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.

Seeds, Sets, or Transplants Preemergence

bensulide (Prefar 4E): 5 to 6 qt/A (REI 12h, Group 8). Incorporate by shallow cultivation or irrigation. Grass control only; should be supplemented with cultivation or another registered herbicide for broadleaf control. Do not plant non-labeled crops to treated land for 120 days.

pendimethalin (Prowl 3.3EC): 1.2 to 3.6 pt/A (45 dh, REI 12h, Group 3). DRY BULB ONIONS ONLY. Apply overtop when onions have two to nine true leaves but prior to weed emergence.

Seeds or Transplants Postemergence

clethodim (Select 2EC):  6 to 8 oz/A (20 dh, REI 24h, Group 1).  Apply to actively growing grasses.  See label for grass height and herbicide rate.  Always use a crop oil concentrate at a rate of 1 gal/100 gal spray mix.  See both container label and any supplemental label available from dealer.

fluazifop (Fusilade DX): 6 to 16 fl oz/A (45 dh, REI 12h, Group 1). For grass weed control only. Apply to actively growing grass weeds (see product label for susceptible stage). Add 1 gal crop oil concentrate or 1 qt nonionic surfactant per 100 gal of spray. Dry bulb onions only.

oxyfluorfen (Goal 2 XL): For postemergence control at 2 to 4 oz/A (REI 24h, Group 14) when applied postemergence to seeded onions that have at least three true leaves. For transplanted onions apply the same rates within two days after transplanting. Multiple treatments at the aforementioned rates may be applied. Do not use a surfactant. Do not tank mix. Two to three days of sunny weather should precede treatment to reduce the likelihood of crop injury. Dry bulb onions only.

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.

sethoxydim (Poast 1.53EC): 1.5 pt/A (30 dh, REI 12h, Group 1). Apply with crop oil concentrate at 2 pt/A. Apply to actively growing weed grasses (see product label for susceptible stage of growth).