Never miss an opportunity to tackle weeds

Collecting and destroying weed seed at harvest has been standard practice on Lance’s farms for over 20 years, first with chaff carts and now with impact mills. Lance has single impact mills attached to two of his harvesters. These custom mills resulted from a project with de Bruin Engineering to build a mechanical drive, single mill suitable for smaller harvesters such as Lance’s John Deere 9750 STS machines.

“Cyclone Seroja in 2021 set us up for a bumper-yielding season and a long harvest,” he says. “Under exceptional conditions on our farm at Goodlands, we ‘found the limit’ of our single mills. The wheat stems were solid, something I’d never seen before, and it created short straw that overloaded the mills, cutting harvest speed in half.”

Lance decided to take the mills off to finish the harvest at Goodlands as quickly as possible, with every intention to put them back on for harvesting at their Pingelly and Corrigin farms. Unfortunately, that didn’t happen, making 2021 the first and only time that harvest weed seed control was not applied across their farms in over two decades.

“In a barley paddock at Pingelly that had no harvest weed seed control in 2021, the next crop was canola, and we missed the crop topping opportunity due to wet conditions but were back in with the impact mills in 2022,” says Lance. “As a result, about 15 per cent of that paddock is infested with ryegrass in this year’s barley crop. This harvest, we intend to crop top barley for the first time, harvest with the impact mills, then windrow and burn to get the weeds back under control in that paddock.”

Although Lance’s crop rotation varies for the three properties at Corrigin, Pingelly and Goodlands, he has a philosophy of not missing an opportunity to tackle weeds and keep the seed bank low. This has resulted in a high level of flexibility that comes with being able to safely dry seed, and Lance is still using mainly older chemistries, which keeps herbicide costs down.

“A well-established crop gives us paddock-wide weed suppression, and then we implement as many tactics as possible to stop weeds establishing and setting seed. In lupins, for instance, there are typically six or seven tactics applied within the season,” he says. “We don’t like it to happen, but occasionally, a small section is missed at sowing, and it is heartening to see very few weeds establishing in those gaps.”

Lance changed from a chaff cart to the impact mill mainly to avoid the need for burning the chaff. They have not had livestock in their system since the 1990s, so they had routinely burned the heaps, although Lance found in the last year with the carts that the heaps composted down without being burned.

“We actually get the same result with the mills as we did with the carts,” he says. “We still cut at beer can height and use the same baffle system to separate the straw from the chaff stream. It doesn’t matter which harvest weed seed method you choose, but adding something at harvest does make a difference to weed burdens the following year.”

The Australian Herbicide Resistance Initiative (AHRI) developed the Ryegrass Integrated Management (RIM) tool that Lance used over 20 years ago to test his farming system, and the results convinced him of the value of harvest weed seed control.

“Herbicide resistance, particularly glyphosate resistance, was going to take us out of cropping if we didn’t start using harvest weed seed control,” he says. “We started doing it, and more than 20 years later we are still using the cheaper herbicides for wild radish and annual ryegrass control. One of the main benefits of using harvest weed seed control is that we still have many of the newer herbicide products up our sleeve.”

Lance is a long-standing supporter of WeedSmart and has adopted all the WeedSmart Big 6 tactics in various ways on their three properties across three different rainfall zones.

Lance’s custom built mechanical drive single mill.