“First we have to take a step back and see what got us into some of these problems, and that’s using the same thing over and over and over,” he said, “and of course weeds will find a way to figure out how to overcome this and become resistant. So, diversity includes chemical diversity, but also rotating crops, rotating HT traits so that gives you more opportunity to rotate to different chemistries, but also including non-chemical methods that help control and reduce the selection pressure for resistance.”
The resistance problem is here now, and it’s growing so diverse strategies should be employed now.
“They should start doing it now,” Strek says. “It’s how many times you apply and you only have a limited number of cycles before you can develop resistance. Unfortunately resistance development has a long period where you’re selecting for these genes that confer resistance and you really can’t see them. They’re kind of in the background noise. And then all of a sudden it enters an exponential phase, so year one you have solitary soldiers, solitary plants. Year two you have bigger patches and then year three it takes over your field and it’s consistently seen in that pattern, that it hits an exponential phase and takes it over. And you don’t want that to happen because then it’s too late.”
Bayer CropScience’s Liberty and LibertyLink is the only non-selective weed control system alternative to glyphosate and their Respect the Rotation program will help farmers understand the system.
Dr. Strek is Head of Profiling and Market Support, Weed Control Research Biology in Frankfurt. Hear the full HAT interview:Dr Harry Strek