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South Dakota 2013 Crop Protection Guide – Corn 23 TANK-MIXES or SEQUENTIAL Accent may be tank mixed with several herbicides to improve broadleaf control. Corn may develop rattailing after the V-11 stage of growth when Accent is tank mixed with products containing dicamba and applied to small corn (V3 stage or smaller) under stress conditions. Use Accent rate as for Accent alone. Refer to label restrictions or the section for each herbicide alone.
Tank mix of Accent with reduced rates of preemergence grass herbicides may be applied early postemergence. Preemergence grass herbicides include Dual II Magnum, Cinch (s-metolachlor), Cinch ATZ (s-metolachlor + atrazine), Prowl (pendimethalin), Surpass (acetochlor), Outlook (dimethenamid), or Lumax (s-metolachlor + mesotrione + atrazine). If tank mixing with Lumax, limit Lumax rate to less than 2 pt/A, use NIS rather than COC, omit the use of nitrogen fertilizer, and apply to broadleaf weeds less than 4 inches tall. Rate for preemergence herbicides is usually 50% of normal rate. Provides residual grass control. Performance best if rain occurs before new weed flush. Atrazine may be added for additional broadleaf control.
Sequential programs provide for reduced rates of preemergence herbicides prior to postemergence Accent. Herbicides include Dual II, Outlook, Harness, Prowl, and Surpass. Rates are usually 50% of normal rate for the preemergence herbicide and should be applied no more than 7 days before planting. Provides early-season protection and expands timing for postemergence application.
ACCENT + ATRAZINE POST. Tank-mix with 0.75-1.5 qt Atrazine 4L per acre. Add COC at 1 gal/100 gal; 28% N may also be added at 2-4 qt per acre. Apply before corn exceeds 12 inches. Performance has been very good in SDSU tests. Note atrazine rate limitations.
ACCENT + BROMOXYNILPOST. Tank mix with 1-1.5 pt bromoxynil 2L per acre. Add NIS at 1 qt/100 gal. Always use drop nozzles after corn exceeds 24 inches; do not apply after 36 inches. Some leaf burn possible. COC or nitrogen fertilizer or other similar additives may increase crop leaf burn. Good performance in SDSU tests.
ACCENT + BROMOXYNIL/ATRAZINEPOST. Tank mix with 1.5-3 pt bromoxynil/atrazine premix per acre. Add NIS at 1 qt/100 gal + 28% N at 2-4 qt per acre. Apply before corn exceeds 12 inches. Some leaf burn possible. COC or 28% N or other similar additive may increase crop leaf burn.
ACCENT + DICAMBA PRODUCTPOST. Tank mix with 0.5-1 pt dicamba 4L per acre. Add NIS at 1 qt/100 gal + 28% N at 2-4 pt per acre. Do not apply after corn exceeds 8 inches. Surfactant may increase corn response to dicamba. Slight grass antagonism under some conditions. Good performance in SDSU tests.
Postemergence control of grass species, such as foxtails (2-4 inches), barnyardgrass (2-4 inches), wild oat (2-4 inches), sandbur (1-3 inches), woolly cupgrass (4 inches) and some broadleaf weed species, such as common lambsquarters (4 inches), pigweed (4 inches), velvetleaf (4 inches), and dandelion (6 inches). Rate equivalent to 0.45-0.63 oz/A Accent 75DF and 0.033-0.047 oz/A Harmony GT XP. Use higher rates for taller grass weeds and for broadleaf weed control.
Add NIS or COC (COC preferred) plus an ammonium nitrogen fertilizer. Add NIS at 0.25% v/v (1 quart per 100 gallons of water) or 0.5% under arid conditions, or COC at 1% v/v or 2% v/v under arid conditions, or add MSO at 0.5% v/v. Add 28 or 32% N at 2 qt/A or AMS at 2 lb/A or, under arid conditions, add UAN at 4 qt/A or AMS at 4 lb/A. Do not use MSO when tank mixing with Callisto at a rate greater than 1.5 oz/A. Use NIS rather than COC when tank mixing with preemergence grass herbicides such as Prowl, Cinch (s-metolachlor), or Lumax and follow ammonium nitrogen fertilizer restrictions listed for the tank-mix partner.
Minimum carrier is 15 gpa for ground equipment (10 gpa if canopy is sparse) or 3 gpa for aerial application. Observe restrictions and precautions as described for Accent. Apply to corn varieties with a relative maturity rating greater than 88 days. Do not apply 24 www.iGrow.org to field corn grown for seed, popcorn, or sweetcorn. Do not tank mix with Basagran, 2,4-D, or other ALS-inhibiting (site of action 2) herbicides unless recommended on the label.
POST. Apply to corn that is less than 16 inches tall and has less than 5 leaf collars, but applications to corn less than 12 inches tall is recommended.
