The development of insect resistance to the key fumigant phosphine is driving renewed interest in the development of alternatives. One such alternative is the use of low oxygen atmospheres that are usually created through the generation of nitrogen. However, the costs of nitrogen generation have been a longstanding barrier to the adoption of the low oxygen atmospheres in agricultural storages such as grains. The research team has taken advantage of recent advances in the cost of nitrogen generation (membrane technology) to assist industry overcome operational barriers to uptake of the technology.

1. biosecurity built on science
Development of low
oxygen/nitrogen technologies
Dr Manjree Agarwal
Murdoch University
Plant Biosecurity Cooperative Research Centre

2. biosecurity built on science
Nitrogen is well known with + and -
Advantages
 Provides alternative to current use of chemistries such as phosphine
 It can add to the “toolbox” for industry as “phosphine break fumigants”
 It may be an option for “organic” markets
Disadvantages
 Costs of nitrogen generation
 Air-tight storage is critical
 Relatively high capital cost

3. biosecurity built on science
Our research has developed nitrogen protocols
• We successfully controlled (100% efficacy in the lab) adult grain storage insects
with 97-99% N2, at a temperature of 20°C and a 2-4 week treatment
• We successfully controlled (100% efficacy in the lab) egg stages of grain storage
insects with 97-99% N2, at a temperature of 25°C and a 4 week treatment
• Wheat, canola and lupine quality has no change during 3 months storage at
>35°C

4. biosecurity built on science
Nitrogen generation is the breakthrough
Two types of nitrogen generator have been
available; Pressure Swing Adsorption (PSA) and
membrane separation
Advances in membrane generation technology
has meant that it can provide nitrogen
atmospheres of 99.5% purity and higher =
quicker kill times
Advances in membrane technology has reduced
the cost of nitrogen generation significantly =
lower costs
We have achieved a cost of about $1.00 per
tonne for nitrogen and are working to reduce
this by half – our target is 50 cents per tonne
PSA
Membrane

5. biosecurity built on science
On-farm trials are very encouraging
We started on-farm trials with two
properties and through our partnership
with Mingenew Irwin Group grower and
Doug Clarke
We have achieved the required nitrogen
purity levels to ensure complete insect kill
We have built a mobile facility that suits
on-farm needs (silo capacity, flexibility)

6. biosecurity built on science
And an industry trial at port was positive
This is where we got our $1.00 per
tonne result – and insights into how
to reduce costs
We are working on a new idea of
recirculation of nitrogen to lower
costs

7. biosecurity built on science
Thank you
For more information, please contact:
China /Australia research: y.ren@murdoch.edu.au
Lab efficacy data: m.agarwal@murdoch.edu.au
Field evaluation: j.newman@Murdoch.edu.au