Charles Sturt University
Graham Centre for Agricultural Innovation

Sowing canola to optimise weed management

There are some simple steps farmers can take when sowing canola to optimise weed management, according to researchers from the Graham Centre for Agricultural Innovation.

Adjunct Research Professor Deirdre Lemerle and Adjunct Associate Professor David Luckett from the Graham CentreAdjunct Research Professor Deirdre Lemerle and Adjunct Associate Professor David Luckett, both from Charles Sturt University (CSU), and NSW Department of Primary Industries (NSW DPI) principal research scientist Dr Hanwen Wu contributed to an article published in the journal, Crop Protection.

The paper examined international research of the opportunities to manipulate canola agronomy and increase the competitive ability by choice of cultivar, seeding rate, row spacing and orientation, and fertiliser use.

Lead author, CSU Professor Deirdre Lemerle said, "Strongly competitive canola crops are a low-cost and relatively simple tactic for integrated weed management.

"They can help reduce dependence on herbicides, retard the spread of herbicide-resistant weeds, extend the life of valuable herbicides, and reduce on-farm production costs through a reduction in herbicide use."

The research found competitive cultivars, especially hybrids, higher canola seeding rates, and optimising row spacing are some of the simple interventions currently available to farmers.

Professor Lemerle said herbicide resistance in weeds means it's becoming more important to grow crops that can out-compete the weeds.

"Breeding is required for improved hybrids and open-pollinated cultivars with traits such as allelopathy, larger seeds with rapid germination and establishment, increased seedling vigour, faster early growth to smother weeds and an extensive root system to utilise nutrient and moisture better than weeds.

"Further studies are also required to determine the morphological, physiological and metabolic traits associated with competitiveness in canola to underpin breeding new genotypes."

'Agronomic interventions for weed management in canola (Brassica napus L.) - A review'  co-authored by Professor Deirdre Lemerle, Adjunct Associate Professor Luckett, Dr Wu and Dr Michael Widderick (Queensland Department of Agriculture and Fisheries), is published in Crop Protection 95 (2017), pp 69-73.

Media Note: Adjunct Research Professor Deirdre Lemerle is based in Wagga Wagga. For interviews contact Graham Centre communications officer Emily Malone on mobile 0439 552 385 or email