Providing practical information to help you protect your farm from biosecurity risks

Chemicals are a biosecurity risk too

June 3, 2014

Sheep drenchThe same chemicals used to control diseases, pests and weeds on your property can also pose a biosecurity threat if not used correctly.

All producers should be fully informed about the chemicals they use for their livestock and crops, how to use those chemicals and what use or withholding restrictions should be adhered to.

One of the biggest biosecurity risks in chemical use on farms is pest, disease and weed resistance. Plant Health Australia’s Program Manager, Biosecurity Planning and Implementation, Brad Siebert, explained how resistance occurs and highlighted phosphine use as a text book example.

“Further development of resistance to phosphine in stored grain pests is a biosecurity threat to Australia’s grain trade. Fumigation must be carried out in sealable (gas tight) storages to ensure concentrations are sufficient to control all insect life stages, especially eggs, pupae and larvae,” advised Mr Siebert.

“Inadequate fumigation can result in insects with increased phosphine tolerance surviving thereby increasing the number of insect populations carrying the genes for phosphine resistance. This ultimately increases the chance of live insects persisting in export grain shipments which can impact trade.”

“The same principle also affects weeds that are not sprayed with the correct chemical and/or dose. If weeds survive after spraying your paddock or crops, you need to act fast, before stronger and more robust weed species spread. Consider how much chemical you are using, an alternative treatment, or double knockdown,” he added.

Animal Health Australia’s Executive Manager Biosecurity, Duncan Rowland said pest and disease resistance is a major problem for livestock and highlighted drenching and antibiotic use as examples.

“Antimicrobial resistance is both a human and animal health concern and is increasingly being recognised as a global problem. Its development and spread is influenced by evolving bacteria that are ‘learning’ how to resist traditional antibiotic treatments. With each incorrect application of antibiotics, diseases can grow stronger.”

“Producers should therefore ensure they are using the prescribed dosage of antibiotic medication and the environment in which the bacteria have developed. If the environmental conditions are ripe for the disease returning, other mitigation measures need to be taken in addition to giving affected animals  medication,” said Mr Rowland.

Sheep producers should also be monitoring drench resistance of the worm burdens which are becoming more of a concern to many producers across Australia. Sheep producers should be careful about what drenches they use and should ensure they are using the correct dosage, at the right time of year, for the right weight of sheep as well as rotating the drench type being used.

More information about chemical usage on farms is available from the Australian Pesticides and Veterinary Medicines Authority.