By Andy Knepp
Northern Illinois Technical Agronomist
Farmers in many areas throughout the Corn Belt have experienced an abnormally dry spring and start to summer, which has set the stage for a very challenging growing season.
When we look at corn root development in 2012, it has been impeded by excessively hot and dry soils. Here in northern Illinois, many farmers in my area have seen rootless corn syndrome, also known as “floppy corn syndrome,” which is caused by limited or lack of nodal root development. Contrary to the old adage that corn “roots down in dry weather,” corn plants in many fields have failed to establish a normal root system.
The subsequent lack of root mass can contribute to additional agronomic challenges as the season progresses. Nodal roots are important since they provide the water and nutrients that a corn plant needs for growth and development, as well as anchor the plant in the soil. Due to the lack of root mass, these plants are more susceptible to lodging throughout the growing season and may even wilt or eventually die in extreme conditions. Because of their already limited root mass, these plants may be also more susceptible to damage from feeding by corn rootworm larvae.
The combination of a mild winter, early spring planting, and hot, dry conditions has created the potential for heavy insect pressure in corn fields this season. Scouting is an integral part of insect management, and I recommend farmers keep a close eye on their fields by employing regular, appropriate scouting techniques and treatment decisions, especially during periods of heavy or sustained pest presence.
Corn rootworm is often a challenging pest seen in northern Illinois, particularly in fields of continuous corn. While it’s still too early to determine how high corn rootworm pressure may be this season, farmers should start digging and evaluating roots for damage now. They also need to keep an eye out for beetle emergence. We normally recommend field scouting for adult corn rootworm beetles during July and August when peak corn rootworm beetle activity occurs, but that peak will occur earlier than normal in 2012. There are already reports of adult emergence in areas of central Illinois. If adult corn rootworm beetle populations are significant, secondary control tactics may be required such as a well-timed foliar application for adult corn rootworm control.
I encourage farmers to consult their Monsanto agronomist, local crop advisor or extension specialist for the most up-to-date pest control information and agronomic recommendations. Farmers can also access insect information online and sign up for automatic alerts at http://www.insectforecast.com/ .