-Mark VanGessel, University of Delaware Extension Weed Specialist
Weekly Crop Update
Some corn fields need to be sprayed for weeds,
but the corn is only 3 to 4 collars. In many ways
this is good because the corn leaves will not
interfere with herbicide spray pattern and will
allow for maximum control. However, that
means it may be two to three weeks until the
corn canopies over. So relying on glyphosate or
Liberty for postemergence weed control, could
run into situations of weeds emerging between
the postemergence sprays and the time corn
canopies over. You should consider a residual
herbicide in this scenario. Be sure to read
individual labels for information on maximum
corn size and recommended adjuvants. The
following table of products will help with your
selection: