Calls for grain protection to match storage type.
As Australian grain growers continue to increase their on-farm storage capacity, matching grain protection to the storage type and proactively working towards preventing potential resistance issues needs to become a priority.
Throughout the grain growing areas of Australia, there are currently several types of insect pests infesting stored grain, so it is important for growers to have an effective resistance management plan in place to combat developing insect resistance in protectants that have been in use for over 30 years.
“Understanding the condition of the silo and the options for protecting grain from insect pests is a crucial decision for farmers who store their own grain,” said Rod McLean of Bayer.
“Farmers spend about $120 per tonne to grow their grain and get it into the bin, whilst the cost of protecting the grain in the bin is around $0.50 to $3.50 per tonne depending on the method used, so it would be a shame to not choose the correct method of protecting the grain and therefore risk losing value or even a sale.”
A recent Bayer commissioned study, shows that almost 90 percent of cereal growers have on-farm storage, with the most common type being unsealed, and many utilising a combination of several storage types.
“Of those named as sealed, 60 percent were over 10 years old and it is doubtful if they are gas tight,” continued McLean. “Many silos are sold as ‘sealed’ but after a few years of use, may not pass the Australian Standard as gas tight.”
The research also uncovered fumigation using phosphine is the most common method used for grain protection, despite the increasing prevalence of insect resistance to phosphine in Australia, most likely as a result of under-dosing from failure to achieve sufficient gas concentration for the required period, which typically occurs in poorly sealed silos.
“For successful fumigation you need to maintain the level of fumigant above a minimum for a week or longer depending on the temperature, so if the silo is not gas tight, this is not possible,” explained McLean.
Bayer’s grain protectant, K-Obiol® EC Combi, can be used in sealed and unsealed storage including silos and sheds due to its liquid form, making it an ideal solution to the risk of infestation.
“When we have examined infested grains we often find two or more insect types,” said McLean. “As different insects have developed resistance to the various grain protectants, it’s clear that to achieve protection, you need to use a combination of grain protectants with different modes of action.”
McLean suggests K-Obiol in combination with either fenitrothion or chlorpyrifos-methyl to provide coverage to all types of insects.