Table 2.6-4. Herbicides for use in new legume seedings or stands less than one year old
See specific product label to determine correct rate for the soil type and weed species found in individual fields.
| Herbicide¹ | Application | Product/A | lb ai/A | Crop | Remarks |
|---|---|---|---|---|---|
|
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| Preplant | |||||
| Batan 60DF (benefin) | Preplant incorporated | 2 lb | 1.2 | Alfalfa, birdsfoot trefoil, red clover, ladino clover, alsike clover | Apply shortly before seeding. Do not use with companion seedings of small grains or forage grasses. |
| Eptam 7E (EPTC) | Preplant incorporated | 3.5–4.5 pt | 3–4 | Alfalfa, birdsfoot trefoil, clovers, lespedeza; not white Dutch clover | Incorporate to a depth of 2–3 inches immediately after application. Follow label recommendations for proper incorporation procedures. Do not use if atrazine was applied within 12 months of planting. |
| Gramoxone SL 2S (paraquat) | Preplant | 2–4 pt | 0.5–1.0 | Alfalfa | Apply in 20–60 gal/A for control of emerged annual weeds. Add 8–32 oz nonionic surfactant/100 gal of spray. Phosphate-containing liquid fertilizer solutions diminish paraquat activity if used as a carrier. Use appropriate precautions when handling paraquat to minimize exposure to the herbicide. Do not use flood jet tips larger than size 20 or spacing greater than 40 inches. (Gramoxone is a restricted-use pesticide.) |
| Roundup 3S²/Roundup WeatherMax 4.5S/glyphosate² |
Preplant | 1–3 qt | 1–3 | Alfalfa, clover, and alfalfa or clover-grass mixtures | Fall applications of Roundup/glyphosate are better than spring applications for control of orchardgrass sods and quackgrass. Spring applications may be used for control of annual weeds. Roundup/glyphosate may be applied in clear liquid nitrogen fertilizers and clear liquid complete-analysis fertilizers. Do not use Roundup/glyphosate with suspension-type liquid fertilizers. |
| Postemergence | |||||
| Buctril 2E (bromoxynil) | Postemergence | 1.0–1.5 pt | 0.25–0.375 | Alfalfa and alfalfa/small grain companion seedings, CREP | Apply in spring or fall to seedling alfalfa with at least four trifoliate leaves. May be applied to a small grain companion seeding up to the boot stage. Weeds should not exceed the four-leaf stage, 2 inches in height, or 1 inch in diameter (whichever comes first). May be used for either spring or fall seedings. Buctril application where temperatures are expected to exceed 70°F at or 3 days following application can result in unacceptable crop injury. |
| Butyrac 200 2E (2,4-DB) | Postemergence | 1–3 qt | 0.5–1.5 | Alfalfa, birdsfoot trefoil, CREP |
Apply in spring or summer when seedling legumes have two to four trifoliate leaves and when weeds are actively growing and no more 3 inches in height, or rosettes are less than 2 inches across. (Water quality advisory.) |
| Extreme 2.17L (imazethapyr + glyphosate) |
Early postemergence |
2.2-4.4 pt |
0.6-1.2 |
Roundup Ready alfalfa |
Apply over-the-top to Roundup Ready alfalfa varieties only. Apply Extreme when the seedling RR alfalfa is in the second trifoliate stage or larger and when the majority of weeds are 1 to 3 inches (height or rosette diameter). Due to breeding constraints, some alfalfa plants may not contain the glyphosate-resistant gene; thus, some seedlings may not survive the application. A typical application rate of Extreme is 3 pt/A. Allow a minimum of 7 days between treatments. Do not feed, graze or harvest for 30 days after application. If replanting is necessary, do not plant alfalfa for 4 months following an Extreme application. |
| Gramoxone SL 2S (paraquat) | Dormant or between cuttings | 1–2 pt | 0.25–0.5 | Alfalfa, clover,or trefoil | For dormant applications, apply any time the alfalfa, clover, or trefoil is dormant. For between-cutting treatments in alfalfa only use the 1 pt. rate and do not treat more than 5 days after cutting. Make only one application on seedling stands. Not labeled for other legumes or alfalfa-grass mixtures. (Restricted-use pesticide) |
