Pull the whorls from 10 plants at 5 locations across the field. Select whorls at random, avoiding damaged plants. Treatments applied after most borers have begun tunneling into plants will be ineffective. The products Ambush 2E or 25W, Asana XL, Dipel ES, Sevin, Lorsban 4E, Penncap-M, Pounce 3.2E or 25W, and Warrior are labelled for center pivot application. You must be sure your system is properly equipped and calibrated before attempting this procedure.
Equipment designed to prevent back siphoning into the well is absolutely essential.
Use the following worksheet to help make decisions about the profitability of treating an individual field. Worksheet for corn borer in whorl stage corn . . . Borers per plant 2. In the past, this practice has been called fertigation for adding fertilizer, herbigation when herbicides were added, fungigation for fungicides, etc. Now it is just called chemigation.