STEADFAST or IRONCLAD (nicosulfuron + rimsulfuron) Site of Action: 2+2
0.75 oz Steadfast 75WDG or Ironclad 75WDG (0.023 + 0.012 lb ai)
1.5 oz Steadfast Q 37.7WDG (0.023 + 0.012 lb ai) Steadfast 75WDG is a premix of 50% nicosulfuron + 25% rimsulfuron. Steadfast 75WDG at 0.75 oz/A is equivalent to 0.5 oz Accent + 0.75 oz Resolve. Weed height should not exceed 4 inches for barnyardgrass, foxtail, wild proso millet, common sunflower, and pigweeds; 3 inches for woolly cupgrass and smartweed; 2 inches for volunteer cereals, sandbur, and wild oat. Adequate soil moisture is required. Rainfall within 5 days will enhance residual activity. Rainfast in 4 hours.
Apply Steadfast to hybrids with a relative maturity rating of 88 days or more. Consult your seed supplier before applying to specialty corn or hybrids with 77-88 days relative maturity.
Applications must include either COC or 1 gal/100 gal or NIS at 1-2 qt/100 gal + AMS or 28% N. Minimum carrier is 15 gpa for ground or 5 gpa for air.
Do not tank-mix Steadfast with Basagran. 2,4-D may cause grass antagonism. Do not tank-mix with foliar applied organophosphate insecticides such as Lorsban, malathion, or parathion. Apply these products at least 7 days before or 3 days after application of Steadfast. May be tank-mixed with Asana XL or Lannate insecticides.
Soybeans may be planted after 15 days; winter small grain 4 months; spring wheat, barley, oats, or rye 8 months; dry beans, peas 10 months; alfalfa 12 months. Rotational guidelines for sunflower and sorghum are based on soil pH. Sorghum may be planted after 10 months and sunflower after 11 months if pH is 7.5 or less. Higher pH requires an 18-month planting restriction for these crops.
Do not graze or feed forage, hay, or straw from treated areas to livestock within 30 days of application.
POST. Apply to corn up to 20 inches or up to and including 6 collars, whichever is most restrictive.
Tank-mix Steadfast 75WDG with full or reduced rates of preemergence grass herbicide to be applied early postemergence.
Preemergence grass herbicides include Prowl, Surpass, and Dual. Rate for preemergence herbicide is 2/3 of full rate. If preemergence herbicide contains atrazine use less than 1.0 lb ai atrazine in tank-mix. If Prowl is used as tank-mix EPOST on small grass use NIS in place of COC. Provides residual grass control. Refer to the label or section for each herbicide alone.
Sequential programs provide for reduced rates of preemergence herbicides prior to postemergence Steadfast. Herbicides include Balance Pro, Dual II, Surpass, and Harness Xtra. Rates are usually 50% of normal rate for the preemergence herbicide. Provides early season protection and expands timing for postemerge application.
STEADFAST + ATRAZINE STEADFAST ATZ
POST. Tank-mix with 0.25-1 lb atrazine 90DF or use 14 oz Steadfast ATZ 89.3 WDG containing 2.7% nicosulfuron (Accent) plus 1.3% rimsulfuron. Apply before corn exceeds 12 inches or 7-leaf collars. Corn earlier than 88 day relative maturity may be injured.
Add COC at 1 gal/100 gal + 28% N at 2-4 qt per acre. Soybeans may be replanted 10 months after application of Steadfast ATZ.
STEADFAST + DICAMBA PRODUCT or MARKSMANPOST. Tank-mix with 0.125-0.25 pt dicamba 4L or use 1 pt Marksman per acre. Add COC at 1 gal/100 gal + 28% N at 2-4 qt per acre. Corn plants may develop some rattailing after the V-11 stage or growth when Steadfast is tank-mixed with products containing dicamba and applied to small corn (V3 stage or smaller) under stress conditions.
STEADFAST + DISTINCTPOST. Tank-mix with 1-2 oz Distinct 70WDG per acre. Add COC at 1 gal/100 gal + 28% N at 2-4 qt or AMS at 2-4 lb per acre.
STEADFAST + HORNET POST. Tank-mix with 2-3 oz Hornet WDG per acre. Add COC at 1 gal/100 gal + 28% N at 2-4 qt per acre.
Option is a sulfonyl-urea herbicide that gives good to excellent control of several annual grasses. Grasses should be treated early for best results. Green and yellow foxtail and wild proso should not exceed 3 inches; woolly cupgrass 2 inches; and barnyardgrass 4 inches. It also controls shattercane and volunteer cereals. Broadleaves including lambsquarters, common ragweed (2 inches), and pigweed and velvetleaf (3 inches) may be controlled. Tank-mix with other herbicides will improve broadleaf control. Rates can be increased to 1.75 oz per acre for larger weeds. Corn tolerance has been good in SDSU tests. Option contains a safener. Treated weeds begin to show yellowing and die in 1-3 weeks. Results are best when weeds are actively growing. Good coverage is helpful.
Minimum carrier is 10 gpa; 15-20 gpa is suggested for dense weed populations. Fields may be cultivated 7 days before or 7 days after application. Option degrades rapidly in the soil. Corn may be replanted 7 days after application; soybeans 14 days, and other crops in 60 days. Add MSO (1.5 pt/A) and 28% or 32% UAN (1.5-2 qt/A). May use AMS (1.5-3 lb/A) instead of UAN.
POST. Apply from emergence to 16 in or V6 stage.
Option may be tank mixed with other herbicides to improve broadleaf control or give residual. Tank-mixes with low rates of atrazine, dicamba, or Distinct have performed well in SDSU tests. Other mixes include Harness, Prowl, Surpass, Outlook, TopNotch, NorthStar, Hornet, and Marksman. A 2(ee) recommendation allows postemergence application of Option (1.5 oz/A) + Lexar with MSO (1 pt/A) and AMS (1 lb/A) on V1 to 5-inch tall corn.
Controls several mustard species, marestail, chickweed, alfalfa, and other broadleaf weed species. Apply while weeds are actively growing. May provide short-term residual control of some small-seeded broadleaf weeds. The rotation interval is 90 days for soybeans, 4 months for winter-seeded cereals, 8 months for spring-seeded cereals, 9 months for sorghum, and 18 months for sunflower, peas, dry beans, or canola.
Add COC at 1% v/v and nitrogen fertilizer, such as 28 or 32% N at 1.5-2 qts/A or AMS at 1.5-3.0 lb/A. Do not apply with aerial equipment. Use a minimum carrier volume of 10 gpa.
EPPS. Apply before weeds are 3 inches tall, after fall harvest or up to 30 days prior to corn planting. Do not apply to frozen ground.
AUTUMN SUPER (iodosulfuron + thiencarbazone) Site of Action: 2 + 2 The addition of thiencarbazone increases suppression of grasses, such as foxtail barely and downy brome (cheatgrass). Rotation interval is 1 month for corn, 2 months for soybeans, 3 months for wheat, and 9 months for barley.
EPPS. Apply in fall to small weeds (less than 3 inches) at least 30 days prior to corn planting.
Good to very good control of several small-seeded annual broadleaves and perennial broadleaves. Does not control mustard.
Better crop tolerance than 2,4-D. Very good tolerance up to 8 inches. May cause brittleness, lodging, or breakage associated with greensnap problems. Risk of injury greatest during periods of rapid growth, especially if crop is beyond suggested crop stage.
Minimum carrier for dicamba 4L is 5 gpa for ground or 3 gpa for air except when sensitive crops may be affected.
Banvel, Clarity, or Sterling contain 4 lb/gal dicamba. Banvel and Sterling are formulated as a dimethylamine salt; Clarity is a diglycolamine salt. Clarity has less temperature or humidity restrictions for application near sensitive crops. Weed control has been 26 www.iGrow.org similar for these products. Minimum carrier for Clarity is 3 gpa for ground and 2 gpa for air. Use precautions to reduce risk of droplet drift. Do not apply if wind is gusty or in excess of 5 mph and moving toward sensitive crops or if expected high temperature is over 80 to 85o F. Slight wind moving away from sensitive crops is preferred to calm conditions. Use less than 20 psi pressure and at least 20 gpa. Use drop nozzles if corn is over 8 inches. Do not apply dicamba when soybeans are nearby if corn is over 24 inches tall or soybeans are over 8 inches or are starting to bloom. A June 20 cut-off date for dicamba is suggested if soybeans are planted at normal dates. Sunflowers become more sensitive after they are beyond the 6-leaf stage. Do not harvest for dairy cattle prior to milk stage or kernel fill. Rates vary according to time of application.
PPS, PRE. Apply up to 1 pt per acre on medium and fine soils with more than 2% organic matter (O.M.). For PPS applications, apply 0.5 pt/A if soils have coarse texture or less than 2% O.M. Do not make PRE applications on coarse texture soils or soils with less than 2% O.M.
EPOST. Apply 0.5-1 pt dicamba per acre when corn is spike to 5-leaf or up to 8 inches. Useful for Canada thistle in seasons where weeds emerge ahead of corn. Some crop effects noted if heavy rain is received soon after application. Consider patch treatments.
POST. Banvel only. Apply 0.5 pt Banvel per acre before corn is 36 inches tall or not later than 15 days before tassel. Use drop nozzles after corn is 8 inches to improve coverage and reduce risk of injury.
MARKSMAN (dicamba + atrazine) POST. Use 2-3.5 pt Marksman 3.2L premix per acre. Marksman contains 1.2 lb dicamba + 2.1 lb atrazine per gallon. Use lower rate on light soil. Apply before corn exceeds 5-leaf stage. Do not use COC or NIS for best tolerance.
Tank-mixes for most situations are listed below. Banvel may be tank-mixed with other herbicides, including Accent, Beacon, Gramoxone (burndown), Roundup (RR corn), Stinger, or 2,4-D.