A weed new to Southern NSW is popping up all over crops causing concern for local farmers.
Fleabane is a major weed difficult to control in northern New South Wales and southern Queensland but has been slowly creeping down into southern NSW over the past five years.
Weeds Research Scientists Dr Hanwen Wu, Senior Weeds Research Scientist, and Eric Coatz, Weeds Research Technical Officer for the NSW Department of Primary Industries, Wagga Wagga are researching ways in which to control the weed.
Mr Coatz says the alarming explosion during summer has seen many mature plants uncontrolled and set millions of seeds and the lack of control is in part due to a lack of knowledge among growers about fleabane as a new emerging weed in the southern NSW area.
“We are seeing increasing inquiries from growers about Fleabane control,” Mr Coatz said.
“Integrated weed management holds the key to reducing the impact of fleabane on crop production, and farmers need to be aware of the signs their crops may contain the Fleabane weed,” he said.
Fleabane has been a major concern for growers in northern NSW and Queensland, but due to the good summer rain researchers are seeing a spike in both Central West and southern NSW crops.
Mr Coatz says there are a few reasons why we are suddenly seeing an outbreak of Fleabane in this area.
“We have had two great summers back to back with great moisture conditions, No Till Farming is also increasing in popularity and farmers over the recent years have de – stocked which means less pasture crops and less disturbance which are all perfect growing conditions for Fleabane,” he said.
Fleabane is a prolific seeder and can spread very quickly with each plant capable of producing 110, 000 seeds.
“The potential risk of Fleabane spreading is huge as it is such a prolific seeder, with the right wind conditions seeds can easily blow onto surrounding properties, making it difficult to control,” Mr Coatz said.
The Fleabane outbreak was sudden with the Weeds Research Scientists called to conduct emergency trials to find control methods.
There are currently trials set up at the Charles Sturt University, Wagga Wagga and near Old Junee where they are trialing 34 different herbicides.
“The research we are conducting is proving Fleabane is resistant to glyphosate, we have already had eight reported cases so far of the weed being resistant to glyphosate,” Mr Coatz said.
“Another problem is Fleabane grows through winter securing a strong root system which can burrow down 30 – 40 cm making it a very robust plant and hard to spray,” he said.
Mr Coatz says the best way to control the weed is to be aware of the best combination of herbicides.
“We are seeing the best control by spraying with an herbicide glyphosate 24D and 10 – 14 days later following it up with a spray seed.
“This method is proving to control 90% of the seedlings and this is the main thing growers should be concentrating on, trying to slow seed set,” he said.
Mr Coatz says Fleabane likes no disturbance and poor competition, so robust crops should be planted to control them.
“Fleabane doesn’t like competition so if you are trying to control Fleabane planting crops like wheat and barley that will compete for sunlight and moisture can help control it.
“Try to avoid crops like chickpeas or lupins which are poorly competitive crops,” he said.
Fleabane also lays dormant through the winter and are relatively hard to spot until it is too late, so farmers need to be on the lookout for potential seedlings.
“Growers need to spray the weed when they are smaller, no larger than 5 -6 cm, as when they are greater than 10 cm your level of control drops off by 40 – 50 %,” he said.
Mr Coatz also says tillage once every five years is a good way to control Fleabane along with changing crop rotations and systems as Fleabane can adapt very quickly creating resistance.
For more information on Fleabane or control methods Mr Coatz urges farmers to contact their local DPI.
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