Controlling Cotton Weeds With A Zero-Tolerance Approach.
⋅ BY CASSIDY NEMEC ⋅
ASSISTANT EDITOR
As a member of Operation Weed Eradication (OWE), BASF is partnering with many in the agricultural industry to help bring solutions to persistent weeds found in row crops.
OWE’s website states “Led by BASF, Operation Weed Eradication, a US-based initiative, is supported by a coalition of industry leaders and weed scientists with one goal: providing our farmers the relevant tools, insights and information to help battle resistant pigweed on farm.”
Palmar amaranth (Amaranthus palmeri) and kochia (Kochia scoparia L.) are two of the main weeds posing a threat in cotton, according to Adam Hixson, BASF technical service representative.
“Just one plant producing its seed can spread across that field in exponential growth in the coming years. It’s extremely resistant to numerous herbicides and numerous modes of action, so taking those last few weeds out is very important to long-lasting, complete weed control,” Hixson said.
He said it is good to pay attention to soil temperatures so as to know germination timing. When that is known, residuals can be better timed. “It’s important to get it before it comes up,” he said.
Last Weed Standing
In addition, Hixson explained the importance of getting every last weed before getting to a point where they begin to spread. “When we think about weed control, we need to think about that last weed standing in the field.”
The Operation Weed Eradication website discussed this as part of the “eradication diligence” component of OWE. “An eradication mindset means going the extra mile to take out the last weed standing before it produces seed.”
In addition to eradication diligence, OWE looks at chemical control and traits (covering proper application, adding in appropriate residuals and finding “multiple, effective sites of action to prevent resistance”), as well as cultural and mechanical practices that help to disrupt seed germination. These practices include:
→ Implementing narrow rows for canopy development.
→ Planting cover crops to assist in suppressing weed growth.
→ Tillage and cultivation to uproot emerged weeds.
→ Crop rotation to allow multiple herbicides and practices to be put into play for weeds.
Role Of Residuals
Hixson emphasized to start the year with strong residuals at planting to keep up with key timing for weed control.
“What I like to recommend is one of those typical cotton residual herbicides at planting combined with some sort of postemergence herbicide. I like to use paraquat at planting… once you get in season, say three to four weeks after planting, you really need to start thinking about your next application that would be some sort of post herbicide combined with a residual herbicide… for us it’s either Liberty or Engenia, plus Outlook.,” he said.
Adam Hixson
Don’t Ignore Field Perimeters
Hixson noted the importance of controlling weeds around the fields in addition to the fields themselves as seed can be rapidly spread while entering and leaving fields.
“If you’re able to control the area around your fields, spray it with something very simple, some sort of burndown… sometimes growers think about the weeds in their fields and not the weeds outside of their fields and how they can potentially drag them [seeds] in as they’re moving equipment to their fields.”
BASF launched OWE in 2019 and continues to work in helping growers eliminate weeds on their farms.
“I think it’s a good mindset to have, and I think it’s important that we are surrounding ourselves with both industry partners and university weed science professors that are really on board with our message.”