INSECT, PLANT DISEASE, & WEED SCIENCE NEWS [No. 88-3] [April 8, 1988]

In This Issue: Lawn Weed Control No-Till Weed Control No-Till Into Alfalfa Sod Lawn Weed Control Post-emergence control of dandelions, shepherdspurse, chickweed, and henbit should have been done by now or should be done soon. Granular forms of 2,4-D, Trimec, and similar herbicides are safest to use under most conditions. However, Trimec and other formulations containing dicamba (Banvel) should be used sparingly next to and under trees and shrubs. Turflon from Dow is also labeled for control of many broadleaf weeds. Liquid herbicide formulations should be applied when there is little or no wind movement and with low spray pressure. No-Till Weed Control Weed control is a key to success with no-till crop production. Control of weeds established at planting time as well as later developing weeds is required. New developments make economical, effective weed control programs available for most situations. One approach is to combine a post-emergence and a residual herbicide applied at planting time. Another is to make an early preplant application of residual herbicides and eliminate the post-emergence herbicide. No-Till Into Alfalfa Sod Killing alfalfa with herbicides is more economical than plowing, is very effective, and leaves the soil less subject to erosion. An excellent seedbed results from herbicide-killed sod whether the crop is planted no-till or following light tillage. The most consistent treatment we have evaluated for alfalfa control is 1 qt. 2,4-D + 0.5 pt. Banvel/A with 2 qt. 2,4-D ester/A a close second. The herbicide approach will cost $5.00-$6.00/A + application compared to $10.00- $15.00 for plowing and seedbed preparation. Alfalfa should be actively growing and have at least 4 of green growth at treatment