Wednesday, 3 January 2001 
Ref 2001/03 

A wax block impregnated with aluminium phosphide is the newest weapon for farmers in their fight against insects in stored grain.

"Controlled continuous release of the gas phosphine is the most effective available way of dealing with insect infestation," says Colin Waterford of CSIRO Entomology.

"The wax block is presently being put through commercial-scale field trials to evaluate its
performance in Australian conditions," says Mr Waterhouse. "It will be marketed overseas by United Phosphorus Limited of India, under licence to CSIRO.

"It will be some time before it is commercially available, but it is an exciting development for on-farm grain storers," he says.

The formulation has been developed over several years by CSIRO in collaboration with United
Phosphorus Limited in India and AusBulk Limited in South Australia. 

Mr Waterford says the new product has major advantages over the existing range of aluminium
phosphide formulations.

"The immediate or controlled continuous release of phosphine from the wax block offers significant benefits compared to the often slow uncontrolled breakdown of existing preparations that react with moisture in the grain bulk to produce phosphine.

"The composition of the block allows for a controlled reaction in a special generator. When water is combined with the product in a reaction chamber, phosphine is released." 

Mr Waterford warns that water should never be added to existing aluminium phosphide formulations to speed up the release of phosphine.

"Add water, and you get an explosive compound," he says.

The new wax block formulation also avoids the problem of powder residues containing excessive
amounts of unspent formulation after fumigation. 

More information from:
- Colin Waterford, CSIRO Entomology (02) 6246 4204
- Len Caddick, CSIRO Entomology (02) 6246 4214

Contacts:
Mr Len Caddick 
Liaison Officer
Stored Products and Structural Pests
CSIRO Entomology
GPO Box 1700 
Canberra ACT 2601 
Australia 
Phone: +61 2 6246 4214 
Fax: +61 2 6246 4202 
Email: Len.Caddick@ento.csiro.au  

Mr Nick Goldie 
Journalist 
CSIRO National Awareness 
PO Box 225 
Dickson ACT 2602 
Phone: +61 2 6276 6478 
Fax: +61 2 6276 6821 
Mobile: +61 0417 299 586 
Email: Nick.Goldie@nap.csiro.au  

Company news release
N3225