WITH much of this year’s bumper winter crop harvest stored on-farm, growers are urged to adopt the correct fumigation techniques to protect the grain and prevent losses and downgrading.
All fumigants must be used in gas tight, sealable silos.
Agriculture Victoria Statewide Specialist Chemicals, Steven Field, said there were a variety of fumigants on the market, including nitrogen and carbon dioxide, but the bulk of stored grain was treated with phosphine generated from products containing aluminium phosphide.
“In Victoria anyone using aluminium phosphide products must hold appropriate authorisation such as an Agricultural Chemical Users Permit issued by DEDJTR,” he said.
“All fumigants must be used in gas tight, sealable storages, the most common of which are silos.
“Many silos on farm may not actually be gas tight, including some that have only recently been purchased.”
Mr Field said all silos used for fumigation should meet the Australian Standard AS2628 and be subjected to a pressure test prior to fumigant use.
“Using fumigants in non-gas tight storages is well known to increase resistance as eggs, pupae and larvae may survive and will carry genes promoting phosphine resistance onto subsequent generations,” he said.
“Despite the committed efforts of some in the grains industry, dealing with this issue over successive years has proven to be difficult.
“The increased resistance to phosphine, in insect populations, highlights the need for everyone involved to take this matter seriously. Failure to do so will lead to phosphine becoming ineffective, leading to increased costs for farmers and potential difficulties in gaining access to export markets.”
The Grains Research and Development Corporation (GRDC) has funded a Grains Storage Extension Project through to 2018 which has delivered high quality resources and educational material for farmers to use.
Farmers are encouraged to visit http://storedgrain.com.au/ or ring 1800 weevil (1800 933 845) to access these resources.
For more information on chemical use in Victoria visit http://agriculture.vic.gov.au/agriculture/farm-management/chemical-use or call Agriculture Victoria on 136 186.
Source: Agriculture Victoria
Support Steven Field’s comments ….. only fumigating in gas-tight sealable silos. Field research in farm silos shows the main cause of fumigation failures is due to leaky, unsealed silos. To successfully kill storage pests we need to hold a minimum phosphine gas concentrations in the silo for a given number of days. e.g. 300 ppm for 7 days, or 200 ppm for 10 days. To ensure your silo is suitable for fumigation, undertake the simple silo pressure test. This test requires no additional equipment on a standard aerated, sealable silo. See http://www.storedgrain.com.au web site and search for “silo pressure test”.