Weekly Crop Update

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

 Acetochlor is a preemergence herbicide for corn that controls annual grasses and some broadleaf weeds. It is in the following products: Harness, Harness Extra, Degree, Degree Extra, Topnotch, Fultime, Keystone, Surpass, TopNotch, and SureStart. These products have had the rotational restrictions modified, allowing more crops to be planted the following spring (previously only soybeans and sorghum). The label now allows for rotation to: alfalfa, clover, barley, potatoes, oats, tobacco, others.

However, the groundwater restrictions have not changed. The restrictions pertain to groundwater quality. The restrictions are based on depth of groundwater within one month of planting and the combination of soil type and organic matter. Do not apply acetochlor if the groundwater depth is within 30 feet and you have sands with less than 3% organic matter, loamy sands with less than 2% organic matter, or sandy loam with less than 1% organic matter.