ONCE country is covered in iceplant, is it gone for good?
The possibility of recovering saline country is the big ticket item for Morawa Farm Improvement Group members running a series of trials this year.
It is not known to what extent iceplant - which fluorishes on saltlands - is allopathic and prevents other plants from germinating in subsequent years.
Across two sites near Morawa, iceplant will be either ploughed in, burnt, raked or left as a control.
The sites will then be sown to ryegrass, barley, triticale, Scimitar burr medic or blue bush.
Further treatments will involve the use of pre-emergent and post-emergent herbicides to control the iceplant.
Agriculture Department development officer Vanessa Stewart said iceplant was an opportunistic coloniser because it is extremely salt-tolerant and drought-hardy.
"The area increased in recent years while conditions favoured its spread, but it will be interesting to see if it continues to dominate these areas this season," she said.
"It is best removed when young but it often colonises areas that are difficult to get at with spray."
Ms Stewart said there had been little herbicide work done since the 1980s and there were few herbicides registered for treating the annual succulent weed.
The following herbicides have been registered for use in cereal crops to control common iceplant :
p bromoxynil/dicamba /MCPA e.g. BroadsideÆ/TrichemÆ
p dicamba + 2,4-D
p dicamba/MCPA, eg BanvelÆ M/KambaÆM
p diflufenican/MCPA, eg Tigrex
Slender iceplant is also the most common plant causing poisoning in the eastern wheatbelt during summer, according to Merredin Agriculture Department district veterinarian Roy Butler.
"Deaths generally occur when sheep are first put on a stubble paddock and are due to high levels of oxalates in the leaves," he said.
"Mortality rates are higher if the sheep are hungry."
But Mr Butler said the deaths were possibly confused with grain poisoning and not reported.
"Often the diagnosis is done over the phone," he said.
"To have a confirmed diagnosis we need to be conducting a post-mortem and then backing it up with laboratory testing.
"In my experience, mortality rates have been up to 5pc and occur within 36 hours of sheep going into a paddock that had iceplant."
Mr Butler said sheep seemed to be attracted to the iceplant and actively seek it out, suggesting that salt was lacking in their diets.
He suggested salt licks that contained low levels of oxalate might help animals develop a degree of tolerance to the chemical, but this has not been proven.