Table 2.3-1. Weed control recommendations for grain sorghum, forage sorghum, sorghum x sudan hybrids.
- See specific product label to determine correct rate for the soil type and weed species found in individual fields. See Table 2.2-8 to determine herbicide effectiveness on problem weeds.
- To reduce injury from Bicep, Bullet, Dual, Guardsman/Max, Lasso, Lariat, Leadoff, Micro-Tech, and Outlook treat sorghum seed with Concep or Screen. Pretreated seed sometimes is available.
- No-till sorghum is possible; if weeds have already emerged, add Gramoxone or glyphosate to the following preemergence treatments.
| Herbicide1 | Crops | Application | Product/A | lb ai/A | Remarks |
|---|---|---|---|---|---|
| Atrazine 90DF | Grain, forage, or sorghum x sudan hybrids | Preplant or preemergence |
1.1-2.2 lb | 1-2 | Do not use on coarse-textured soils or soils with less than 1% organic matter. Atrazine is most commonly used in combination with other herbicides at 1.1 to 1.7 lb/A. On highly erodible ground with less than 30% surface residue, no more than 1.8 lb 90DF may be applied prior to crop emergence. See an atrazine label for additional restrictions. (Restricted-use pesticide and water quality advisory) |
| Dual II Magnum 7.64E/Cinch (s-metolachlor) |
Grain, forage, or sorghum x sudan hybrids | Preplant or preemergence |
1-1.67 pt | 0.96-1.6 | Sorghum seed must be treated before planting with Concep or Screen to avoid severe Dual/Cinch injury. (Water quality advisory) |
| Lorox 50DF | Grain or forage | Preemergence | 0.5-2.0 lb | 2.5-1.0 | Lorox can be tank mixed with other labeled herbicides for expanded weed control in sorghum. Sorghum seed must be planted at least 1 inch deep. Do not apply over top of emerged sorghum and within 75 days of harvest. |
| Micro-Tech 4ME or Lasso 4E (alachlor) |
Grain | Preplant or preemergence |
1.5-3 qt | 1.5-3 | Sorghum seed must be treated before planting with Screen or Concep to avoid severe alachlor injury. Early postemergence applications of Lasso on up to 5-inch-tall sorghum may be made to safened or unsafened seed. Use the higher rates in areas of yellow nutsedge and heavy weed infestation. (Restricted-use pesticide and water quality advisory) |
| Outlook 6.0E (dimethenamid-P) |
Grain | Preplant or preemergence |
10-21 fl oz | 0.47-0.98 | Sorghum seed must be properly treated with an approvedchloroacetamide herbicide safener (Concep or Screen). Sorghum forage may be grazed or fed to livestock 60 or more days after application. Harvest grain or fodder 80 days or more after application. (Water quality advisory) |
| Ramrod 4L (propachlor) |
Grain | Preemergence | 2.5-4 qt | 2.5-4 | Ramrod is similar to Dual or Lasso, although higher rates are necessary to achieve equivalent control. Apply preemergence immediately after planting. Controls most annual broadleaved weeds and grasses. Higher rates are for clay soils with at least 3% organic matter content. Do not graze or feed forage to dairy animals. |
| Herbicide1 | Crops | Application | Product/A | lb ai/A | Remarks |
|---|---|---|---|---|---|
| Bicep II Magnum 5.5L / Cinch ATZ or Bicep Lite II Magnum 6L / Cinch ATZ lite (s-metolachlor + atrazine) |
Grain, forage, or sorghum x sudan hybrids | Preplant or preemergence |
2.1-2.6 qt or 1.1-1.5 qt |
2.9-3.6 or 1.65-2.25 |
Sorghum seed must be treated before planting with Concep or Screen avoid severe Bicep injury/Cinch ATZ injury. Do not use on soils with less than 1% organic matter. (Restricted-use pesticide and water quality advisory) |
