Pre-harvest Perennial Weed Control
Tuesday, August 14, 2018
The later stages of the growing season are a very effective time for controlling perennial weeds such as Canada thistle, quackgrass, and dandelion.
“At this time of the year, perennial weeds are preparing for winter by putting energy reserves into their root systems and the application of a glyphosate product now generally provides very good control of these weeds,” says Mark Cutts, crop specialist at the Alberta Ag-Info Centre. “Glyphosate is a systemic herbicide that moves through the foliage into the root system and results in the death of the entire plant. Applying glyphosate to a standing crop is referred to as pre-harvest and has become a very common management practice. It should be noted that in order for the glyphosate application to be effective, the weeds need to be actively growing,” Cutts adds. “With drier conditions in areas of the province this growing season, an evaluation of these weeds should be made before an herbicide application.”
Cutts says that producers considering pre-harvest as a management tool for their crops should consider several factors.