Get a jump on weeds

Friday, May 21, 2021

What options are available for producers to manage problematic weeds?

by Taryn Milton

One of the top items on a producer's to-do list this planting season may be to review which weeds they need to battle this year.

Depending on the province and soil zone you're in, the weeds that you'll encounter this year can vary. An effective way to get a jump on managing your weed situation is to assess, plan, implement and evaluate, says Rory Cranston.

Cranston is a cereal and pulse technical development manager at Bayer CropScience.

"You need to assess and find out what weeds are in your field. What are your targets? I don't think it's worthwhile controlling a target that's not there. But what do you need to control? What's your driver weed? Then you have to have the plan in place," he tells Better Farming.

"Then the implementation is just following along on that plan, following up with it and putting it into place, and then evaluating its success," says Cranston.

Following this advice can help producers determine a proper plan of action and drive their growing season plans.

Since weed pressures and options to control them can vary, Better Farming connects with experts to learn about weeds that are causing problems in the Prairie provinces and new herbicides that are on the market to control them.

The experts also offer tips on weed management and share their insights on how herbicide resistance is affecting producers.

Weeds on the Prairies

In Western Canada, some of the prevalent weeds include kochia, wild oats, cleavers, volunteer canola, dandelions, narrow-leafed hawk's beard, wild buckwheat, hemp nettle and green and yellow foxtail.

For the most part, the region in which you're located determines which weed is going to cause you the most trouble, but a weed on many Prairie producers' minds is kochia.

"We're seeing some Group 4-resistant kochia, so there is Group 2-, 4- and 9-resistant kochia in southern Alberta. So, obviously the Group 9 are glyphosate resistance – that's fairly large right now – but now there is a Group 4-resistant population starting to show up in certain areas. That's making it very difficult to manage," says Andrew Reid.

Reid is the technical marketing specialist for herbicides at BASF.

Kochia is traditionally a brown-soil-zone weed, but it's moving north, says Holly Nicoll. She is the head of marketing for Canada at Nufarm.

"Now, it's in the dark brown soil zone and even starting to get into the black soil. So, it's becoming more of an issue for growers. That weed is just a challenge for herbicides because of resistance and so it's continuing to be a problem," she tells Better Farming.

Weed management

Weeds are not going to go away on their own, so how can producers deal with them?

"One of the key things around weed control is the importance of having a really strong crop competition," says Kelly Bennett. "So, getting your crop off to a good start, making sure it's starting out weed free, so you get good, vigorous seedling development is really important. Making sure you've got good starter fertilizer with it, your seed-placed phosphate in for that rapid early growth of the seedlings, as well as seed treatments to prevent disease. Because if you have a very healthy, vigorous, rapidly growing crop, that helps out with your weed control."

Bennett is the Western Canada category leader for herbicides at Corteva Agriscience.

Crop rotation is also important to help with weed control.

"Rotating your crops provides different environments for different weeds. So, it does keep the weeds off balance. Even changing your timing of weed control is important. If you've got a particular field that is always the latest field or always the earliest field, switching it up a bit and maybe delaying your timing on that early field, just to change the time when you're going after those weeds in a pre-seed application is good for resistance management," Bennett tells Better Farming.

Nicoll agrees that crop rotation is important. The team at Nufarm offers other suggestions to help producers with weed management.

They recommend a layering herbicide program, which means focusing on both pre-seed and in-crop herbicides while also using herbicides with different groups that target the same weeds. They also encourage producers to check their spray coverage, says Nicoll.

"Make sure that your sprayer is doing a good job and it's getting the herbicide where it needs to go on those weeds. Make sure that you're using adequate water volumes and the right sprayer nozzles for the herbicide. Use nozzles that are in good condition and ensure the boom heights are adjusted to the height based on the product that you're applying on the sprayer. Another big one to watch is your speed," she says.

The Nufarm team also advise producers to be aware of their active ingredients and to change up the modes of action. Finally, they stress the importance of paying attention to water quality.

The BASF team recommend scouting your fields to know where you are starting, says Reid.

"Understand what weeds you have, what pressures you have in each respective field to really formulate a management plan for each individual field. That gives you the best opportunity to manage those weeds," he tells Better Farming.

Weed management overall often does not just mean using herbicides. It also includes management tools such as tillage and residue management. When you do use herbicides, though, you can look into certain aspects of that practice as well, says Reid.

It's good to "look at all the options you have available in terms of products. Just because you've used the product in the past and it worked really well for you, doesn't necessarily mean that you should be using it year over year over year. That's one reason why we get some resistance issues.

"Rotate herbicides, rotate modes of action, make sure you're doing all those little things that prolong the effectiveness of the modes of action we have today, because companies just aren't producing new modes of action like they used to," Reid says.

Management options

While new options are not introduced as often these days, producers have some choices for the 2021 season.

BASF has a new pre-seed herbicide for canola production called Certitude.

"It's a new mode of action for canola production that provides control of all resistant biotypes of kochia as well as volunteer canola," says Reid.

Another pre-seed herbicide from BASF that will likely be available in 2022 is Smoulder. It's a herbicide for wheat and barley growers and helps control volunteer canola and provides a burndown for all Group 2-, 4- and 9-resistant broadleaf weeds, Reid tells Better Farming.

