 growing season continues to look good, as the rains have fallen and temperatures, for the most part, have been in the 80s through mid-July. Cool nights and warm days with plenty of moisture are ideal corn growing conditions. In 2003, looks weren't deceiving with the corn crop, as it performed as expected with excellent yields. On the other hand, last year's soybean crop also appeared excellent this time of year, but when all was said and done at harvest time, it was very disappointing for soybean growers in the Peoria area. A dry August, combined with an eruption of soybean aphids, caused the yield reduction.

Corn pollination has occurred, and the weather was excellent during the first two weeks of July. With pollination history, we're heading into the home stretch for the 2004 growing season. Will looks be deceiving this year?

There's a potential problem looming under the soil surface in some cornfields. The culprit is Western Corn Rootworm. Needless to say, it isn't a farmer's best friend.

As the name implies, the corn rootworm has a large appetite for corn roots. They've been actively feeding and, in some areas of the Peoria region, have done extensive damage. How big of a problem could this be? With clipped roots, the corn plant becomes much more susceptible to dry weather. Loss of roots also makes the corn plant vulnerable to wind damage. There's already been some corn "goosenecked" with a couple of storms that came through in early July. As the ear develops kernels, more weight is added to the mid section of the plant, which, in turn, causes more pressure on the stalk and rooting system.

What are some avenues farmers can use to combat the corn rootworm problem? Crop rotation has been the best defense against the insect. A common practice by farmers is to plant a field in corn followed by soybeans the following year. Corn rootworms must feed on corn roots to develop and mature properly. If they hatch in a field rotated out of corn, they'll starve to death because they can't move more than 10 to 20 inches in search of food.

During the last few years, it looks like the corn rootworm has developed a plan of its own to maneuver around the crop rotation practice. A new variant of the Western Corn Rootworm has been discovered that actually favors soybeans over corn for laying its eggs. Because the new variant thrives in soybean fields, it increases the risk of economic injury to corn planted in a field that grew soybeans the year before.

Another tactic the corn rootworm has developed is an extended diapause. Diapause is a resting period during which the insect doesn't develop. Extended diapause is associated with corn rootworms, where eggs remain in the soil for two winters rather than hatching in the spring following the first winter. With a crop rotation of corn and soybeans, the eggs hatch and are ready to feed on the corn crop two years later.

So what's a farmer to do? A new technology called YieldGard Rootworm-protected corn was developed and registered by the U.S. Environmental Protection Agency. YieldGard Rootworm corn contains a protein from Bacillus thuringiensis (Bt), a common soil microorganisim that specifically targets corn rootworm larvae, allowing the corn plant to naturally protect its roots against the larvae.

Time will tell what the rest of the 2004 growing season has in store for farmers, but if the winds are calm and the corn is still standing at harvest, it's probably going to be another good year-at least for corn. IBI