After spending close to 2,500 hours over the last five years operating a sprayer equipped with optical spraying technology on his farm near Fisk, Saskatchewan, Carl deConinck Smith is not only an early adopter, but also a proponent of weed-sensing technology on sprayers.
“Five years ago, we felt it was about a three-year return on investment. Now, with the increased chemical costs it’s a two-year return on investment,” he says, referring to the optical “green-on-brown” Weed-It system that’s installed on his John Deere sprayer.
Savings on herbicides for burn-off, where green-on-brown camera systems are typically used, range from 30 per cent to as high as 90 per cent, he says, in this new Canola School episode, filmed at Canola Week in Saskatoon, Sask., earlier this winter.
“You’re probably going to average around 60 per cent on an 8,000 acre burn-off…so yeah, it is significant,” says deConinck Smith.
Before talking chemical savings, the first question he says he’s usually asked is ‘how do you know how much chemical to mix?’
“The easy answer is it usually doesn’t matter, because if you have a system like this, you’re generally doing lots of acres. So at the end of 1000 acres, if you have to turn it to just a full spray, that’s fine,” says deConinck Smith. “The long answer is after just a handful of fields, you get a pretty good eye for surveying, looking at a field, you’ll know that it might run an average of that two to four gallons an acre. So you’ve got a pretty good idea once you have some experience with it.” (article continues below video)
As far as he knows, his farm’s sprayer is also the only one in the world that’s equipped with both an optical spraying system and a direct injection system that essentially mixes chemical with water for spraying on-demand — also alleviating some of the issues around knowing how much to mix before loading up the sprayer.
Over time, he says it’s important to understand what optical or spot spraying systems are good at and what they’re not good at. For example, they’re better at targeting broadleafs and weeds that grow in patches than newly-emerged grassy weeds, such as a wild oat seedling.
“That’ll give you an indication — when you go look at your field, what type of weeds you have — whether you need a background rate or just a spot spray. There’s a little bit of a learning factor with it,” he says.
While several companies are developing and introducing “green-on-green” technologies designed to identify and target weeds in a growing crop, deConinck Smith believes there’s more low-hanging fruit that can be accomplished with green-on-brown systems. That includes developing sprayer operators’ trust in weed-sensing systems, where it’s not as simple as mixing chemical and watching tank levels drop in correlation to the acres covered.
While manufacturers and tech companies are making major investments in green-on-green technology, there are still questions about acceptable levels of precision and accuracy that need to be answered, he notes.
“If it’s 80, 85 per cent accurate. That’s fine for a first pass application, but that might not be acceptable for many farms on that second or last pass, because it’s our last chance to get all the weeds that we need to get controlled before the crop matures,” explains deConinck Smith.
Looking forward, he anticipates introducing more automation to spraying, as deConinck Smith is also working with Raven on its OmniPower autonomous platform (formerly known as DOT). “The next step is definitely to look at putting the spot spray technology on autonomy. I’m also looking at companies like SwarmFarm out of Australia. That’s definitely the kind of systems that are on our radar, just to make things just a little bit more efficient and to do more acres with the same amount of people and labour.”
Check out the Canola School episode above for more with Carl deConinck Smith, who farms near Fisk, Saskatchewan, on the lessons he’s learned using optical spraying technology over the last five years.