What to Spray for Corn Borers

Corn Borer Herbicides

• About 10 herbicides provide good European corn borer control, according to the University of Tennessee Extension Service. These include Baythroid, Capture, Furadan, Asana, Mustang Max, Pounce, Sevin XLR, Tracer, Warrior and Intrepid. The chemicals are all applied at varying rates depending on the age of the corn and the age and level of borer infestation.

Aerial Application

• Once you choose the chemical and determine the application rate, you can determine the. The amount of chemical is mixed with the water application rate per acre of the aerial applicator. In most cases, this is 4 gallons of water. Aerial application is commonly done in the early morning or other times when the winds are calm. Spray the corn if eggs or larvae are noted on half the plants but before the larvae begins boring into the plants.

Ground Application

• Ground application equipment commonly uses larger volumes of water than spray planes. Adjust and calibrate the rate of application of the spray equipment and mix the chemicals with water to create a mix that applies the proper chemical dose of the chosen chemical. The process is the same as for the aerial applicator although the common spray rate is about 20 gallons per acre.

Scouting

• Check for European corn borers in June and July, depending on local climate and growing seasons. Borers noted at this time are the first generation of the insect for the year. Effective control of the first generation reduces the later generations in August or September. The corn plants are smaller and provide less cover for the insects giving a better control as well. Spray the crop if small holes that look like the plant was blasted with pellets from a shotgun are apparent in 25 percent of the plants. Spray the corn again in the late summer if the insects are found on a quarter of the plants in August.