Date of this Version
Insect Science, Plant Disease, & Weed Science, University of Nebraska Cooperative Extension, Institute of Agriculture and Natural Resources 89(17) (September 26, 1989)
In This Issue:
- Husk Thistle Control
- Field Bindweed and Other Perennials
- Fall Weed Control in Alfalfa--Don't wait Too Long
- Fall Lawn Weed Control
Musk Thistle Control
October and early November are excellent times to control musk thistle providing the weather cooperates. A good fall control program normally eliminates the need for spring control. This is because plants that would flower next summer are normally growing in the fall. However, the success of a fall control program depends on adequate fall rainfall. Dry weather reduces musk thistle seed germination and plant establishment. Where the weather has been dry, there may be no plants to control. Examine the site and determine if the thistle population justifies spraying. Herbicides and per acre rates to use on musk thistle are Tordon ·22K at 6 to 8 fluid ounces, 2,4-D + Banvel at 1.0 lb + 0.5 pt, and 2,4-0 at 1.5 to 2.0 lb. These treatments are ranked in order of effectiveness for fall application. When mild, moist conditions prevail, all three treatments are effective. Under very dry, cool conditions only Tordon can be expected to perform well. Treatments should be applied after October 1.
Field Bindweed and Other Perennials
Perennial weeds including field bindweed, Canada thistle, and others can be effectively treated with herbicides in the fall. Food storage in the root system of these plants is taking place in the fall. Herbicides applied at this time to plants with excellent top growth readily move down to the roots along with the food. In the fall, temperatures and soil moisture are generally more favorable for plant growth than during the summer, a condition required for best herbicide performance.
Fall Weed Control in Alfalfa--Don't wait Too Long
Fall is an excellent time to control weeds in established alfalfa. Fields that were weedy this year will almost certainly be weedy again next year unless preventative measures are taken. Many times the problem is not recognized until the alfalfa "greens up" in the spring--then it is too late for most herbicides. This year get a "jump" on the problem.