| Kerb 50W (pronamide) | Growing or dormant | 1–3 lb | 0.5–1.5 | Alfalfa, birdsfoot trefoil, crown vetch, clovers | Apply in fall or early winter before winter freeze-up. Apply when soil is 50°F or less. Do not use on alfalfa-grass mixtures. (Restricted-use pesticide) |
| MCPA amine 4S | Postemergence | 0.5 pt | 0.25 | Alfalfa, clovers, or trefoil with small grain companion seeding, CREP | Treat after the grain is tillered when legumes are 2–3 inches tall. Do not use more than 6 gal of water/A; higher volumes may result in injury to legumes. Do not spray when grain is in the boot to dough stage. Do not use on sweet clover or vetch. |
| Poast Plus 1.0E or Poast 1.5E (sethoxydim) |
Postemergence | 1.5–3.75 pt or 1.0–2.5 pt |
0.19–0.47 | Alfalfa, clovers, and birdsfoot trefoil | Apply to actively growing grasses at the size recommended on herbicide label (generally less than 8 inches tall). Always add an oil concentrate or Dash to the spray solution. Nitrogen solution may be added for improved control of certain species. A second application may be needed for complete control of perennial species. May be tank-mixed with 2,4-DB to broaden the weed-control spectrum. |
| Pursuit 2S/70DG (imazethapyr) | Early postemergence | 3–6 fl oz 1.08–2.16 oz |
0.047–0.094 | Alfalfa, CREP | For pure seeded alfalfa only. Apply when alfalfa has 2 trifoliates or larger and when weeds are 1–3 inches in height or rosette width. Include surfactant or oil concentrate plus nitrogen solution in tank. Tank-mix with Buctril or Butyrac to broaden control spectrum. |
| Raptor 1AS (imazamox) | Early postemergence | 4–6 fl oz | 0.031–0.047 | Alfalfa | For pure seeded alfalfa only. Apply when alfalfa has 2 trifoliates or larger and when weeds are 1–3 inches in height or rosette width. Include surfactant or oil concentration plus nitrogen solution in tank. Tank-mix with Buctril or 2,4-DB to broaden control spectrum. |
| Roundup 3S²/Roundup WeatherMax 4.5S/glyphosate² |
Postemergence (spot treatment) | 2% sol. (2.5oz/gal) | Alfalfa, clover, and alfalfa or clover-grass mixtures | For spot treatment only of problem weeds in forages. Apply to actively growing susceptible weeds. Avoid contact with desirable species as severe injury or death can occur. No more than 1/10 of any acre should be treated at one time. Further application may be made at 30-day intervals if necessary. | |
| Roundup/glyphosate | Postemergence | varies | 0.75–1.5 | Roundup Ready Alfalfa only | In RR alfalfa varieties only, apply 22 to 44 fl oz/A Roundup Weather Max 4.5S or 32 to 64 fl oz/A glyphosate 3S formulations to seedling alfalfa at the 3 to 5 trifoliate stage and to weeds less than 4 inches tall. An initial glyphosate application is also necessary at this timing to remove the small percentage of glyphosate-susceptible alfalfa plants that are present in the new seeding. Wait at least 5 days after application before grazing or haying. |
| Select 2EC (clethodim) | Postemergence | 6–8 fl oz | 0.09–0.125 | Alfalfa, birdsfoot trefoil | Apply to actively growing grasses at the size recommended on herbicide label (generally less than 6 inches tall). Always use a crop oil concentrate (1 qt/A) in the spray solution. May be tank-mixed with 2,4-DB for broadleaf weed control; however, temporary crop injury may occur. For annual bluegrass control, apply 6–16 fl oz before the 4-leaf stage of bluegrass. Clethodim is also be available as Select Max 0.97E. |
| Sinbar 80W (terbacil) | Dormant | 0.33–0.5 lb | 0.27–0.4 | Alfalfa | Apply in fall after alfalfa becomes dormant or in spring before 2 inches of new growth. Apply before weeds germinate or before they exceed 2 inches in height or width. Do not use on alfalfa-grass mixtures. |
