Canola flowering period key to good yields in SE

Speaking at the FAR Australia and GRDC Hyper Yielding Crops and Pulse Agronomy Field Day at Millicent earlier this year, Mr Ware said croppers in high rainfall zones may have large canola flowering windows, but because of sunshine, the ideal time for flowering was still a short timeslot, at the start of September.

"In an environment like this (high rainfall zone) where you're trying to avoid frost at one end of the season and heat at the other, canola can start flowering at any time from the start of August, to well into September, whereas somewhere like the Mallee you might only have a few days to get it right," Mr Ware said.

"So you have a massive window, but you start becoming limited by sunlight, so you need an opportunity where the canola starts to fill grain without being sunlight limited."

Mr Ware said an EPAG study where canola was covered with shadecloth and checked weekly through flowering, showed yield could be depressed by as much as 40 per cent.

"If you suppress that sunlight, you're shutting off the plant's ability to convert sunlight into green material," he said.

"During flowering, the majority of all the critical parts of the plant are forming, and if you depress the plant at that time, your yield is going to be massively depressed.

"So you have to be able to maximise the ability to convert that sunlight that you have available, into grain."

Sowing time in early to mid-May is a key detail to ensure canola flowering happens in the ideal window, providing it is matched with the right variety.

"All germplasm we have available in Australia right now have vernalisation requirements (a need for a period of cold temperatures to move the plant from vegetative to flowering), so if the cold requirement is met in June, the crop can make a run for home and flower fairly quickly," Mr Ware said.

He said there was often a trade off between flowering windows and biomass.

"Varieties that require a really strong period of cold will flower in mid-September, which is an optimal flowering window, but they have less biomass," he said.

"With canola, biomass equals yield, the more biomass you can grow, the more you can turn into grain."

A "HUNGRY" crop, such as a canola crop yielding 4.5 tonnes a hectare, does not need nutritional requirements for the growing season supplied at seeding, as long as nutrients are available when needed, according to FAR Australia managing director Nick Poole.

"You want to have a good soil nitrogen reserve that will mineralise through the course of the season, not necessarily something readily available in the autumn," Mr Poole said at a recent Hyper Yielding Crops event at Millicent.

"High-yielding crops aren't always about about applying more artificial fertiliser, it's about setting up a farming system that produces high yields.

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"From one to four weeks after you start flowering, you don't want anything limited, at that time of year is when you want the crops humming."

He said soils suited to producing high-yielding crops would perform well in the absence of fertiliser, but would be further enhanced by fertiliser applications.

"If you want to produce a 14t/ha cereal crop, you can probably still yield 10t/ha with no fert application," Mr Poole said.

"The holistic package of being able to create a high-yielding canola crop is well on the way, you just have to look at what genetics are best for your paddock and flowering period, do some soil testing and assess nutrition requirements, and you're ready to go."