WHEN one thinks of winter wheat varieties you certainly don’t think about the low rainfall zone – winter wheat is very much a tool used by those in areas with cool and wet growing seasons.
However, a LaTrobe University researcher has said the development of a winter wheat suitable for planting in the low rainfall zones of Australia could have merit in enabling farmers to opportunistically use early moisture.
“The key determinant for yield in low rainfall zones is getting flowering timed right,” said David Cann at last week’s Birchip Cropping Group main field day.
“Get crops flowering too early and you’ve got a high frost risk, whereas if they flower too late you run the gauntlet of running into some serious heat events.”
He said winter wheat varieties were much more stable in their flowering time due to the vernalisation requirement.
“This means the time of sowing is not as big a driver on when the plants will flower and means we can time that flowering to the ‘sweet spot’ even with some variation in when it goes in.”
Mr Cann said this could allow farmers to make good use of heavy late summer or early autumn rainfall.
“It does occasionally happen you get a big dump of tropical moisture in say February or March but with spring wheat there is a limit as to how early you can plant it due to the frost risk, a winter wheat would be a safer way of allow farmers the chance to increase yield potential on an opportunistic basis.”
He said there were other benefits, such as the potential for a dual-purpose grain and graze line providing critical feed over the late autumn feed drought.
However, he said there was a lot of research to be done before farmers in semi-arid zones had a good range of winter wheat options.
“At present Longswood is the only winter wheat developed specifically for lower rainfall zones, with most of the breeding focus on the higher rainfall zones with longer growing seasons,” he said.
As part of his research, Mr Cann is working on two trials at the BCG trial site.
The first project is designed to compare winter and spring wheat lines from the same family to identify how yield is formed differently in the two types.
The second trial aims to find phenotypic traits in early winter wheat crosses that could be of use to breeders in the future.