Harvest trials of the Tecfarm Seed Mill have been successfully completed over two seasons in two variants, as well as extensive static bed tests over hundreds of hours and five years since initial concept and patenting.
The Tecfarm design teams’ goal was to provide a simple and reliable Harvest Weed Seed Control unit that is affordable for as many farms as possible. The innovative design stands alone with its unique method of milling via exchange of seeds across a gap between two adjacent circular housings, into the path of opposing high speed impact bars. The WeedHOGs’ engineering is quite simple, but uses complex interactions of air and material. Much research has been devoted to gaining an understanding of the physics involved
Development: After limited field trials during the 2018 harvest with a unit mounted on a Case 9120 and many hours of test bed work, 2019 harvest trials were conducted in the Western Australian Central Wheatbelt over an extended period, with a pre-production unit operating on a Case 7230 in several crop types. This unit has since been purchased by the farmer who trialled the machine. 2018 harvest results showed a big reduction in Annual Ryegrass germination(the main winter crop weed in Southern Australia) using large grow out plots, trays and petri dishes as well as field counts.
2019 was a year of intense work on small variations of the principle involved. The advanced prototype trialed during 2018 harvest was studied at length, refined and given higher capacity. This was achieved by doubling the effective area within the mill, the “Quad Rotor” design and adding additional impact points on each rotor to give greater efficiency.
A consistent 80% direct kill out of the mill was obtained, with mounting evidence through research here and overseas as far back as 1958 indicating that complete destruction is not necessary to render seeds unviable after several months exposure in a field environment. Observations by Tecfarm personnel verified this phenomenon quite early in testing. It has very big implications for how much energy is required for long term weed control using a mill. As well as Wimmera rye grass, larger weed and volunteer crop seeds have practically a total kill. The low power requirement of the WeedHOG means most harvesters are capable of sufficient power, with no aftermarket ‘remapping/chipping’ of engines to obtain a power boost.
Tecfarm is also aiming to providing a mill that is suited to the smaller harvesters as soon as practicable. The low power requirement for this design makes it an achievable goal.
It has been observed during R & D that as well as completely destroying a large percentage, the mill fragments and damages a high proportion of the remaining seeds. Chaff material tends to be left somewhat intact with a low amount of very fine material. This may be a reason for the units’ observed low power requirement. The 2019 Quad Rotor Mill indicated power use at around 40HP (30Kw). Energy is not wasted in making a high proportion of dusty, fine particles.
A major reason for the persistence of annual ryegrass in cropland is its tendency for high levels of dormant seed preventing full germination in any one generation. After passing through this mill the small number of seeds escaping a total kill are observed to have almost all suffered damage and appear to have their natural high level of dormancy broken, a trait that is useful to allow spraying out early in the cropping season. Attack by soil borne fungi, microbial activity etc. is also something that seems to happen to damaged seed that has had its’ protective coat compromised. This environmental aspect of the effect of seed mills on seed viability has been seen here at Tecfarm and also observed by US researchers. https://aces.illinois.edu/news/harrington-seed-destructor-kills-nearly-100-us-agronomic-weed-seeds-lab-study It means that quite possibly the need for total destruction of seed is not necessary for good control. This has very practical implications for mill design going forward. Attack by soil fauna and pathogens after even minimal damage to seed coats is very beneficial in giving ‘free’ control.
Features of the WeedHOG:
- Low capital cost
- Simple fitting on farm
- Good efficacy on common weed species and volunteer crop seeds
- Unique self-centering rotor design eliminates expensive specialized balancing
- Easy maintenance and low cost rotor bar replacement
- Impact bars are rotatable to maximize service life
- Bar sets can be added or removed to suit field/crop conditions and power availability
- Simple changeover to windrow mode
- Integral Bolt Traps
The future: With successful engineering and efficacy tests carried out during 2018 and 2019 harvest, limited commercial release in Western Australia is approved for early 2020.
Give us a call anytime if you would like to have a chat. Tom: 0428 611 309. Matt: 0447 180 958.
The Tecfarm weed mill is protected under one or more of the following patents: Provisional patent application 2015903508. International patent application PCT/AU2016/050802. National patent applications USA PCT/AU2016/050802 // Australia No.2016314137. European Union No.P20150710 // Canada PCT/AU2016/050802