February may seem early to think about a spraying strategy for the coming growing season but doing so now may pay off later in weed kill and crop yield.
This is the take-home message from a 2021 Manitoba Canola Growers webinar on in-crop spraying, hosted by Jay Whetter of the Canola Council of Canada (CCC) and featuring Tom Wolf, a sprayer expert and scientist at Saskatoon-based Agrimetrix Research and Training, and Ian Epp, a CCC agronomy specialist. Although the experts were focused primarily on a last-minute checklist for in-crop spraying of canola, the advice offered also crossed commodity lines.
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And time management is at the top of that checklist. The adage “you can’t manage what you don’t measure” can be applied here. Or, as Wolf puts it, “take time to account for time.”
“This is the time to take note of things that are happening. And the best tools, really, include a notepad and a stopwatch,” maintains Wolf. “We always underestimate how long it takes us to do things because we don’t start measuring at the right time.”
As you begin spraying, Wolf suggests timing how long it takes to fill and clean your sprayer tank, load your tender truck and prime the sprayer. This data can help you learn to manage these and other tasks, making sure they’re done in anticipation of — rather than on — prime spraying days.
Filling the sprayer is probably the most time-consuming of all preparation activities and the time it takes needs to be recorded, he says.
“Cleaning the sprayer is another big one — cleaning filters, flushing — anything like that. Express the time taken as a total proportion of the time spent over the total time spraying. I’d be curious to see what you come up with.”
What you don’t want is to waste good spraying conditions performing routine tasks and maintenance, says Wolf.
“Are you fuelling up on a good spray day? You didn’t fuel up when you came home last night? That’s 15 minutes you’ll never get back. Are you loading your tender truck or your pickup truck on a good spray day? Shouldn’t you be spraying? Are you unaware of some of the specifics of the product label? You’re cutting into the spray time.”
Look for opportunities to reduce the time it takes to, for example, fill the tender truck with water. “If you have a tender system but it’s empty and it has to go home, that’s an hour gone,” says Wolf.
“I have a customer that uses a large reservoir tank in her yard with a 20-horsepower, five-inch pump. That’s 1,000 gallons per minute. She fills an entire tender in about 10 minutes, so the sprayer doesn’t wait.”
One action producers might want to consider taking in the future to make regular sprayer maintenance more efficient is investing in a recirculating boom. These save money and waste by recovering spray back to the tank during priming and rinsing, Wolf says.
“The recirculating boom saves product and saves time for priming. You can prime without spraying.”
And if you think you’re spending too much time sanitizing your sprayer, you probably are. A classic triple rinse alone usually takes 30 to 45 minutes. A continuous rinse system may help, says Wolf. A “rinse pump” permits the main product pump to operate simultaneously, emptying the product tank and spraying the rinsate out of the boom.
“The people who have put in these continuous rinse systems, which … allow you to spray at the same time as rinsing, are saving tons of time,” he says.
Clean sprayer thoroughly
Record-keeping can also play an important role in keeping track of crop protection products you’ve applied, says Epp. It’s no longer enough to rely on memory.
“If this was 20 years ago, we’d just be coming out of our pre-burn where we would have been spraying straight glyphosate on everything. Because glyphosate’s a pretty easy rinse-out, we’d be off to the races.”
However, times have changed. “Now, if you’ve been doing some planning in winter, you’ve probably had two or three modes of action alongside glyphosate to improve weed control (in the pre-burn).”
This makes a double-check of sprayer cleanliness even more important than in the past, says Epp, who illustrated his point with a real-life case of Group 2 damage of LibertyLink canola.
“The grower had been adding some tank-mix partners in the pre-burn and had no issues, no residuals — things looked good. They went to spray the first tank of Liberty (herbicide).
“Now, Liberty, on top of being a widespread canola herbicide, is very good at scrubbing out certain other herbicides from your tank. So, if you’ve done a medium job of cleaning your sprayer but haven’t quite got everything cleaned out, you might have issues.”
Spray early
Generally, the best time to spray herbicide is early, says Epp. Exceptions may include instances in which weed counts are very low, dry conditions have slowed all plant growth, or the pre-seed burnoff was effective enough to get ahead of weeds. Otherwise, there’s no point waiting for more weeds to pop up.
“Early weed control is free yield,” says Epp. “Waiting for those extra couple of weeds may seem like a good idea but you’re not protecting yield. Those weeds are taking up nutrients and moisture, so spray early.”
Get boots in the field
One of the best ways to get the most from a herbicide application is to scout beforehand for weed pressure, says Epp. Scouting for insect pressure, herbicide residue and other crop threats is also key.
“There’s nothing that replaces the boots in the field,” he says. “(Late May) is a really critical time to be scouting not just for weeds but for flea beetles, frost damage and stand establishment. It’s a very critical time for canola. Make sure you get a good record of what’s in your field. Is the weed pressure heavy, light or not so bad?”
When it comes to weeds, you should know beforehand what you’re looking for and watch out for any changes to their populations, says Epp.
“Species can change a lot from year to year. If you’ve been in farming for a while, you’re probably experts on the topical weeds in your individual fields. Are they bigger this year or are they smaller?”
Epp likes to take note of the top three biggest weeds in a field by both number and size. By doing so, growers have data that can help them make management decisions.
“Do I need a tank-mix partner? Are there any special weeds in there? What are my herbicide-resistant weeds?” he adds.
Irregularities, in general, are important to take note of.
“Is there a patch I’m scouting that looks kind of weird? I like putting in pin flags to mark these in the field and then come back two weeks after an application to see if the weeds actually died. Was the rate of my product actually correct? Is there herbicide resistance or something I need to be putting in my records so I can make better decisions in winter?”
Read the label and stay on it
More than 90 per cent of canola is destined for export markets, says Epp. At the same time, issues with regulations and trade agreements are growing. Other crops in Western Canada face similar challenges.
The best way to ensure market access for your crop is to read and follow product labels to ensure the correct spray rate, timing and pre-harvest interval (PHI). The latter is the minimum amount of time between the last application of a specific product and when the crop can be harvested.
Ideally, producers should be applying crop protection products as early as possible, so timing and PHI don’t become an issue. However, life happens, says Epp, and the good news for canola growers is they can apply a second round of herbicide.
“As we get later in the season things happen. The fields get too wet, a product doesn’t work, the sprayer breaks down, you don’t follow Tom’s advice and you spend all of your time unloading your sprayer and not actually spraying. Sometimes we have unfortunate circumstances where we have to apply late, but making sure we’re on-label is really, really important.”
If you’re in doubt about the PHI or other spraying intervals on your crop, the Spray to Swath Interval Calculator at keepitclean.ca may be able to help, adds Epp.
The full webinar can be found on YouTube.
