Is it too late to save glyphosate?
GroundCover™ Issue: 104
Weeds specialist Dr Ford Baldwin of Practical Weed Consultants in the US thought Roundup Ready® soybeans were a miracle when they became available in 1995: “The technology was superior to anything we had seen,” he said.
At the time of its launch, Dr Baldwin believed the technology would lower input costs and result in simpler, more efficient weed management for growers. And it did – for about 10 years.
But warning bells started to ring when paddocks were no longer 100 per cent clean. A few scattered weeds appeared in 2005, which became small strips of weeds a year later and then larger streaks in the third year.
To address the problem, many growers doubled their glyphosate rate or treated crops several times during the growing season. “The following year, they didn’t harvest because the field was so infested with glyphosate-tolerant weeds,” Dr Baldwin recalled.
Just as quickly as the Roundup Ready® technology rose to the top, he said, within four years it went the other way because glyphosate had been overused.
Dr Baldwin said that if you look at the technology now in the US, resistance is found within all the key weed species, meaning some growers have had to resort to hand-weeding and tillage to deal with tolerant plants. He said nobody within the industry – growers, consultants or chemical company representatives – believed the problem of resistance would become so bad so quickly.
“A lot of people say: ‘when you start seeing some escapes, change your program,’ but when you start seeing escapes, it’s too late,” he said.
For the US, Dr Baldwin feels it is too late to save glyphosate in its present form. Although US growers will continue to use glyphosate, Dr Baldwin does not think it will be the dominant herbicide going forward because of weeds resistance. Consequently, he said, many southern US growers are turning to glufosinate (Group N herbicides, such as Basta® and Liberty®) to achieve broad-spectrum weed control.
“And there’s a great opportunity for growers in areas without glyphosate resistance to be proactive about their weed control by not overusing glyphosate.”
Dr Ford Baldwin,
GRDC Project Code GCS10000