A new SAGIT-funded project is giving a local perspective to the national problem of weed management for SA growers by evaluating and optimising settings for a new weed seed control technology.
Capturing and controlling weed seeds is a key component of Integrated Weed Management (IWM) strategies to prevent herbicide resistance and minimise the cost of managing weeds.
Along with other methods and technologies such as chaff carts, narrow windrow burning and the Harrington Seed Destructor, the Seed Terminator has become available to growers this year. The Terminator uses hammermill technology and incorporates a mechanical drive system, driven by the harvester engine.
Trengove Consulting’s Sam Trengove says the project will ensure growers are getting the optimal weed control in South Australian conditions.
“A lot of the IWM work so far has focused on ryegrass in wheat crops, but in SA legumes feature prominently in the crop rotation and have different weed species that are more problematic such as medics, tare, bifora, bedstraw and indian hedge mustard, so we are aiming to work out the best set up for these crop and weed scenarios.”
The project is testing 11 different weed species and four crop chaff types on a static machine, varying settings in the machine as well as chaff flow rate to simulate different scenarios encountered in the field. Processed chaff and weed seeds are collected and are being tested at the University of Adelaide for germination assessment. Power consumption is also being measured during the testing process. Field-scale trials will also be performed at harvest to validate the results and will assess both weed seed control, power and fuel consumption and harvester capacity.
The four chaff types – wheat, canola, faba bean and lentil – and 11 weed species – ryegrass, brome, turnip, prickly lettuce, medic, tares, lentil, wild radish, bifora, bedstraw, marshmallow and wild oats – represent a wide range of growers’ conditions across South Australia.
“We expect it will be possible to achieve control approaching 100 per cent control for weed seeds that enter the Seed Terminator, and anecdotally we can see there are not many seeds making it out of the machine intact, but the big question is what is the cost in terms of fuel consumption and harvester speed to achieve this,” Mr Trengove says.
“We are hoping to find a sweet spot where there is a good balance between weed seed control and harvest costs where growers are achieving good efficacy without trading off too much harvester capacity or fuel useage.”