When it comes to precision-farming technology, automated spot spraying of weeds would be a science fiction dream come true.
If it lives up to its promise, farmers would save countless dollars in reduced herbicide use, benefit the environment, and maybe even gain the upper hand in battling herbicide resistance.
In Canada, the face of spot spraying has been Weed-It — a unit that’s become virtually synonymous with the so-called ‘green-on-brown’ precision-spraying technology touted as ideal for pre-seeding burn-down.
Although producers love the idea, their enthusiasm is tempered by both the cost — about $1,500 per foot of boom — and its utility, said Ken Coles, general manager of farmer-directed research organization Farming Smarter.
“The fact that it’s really only a tool for pre-seed burn-down and chem fallow-type applications probably limits people’s excitement because they usually buy a sprayer to do everything,” said Coles.
Farming Smarter hosted reps from Croplands Equipment at a field day earlier this summer to talk about the latest iteration of the Weed-It, the Quadro.
The Quadro sprays in three modes: full coverage, dual function (which can shift between low- and high-application rates) and spot spraying. But it can’t spray weeds in crop — that requires ‘green-on-green’ sensor technology, which is still in its fledgling stages and limited mainly to the European arena.
Another barrier to adoption of spot-spraying technology is that it is high tech.
“A lot of people know that any machine with that kind of complexity takes the control from the farmer in a sense because they can’t fix and tweak their own equipment — they have to rely on someone like a technician or a highly skilled person to come in,” said Coles. “That definitely scares people a little bit.
“I think in general there’s a certain hesitation because of cost and fear of technology. I think these are things that develop and improve over time; (products) need to be calibrated and fine-tuned.”
Still, the potential for significant herbicide savings is very attractive, said Coles.
Croplands, a subsidiary of Nufarm, says the Weed-It Quadro can save up to 90 per cent on chemical costs when spraying early weeds. It also claims a payback period of around two years for producers spraying 8,000 acres per year.
“That definitely caught people’s attention,” said Coles. “When the presenters talked about the amount of cost savings and the ability to use expensive pesticides sparingly, then I think that certainly generated a certain amount of interest.
“There’s also the fact that it’s on a full-scale, high-clearance sprayer with a detachable boom.”
The farmer attendees also seemed to enjoy the highly visual presentation by Croplands reps, added Coles.
They placed water-sensitive paper next to a weed and demonstrated how the chlorophyll-detecting sensors could differentiate between the two objects. Croplands says these sensors can sense a green weed in a field (even at night) and command spray nozzles to target it in an area as small as a centimetre.
“They could visually see the spray turn on and off as it was going over a weed.”
Croplands, which also operates in Australia, says it has sold more than 10,000 of the Weed-It sensors to farmers and customer operators Down Under. Parts of Australia have particularly severe outbreaks of herbicide-resistant weeds — that and reducing herbicide costs are commonly cited as the main drivers of Weed-It’s success in that country.