Agronomy and Horticulture Department


Date of this Version



Insect Science, Plant Disease, & Weed Science, University of Nebraska Cooperative Extension, Institute of Agriculture and Natural Resources 89(01) (March 7, 1989)


Copyright 1989 University of Nebraska


In This Issue:

  • Herbicide Carryover Concerns for 1989
  • Alfalfa Weed Control
  • Miracle Products Via Telephone

Herbicide Carryover Concerns for 1989

The dry conditions experienced during the 1988 growing season have raised concerns about herbicide carryover and recropping practices for this spring. Herbicide residues can be lost through several processes, many of which are dependent on environmental conditions. Dry weather results in less chemical and microbial breakdown as well as reduced plant uptake. Growers need to be aware of potential carryover problems when planning next year's crop rotation.

Alfalfa Weed Control

Warm weather will spur the development of winter annual weeds in alfalfa. Downy brome, pennycress and other mustards can be effectively controlled with herbicide treatments at this time of year. Many times the weed problem isn’t recognized until· the alfalfa "greens up" in the spring--then it t s too late for most herbicides. A word to the wise: "Scout alfalfa fields now and plan control programs accordingly."

Miracle Products via Telephone

“Miracle herbicides" are again being sold by long distance telephone. In one case we know of, the salesperson claims the product can be used in soybeans and corn postemergence to control most annual weed problems and only costs about $69.00 per gallon. The material is actually diquat and contains 1.85% herbicide on a weight basis. There are two problems as we see it: 1) Diquat is not labeled on corn and can only be used in soybeans as a harvest aid and 2) Ortho's formulation of diquat contains 35.3% herbicide and costs about the same.