Weeds Pages
| Common name | Amount per acre | REI‡ | PHI‡ | |
|---|---|---|---|---|
| (Example trade name) | (hours) | (days) | ||
| Not all registered pesticides are listed. The following are listed alphabetically. When choosing a pesticide, consider information relating to environmental impact, resistance management, the pesticide's properties, and application timing. Tank mixes may be necessary to achieve desired control; see Susceptibility of Weeds to Herbicide Control for information on specific weed control. Always read the label of the product being used | ||||
| PREPLANT | ||||
| A. | GLYPHOSATE | 1.1–3.7 lb a.e. | ||
| (Roundup PowerMax) | 1–3.3 qt | 4 | NA | |
| WSSA MODE-OF-ACTION GROUP NUMBER1: 9 | ||||
| COMMENTS: A nonselective, foliar herbicide applied to premade beds before planting to kill emerged weeds. Allow 3 days after treatment before planting. Use the lower rate for annual grasses and weeds, the higher rate on perennial weeds. Consult the label for specific recommendations on particular weed species. Do not apply to weeds stressed for moisture. For perennial weeds, allow 7 days after application before cultivating. | ||||
| B. | METAM SODIUM 42% product | |||
| (Vapam HL)* | 37.5–75 gal | See label | NA | |
| COMMENTS: Soil should be free of large clods and irrigated about 2 weeks before application of the metam sodium. For flood applications, meter metam into water continuously throughout the entire irrigation. Sprinkler applications are much quicker; after running the sprinklers 5 to 10 minutes to moisten the soil surface and to be sure the system is working properly, inject the total amount of metam into the pump in about 20 minutes, then shut off the system. In any chemigation system, it is very important to have controls in place to prevent water flowing backward into the uncontaminated water source. Fumigants such as metam sodium are a source of volatile organic compounds (VOCs) but are minimally reactive with other air contaminants that form ozone. Fumigate only as a last resort when other management strategies have not been successful or are not available. | ||||
| POSTPLANT | ||||
| PREEMERGENCE (Before crop and weeds emerge) | ||||
| A. | BENSULIDE | 5–6 lb a.i. | ||
| (Prefar 4-E) | 5–6 qt | 12 | 0 | |
| WSSA MODE-OF-ACTION GROUP NUMBER1: 8 | ||||
| COMMENTS: A preplant incorporated herbicide that controls annual grasses and certain broadleaf weeds such as purslane and pigweed. Bensulide is not effective on wild oats or volunteer cereals. Apply in 10 to 50 gal water/acre and incorporate to a depth of 1 to 3 inches. This herbicide has a long residual (6 months or more in some soils) and 120-day plantback restriction for nonlabeled crops. | ||||
| B. | LINURON | Cilantro: 0.5–1 lb a.i. Parsley: 0.5–1.5 lb a.i. |
||
| (Lorox DF) | Cilantro: 1–2 lb Parsley: 1–3 lb |
See label | Cilantro: 21 Parsley: 30 |
|
| WSSA MODE-OF-ACTION GROUP NUMBER1: 7 | ||||
| COMMENTS: Apply after planting, incorporate with sprinklers. Will control many broadleaf weeds and annual grasses. A postemergence treatment is also allowed, but must not exceed a total of 3 lb linuron/acre per year. | ||||
| C. | PROMETRYN | Cilantro: 1–1.6 lb a.i. Parsley: 0.5–2 lb a.i. |
||
| (Caparol 4L) | Cilantro: 2–3.2 pt
Parsley: 1–4 pt |
12 | 30 | |
| WSSA MODE-OF-ACTION GROUP NUMBER1: 5 | ||||
| COMMENTS: Apply after planting, incorporate with sprinklers. Will control many broadleaf weeds and annual grasses. Note for parsley in California: if a rate higher than 1.0 pt/acre is applied, then only one application is allowed. A postemergence treatment is allowed for parsley only, but must not exceed 1pt per application. If preemergence treatment on parsley did not exceed 1.0 pt/acre, then up to two post emergence treatments of 1.0 pt/acre are allowed. No postemergence treatments are allowed on cilantro. | ||||
| POSTEMERGENCE (After crop and weeds emerge) | ||||
| A. | CLETHODIM | |||
| (Select Max) | Label rate | 24 | 14 | |
| WSSA MODE-OF-ACTION GROUP NUMBER1: 1 | ||||
| COMMENTS: A systemic herbicide with no soil residual. Controls annual bluegrass in the 2- to 3-leaf stage as well as other annual and some perennial grasses. Do not apply through any type of irrigation system. Always apply with a crop oil concentrate (oil adjuvant). Use higher rate on perennial grasses. | ||||
| B. | LINURON | Cilantro: 0.5 lb a.i. Parsley: 0.5–1.5 lb a.i. |
||
| (Lorox DF) | Cilantro: 1–2 lb Parsley: 1lb |
See label | Cilantro: 21 Parsley: 30 |
|
| WSSA MODE-OF-ACTION GROUP NUMBER1: 7 | ||||
| COMMENTS: May be applied twice, first when the crop is 3 inches tall. Good control of emerged broadleaf weeds, small grasses, and suppression of yellow nutsedge. Total per season must not exceed 3 lb/acre (or 1.5 lb a.i./acre). | ||||
| C. | PROMETRYN | Parsley: 0.5–2 lb a.i. |
||
| (Caparol 4L) | Parsley: 1–4 pt | 12 | 30 | |
| WSSA MODE-OF-ACTION GROUP NUMBER1: 5 | ||||
| COMMENTS: A postemergence treatment is allowed for parsley only, not for cilantro. Up to two postemergence treatments of 1.0 pt/acre each are only allowed if preemergence treatment did not exceed 1 pt/acre. Incorporate with sprinklers. Will control many broadleaf weeds and annual grasses. | ||||
| D. | SETHOXYDIM | 0.09–0.46 lb a.i. | ||
| (Poast) | 0.5–2.5 pt | 12 | 15 | |
| WSSA MODE-OF-ACTION GROUP NUMBER1: 1 | ||||
| COMMENTS: A selective foliar herbicide for control of grasses. A surfactant (crop oil concentrate or nonionic surfactant) is recommended. Safe to the crop. Not effective on drought-stressed grasses or certain species (e.g., annual bluegrass, sprangletop). | ||||
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest. |
| 1 | Group numbers are assigned by the Weed Science Society of America (WSSA) according to different modes of action. Although weeds may exhibit multiple resistance across many groups, mode of action numbers are useful in planning mixtures or rotations of herbicides with different modes of action. |
| * | Permit required from county agricultural commissioner for purchase or use. |