Harvest weed seed control (HWSC) comprises a set of tools and tactics that prevents the addition of weed seed to the soil seed bank, attenuating weed infestations and providing a method to combat the development and spread of herbicide-resistant weed populations. Initial HWSC research efforts in Nor … The spread of multiple-resistant weeds threatens Iowa’s production system.
Current outlook and future research needs for harvest weed seed control in North American cropping systems
Harvest weed seed control (HWSC) comprises a set of tools and tactics that prevents the addition of weed seed to the soil seed bank, attenuating weed infestations and providing a method to combat the development and spread of herbicide-resistant weed populations. Initial HWSC research efforts in North America are summarized and, combined with the vast area of crops suitable for HWSC, clearly indicate strong potential for this technology. However, potential limitations exist that are not present in Australian cropping systems where HWSC was developed. These include rotations with crops that are not currently amenable to HWSC (e.g. corn), high moisture content at harvest, untimely harvest, and others. Concerns about weeds becoming resistant to HWSC (i.e. adapting) exist, as do shifts in weed species composition, particularly with the diversity of weeds in North America. Currently the potential of HWSC vastly outweighs any drawbacks, necessitating further research. Such expanded efforts should foremost include chaff lining and impact mill commercial scale evaluation, as this will address potential limitations as well as economics. Growers must be integrated into large-scale, on-farm research and development activities aimed at alleviating the problems of using HWSC systems in North America and drive greater adoption subsequently. © 2020 Society of Chemical Industry.
Keywords: herbicide resistance management; integrated weed management; soil seed bank.
© 2020 Society of Chemical Industry.
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October 21 Harvest Weed Seed Control Clinic
The spread of multiple-resistant weeds threatens Iowa’s production system. In order to slow the expansion of resistance, greater diversity in weed management is necessary. An October 21 workshop will discuss one potential alternative weed management tool that is used in other parts of the world: harvest weed seed control. This clinic should be of interest to anyone interested in learning how farmers in other regions are adopting to the threat presented by herbicide resistance. 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.
Harvest weed seed control is an alternative weed control tactic that targets weed seeds before they are shed from the plant. It uses the combine to intercept weed seeds and prevent them from entering the seedbank and contributing to future problems. This can be accomplished in several ways, including removing chaff from combines, grinding chaff and weed seed, or windrowing/tramlining chaff.
Dr. Michael Walsh is the director of Weed Research at the University of Sydney, Australia, and one of the world’s leading authorities on harvest weed seed control. Australian farmers face some of the world’s worst problems with herbicide resistance, and are rapidly adopting harvest weed seed control as a means of diversifying weed management.
Dr. Walsh and Iowa State University Extension and Outreach will host a harvest weed seed control clinic at the ISU Field Extension Education Laboratory (1928 240 St., Boone, Iowa) on Monday, October 21 beginning at 10:00 AM. During the morning the principles of harvest weed seed control will be discussed. After lunch, weather permitting, Dr. Walsh will demonstrate the types of combine modifications used to separate weed seeds from other materials entering the combine. The clinic will conclude by 3:00 PM.
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). While this clinic is free and open to the public, we ask that you please RSVP to Meaghan Anderson at [email protected] or 319-331-0058 by Monday, October 14 to ensure an accurate lunch count.