Agricultural Information About Corn Herbicides

Proper and timely use of herbicides will increase your annual corn yield.

Corn herbicides are chemicals used to eliminate weed growth in fields to aid in increasing crop yields. The effectiveness of these herbicides depends on a number of factors including timeliness, method of application and effectiveness of the herbicide.

Timing

Delaying herbicide application can result in dramatically reduced crop yields. Depending on the herbicide, they are to be applied at certain stages of the plant growth. For example, some herbicides need to be applied while the plant is between 0 and 20 inches high. If the plant growth has already exceeded these measurements, an alternate herbicide for larger corn plants may need to be substituted.

Effectiveness

Different herbicides have varied effects on weeds. Some are effective on barnyard grasses, crab grass, and quack grass but little effect on Johnson grass. It is essential to be familiar with the common types of grasses and weeds in your area and choose your herbicides accordingly.

New Options

New corn herbicide options are being premiered for more effective weed control. Some can be applied to corn plants until they are 12 inches tall. Others can be applied until plants are 30 inches tall and work best in combination with other herbicides.

References

• UW Extension: Corn Post-Emergence Control Timing Important for 3 Reasons
• Agronomy Guide 2011/2012: Relative Effectiveness of Corn Herbicides on Grasses, Grasslike Species and Broadleaf Weeds
• Factors Shaping Trends in Corn Herbicide Use
• C.O.R.N. Newsletter: New Herbicides for 2011