TIMING flowering to best avoid stresses such as frost and heat will play a big role in boosting canola yields according to a SARDI agronomist.
Andrew Ware, based at Port Lincoln on South Australia’s Eyre Peninsula, said trials had demonstrated the clear benefit of having canola flowering at the right time.
Speaking at a Grains Research and Development Corporation (GRDC) forum in Nhill, Mr Ware said farmers needed to work back from the ideal flowering period for their region and assess the optimal sowing date based on the variety’s phenology.
He said varieties such as Stingray and Hyola 575 could be planted quite late for canola because of their fast phenology but said other lines such as Victory and Archer were slow to develop and needed to be planted earlier.
“When the faster varieties are planted on April 15 at Nhill they start to flower earlier than the optimum time, but if you delay that to May 15 then flowering will begin at the right time.”
The different windows for sowing can be used by growers to make it easier to get all crops in on time at sowing.
Mr Ware said data collected from trials in Victoria showed the optimal flowering window varied widely, from July 13 in parts of the Mallee, where heat stress can occur from late August onwards, to 14 August in the high rainfall zone of the Western District.
Early flowering leads to higher frost risk and increased risk of blackleg infection and will not have the chance to build up a good level of biomass, which is a critical factor in canola yield.
On the other hand, heat stress and drought are major risks if crops are late flowering.