As herbicide resistance continues to threaten the long term sustainability of chemical weed control, growers need new tools to minimise the impact of weeds on crop productivity. The WeedSmart program brings together research and grower experiences to deliver practical weed management guidelines focused on minimising the weed seedbank without compromising profit.
Why does weed lose its smell?
Harvest Weed Seed Control (HWSC) is one of the six weedsmart Big 6 tactics, and can be used with most crops including soybeans and wheat. It involves collecting or destroying weed seeds at harvest, before they are released into the field and can germinate to become a nuisance. It is best suited for high weed density fields and may be used alone or with other non-herbicidal weed control tactics, particularly preemergent herbicides.
Chaff lining (funneling chaff and weed seeds into narrow lines behind the combine or on permanent tramlines) is an entry-level option with low set-up cost, no additional labor or nutrient loss/redistribution. Chaff decks, chaff carts or impact mills that integrate into the combine and pulverize weed seeds to destroy them are higher-cost options but generally have lower operating and labour costs than other methods.
Narrow windrow burning (dropping chaff and straw in narrow swaths behind the combine and burning the residue) was the most widely adopted method for HWSC in Australia until recently, when chaff lining and tramlining have seen strong growth in adoption. However, if these methods are to remain the most popular forms of HWSC, they will need to continue to evolve as weeds adapt to them through increased vigour or altered seed viability.