Grainswest - Tech 2022

Tech 2022 grainswest.com 41 to work.” Spring moisture is crucial for this rotation to work, Gosling admits. Seeding date is also a very underutilized tool, he said. “If you've got a field with weeds that are really winning the war, so to speak, I would put seeding dates further back in the calendar, get aggressive with a pre-seed burn-off and wait for conditions that allow a crop to come up as quickly and aggressively as possible, with higher seeding rates.” In worst case scenarios, Gosling recommends switching to forage. “It’ll typically be really, really ugly until that forage gets established,” he said. “But a lot of these weeds need some sort of tillage to encourage germination, so if we can get a good forage established in there ….” But not all Prairie farmers have access to forage equipment, which makes this option less feasible. Gosling’s final recommendation is one that is often not well received. Depending on the weed, plowing can be a useful tool to bury weed seed enough that it can’t germinate. “It’ll probably be a last strategy,” he said, adding that plowing is certainly not a strategy for wild oat management as it can germinate from a very deep profile. His real hope, though, is that sensor technology, including spot sprayers and drones, becomes more readily available and utilized. He doesn’t know of any farmers who now use such methods. An expert in spray application technology, Wolf’s expertise lies in spray drift, pesticide efficacy and sprayer tank cleanout. As someone who has focused his career on the use of spray technology, he discusses herbicide resistance with mixed feelings. “Resistance to herbicides is caused by the use of herbicides,” he said. “Some of the solutions to herbicide resistance are, in the short-term, herbicides, strangely enough. Which, however, will lead to more resistance,” he added. “It's not a long-term solution.” Wolf admitted it’s a conundrum. The only true way to manage herbicide resistance is to not spray. But since this is simply not feasible, especially on large farms, he divides his approach into two lines of thinking. The first is to try to develop methods that prolong the utility of herbicides, but the other is develop a backup option for when herbicides are no longer viable. “Really, we just need one weed, just one, that doesn’t allow us control with any herbicide,” he said. “Because what do you do with that one weed? It will now thrive regardless of what you do with chemicals. “That weed doesn’t have a name right now but it could be palmer amaranth,” he added. “If you can’t control palmer amaranth with herbicides, then you have no choice but to go to non-herbicidal methods. And I think we would be wise to plan for that day.” Like Gosling, Wolf has high hopes for sensor technology in the short-term. Spot sprayers, for instance, would allow for the use of multiple effective modes of action, previously considered too expensive, in a targeted way. Spot sprayers can be powerful agronomic tools beyond spraying, too. Wolf knows a farmer in western Saskatchewan who uses the spray volume map that his sprayer produces to work out the location of problematic weed patches. He then investigates the field to see what else can be done to manage the problem. Wolf pointed to further developments in the use of spray maps. For instance, he said, Geco Engineering founder and CEO Greg Stewart is categorizing the colour and shape of weed patches in an attempt to predict whether a shape is associated with a particular colour or resistance. “If you have a shape or a patch that might be long and narrow, it’s perhaps spread by a combine, so the Seed Destructor might be a useful intervening tool,” said Wolf. An Australian invention, the Harrington Seed Destructor uses a mechanical mill to crush weed seeds as they exit the combine at harvest, which prevents them from returning whole to the soil. Another option is green-on-brown sprayer, WEEDit from Dutch company Rometron. The sprayer senses plants by measuring reflected light that is associated with photosynthesis. The system works well, can detect small weeds and supports travel speeds of up to 24 km/h, said Wolf. There are about 12 such systems in operation in Western Canada, primarily southern Alberta and Saskatchewan. A second system called WeedSeeker, produced by Trimble, uses normalized difference vegetation index (NDVI) to detect green plants. It has similar features to WEEDit, but lags a bit in resolution, said Wolf. Green-on-brown systems pay for themselves in the long- term, said Wolf. A simple calculation of $10 per acre for a pre-burn application on 10,000 acres, requires $100,000 in chemicals. Green-on-brown sprayers can lower herbicide use by as much as 70 per cent, which saves a farmer $70,000 in a year. At a cost of approximately, $200,000, the machine can be paid off in just three years. A more conservative estimate would have it paid off in five, said Wolf. Green-on-green sprayer systems can detect weeds in green crop and selectively spray them as needed. Bilberry’s Greenview sprayer, the current leader in this area, is now commercially available only in Australia. Additional options now near market-ready include John Deere’s See & Spray Ultimate, Greeneye, Carbon Bee, Exxact Robotics and Precision AI. While these tools are not yet available, it’s important farmers take the time to look forward and plan for the inevitable. “This is a human problem, not a technological problem,” said Wolf. “The recognition of the problem is what is actually the problem. “I mean, I see the writing on the wall,” he added. “It's always difficult to predict the future, but if we look at past trends of the development of resistance, it’s going up in a linear way with time. We would be silly to ignore that trend. If our practices don’t change, it will continue to grow.”