| Bullet 4ME or Lariat 4L (alachlor + atrazine) |
Grain | Preplant or preemergence |
2.5-4 qt | 2.5-4 | Sorghum seed must be treated before planting with Screen or Concep to avoid severe injury. Lariat may be applied early postemergence on up to 5-inch-tall sorghum that is safened or unsafened seed. (Restricted-use pesticide and water quality advisory) |
| Guardsman Max 5L or G-Max Lite 5L (dimethenamid-P + atrazine) |
Grain | Preplant or preemergence |
2.4-4 qt or 2-3.5 pt |
1.5-2.5 or 1.25-2.2 |
Sorghum seed must be properly treated with an approved chloroacetamide herbicide safener (Concep or Screen). May be applied postemergence to grain soghum up to 12 inches tall. Sorghum forage may be grazed or fed to livestock 60 or more days after application. Harvest grain or fodder 80 days or more after application. (Restricted-use pesticide and water quality advisory) |
| Herbicide1 | Crops | Application | Product/A | lb ai/A | Remarks |
|---|---|---|---|---|---|
| 2,4-D amine 4S | Grain or forage | Postemergence | 0.75-1.25 pt | 0.36-0.6 | Apply to sorghum that is 6 to 15 inches tall prior to boot stage Use drops if taller than 8 inches. Crop tolerance decreases as size increases. Do not harvest or graze for 7 days. See label for additional instructions. |
| Aim 2EW | Grain or forage | Postemergence | 0.5-1.0 fl oz | 0.008-0.016 | Apply to weeds 1 to 4 inches tall. Include a nonionic surfactant (NIS). Tank mixing other herbicides increases the spectrum of weed control. |
| Aim 40 WDG or Aim 1.9EW (carfentrazone) |
Grain | Postemergence | 0.33 oz or 0.5 fl oz |
0.008 oz | Aim has good activity on certain broadleaves, including lambsquarters, pigweed, velvetleaf, and nightshade, and provides suppression of others. Tank-mix to broaden weed control spectrum. Apply through the 6-leaf sorghum growth stage and when weeds are less than 4 inches tall. Include nonionic surfactant at 2 pt/100 gallons of spray mixture. Temporary leaf speckling may occur after application. |
| Atrazine 90DF | Grain, forage, or sorghum x sudan hybrids | Postemergence | 1.3-2.2 lb | 1.2-2 | Apply 1.3 lb with 1 qt crop oil concentrate for broadleaves only. Apply to sorghum after the 3-leaf stage, but before 12 inches in height. Higher rate may provide some grass control (not effective on fall panicum or crabgrass). Do not use on coarse-textured soils. Do not graze or feed for 21 days. If atrazine was used previously that same season, do not exceed a total of 2.5 lb ai/A per calendar year (2.5 qt). See label for additional restrictions. (Restricted-use pesticide and water quality advisory) |
| Buctril 2E (bromoxynil) or Buctril + Atrazine 3L (bromoxynil + atrazine) |
Grain, forage, or sorghum x sudan hybrids | Postemergence | 1-1.5 pt or 1.5-3 pt |
0.25-0.375 or 0.56-1.12 |
Apply 1 pt from emergence to preboot or 1.5 pt from 4 leaf to pre-boot (12 inches for Buctril + atrazine) when weeds are in the 2- to 4-leaf stage. Do not graze or feed for 45 days. Consider previous atrazine applications and do not exceed 2.5 lb (qt)/A/year. (Buctril + atrazine is a restricted-use pesticide and carries a water quality advisory.) |
| Clarity 4S / Banvel 4S (dicamba) or Marksman 3.2L (dicamba + atrazine) |
Grain, forage, or sorghum x sudan hybrids | Postemergence | 0.5 pt or 1.5-2 pt |
0.25 or 0.6-0.8 |
Apply to sorghum after the 3-leaf stage and before 15 inches tall (12 inches for Marksman). Use drop nozzles after sorghum is beyond 8 inches tall. Do not use oil or surfactant. Do not graze or feed treated forage to animals before 21 days after application or wait at least 37 days to harvest for hay. Consider previous atrazine applications and do not exceed 2.5 lb (qt)/A/year. (Marksman is a restricted-use pesticide and carries a water quality advisory.) |
