Good biosecurity practices are important at every step of product management; from ensuring seed is pest and weed free, to the responsible use of chemicals, and good grain storage practices.
Seed can be a source of diseases, pests and weeds. You cannot accurately assess seed quality just by sight. Seed that carries pests can appear clean and healthy at the time of purchase.
Obtain seed from reputable suppliers. Ask where the seed originally came from and always try to purchase certified or quality assured seed.
Read the label for information on pure seed content or obtain a Statement of Analysis detailing seed purity, weed seed content and germination quality.
Keep a copy of the certification report on record as this will assist with any trace-back activities should a new pest be found.
More information on Organic grains product management
It is very useful to be able to trace the movement of produce onto and off your property. Traceability is often a component of Quality Assurance schemes such as Graincare QA, or Better Farm IQ or an industry Best Management Practice program.
Records (including seed source, health testing specifics and authenticity records) should allow you to trace grain on your farm back to its source.
Similarly, these records should also include where grain or hay goes when it leaves your property.
Being a member of an Auditable Quality Assurance scheme is recommended for biosecurity purposes as well as ensuring that you comply with requirements for market access, meeting trade specifications, customer expectations and food safety.
In a deregulated grain market, on-farm grain storage is becoming more common and brings additional biosecurity risks to your property.
If stored grain is not properly managed it can become infested with pests that can be difficult and costly to control. To maintain pest-free stored grain of good quality and value, growers need to:
Spilt or residual grain can provide shelter and food for pests allowing large numbers of storage pests to fly and infest other grain storage sites once conditions warm at the start of spring.
Make sure that grain handling equipment like headers, augers, field bins, silos and bulk storages are cleaned before and after harvest.
It is good practice to separate the first grain to pass through headers and grain handling equipment at the start of harvest as there is a high risk that it may contain pests. Use it quickly for stock feed, or plan to aeration cool, then fumigate within four weeks.
Grain should be loaded and unloaded on compacted surfaces away from production areas. Containers and bags of plant and seed material should be covered during transport.
Aeration fans fitted to grain stores reduce the grain temperature and the ability of pests to breed. Aim to keep grain at less than 23 degrees in summer and less than 15 degrees in winter. Aeration also reduces moisture content which maintains grain quality.
Regular monitoring of stored grain is essential. Stored grain should be inspected every month for live insects and grain should only be treated when insects are found. Seek advice on the best way to treat any pest you detect.
More information about the management of biosecurity risks for organic grain crops can be found here.
Grain markets demand that delivered grain is free from live insects, but they also have limits on acceptable levels of chemical residues. Identify the particular pest, use an appropriate fumigant, and check that grain buyers or potential markets will accept any insecticides you intend to use.
When fumigating stored grain, always read the product label, follow all directions, and abide by withholding periods. Fumigants such as phosphine are only effective when used in well-sealed grain storage facilities.
For more information about the biosecurity of stored grain and identifying insects, see the Monitoring stored grain on-farm booklet, available from a Grains Biosecurity Officer or from planthealthaustralia.com.au/gfbp.
Since most grain ends up being used as human food, even if fed to livestock, inappropriate use or application of pesticides can pose a risk to human health through the presence of chemical residues.
Chemical residues on grain can result in grain being rejected from export and domestic markets.
Pesticides must be used in accordance with label instructions. In most states and territories, farmers and contractors who apply pesticides must complete an accredited chemical training course (for example ChemCert® or SMARTtrain) to gain the appropriate training, knowledge base and legal requirements for the safe use of pesticides.
Details about regulations for agricultural and veterinary chemicals can be found on the Australian Pesticides and Veterinary Medicines Authority website apvma.gov.au, or from relevant state agencies. Be aware that regulations change over time, so you need to check for updates regularly.
From a biosecurity perspective sealable, aerated silos are the best storage facility for grains. In addition to protecting the quality of the grain, effective fumigation of pests can only be carried out in a sealed, gas-tight silo. Check that a new silo meets the Australian Standard for sealable silos (AS2628) and pressure test regularly to ensure it remains gas-tight over time.
Australian Standard AS2628 states that new sealable silos must pass a five minute half-life pressure test. Existing silos are considered to be well-sealed when they pass a three minute half-life pressure test.
Passing a three minute half-life pressure test means that once pressurised, using the silo’s aeration fan or an air compressor, it will take more than three minutes for the pressure inside the silo to drop by 50%. If the pressure drops by 50% in less than three minutes the silo is not well sealed and shouldn’t be used for fumigation until it has been made sufficiently sealed to pass the test.
For more information on sealable silos, pressure testing silos and grain storage please see GRDC Grain Storage Extension at storedgrain.com.au.
Phosphine fumigation is a commonly used and inexpensive method for treating insects in grain storages, but phosphine-resistant insects are becoming more common.
Inadequate fumigation or under-dosing results in the survival of insects with increased phosphine tolerance. They can survive fumigation and jeopardise the acceptance of grain consignments by buyers or authorities.
Resistance to phosphine in stored grain pests is a biosecurity threat to Australia’s grain trade. Eventually phosphine will not be effective if poor fumigation practices continue.
Phosphine fumigation must be carried out in sealable (gas-tight) storages so that the fumigant stays at the appropriate level for the duration of the fumigation. A high concentration is required to control insects at all life stages (eggs, pupae, and larvae).
Grain residues can provide shelter and food for pests. Make sure that grain handling equipment like headers, augers, field bins, silos and bulk storages are cleaned before and after harvest.
Always follow the label instructions when using phosphine. For safety, place signs on all access points to the site while fumigation and ventilation is being completed. The sign must contain the words DANGER – POISONOUS GAS – KEEP AWAY, and preferably indicate the start and finish date of the fumigation and ventilation periods.
The sign below is suitable and a template for producing one is in the toolkit on the grains industry page at farmbiosecurity.com.au or from a Grains Biosecurity Officer.
Record the fumigation so that you can demonstrate that you have met the withholding period. A fumigation record keeping sheet is available.
No more than three phosphine fumigations should be conducted on any single parcel of grain.
More information on Organic grains product management.
With zero market tolerance for live pests in grain, storage is no time to forget about biosecurity. Working closely with grains storage specialists, the Monitoring stored grain on farm manual pulls together information from a number of other resources, complementing those already produced by the GRDC Grains Storage Projects.