K-Obiol FAQ

Get the answers to the most frequently asked questions about K-Obiol from our team of experts in Stored Grain Management.

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FAQs on K-Obiol

What is K-Obiol?

K-Obiol is a synergised grain protectant for use on uninfested cereal grain. A “protectant” (sometimes also called “contact pesticide”) protects grains from insects rather than killing insects once they have infested the grain (think of it working like a personal insect repellent). If the grain is already infested it will need to be fumigated or treated to kill the live insects. 

K-Obiol can be used on all cereal grains including malting barley and sorghum. It is not suitable for oil seeds or pulses. K-Obiol can be used in any type of storage, sealed or unsealed, providing the K-Obiol can be evenly distributed on the grain as the grain is fed into the storage. 

Do I need to complete stewardship training to access K-Obiol?

The use of K-Obiol for the control of Stored Grain Pests is subject to a stewardship program. Envu only permits users who have successfully completed the product training course to purchase and use K-Obiol to become a ‘approved user’. Approved users should be aware of the Australian Grain Industry Code of Practice and, in particular, their responsibility to advise the buyer of grain that it has been treated with ‘K-OBIOL EC COMBI SYNERGISED GRAIN PROTECTANT’. Where possible this should be done using the GTA (Grain Trade Association) ‘Grain Commodity Vendor Declaration’. For further information, visit the GTA website www.graintrade.org.au, and to access the training package, visit www.au.envu.com.

What is the active ingredient in K-Obiol?

The insecticide active ingredient in K-Obiol is deltamethrin. K-Obiol also contains piperonyl butoxide which acts as a synergist. A synergist acts to make the active ingredient more effective and hence improve the cost/benefit performance of the product. Deltamethrin is an active ingredient found in many pesticides in agriculture and commercial use.

What is the difference between a protectant and a fumigant?

A fumigant e.g. phosphine (sold under various trade names such as “Quickphos”,Fumaphos” and “Phostoxin”), is a gas which kills insects. It needs to be retained in the grain for several days, sometimes up to more than a week, for it to be effective.

Effective fumigation requires the grain storage to be sealed to retain the gas.

“Sealed” means gas-tight, meeting the Australian Standard AS 2628-2010. If the silo is not gas-tight, the fumigation will not be successful and there will be insects left to breed and reduce the value of the grain. It can also hasten the increase of insect resistance to the fumigant. Fumigants give no residual protection.

Where can K-Obiol be used?

K-Obiol can be used on any cereal grains provided they are not infested with insects. The cereals which can be treated with K-Obiol include wheat, barley (malting and feed), maize, rice and sorghum. K-Obiol is not suitable for use on oil seeds and pulses.


Grain protectants like K-Obiol leave a low level of chemical residue on the grain. Provided K-Obiol is used at the label rate and the grain receives only a single treatment, chemical residues on the grain are acceptable to the Food Safety Standard of Australia and New Zealand. These treated grains can be used in all markets in Australia except for “organic” or pesticide residue free (PRF) markets.




At what rate do I apply K-Obiol to my grain?

There is only one rate of application for K-Obiol and it is easy to remember – 1 L treats 50 tonne BUT it must be diluted to apply.
1 litre of K-Obiol is diluted in water to 50 litres.
1 litre of the dilution is used per tonne of grain (all grain types).

Should K-Obiol be used in combination with other protectants?

The short answer to this question is “Yes”.
Some naturally occurring insect biotypes resistant to K-Obiol may exist through normal genetic variability in any insect population. The rice weevil, granary weevil and maize weevil (Sitophilus spp.) show this trait and so it is recommended K-Obiol is used in combination with another registered grain protectant product.

Where can I purchase K-Obiol?

If you wish to purchase K-Obiol EC you will need to have completed the required K-Obiol training

K-Obiol is available from all the major rural suppliers including AgLink, AGnVET, CRT, Elders and Nutrien and some independent stores. All locations must have at least one member of their staff who has done the retailer training in K-Obiol and will be able to offer assistance

Note: K-Obiol is not avaliable in WA except under special conditions and approval by the WA Department of Agriculture and Food. Click here to locate store