Resistance is not going away
Soybean growers in Eastern Canada will continue to face new and emerging weed resistance threats on their farms. As planning starts for the 2020 crop, Canada fleabane has now spread across all major soybean production areas in Ontario and has started to gain a foothold in Western Quebec. The latest weed to develop resistance to glyphosate in addition to several other herbicide modes of action is waterhemp. It’s enough to make a grower throw their hands up and give up the fight.
Trouble is that resistant weeds like waterhemp and Canada fleabane are aggressive, and if not kept in check will significantly reduce yields. The best way to manage resistant weeds is to develop what agronomists call an “integrated weed management plan” that includes as many tools as possible. Part of the plan focuses on herbicide groups and modes of action. The more herbicide groups you can introduce into the plan, the better the odds of getting excellent weed control and avoiding a resistance “wreck” on your farm.
IP soybeans require a proactive and robust crop plan
The 2020 season is seeing renewed interest in IP soybeans in Eastern Canada. IP growers know that the trade-off for higher premiums is a requirement for a robust herbicide program usually involving at least two passes. They don’t have the luxury of additional herbicide tools like glyphosate, glufosinate and 2,4-D to help control weeds in post-emergence applications. That’s why pre-emergence herbicides are so critical to the success of an IP soybean crop. The range of choices and efficacy of post-emergence herbicides for conventional soybeans are very limited.
Starting in 2020, growers will have a new tool to make sure they can start an IP soybean crop on the right foot. It’s called Commenza™, a new herbicide from Corteva Agriscience™ for burndowns and pre-emergence applications in soybeans.
Commenza checks many boxes for IP soybean growers
Commenza herbicide co-pack from Corteva satisfies all of these basic grower requirements for a new pre-emergence herbicide for soybeans.
- Multi-mode of action: Commenza contains three trusted active ingredients (S-metolachlor, metribuzin and flumetsulam) from three different herbicide groups (group 2, 5 and 15 herbicides). More importantly, the three modes of action in Commenza deliver overlapping effective control of most important annual weeds, including resistant biotypes. This means that at least two of the three herbicides in Commenza are working on any given weed providing a minimum of two lines of defense against resistant weeds.
- Cross-spectrum activity: Commenza controls both broadleaf and grass weeds. Managing a full spectrum of weeds gives your IP soybean crop a clean start and puts obtaining excellent weed control within your reach.
- Efficacy on the key resistant weeds: Canada fleabane and waterhemp are the two most widespread glyphosate resistant weeds soybean growers face in Eastern Canada. On top of those, there are a number of annual weeds resistant to group 2 herbicides. With three modes of action, Commenza provides a strong defense against weeds such as Canada fleabane, nightshade and weeds in the Amaranthus family such as pigweeds and waterhemp.
- Flexible tank-mix options for no-till: No-till burndowns with Commenza will require a glyphosate and possibly an additional knockdown herbicide for fleabane control such as Elevore™. Following the proper mixing order for the tank-mix, a one-pass burndown can be achieved with a Commenza burndown and residual program.
Commenza is available from Corteva Agriscience for the 2020 season
This spring consider Commenza as your pre-emergence herbicide providing cross-spectrum activity, including control of resistant weeds. Ask your local crop protection retailer or Corteva representative about how Commenza fits into your farm’s 2020 crop plans.