DURUM variety selection should focus on qualities including yield potential, disease resistance and grain quality characteristics, rather than development speed according to a SAGIT-funded project.
Trials investigating the drivers of flowering time in durum wheat have discovered the main driver of current commercial varieties is accumulated temperature and photoperiod.
This was one of the key findings in the project undertaken by PIRSA SARDI Agronomy group researchers Dr Courtney Peirce and Melissa McCallum.
While that means there are currently no varieties suited to pre-Anzac Day sowing as they would flower too early, it does mean that if growers target their durum sowing window for the same time as Scepter (a bread wheat variety best suited to late April-early May sowing) they will most likely achieve flowering in the optimum period to maximise grain yields.
“In our field trials, even from our first sowing date in early April, there was only two weeks difference in flowering between the first and last durum variety compared to four weeks for bread wheats.” Dr Peirce said.
“Compared to other countries and bread wheat, durum breeding in Australia is still fairly new with there not being much diversity in the development speed of current commercial varieties.”
This limits the flexibility that growers currently have with slower developing bread wheat cultivars to target earlier planting opportunities in April and means growers have a relatively narrow period to sow durum in order to achieve peak potential yields.
“The lack of variation in development speed for durum means variety selection should focus on other variety qualities, including yield potential, disease resistance and grain quality characteristics.” Dr Peirce said.
Dr Peirce said an exciting project find was the discovery that durum variety Saintly has the same flowering controls as Scepter.
“This means that we can make direct comparisons between the two, as they were exposed to the same environmental conditions whilst at the same growth stage,” she said.
Dr Peirce says she is currently conducting further research into durum flowering times, which should be of benefit to growers.
“We are currently using APSIM, a crop simulation model, to characterise the optimum flowering window for durum for a number of different locations around South Australia,” she said.
“We will update variety recommendation for key growing regions. For example, while Saintly can be managed similar to Scepter, new durum releases such as DBA-Aurora and DBA Spes require sowing a week earlier.”
“With knowledge from this project we can then provide growers with information on when varieties should be sown to achieve flowering within this optimum period where environmental stresses from frost, cold and heat are minimised.”
Dr Peirce said research into durum breeding was still relatively new and there was not much variation in the development speed of varieties.
“A durum’s optimum flowering window is likely to be narrower than that of bread wheats,” she said.
Other considerations are important, as durum has greater sensitivity to environmental stresses (cold and heat stresses) and increased susceptibility to crown rot. This means growers need to pay attention to paddock rotation, and frosty landscapes should be avoided.
Research from the project is currently being prepared for a scientific publication.