Nufarm has a new product called ThunderHawk.

ThunderHawk is "a great fit for farmers in the dark brown and black soil zones ahead of seeding cereals. It has three modes of action in it, so it delivers an excellent fast-acting control on a wide spectrum of broadleaf weeds. It also provides some longer residual activity on volunteer canola," says Nicoll.

Nufarm also has a new option for their soil active pre-emergent herbicide called Fierce.

"We've had (Fierce) on the market for a few years; it was in a dry formulation. We're excited to launch a new liquid formulation which is more convenient for farmers to use and handle. We're also finding that the liquid formulation activates easier under soil moisture conditions in springtime," adds Nicoll.

Bayer has some newer products to Western Canada that help with kochia and wild oats, says Cranston.

"Infinity and Infinity FX are absolutely outstanding at controlling kochia. For wild oats, we have our Varro franchise, as well as our Olympus herbicide," he says.

Corteva has some new products for the upcoming year including two new broadleaf herbicides, Exhilarate and Prominex, which contain the new Arylex active, says Bennett.

"Exhilarate is a workhorse-type product and really solid on weeds like cleavers, chickweed, buckwheat, but also gets narrow-leafed hawk's beard and volunteer alfalfa," explains Bennett. "Prominex is more of a premium- category product. It controls perennial broadleaf weeds like Canada thistle, dandelion and also a very wide range of annual broadleaf weeds."

The herbicide is an upgrade from a previous product, says Bennett.

"We've upgraded Rezuvant to a formulated product for more convenience. That is one of the things we focus on from an innovation standpoint as well. It's not just about new actives or new modes of action, it's also about increasing value and convenience.

"So, Rezuvant XL is now a formulated version of the grass and broadleaf components that were in it before. This will make it more convenient to use and it's mainly directed in the black soil zones for barley and wheat growers," Bennett explains.

Another new product from Corteva is Bindem, which is a compatibility agent for broadleaf herbicide tank mixing and is for use with its product Simplicity GoDRI.

"Simplicity GoDRI is a dry formulation. It refers to a particular type of dry formulation technology that disperses and mixes really well in the spray tank, as opposed to some," Bennett says.

"It does require a compatibility agent when mixing with broadleaf herbicides, so we brought out a new one called Bindem, which makes sure that the spray solution stays consistent in the spray tank and sprays out well. Bindem is going to be available on the market this year to use with Simplicity GoDRI."

Another option for producers this year comes from FMC Corporation. Its Authority Supreme herbicide offers two-in-one pre-emergent protection against grassy and broadleaf weeds for field peas, chickpeas and soybeans. It can be applied pre-plant or pre-emergence up to three days after planting, says Katrina Schmidt, marketing manager at FMC.

FMC also has its Command Charge herbicide that provides extensive burn off of broadleaf weeds with extended control of cleavers ahead of canola.

"Command Charge provides early season weed control that is critical to plant stand establishment in canola which can help secure yields. It has the added benefit of introducing a unique Group 13 active to combat resistance," Schmidt tells Better Farming.

Herbicide resistance

While having options for producers to use on their fields is good, herbicide resistance is a looming issue that always needs to be thought about, says Cranston.

"For a long time, we always kind of felt that herbicides were that silver bullet for controlling weeds. Well, that's not the case now," he says. "We're seeing weed species developing more resistances in the fields."

That is why it's important to use multiple management tools when tackling weeds, says Cranston.

"We need to be thinking of everything we can do. It goes back to the concepts of would you rather have one big hammer or a thousand tiny hammers? Each of them works a little bit," he adds.

Reid agrees.

"There are so many things that growers can utilize to help manage weeds, in general, that go beyond just using herbicides," he says. "If we continue to do some of the things we've done in the past like overly rely on certain modes of action, we're going to continue down a troubling path like we've seen with resistance issues," he says.

And the more resistance issues farmers have to deal with, the bigger impact it will have on their bottom line.

"There are so many areas that it is affecting. I would say yields are affected and quality is affected. There are the challenges at harvest time when you try to take the crop in through the combines and there's lots of green weed material and it's going through the machines. Once it's in the bin, it causes some issues there and it's just really frustrating for farmers. It creates a lot of headaches," says Nicoll.

But if farmers don't pay attention to potential herbicide resistance, they can end up unprepared when it does happen to them, says Nicoll.

"You're scrambling to figure out how to get the problem under control. It just takes a lot of extra management and that affects the bottom line," she adds.

Producers in Western Canada are actually doing a good job at managing herbicide resistance compared to producers in the United States, says Bennett.

"If you compare what we've been doing in Western Canada to some of the things they've seen, especially in the U.S. and the southern U.S., where they were using glyphosate-tolerant crops back to back and spraying only glyphosate year after year after year. In Western Canada, we have much better crop rotations. We're rotating from cereal crops to canola, peas, lentils and now soybeans and corn.

"I commend farmers. It's a tough thing to manage because they also have to make economic decisions around their crop rotations.

"There's absolutely room for improvement and a lot of education is still needed, but by and large, I'd say compared to when I started out in this industry 38 years ago, farmers are generally doing a pretty good job," says Bennett. BF