Scoping early sown canola in Western Australia

Document Type

Conference Proceeding

Publication Date


Conference Title

Australian Society of Agronomy 16th Annual Conference 2012: Capturing Opportunities and Overcoming Obstacles in Australian Agronomy

Place of Publication

Armidale, NSW


early sowing; canola establishment; soil moisture; dry sowing; rainfed; seasonal conditions


Agricultural Science | Agronomy and Crop Sciences


Ability to successfully establish crops early in the season is considered an advantage for most crops in the Mediterranean type of rainfed environment but review of literature suggests that it can be particularly advantageous for canola. But such early sown canola runs the risk of crop failure due to early moisture stress. We investigated crop emergence, survival and grain yield of an open pollinated canola variety Tanami seeded at 4kg/ha seed rate in April at Dryland Research Institute at Merredin after creating a gradient of moisture levels created by artificial irrigation ranging from equivalent rainfall of 5mm to 42.5mm. We found that response curve on all of the three traits namely, crop emergence, survival through dry period and grain yield, consisted of three segment; a sharply improving ‘damage’ regime where the level of trait is lower than timely sown crop, followed by a ‘sustain’ regime where level of trait is at par with the timely sown crop and finally ending in the 'advantage’ regime where trait level increases above the timely sown crop in proportion to the level of irrigation. We suggest, however, that the rainfall levels corresponding to these segments of response curve can vary with location, season, soil type, fertiliser regime, pest control and cultivar.