by David Bennett
It’s that time of year when the migration of waterfowl has begun and hunters unlock the gun cabinet and pull on camo. It turns out those wonderful ducks may be carrying more than the odd band and a desire for warmer climes.
Is the rapid spread of herbicide-resistant pigweeds in the Mid-South at least partially attributable to the flyway? A recent study out of Missouri says it is quite likely.
In 2014, Jaime Farmer was a weed science program graduate student under Dr. Kevin Bradley at the University of Missouri. That fall, Farmer — now a Pioneer agronomist for western Missouri — began collecting hunter-harvested ducks. In 2015, Farmer and colleagues did a feeding study and repeated the collection of ducks and snow geese.
Farmer, who spoke with Delta Farm Press in early December, explains what the study showed.
What precipitated the start of the study?
“A couple of things came together. First, my predecessors in the program were avid waterfowl hunters. Dr. Bradley had been tracking the movement of Palmer amaranth throughout Missouri for a few years before I got there.
“One of the things they noticed was that a lot of the areas in counties they were finding the weed were in river bottoms. Western Missouri has two main river systems flowing through. Until then, most of the Palmer amaranth had been contained in the Bootheel.
“The first thought was ‘maybe it’s flooding that dispersing the seed in these bottoms.’ But what was interesting was the movement of the Palmer was from south to north – opposite of the water flow direction. That’s when they came up with the possibility that waterfowl may be responsible for spreading the seed. Farmers pointed out that a lot of ducks and geese had been in fields over the winter and then they found pigweeds there the next growing season.
“When I got to the program, he asked if I could figure out a way to answer whether waterfowl was the answer. We began looking at literature, decided to find out if waterfowl were even eating Palmer amaranth and waterhemp seed and, if so, what potential does that seed have to make it through the bird and still be viable.”