Improperly sealed silos can lead to fumigation-resistant pests. ABHR spoke with John White, Allied Grain System’s managing director, to find out how it’s helping protect Australian growers from this threat.
In 2007, the grains research and Development Corporation (GRDC) found a population of insects resistant to phosphene.
The rusty grain beetle was not the first insect pest to develop a strong resistance to phosphene. However, the population that was uncovered had the strongest level of resistance to the chemical anywhere in the world, and could not be controlled with the label rate, according to the GRDC.
Strong resistance to phosphine can develop and spread quickly. Resistance in stored grain insects has now spread throughout the grain growing regions in all states.
“For example, after its first detection in 2007, rusty grain beetle had spread to four farms by 2011 – in NSW and South Australia. However, by 2021 it had spread to Queensland and Victoria, with a total of 53 detections across eastern Australia,” the GRDC said on its website.
The main culprit behind the spread is the misuse of phosphene, particularly in unsealed storage. The GRDC said phosphine requires time to be effective against all life stages, particularly eggs, and should only be used for grain fumigation in gas-tight storages.
When used in non-sealed structures, phosphene concentrations can fall below the recommended levels. As a result of multiple failed fumigations, the insect populations can develop a resistance.
John White, Allied Grain System’s managing director, said that there are only a few fumigants available for Australian grain exporters and growers, so if a pest population becomes resistant enough there could be dire consequences to the nation’s biosecurity.
One of the ways Allied Grain Systems is helping stop this risk is through its range of sealed silos. The company began working on its sealing technology in 2008 to provide a solution for its Australian customers.
“The rest of the world doesn’t have as strict requirements,” he told ABHR. “In North America and Europe, cold weather tends to kill their bugs.”
“We’ve become market leaders in sealing valves and have started to export our equipment to Asia and India.
“The vast majority of the bins we build these days are sealed – it’s part of everyday life for our customers and we have developed designs and manufacturing techniques to support them.”
Allied Grain Systems ensures its silos meet Australian Standard AS2628-2010. This means its silos pass a five-minute, half-life pressure test. The pressure in the vessel is increased to around 500 pascals, and the test ensures this level doesn’t decrease to lower than 250 pascals after five minutes have passed.
The company also supports its equipment with spare parts and backup assistance if required. On larger jobs, its staff can design programmable logic control systems to help automatically fumigate a silo.
White said the company aims to stay a market leader in sealed silos.
“We learn our customer’s requirements and their fumigation needs so that we can design a system to suit. Quite often, we will design these silos in such a way that they can be retrofit with a higher level if the customer wants to upgrade later down the line,” he said.
“Sealing and fumigation are often overlooked, but they are a vital part of the country’s grain industry. If not done right, there could be disastrous effects for the entire country.”