Oct 11, 2024 06:07 PM
https://www.technologyreview.com/2024/10...eeds-food/
EXCERPTS: Since the 1980s, more and more plants have evolved to become immune to the biochemical mechanisms that herbicides leverage to kill them. This herbicidal resistance threatens to decrease yields—out-of-control weeds can reduce them by 50% or more, and extreme cases can wipe out whole fields.
At worst, it can even drive farmers out of business. It’s the agricultural equivalent of antibiotic resistance, and it keeps getting worse.
[...] Water hemp (Amaranthus tuberculatus), which can infest just about any kind of crop field, grows an inch or more a day, and females of the species can easily produce hundreds of thousands of seeds. Native to the Midwest, it has burst forth in much greater abundance over the last few years, because it has become resistant to seven different classes of herbicides. Season-long competition from water hemp can reduce soybean yields by 44% and corn yields by 15%, according to Purdue University Extension.
Most farmers are still making do. Two different groups of herbicides still usually work against water hemp. But cases of resistance to both are cropping up more and more. “We’re starting to see failures,” says Kevin Bradley, a plant scientist at the University of Missouri who studies weed management. “We could be in a dangerous situation, for sure.”
Elsewhere, the situation is even more grim. “We really need a fundamental change in weed control, and we need it quick, ’cause the weeds have caught up to us,” says Larry Steckel, a professor of plant sciences at the University of Tennessee. “It’s come to a pretty critical point.”
[...] “We’re too narrow-visioned, focusing on herbicides as the solution,” says Steven Fennimore, a weed scientist with the University of California, Davis, based in Salinas, California.
Fennimore specializes in vegetables, for which there are few herbicide options, and there are fewer still for organic growers. So innovation is necessary. He developed a prototype that injects steam into the ground, killing weeds within several inches of the entry point. This has proved around 90% effective, and he’s used it in fields growing lettuce, carrots, and onions. But it is not exactly quick: It takes two or three days to treat a 10-acre block.
Many other nonchemical means of control are gaining traction in vegetables and other high-value crops. Eventually, if the economics and logistics work out, these could catch on in row crops, those planted in rows that can be tilled by machinery.
A company called Carbon Robotics, for example, produces an AI-driven system called the LaserWeeder that, as the name implies, uses lasers to kill weeds. It is designed to pilot itself up and down crop rows, recognizing unwanted plants and vaporizing them with one of its 30 lasers. LaserWeeders are now active in at least 17 states, according to the company.
You can also shock weeds by using electricity, and several apparatuses designed to do so are commercially available in the United States and Europe. A typical design involves the use of a height-adjustable copper boom that zaps weeds it touches. The most obvious downside with this method is that the weeds usually have to be taller than the crop. By the time the weeds have grown that high, they’ve probably already caused a decline in yield.
Weed seed destructors are another promising option. These devices, commonly used in Australia and catching on a bit in places like the Pacific Northwest, grind up and kill the seeds of weeds as wheat is harvested.
[...] In general, AI-driven rigs and precision spraying are very likely to eventually reduce herbicide use, says Stephen Duke, who studies herbicides at the University of Mississippi: “Eventually I expect we’ll see robotic weeding and AI-driven spray rigs taking over.” But he expects that to take a while on crops like soybeans and corn, since it is economically difficult to invest a lot of money in tending such “low-value” agronomic crops planted across such vast areas.
A handful of startups are pursuing new types of herbicides, based on natural products found in fungi or used by plants to compete with one another. But none of these promise to be ready for market anytime soon... (MORE - missing details)
EXCERPTS: Since the 1980s, more and more plants have evolved to become immune to the biochemical mechanisms that herbicides leverage to kill them. This herbicidal resistance threatens to decrease yields—out-of-control weeds can reduce them by 50% or more, and extreme cases can wipe out whole fields.
At worst, it can even drive farmers out of business. It’s the agricultural equivalent of antibiotic resistance, and it keeps getting worse.
[...] Water hemp (Amaranthus tuberculatus), which can infest just about any kind of crop field, grows an inch or more a day, and females of the species can easily produce hundreds of thousands of seeds. Native to the Midwest, it has burst forth in much greater abundance over the last few years, because it has become resistant to seven different classes of herbicides. Season-long competition from water hemp can reduce soybean yields by 44% and corn yields by 15%, according to Purdue University Extension.
Most farmers are still making do. Two different groups of herbicides still usually work against water hemp. But cases of resistance to both are cropping up more and more. “We’re starting to see failures,” says Kevin Bradley, a plant scientist at the University of Missouri who studies weed management. “We could be in a dangerous situation, for sure.”
Elsewhere, the situation is even more grim. “We really need a fundamental change in weed control, and we need it quick, ’cause the weeds have caught up to us,” says Larry Steckel, a professor of plant sciences at the University of Tennessee. “It’s come to a pretty critical point.”
[...] “We’re too narrow-visioned, focusing on herbicides as the solution,” says Steven Fennimore, a weed scientist with the University of California, Davis, based in Salinas, California.
Fennimore specializes in vegetables, for which there are few herbicide options, and there are fewer still for organic growers. So innovation is necessary. He developed a prototype that injects steam into the ground, killing weeds within several inches of the entry point. This has proved around 90% effective, and he’s used it in fields growing lettuce, carrots, and onions. But it is not exactly quick: It takes two or three days to treat a 10-acre block.
Many other nonchemical means of control are gaining traction in vegetables and other high-value crops. Eventually, if the economics and logistics work out, these could catch on in row crops, those planted in rows that can be tilled by machinery.
A company called Carbon Robotics, for example, produces an AI-driven system called the LaserWeeder that, as the name implies, uses lasers to kill weeds. It is designed to pilot itself up and down crop rows, recognizing unwanted plants and vaporizing them with one of its 30 lasers. LaserWeeders are now active in at least 17 states, according to the company.
You can also shock weeds by using electricity, and several apparatuses designed to do so are commercially available in the United States and Europe. A typical design involves the use of a height-adjustable copper boom that zaps weeds it touches. The most obvious downside with this method is that the weeds usually have to be taller than the crop. By the time the weeds have grown that high, they’ve probably already caused a decline in yield.
Weed seed destructors are another promising option. These devices, commonly used in Australia and catching on a bit in places like the Pacific Northwest, grind up and kill the seeds of weeds as wheat is harvested.
[...] In general, AI-driven rigs and precision spraying are very likely to eventually reduce herbicide use, says Stephen Duke, who studies herbicides at the University of Mississippi: “Eventually I expect we’ll see robotic weeding and AI-driven spray rigs taking over.” But he expects that to take a while on crops like soybeans and corn, since it is economically difficult to invest a lot of money in tending such “low-value” agronomic crops planted across such vast areas.
A handful of startups are pursuing new types of herbicides, based on natural products found in fungi or used by plants to compete with one another. But none of these promise to be ready for market anytime soon... (MORE - missing details)
