Cage mill system provides Harvest Weed Seed Control
Redekop Seed Control Unit, an integrated reversible cage mill with blade system that provides Harvest Weed Seed Control, was assessed for volunteer canola control. Blade configuration in combination with chaff feeding rate did not affect volunteer canola control, which remained above 99%.
Harvest Weed Seed Control (HWSC) targets weed seeds at harvest to prevent them from returning to the seedbank. It is an important herbicide resistant management tool in Australia, and is being researched in Western Canada.
There are currently four integrated impact mills on the market that provide HWSC: the iHSD v.12, the Seed Terminator, the WeedHOG and, the Canadian-made Redekop Seed Control Unit (SCU). The SCU is an impact mill that incorporates a blade system in the centre of the mill with the goal to increase suction into the mill and airflow through it.
The objectives of this research by AAFC Lacombe was to evaluate weed seed control with the Redekop SCU, optimize blade configurations between all fan blades and a cutting blade/fan blade combination, and determine if weed seed control levels remain high at higher chaff feeding rates.
Volunteer canola was chosen for its high viability, limited primary dormancy and rapid germination, making it an ideal study species for HWSC. It is also the 4th most abundant weed in annual field crops on the Canadian Prairies based on the most recent weed survey conducted after post-emergence herbicide application. Canola also showed similar destruction rates as other weed species when previously tested by other impact mills.
Wheat chaff was collected from a field near Saskatoon, Saskatchewan with a chaff cart system. Ten thousand seeds of canola was mixed with 3.056 kg of wheat chaff, and fed into the cage mill with a conveyor belt. Chaff feeding rates were 5 or 10 tonnes of chaff per hour.
Blade configurations tested included 8 fan blades, or a combination of 4 fan blades and 4 cutting blades.
After going through the cage mill, processed samples were cleaned, and the recovered whole and partial seeds were placed into germination boxes to test for viability.
Greater than 99% control
Blade configuration, chaff feeding rate, and their interactions did not significantly differ for volunteer canola control. Average volunteer canola control across treatments was 99.5%. This is similar to control previously observed by the tow-behind Harrington Seed Destructor on volunteer canola, as well as being in the range of control measured on other weeds with the iHSD. It is also the same range of control expected of the Seed Terminator system.
The goal behind the addition of the blades is to improve airflow and suction through the mill in an effort to decrease energy requirements. While the energy requirements were not tested in this study, if lower energy needs are achieved by the addition, the incorporation of the blade system is an important step in the evolution of integrated mill systems for weed control as it may result in decreased power requirements, decreased fuel use and decreased operating costs.
Financial support for this research was provided by Redekop Manufacturing.
Tidemann, B.D., Kubota, H., Reid, P., and Zuidhof, J. (2020). Initial Testing of a Cage Mill with an Incorporated Blade System on Volunteer Canola. Can. J. Plant Sci. 2020-0010. https://www.nrcresearchpress.com/doi/abs/10.1139/CJPS-2020-0010
