Growers in Western Australia storing grain on farm now have another chemistry with a different mode of action to add to their rotation for the control of insect pests, thanks to the recent APVMA approval of K-Obiol EC Combi for the on-farm use.
K-Obiol, which contains the active ingredient deltamethrin, is a synergised grain protectant that can be used to treat malt barley, wheat, oats, sorghum, rice, maize and other cereal grains, and provides protection against the main stored grain insect pests, in particular lesser grain borer, for up to nine months.
Segment business manager at Envu Paul Crack says the approval of K-Obiol for on-farm use in WA means growers will now have multiple options to control insect pests in stored grain, which provides a range of benefits, particularly from a resistance point of view.
“Previously growers only had the option of fumigation or very old chemistry in Fyfanon, so K-Obiol is another product that has never been used in Western Australia before, and it will be very strong and effective in controlling a range of insect pests,” Mr Crack said.
“From an industry stewardship point of view, having another insecticide that is available in the grain storage market that is a different mode of action to anything else that has been used in Western Australia before is a really big win for the industry in terms of insecticide resistance.
“Resistance is a growing issue across the entire country, and repeated uses of the same product over many decades has resulted in many populations of insects becoming resistant to many commonly used insecticides. This being a new mode of action will extend that resistance period out even longer by allowing for the rotation of chemistry.”
Grain Producers Australia chair and WA grain producer Barry Large said his organisation supported the delivery of new technologies and tools that helped growers become more profitable and sustainable, so the approval is a welcome one for Western Australian growers.
“We know insecticide resistance is an issue that we need to manage as an industry and growers need more options to help them get the job done properly,” he said.
“That’s why this is a good outcome for growers with another option to help protect their grain from damage by insect pests.”
While any product in WA that will be delivered to Co-operative Bulk Handling (CBH) facilities needs to be pesticide residue free (PRF) and cannot be treated with K-Obiol, the latest APVMA approval is a really big win for those growers that are storing grain on-farm.
“Growers can use a product like K-Obiol to store their grain on-farm for up to nine months and keep it pest-free while maintaining grain quality, which is one of the biggest challenges,” Mr Crack said.
“If grain quality decreases because of insect infestation then grain price drops as well, so by using a reliable product like K-Obiol it allows farmers to confidently play the grain market knowing they will have insect-free grain when it comes time to market it. That will give them a big advantage in capturing the best price possible for their grain.”
To ensure no pesticide-treated grain enters the PRF market, Mr Crack said Envu has strict protocols in place for both agents selling K-Obiol, and growers who intend on purchasing it.
“All agents selling K-Obiol need to undergo a stewardship training process to ensure they understand the limitations around using K-Obiol, and growers wishing to purchase K-Obiol also need to have undertaken a stewardship program prior to purchase.
“That program outlines all of the different constraints around using K-Obiol and the markets that it excludes growers from if they do use it. The stewardship program is accessible via an easy-to-use online portal that we have developed, and once successfully completed, growers and agents will get a certificate of completion.
“To uphold their end of the stewardship program, agents will also have the ability to search through a database to see that growers have completed the program and are approved to purchase the product.”
Mr Crack said while knowing the different constraints around using any product, not just K-Obiol, is really important, reading the label to understand use rates and restrictions around the PRF market in WA is essential.
“For K-Obiol in Western Australia, it is extremely important to understand the use rates and to make sure you do not exceed any of the existing MRLs. It is also outlined on the label that any grain to be treated and delivered to the CBH requires pre-approval to ensure the export market is not compromised.
Mr Crack said it is also important to wear the correct safety gear, so following the label directions carefully is essential.
Applied via a pump and tank arrangement with a nozzle that sprays product onto the grain as it moves up the auger, K-Obiol is suitable for use in both sealed and unsealed silos, which he said will provide Western Australian growers with greater flexibility.
“To treat grain properly, K-Obiol must be applied alongside the registered organophosphate in WA, malathion, and growers should stick precisely to the recommended dilution and application rate,” he said.
“This will help protect against insecticide resistance and ensure the entire spectrum of stored grain pests are controlled.”
While K-Obiol will give grain long-term protection from insect infestations, Mr Crack said it is not registered to control live insects, so it is important that grain is not infested before treatment.
