By Clint Thompson
University of Georgia Cooperative Extension weed specialist Stanley Culpepper encourages vegetable growers to diversify their management programs against nutsedge. This protects against potential resistance and provides adequate control.
“In general, I would say with our guys, I’m not overly concerned because our fields with our most nutsedge, they get fumigation, they get tillage and they get herbicides,” Culpepper said. “My guys are quite diverse. Will we have resistance one day? Sure, we will, but we are quite diversified in our management approach. We’re not selecting for resistance, say compared to an agronomic guy who goes out and sprays roundup or dicamba three times.”
According to Alabama Cooperative Extension, purple nutsedge and yellow nutsedge are prevalent in most areas where vegetables are grown. Both are perennial weeds that propagate mainly by the production of tubers. While growers maintain control of nutsedge, it comes at a cost, says Culpepper.
“That pest is still the most problematic. Doesn’t necessarily mean we’re not controlling it, but we’re spending a lot of money to control it that we wouldn’t have to spend if it wasn’t so problematic,” Culpepper said. “The one that’s causing us the most money without a doubt in the plasticulture system is nutsedge.”
Why Is It So Problematic?
Farmers who implement plasticulture still struggle with nutsedge because it can penetrate mulch.
“Even if you haven’t poked a hole in the mulch, nutsedge can penetrate it itself. It can damage the mulch and be there before you plant. It can come at any time even if your plant is shading out the plant hole. It’s very unique that way,” Culpepper said. “Is it killing us? Is it hurting our guys? No, I think we’re doing a pretty daggum good job. It’s a repetitive challenge and costing us a lot of money to try to manage.”
Diversification is key since there are very few herbicides that are effective regardless of the vegetable crop being grown. It is not like peanuts where farmers can apply Cadre or cotton where Roundup can be applied. Nutsedge control in vegetables is limited to a couple of products.
“It’s there and probably in every single field but they’re doing a really good job controlling it. It’s not like some disease that jumped on us last week and is going to wipe us out. That’s not it at all,” Culpepper said. “But that’s the one I still say is most challenging for our vegetable growers in plasticulture systems.”