If you have been in the agricultural business for more than 10 years, you know that weed resistance is becoming old news. Since the start of the 2000s, researchers have discovered dozens of weed types that have developed resistance to several popular herbicides.
But perhaps no weed resistance has gained more attention than the increasing number of types that can now fend off glyphosate applications. As the most popular herbicide in the industry, growers have largely used glyphosate to control all their weed problems as a single-shot solution during the last two decades.
Those days may be ending, however. At last count, 24 states had confirmed glyphosate-resistant weeds growing in them, most of these spread out among the key corn/soybean/cotton producing areas of the country. Among this group were particularly hard-to-control weeds such as waterhemp, pigweed and marestail.
Now I’ve heard all about how damaging these resistant weeds can be to crop yields and harvesting equipment for growers. But the additional cost to combat these weeds is staggering. On a recent tour of crop fields in Arkansas, grower Malcolm Haigwood spelled out in graphic detail just how expensive fighting glyphosate-resistant weeds has become.
“A few years ago, it used to cost me between $12 and $15 per acre to control these weeds,” said Haigwood. “Last year, it cost me between $65 and $80 per acre, using more applications and more crop protection products to achieve the same level of control.” He further predicted that with the increased materials, labor and fuel costs associated for these weed control efforts, his cost per acre in 2012 could reach near $100.
Several companies, including Dow AgroSciences (which hosted the tour), are working on new herbicides to help re-establish some of the effectiveness of glyphosate, but most of these are still a few seasons away from being market ready. In the meantime, Haigwood says the biggest issue he is facing with other growers is denial that their fields have glyphosate-resistant weeds in them.
“Many of these friends tell me they must have gotten a hold of some bad chemical when the weeds don’t die,” he said. “Let me tell you – I’ve sprayed hundreds of thousands of acres since the 1960s and I’ve never had any bad chemical. If the weeds don’t die, they are probably resistant.”
Where this growing weed resistance problem goes is anybody’s guess right now. But one thing is certain – the days of a single-shot crop protection solution such as glyphosate are probably coming to an end.