| Laddok S-12 5L (bentazon + atrazine) |
Grain, forage, or sorghum x sudan hybrids | Postemergence | 1.3-2.3 pt | 0.82-1.45 | Use on up to 12-inch-tall sorghum. Include crop oil concentrate or nitrogen solution with Laddok applications. Do not graze or feed for 21 days. Consider previous atrazine applications, and do not exceed 2.5 lb (qt)/A/year. (Restricted-use pesticide and water quality advisory) |
| Paramount 75DF | Grain | Preemergence to postemergence | 5.3-8.0 | 0.25-0.375 | Apply Paramount to grain sorghum at 5.3-8 oz/A from pre to 12-inch tall sorghum for control of certain annual grasses and suppression of common broadleaves. To enhance activity, tank mix with atrazine or other labeled herbicide for sorghum. Do not allow grazing of treated area. Do not harvest hay from treated area for at least 10.5 month after application. See label for additional restrictions. |
| Peak 57WG (prosulfuron) |
Grain | Postemergence | 0.5-1 oz | 0.018-0.036 | Peak controls many annual broadleaves and suppresses some perennial broadleaves. Apply to sorghum between 5 and 30 inches in height when broadleaf weeds are small (1–4 inches) and actively growing. The 0.75 oz/A is the standard rate. Include a nonionic surfactant or crop oil concentrate in the spray solution. Peak may be tank-mixed with Banvel, Clarity, 2,4-D, atrazine, Buctril, Buctril + atrazine, or Marksman. Do not plant normal field corn for 1 month, soybeans or tobacco for 10 months, or alfalfa or clover for 22 months. Wheat, barley, oats, and rye have no rotation restriction; see label for additional cropping and other restrictions. |
| Permit 75DF (halosulfuron) |
Grain | Postemergence | 0.67 oz | 0.032 lb | Apply Permit to milo from the 2-leaf stage through layby (before grain head emergence). Temporary stunting may occur following application if crop is under stress; crop will recover under normal growing conditions. Do not graze or harvest for forage for 30 days following application. See Table 2.2-19 for recrop information. |
| Roundup 3S / Roundup WeatherMax 4.5S2 / glyphosate / Touchdown Total 4S | Grain (grain <30% moisture) | Postemergence | 1-2 pt | 0.5-1.0 | Apply to grain after it has <30% moisture content and at least 7 days before harvest. Do not apply to sorghum grown for seed. |
| Shotgun 3.25L (2,4-D + atrazine) |
Grain, forage, or sorghum x sudan hybrids | Postemergence | 2 pt | 0.81 | Shotgun is a mixture of atrazine + 2,4-D. Apply 2 pint per acre broadcast (0.56 lb atrazine + 0.25 lb 2,4-D) from spike to 4-leaf stage (8 inches tall). See atrazine restrictions at end of Table 2.2-7. Do not graze or feed forage from treated area for 21 days following application. See Table 2.2-19 for recrop information. (Restricted-use pesticide and water quality advisory) |
| Weedmaster 3.87S (dicamba + 2,4-D) |
Grain, forage, or sorghum x sudan hybrids | Postemergence | 1 pt | 0.48 | Apply 1 pt/A to sorghum in the 3–5 leaf stage (4–8 inches tall). For best results, apply when weeds are less than 3 inches tall. Do not use adjuvants or crop injury may result. Grazing/silage restrictions: 0 days for nonlactating animals; 7 days for lactating animals; do not harvest for silage or hay within 37 days after treatment; do not graze meat animals within 30 days of slaughter. |
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