AS canola production spreads into lower rainfall areas from its traditional high rainfall heartland, an important grower decision is whether to grow hybrid or open pollinated (OP) varieties.
Hybrid canola is more vigorous and competitive against weeds, and can yield up to 20 per cent more than OP varieties, but is a more expensive system due to significantly higher seed costs.
Research funded by the Grains Research and Development Corporation (GRDC) suggests that hybrid varieties can be more profitable than OPs in medium and high yielding environments, but OPs tend to be more profitable in lower yielding areas.
The study in 2013 and 2014 compared the performance and gross margins for hybrid and OP canola across a wide range of environments in Western Australia and in National Variety Trials across Australia.
Led by CSIRO and involving the Department of Agriculture and Food (DAFWA), ConsultAg, Planfarm and the Department of Primary Industry, New South Wales, it tested about 20 canola varieties in five field experiments in low, medium and high rainfall areas of WA at Merredin, Cunderdin and Kojonup
Seeding rates were set to achieve 40 plants per square metre.
CSIRO researcher Heping Zhang said the research showed that the yield performance and profitability of hybrids depended strongly on growing season rainfall and the magnitude of the yield advantage of hybrid varieties over OPs.
“Gross margins were strongly linked to yield potential – hybrid canola was profitable only when the gains from the higher yield outweighed the cost,” he said.
Dr Zhang said the greater yield advantage of hybrids meant they were generally more profitable than OPs in favourable environments where rainfall was relatively high and the growing season was relatively long.
“However, in areas of low rainfall coupled with high temperatures during the seed filling period, hybrids showed no or only small yield advantages over OPs,” he said.
“Hybrids were less profitable than OP triazine tolerant canola in these less favourable environments because the cost associated with seed usually outweighed any small yield benefits.”
ConsultAg agronomist Garren Knell said the research showed that hybrid varieties were generally more profitable only in areas where canola yields regularly exceeded 1.3 tonnes per hectare.
“In most areas of the WA grainbelt, the question for growers becomes – do I use hybrids simply as a weed control tool due to their greater vigour, even if they’re not necessarily making me more money in the short-term,” he said.
“A big issue for growers in these areas is that hybrids are riskier because of the higher upfront costs associated with seed costs – and growers take on that risk.”
Meanwhile, Mr Knell said research under the project comparing different canola herbicide tolerance groups confirmed that while Roundup Ready canola provided a valuable, alternative weed control option, growers in medium- to low-yielding areas in particular needed to weigh up this longer-term benefit against the system’s short-term higher cost and risk.
“In the short-term at least, the Roundup Ready system is generally more profitable only in higher rainfall zones, while the triazine tolerant system using grower-retained seed is significantly cheaper and a much lower risk for growers in most other areas,” he said.
CSIRO research under the project ‘Achieving stable and high canola yield across the rainfall zones of WA’ is continuing in 2015.
It will further investigate genetic traits associated with yield variations between the herbicide tolerant groups and between varieties within the same herbicide tolerant group.
The project complements the ‘Tactical break crop agronomy in WA’ project, led by the Department of Agriculture and Food WA (DAFWA) and also funded by the GRDC.
Varietal information for canola growers is available in the Canola Variety Guide for WA 2015.
Dr Mike Ewing is GRDC western regional panel deputy chairman.