Control of marestail in no-till soybeans
Fall-applied Canopy or other chlorimuron- or cloransulam-containing herbicides will not provide residual control of ALS-resistant marestail into spring, and residual herbicides should largely be reserved for spring application (at least with regard to marestail - residual control of other weeds can occur).
Spring-applied residuals should include active rates of non-ALS herbicides - metribuzin, flumioxazin (Valor), or sulfentrazone (Authority). Low rates of premix products (Canopy, Valor XLT, Sonic, Matador, etc) may not provide a high enough rate of the non-ALS herbicide.
In burndown applications, there will be no added effectiveness on emerged marestail from products that contain chlorimuron or cloransulam, which makes the other herbicides in the mix more important.
LibertyLink soybeans - the most effective marestail control strategy
LibertyLink soybeans are the most effective tool for management of herbicide-resistant marestail, especially in fields with high marestail populations.
Use burndown and residual herbicides as outlined on the next two pages. Apply Liberty POST (29 oz/A) before marestail plants exceed 6 inches in height. Liberty can be applied POST at rates up to 36 oz/A for taller plants or plants that have survived previous herbicide treatments, but control may be variable. Follow with a second POST application of Liberty as necessary.
Liberty is a contact herbicide and effective activity is dependent upon use of the appropriate spray volume (at least 15 gpa) and nozzles. See label for specific information.
Steps for effective management of marestail
1. Use fall herbicide treatments in fields with a history of problems or where marestail seedlings are observed in fall. The primary goal of a fall treatment is control of emerged plants, and it is not a substitute for a preplant herbicide treatment the following spring. An application of burndown and residual herbicides is still required closer to the time of planting in fields that were treated in the fall. For fall applications, we suggest using 2,4-D as the base herbicide to control marestail, and combining it with one of the following to ensure control of other winter weeds:
• glyphosate; dicamba (or premix - Brash, WeedMaster, Outlaw, Rifle); Basis; Express; a low rate of Canopy/Cloak EX or DF; or metribuzin
• can add Canopy/Cloak to other herbicide combinations to obtain residual control of weeds into spring. However, do not expect residual from fall-applied Canopy/Cloak to adequately control spring-emerging marestail. We do not recommend the use of other residual herbicides in the fall due to cost and lack of residual control into spring.
- Scout for aphids in winter wheat
- El Niño development stalled out, but wet winter still predicted
- Ag markets posted divergent closes Wednesday
- Farm bill program to help farmers affected by severe weather
- Israel panel proposes 25-42% tax hike on mining companies
- Ag markets moved almost unanimously higher Wednesday morning
- How much corn can the ethanol industry use?
- Economist: Taxing P could reduce risk of algal blooms
- Commentary: Government wants farmers to quit farming
- Source shows half of GMO research is independent
- Ag markets made a generally mixed showing Thursday night
- What is the relationship between maturity group, yield?