Two weed resistant seed varieties are popping up across the Commonwealth faster than management practices can control. Palmer Amaranth also known as ‘pigweed,’and its cousin variety Water Hemp were first noticed in 2010 in just a portion of the state, now University of Kentucky Extension Weed Specialist JD Green says every county has at least one variety.
“The genetic selection has already occurred in these plants, for example with glyphosate resistance, and the seed source is coming from populations that are already resistant and then when they get transferred into these areas, it is just noticeable because we aren’t controlling them with the tactics we are custom to using with our weed control programs,” said Green.
Green says most of the seeds are getting transferred via used farm equipment purchases. He says farmers are resorting to intensive labor practices, like hand pulling or hoeing the weeds because the typical weed killing agents aren’t working. He says a new effective weed killing variety will likely take years to get on the shelf.
When Green began his career, almost 30 years ago, Johnsongrass was the weed of concern, so that drove most of the management plans.
“...and that weed still exists, but now we have tools to deal with that plant, like roundup ready,” said Green.
Green says new modes of action need to be implemented and that takes research in new herbicide chemistries, something that has lost significant funding over the years.
