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Timing canola flowering to maximise yields

In many cropping areas this season, we are likely to have good planting moisture and crops will be able to get going straight away.

That puts the focus on the best time to sow crops in each area. Growers will be keen to sow early to take full advantage of the soil moisture, but need to look ahead to when each variety they plant might start to flower.

Canola coming into flower at the wrong time can increase risks, particularly relating to:

  • The length of the flowering window
  • Potential frost damage at the start of flowering
  • Potential heat damage towards the end of flowering
  • The potential for Sclerotinia and upper canopy blackleg in early flowering crops.

These tables are from the latest update of the GRDC’s Ten Tips to Early Sown Canola

Optimal Start of Flowering Infogrpahic - Canola Article

The next component to getting the flowering time right is to consider the phenology (characteristics of crop stages) of the variety you are planting. OCPP research has fine-tuned the phenology for many different varieties.

The development of canola in Australia is mainly driven by temperature (thermal time), but is also affected by vernalisation and photoperiod to differing degrees in different varieties.

The latest research has enabled the industry to start classifying different varieties into phenology responses to sowing time and maturities, as shown in this table from the new edition of the GRDC’s  - 20 tips for profitable canola - central & southern nsw:

20 tips for profitable canola chart

The latest advance in this work was done by the NSW DPI around Wagga in 2020. Their phenology profiles include some new varieties like InVigor T 6010 and InVigor R 4520P, which we can now compare to our old favourites like InVigor T 4510.

The shaded area is the optimum flowering period for Wagga Wagga (31 July – 1 September). Note that some of the varieties sown on 26 March flowered sooner than we would typically see because there were some warmer days through May and June which led to some quicker accumulated thermal time and therefore earlier flowering.

flowering dates canola chart

Phenology of commercial and new release canola varieties at Wagga Wagga in 2020. Danielle Malcolm (NSW DPI, Wagga Wagga), Rohan Brill (formerly NSW DPI, Wagga Wagga) and Warren Bartlett (NSW DPI, Wagga Wagga); Don McCaffery (NSW DPI, Orange)

New varieties come out every year and this research work keeps adding detail to our understanding of optimum timings. It’s important we all keep up with the latest information in each growing area – generally available through the GRDC or each state’s DPI – to help choose sowing dates for each variety that lead to the optimal start of flowering, a key to the profitability of our canola crops.