Weed Control

NOTE:  For the herbicides listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, days to harvest (dh), REI, and special instructions. In many cases there are other products available with the same active ingredient. Please see Table 17 and Alphabetical Listing by Trade Name for more information on products with the same active ingredients. 

Stale Seedbed

glyphosate (Roundup 4S): 1 to 5 qt/A (REI 12h, Group 9). See Stale Seedbed Technique.

Preplant Incorporated

cycloate (Ro-Neet 6E): 3 to 4 pt/A (REI 12h, Group 8). Preplant incorporated. Use lower rate during hot weather and/or dry soil conditions. To reduce the risk of crop injury, apply and incorporate 7 to 10 days before planting, then rework soil at planting. Use on sandy mineral soils only.

Postemergence

pelargonic acid (Scythe 4.2): 3% to 10% (REI 24h, Group 27). Use a 3-5% solution for annual weeds (4-6 oz/gal water), a 5-7% solution for biennial and perennial weeds (6-9 oz/gal water), and 7-10% solution for maximum burndown (9-13 oz/gal water). Delivery rate for boom applications should be 75 to 200 gal spray solution/A; complete coverage of weed foliage is essential. Use a DIRECTED/SHIELDED SPRAY; contact with crop will cause injury. For hand-held equipment, spray to completely wet all weed foliage but not to the point of runoff. Repeat applications as necessary. Tank mixes are allowed with this product. These include tank mixes with glyphosate (Roundup), sulfosate (Touchdown), and residual herbicides. See label for complete details.

phenmedipham (Spin-aid 1.3 EC): 3 to 6 pt/A (40 dh, REI 24h, Group 5). Do not use when expected high temperatures will be above 75°F. For best results, spray when weeds are in the 2-leaf stage. Use the 6-pint rate only on well-established crops that are not under stress. Spinach plants must have at least six true leaves. For processing spinach only.

clopyralid (Stinger 3S): 2.5 to 5 oz/A (21 dh, REI 12h, Group 4). Apply once or twice to control certain perennial and annual broadleaf weeds when the crop has between 2 and 5 leaves. Do not exceed 8 oz/acre/crop. Stinger controls weeds in the composite and legume families. Common annuals include galinsoga, ragweed, pineappleweed, clover, and vetch. Perennial weeds controlled include Canada thistle, goldenrod species, aster species, and mugwort (wild chrysanthemum). Stinger is very effective on small seedling annual and emerging perennial weeds less than 2” to 4” tall, but is less effective and takes longer to work when weeds are larger. Use 2 to 4 ounces/A to control annual weeds less than 2” tall. Use 4 to 8 ounces/A to control larger annual weeds. Apply 8 ounces/A to suppress or control perennial weeds. Spray additives are not needed or required by the label and are not recommended. Stinger is a postemergence herbicide with some soil residual activity. Observe replant restrictions on the label or injury may occur from herbicide carryover.

sethoxydim (Poast 1.5L): 1 to 2 pt/A (15 dh, REI 12h, Group 1) postemergence. Apply with crop oil concentrate at 2 pt/A. Apply to actively growing weed grasses (see product label for susceptible stage of growth). Do not cultivate for five days prior or seven days after Poast application. Do not apply Poast when air temperature exceeds 90°F and when the relative humidity exceeds 60%.