Australia
March 22, 2012
Barley ‘head loss’ had a bigger than usual effect on crop yields during Western Australia’s recent weather-affected harvest, but the good news is that new research into the problem is starting to generate results.
A project funded by the Grains Research and Development Corporation (GRDC) has identified barley varieties and breeding lines tolerant to head loss and singled out straw strength and plant height as key characteristics influencing head loss.
The Department of Agriculture and Food (DAFWA) is leading the research, working with the University of Adelaide’s barley breeding program and the South East Premium Wheat Growers Association (SEPWA).
DAFWA research officer Dean Diepeveen collects barley samples for straw strength testing.
The research was presented at the SEPWA 'Harvest Review, Season Preview' event in Esperance on March 9, which was supported by the GRDC.
Head loss, which is particularly prevalent in barley at maturity, is when the head falls off the stem prior to harvest, resulting in yield losses.
It has been an ongoing problem for growers in WA’s South Coast region and in South Australia’s Eyre Peninsula.
But the 2011-12 harvest delays caused by unfavourable weather conditions meant that growers in other parts of WA also experienced significant barley head loss.
The project supervisor with DAFWA, Chengdao Li, said the research aimed to understand the head loss risk among commercially available varieties and advanced breeding lines; understand the molecular basis of head loss; and develop selection tools that breeding programs could use to breed new barley varieties with better head loss tolerance.
“This information is critical to enable growers to select suitable varieties and to allow breeders to develop varieties suited to coastal regions,” he said.
The research had already identified some very promising breeding lines with reduced head loss, including the current malting barley variety Vlamingh .
“We need to understand the genetics behind the tolerance of these lines so that we can develop molecular tools to select breeding lines with low head loss,” Dr Li said.
He said the shorter stems on dwarf varieties appeared to be stronger than those of conventional tall varieties that were longer stemmed, and researchers aimed to find out whether this was because dwarf varieties were stronger, or simply shorter and less prone to bending in the wind.
DAFWA researchers had successfully isolated the most common dwarfing gene in the current malting barley varieties.
“Because plant height is a key characteristic influencing barley head loss, the dwarfing gene marker will provide a diagnostic tool for use in breeding programs,” Dr Li said.
“Using a dwarfing gene marker is important because there are several different dwarfing genes in barley and different genes have different effects on agronomic traits.”
DAFWA research officer Dean Diepeveen said it was critical to combine the DAFWA small plot trials and the SEPWA large scale field trials to give the best estimate of the head loss risk among the current malting barley varieties.
He said the risk of head loss from delayed harvesting varied significantly between varieties.
“Growers in coastal regions could reduce the head loss risk by selecting the tolerant varieties Vlamingh and Baudin , instead of Buloke and
Gairdner ,” Dr Diepeveen said.
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