ethofumesate (Nortron SC, Ethotron)
Carrots only, in Oregon and Washington only
Rate Coarse soils: 1.5 lb ai/a (48 fl oz/a). Medium-texture and fine soils: 2 lb ai/a (64 fl oz/a)
Time Apply after planting and activate with at least 0.5 inch water. If sufficient water will not be available to incorporate the herbicide, incorporate it mechanically before or at planting.
Remarks Do not use smaller than 50 mesh screen and avoid overlaps, which may increase risk of crop injury.
Caution May cause temporary leaf fusion, distortion, and stunting when used as label directs and under normal growing conditions. If crop is lost due to unfavorable growth conditions after application, do not plant anything except sugar beets, table beets, carrots, onions, garlic, shallots, or ryegrass.
Site of action Group 16: unknown
Chemical family Benzofuran
linuron (Lorox DF, for carrot, celery, celeriac, parsnip; or Linex 4L, for parsnip only)
Rate Carrots: 0.5 to 1 lb ai/a (1 to 2 lb/a Lorox); celery and parsnips: 0.75 to 1.5 lb ai/a (1.5 to 3 lb/a Lorox)
Time Preemerge and postemerge to carrots; Preemergence to parsnips; Post-transplant to celery and celeriac.
Remarks Use lower rates on light soils, but do not use on extremely sandy soils or soils with less than 1% organic matter. Plant seed at least 0.5 inch deep and apply preemergence only once per season. Carrots and celery may be followed by postemergence applications, but do not exceed 3 lb/a per season. REI is 8 days on handset irrigation and 24 hr for all other activities. Caution Consult label for planting sensitive crops within 4 months.
Site of action Group 7: photosystem II inhibitor
Chemical family Substituted urea
pendimethalin (Prowl H2O, Hydrocap. Stealth)
Rate 0.95 lb ai/a (2 pints/a)
Time Postplant, before crop and weeds emerge (within 2 days of planting), and at layby.
Remarks May be applied by air, ground, or chemigation postplant, but only by ground equipment at layby. Do not apply over the tops of carrots, because crop may be injured.
Caution Note the crop-injury disclaimer on this label. BASF recommends testing this herbicide on a small part of the target crop to determine whether damage is likely. Do not exceed 2 pints/a per season. Preharvest interval is 60 days.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
prometryn (Caparol 4L)
Carrots, celery, and celeriac
Rate 1 to 2 lb ai/a (2 to 4 pints/a Caparol per application)
Time Apply after planting through 6-leaf stage of carrot; for celery, after planting or after 2-3 leaf stage; for celeriac, apply after transplanting at 6-8 leaf stage.
Remarks Do not exceed 8 pints/a of Caparol 4L per crop cycle. Use in at least 20 gal/a spray volume. Use adjuvants only with layby applications. PHI is 30 days for carrot, 40 days for celery, and 60 days for celeriac. Within the rate ranges given, use the lower rate on relatively coarse-textured soils and soils low in organic matter; use the higher rate on relatively fine-textured soils and soils high in organic matter. Apply before weeds are 2 inches tall.
Caution Consult label for rotational restrictions, which typically exceed 5 months after application for sensitive crops.
Site of action Group 5: photosystem II inhibitor
Chemical family Triazine
S-metolachlor (Dual Magnum)
Carrots and parsnips only; Oregon only
Rate 0.64 lb ai/a (0.67 pints/a)
Time Make a single broadcast application of Dual Magnum to soil surface after planting but before weeds or crop emerge. For effective weed control, soil must be clean-tilled.
Remarks Special local needs indemnified label (OR-060012). This label is available only through the Syngenta Farm Assist website (http://www.farmassist.com).
Make uniform applications in at least 15 gal/a of water. A band application also may be used. Irrigate after application to activate the herbicide if rain is not expected. If the crop is irrigated, use 0.5 inch of water shortly after planting to incorporate the herbicide. Excessive irrigation before the crop emerges may increase the risk of crop injury.
Caution Do not mechanically incorporate Dual Magnum. Do not use Dual Magnum if the planting operation creates a furrow or trough over the seed row into which rain or irrigation water will collect, and thus concentrate the herbicide over the row. Do not use on coarse soils with less than 1.5% organic matter or on any soil with greater than 10% organic matter. Do not exceed a total of 0.67 pint/a of Dual Magnum in any single application nor in total applications per crop.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide