The Ohio State University shares these four guiding principles of marestail management to help no-tillers battle this problem weed.

Takeaways

• Combination of fall and spring burndown herbicides is most effective. Overwintered plants are difficult to control with spring burndown alone.
• Marestail plants should be dead or dying prior to crop emergence.
• Most populations are resistant to both glyphosate and ALS inhibitors (site 2) such as Classic and FirstRate. Populations in some areas are becoming more difficult to control with 2,4-D also.
• There are no POST options in Roundup Ready or non-GMO soybeans, so in-season control depends solely upon use of effective residual herbicides.
• For control after crop emergence, combinations of several residual herbicides are more effective than single active ingredients.
• LibertyLink and Xtend soybeans provide for effective POST options.

STEP 1. FALL HERBICIDES

• Soybeans—2,4-D plus one of the following: glyphosate, dicamba, Basis, Canopy/Cloak, metribuzin
• Corn—2,4-D plus one of the following: glyphosate, dicamba, Basis, simazine, metribuzin
• Keep herbicide cost less than $10
• Avoid use of other residual herbicides; save them for spring

STEP 2. SPRING BURNDOWNS, FOLLOWING FALL HERBICIDES

• Glyphosate + one of following: 2,4-D, Elevore + 2,4-D, Sharpen, Zidua PRO
• Gramoxone (2 to 3 pt) + 2,4-D + metribuzin
• Glufosinate + metribuzin
• Can add metribuzin (0.3 to 0.5 lb ai) and/or 2,4-D to most of these
• Glyphosate + dicamba (Xtend soybeans)
• Elevore, 2,4-D have plant-back restrictions

SPRING BURNDOWNS, NO FALL HERBICIDES

• Glyphosate + Sharpen/Zidua PRO + 2,4-D + metribuzin
• Gramoxone  (4 pt) + 2,4-D + metribuzin
• Glyphosate + dicamba (Xtend soybeans)
• Glyphosate + dicamba + Sharpen (Xtend soybeans)
• Glufosinate + Sharpen + metribuzin
• Metribuzin rates—0.3 to 0.5 pounds per ai

STEP 3. INCLUDE RESIDUAL HERBICIDES WITH SPRING BURNDOWN

• Flumioxazin—Valor and Fierce products, Surveil, Envive/Enlite, Trivence, Panther Pro, others
• Sulfentrazone—Authority products, Sonic, others
• Metribuzin—various products and premixes
  • Equivalent of 0.3 to 0.5 lb ai metribuzin
  • Add more metribuzin as necessary if rate in premix is low
• Residual herbicide mix should be more complex in Roundup Ready and non-GMO soybeans due to lack of effective POST options (or in Xtend to avoid POST use of dicamba)
  • Panther Pro, Trivence
  • Metribuzin plus one of following: flumioxazin, sulfentrazone, Sharpen (1.5 to 2 oz)

STEP 4. POSTEMERGENCE OPTIONS

• Roundup Ready or non-GMO soybeans?no effective POST options
• LibertyLink soybeans
  • Glufosinate—Liberty, Cheetah, Interline, etc
  • Marestail plants less than 6 inches tall
• Xtend soybeans
  • XtendiMax, Engenia, FeXapan (plus glyphosate)
  • Apply by early June and prior to R1 stage
  • Risk of off-target movement; see label and other information from manufacturers and universities
• Enlist soybeans
  • Enlist Duo, Enlist One
  • Glufosinate
  • Most effective: glufosinate + Enlist Duo

Multiple-resistant marestail surviving treatment with (from left to right) glyphosate alone, ALS inhibitor (site 2) alone, and a combination of glyphosate plus ALS inhibitor. Photo from The Ohio State University.

Related Content

Options For Burndown Of Marestail In No-Till Soybeans

Using Fall Herbicide Treatments For Marestail

Controlling Marestail Post-Emergence In Corn