AS the threat of Fall armyworm continues to trend south, agronomists and industry bodies are exploring ways of limiting the pest’s potential damage.

Elders is among those on the frontlines and has enlisted the help of Toowoomba-based technical services manager Maree Crawford to help find an answer to the increasing threat.

Ms Crawford has so far found that drastic measures have failed to prevent damage, but a more integrated approach was preserving crop yields.

“This pest is a serious threat to some crops and there is a tendency for growers and advisors to overuse synthetic pyrethroids up front and this approach is not proving successful,” Ms Crawford said.

“Elders agronomists address Fall armyworm outbreaks in a very structured way, using an integrated pest management approach based on the individual circumstances.

“You have to take a lot of factors into account, like the weather, the lifecycle stage, the crop species and its risk profile, and the extent of the infestation.”

The research comes after Fall armyworm were discovered in a maize trial plot in Georgetown, northern Queensland in February.

Since then, the pest has been spotted in several locations in Queensland, as well as Hillston, Croppa Creek, Breeza, Forbes, Dubbo, Narrabri, Wee Waa, Maitland, Moree and Boggabilla in NSW.

“If you nuke everything, your not going to have the beneficals to clean up new egg lays and hatchings underneath the leaf where your sprays have failed to reach all of the Fall armyworms,” Ms Crawford said.

 Elders Toowoomba agronomist Matt Kenny checks one of the trapview units being used to monitor for early flights of Fall armyworm. Photo: Supplied

Ms Crawford said once the pest got past the past the 10mm-long third instar stage it was almost impossible to prevent large-scale crop damage and in turn it was crucial for farmers to spray in the evening.

“When they are transitioning from the third to the fourth instar, we find them inside the whorl of the plant,” she said.

“They cover themselves down in the whorl with frass, which is their waste, and the chemical can’t get to that, it just sits on top and doesn’t penetrate them.

“It’s critical to spray in the evening, when the largely nocturnal larvae are out feeding.

“It’s a bit of a concern but I think it is manageable with proactive, vigilant practices and the array of chemistry we’ve got access to, we can manage the pest in most crops and limit the damage.”

The threat has Maize Australia executive officer Liz Mann on high alert and urging growers to be vigilant.

“Fall armyworm is moving south and it is a bit of a concern,” Ms Mann said.

“I think it and other pests may be one of the biggest challenges facing producers this season.

“We know producers are usually right on top of these kinds of things and we’re hoping it won’t be too much of a factor ahead of the summer season.”

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