Weed Seed Control Clinic Will Explore Harvest as a Control Method

An Australian expert will discuss ways farmers can reduce weed seed additions to soil during harvest

October 2, 2019, 1:38 pm | Meaghan Anderson, Robert Hartzler, Prashant Jha

AMES, Iowa – Controlling weeds has always been one of the biggest challenges of producing a crop, and with the ever-present issue of herbicide resistance, farmers are constantly searching for new solutions.

Some practical, but innovative ideas will be explored during an Oct. 21 workshop, when Australian researcher Michael Walsh visits Iowa State University to talk about the various ways farmers can harvest and destroy weed seeds from the combine.

combining soybean field.Walsh is director of weed research at the University of Sydney, Australia. Weed resistance in Australia is among the worst in the world, and Walsh has explored a number of seed harvest solutions, including removing chaff from combines, grinding chaff and weed seed, and windrowing/tramlining the chaff.

Walsh will host a harvest weed seed control clinic at the Iowa State University Field Extension Education Laboratory Oct. 21, from 10 a.m. to 3 p.m. The morning session will focus on the principles of harvesting weed seeds as a method of control, and following lunch, Walsh will demonstrate the types of combine and equipment modifications used to separate weed seeds from other materials entering the combine.

Meaghan Anderson, field agronomist with ISU Extension and Outreach, said the workshop will be a great opportunity for participants to learn about weed management tactics of other countries, while also considering the potential for use on their own farm.

“'Harvest weed seed control’ is an alternative weed control tactic that targets weed seeds before they are shed from the plant, using the combine to intercept the seeds and prevent them from entering the seedbank and contributing to future problems,” she said.

According to Anderson, some Australian farmers are using combines that are modified to either pull a machine that collects and crushes the weed seed, or modified internally, in a way that collects and grinds the seed, or deposits the chaff behind the combine.

Anderson said some of the methods may not work in the United States, at least not currently, but there may be some ideas for the future.

“While the technology is not currently available for our system, it is likely this will be a tool that will be of value in the near future,” she said.

One thing she’s certain about is the continued fight against herbicide resistance. Harvesting weed seeds before they have a chance to fall to the ground could provide farmers one more option.

The clinic is free and open to the public. Attendees may be eligible to receive up to 4.0 pest management Certified Crop Adviser (CCA) continuing education units for their attendance at the clinic (pending approval). Iowa State’s Field Extension Education Laboratory is located at 1928 240th St., Boone, Iowa.

To help with the lunch count, RSVP by Oct. 14 to Meaghan Anderson at mjanders@iastate.edu or 319-331-0058.


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