Corn Herbicides and Soil Insecticide Interactions

by Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

A number of corn herbicides have label precautions about use of an organo-phosphate insecticide at planting due to potential crop injury. This includes the insecticides Counter (terbufos), Lorsban (chlorpyrifos), and Fortress (chlorethoxyfos). The herbicides include both soil-applied and postemergence herbicides. Some of the common products include Callisto (Halex GT); Resolve (Steadfast, Basis); Accent; or Capreno. Many of the Group 2 (or ALS-inhibiting herbicides) have these precautions. The list of herbicides can be found at http://extension.udel.edu/ag/files/2012/08/CornWeedguide.pdf and go to Table 19.

Unfortunately, most corn seed companies no longer designate hybrids as either IT or IR. So if you are not sure, take the cautious approach and assume the hybrid is a “standard” hybrid (no enhanced tolerance for imidazolinone herbicides); and follow the most restrictive guidelines.
Source: Read More from Weekly Crop Update

About Mark VanGessel

Dr. Mark VanGessel is an Extension Specialist and Professor in Weed/Crop Management at the University of Delaware.

This is an archived post. For up-to-date recommendations visit the Weekly Crop Update @ http://extension.udel.edu/weeklycropupdate/

Remember: The label is a legally-­binding contract between the user and the manufacturer. The user must follow all rates and restrictions as per label directions. The use of any pesticide inconsistent with the label directions is a violation of Federal law.