The prospect of ongoing dry weather and the current low prices for crops like chickpeas have many northern grain growers preparing to store grain on-farm from this year’s harvest in the hope of cashing in on higher prices in the future.
On-farm storage provides farmers with this additional marketing flexibility and it has been encouraging to see more and more producers investing in recent years in the infrastructure required.
However, for the strategy to be effective, good equipment and hygienic farm practices are essential to protect the grain from damage from insect pests and loss of quality.
At the start of harvest be sure to remove any grain residues and clean thoroughly all empty storages and grain handling equipment which may have provided a breeding habitat for pests. Growers should consider treating machinery and storages with dryacide prior to the commencement of harvest.
Freshly-harvested grain is usually around 30°C, which is also an ideal breeding temperature for pests – to overcome this an aerated storage system is needed that can maintain temperatures of less than 23°C during summer and less than 15°C during winter, which will account for 85 per cent of pest problems.
When placing grain into storage, first run the aeration fans continuously for 2-3 days to create even moisture conditions. Growers should then push a second ‘cold front’ through to cool the grain by running the fans for the coolest 9-12 hours of each day for the next 3-5 days.
Stored grain should be monitored monthly for the incursion of insects, preferably by positioning insect traps and sampling at the top and bottom of storages.
If insect pressures do arise, the only option is to fumigate with phosphine (no alternate knock-down is available). For this to be effective, the storage must be gas tight so that the phosphine can be maintained at a level high enough to kill grain pests at all stages of their life cycle (egg, larva, pupa and adult).
Just like any pesticide, it is important to rotate chemical groups when treating grain in storages to minimise the risk of resistance developing among insect populations.
When doing this be sure check the labels for the suitability to different crops and correct application rates. For example, two of the newer products on the market are Conserve On-Farm and K-Obiol – the former is not yet registered and is still on-permit for use only on cereals but not on maize, pulses, malting barley and rice, while the latter can be used on all cereals, including malting barley and sorghum and again not on pulses.
Growers should be aware of the protocols and documentation required for these products.
Finally, it is important that stored grain should be monitored for the incursion of insects, as well as correct grain temperature, moisture content, and changes in grain quality or germination.
More detailed information about seed fact sheets are available at www.storedgrain.com.au.
Rob Taylor, GRDC Northern Panel, Macalister, Qld
07 4663 5242, 0427 622 203
Michael Thomson, Senior Consultant, Cox Inall Communications
07 4927 0805, 0408 819 666