Australia - Two solutions combined to help maize growers gain the Edge over Fall armyworm

ADAM Harber has seen firsthand how much damage Fall armyworm can do to a crop and how quickly it can happen.

″It was 2020, the first year Fall armyworm was detected in Australia, when it came through the Torres Strait and it had moved its way down the coast to Bundaberg where I was at the time,″ Mr Harber said.

″We knew it could be devastating but there is nothing like seeing it.″

The farm where Mr Harber was working was growing forage crops and has seen first-hand the impact of FAW.

″We’d had experience with grubs before, but I’d never seen something that can decimate a crop so quickly,″ Mr Harber said.

″The plants might be three foot high one week and then you’d come back a day or two later and they’d be just completely decimated. It was pretty devastating, and a lot of investment was wiped out.

″The response was to throw every possible chemical at it to try to control it, but we quickly realised it didn’t work.″

Enter Intrepid Edge

Fast forward a few years, Mr Harber now works as a Territory Sales Manager at Corteva Agriscience, and the company offers a powerful new tool for the management of Fall armyworm (FAW) in pulse and maize crops.

Intrepid Edge^® Jemvelva^® active combines two unique modes of action from Group 5 and 18 insecticides, with active ingredients Jemvelva and methoxyfenozide delivering both a fast-acting knockdown of pests and a residual activity that protects the crop between applications.

Intrepid Edge is active on eggs, all larval instars and adults, while being selective to key beneficial insects.

Gloucester Rural Supplies Manager-Director, Troy Higgins, said since FAW arrived three years ago, its prevalence had increased to become a significant pest in both crops and pastures.

Adult FAW can migrate almost 500 kilometres per generation and produce up to 2000 eggs in their lifetime, leading to fast population build-up. The larva is the damaging stage of FAW, attacking a broad range of crops with a preference for maize.

″It took a bit of time to actually identify what was attacking maize crops early in the piece, as most people thought it was Heliothis, but every maize crop planted last year was damaged in some way from FAW″ Mr Higgins said.

″Any crop planted early in the season, in early October, was hardly damaged compared to those planted later, from mid-November onwards. The early crops may have been under less stress from moisture, and a bit cooler soil and air temps prevented hatching of FAW, whereas the later-sown crops were heat and moisture stressed, making them a far easier target for the pest.

″Crop yield in some instances would have been reduced by at least five tonnes per hectare.″

Intrepid Edge a ″no brainer″

Mr Higgins said he recommended Intrepid Edge to growers due to its dual actives for resistance and the activity on all life stages of FAW.

″An absolute no-brainer,″ he said.

″It’s a great quality product with low risk to humans and beneficials, and longer-lasting control than most insecticides. With its longer activity, cost per hectare is also reduced.″

Mr Harber said at $50 per hectare, Intrepid Edge offered a level of assurance at a competitive price.

″We hope Intrepid Edge puts confidence back into the market because, unfortunately, FAW is here to stay and growers need a product like this to add to their management strategy.

″No one tool is going to help you successfully manage FAW. It needs a combination of practices, including natural enemy populations. This is another feature of Intrepid Edge because it is soft on beneficials and suitable for Integrated Pest Management.″

Tolerance for Intrepid Edge is very high for all labelled crops with no demonstrated negative effects, regardless of plant stage or environmental conditions.

Pheromone traps can be used to alert growers to the arrival of FAW adults to an area, however fields should be scouted at a minimum of once per week or more often when conditions favour infestations.

Intrepid Edge should be applied when FAW exceed spray thresholds anytime during crop development and up to 28 days prior to harvest to comprehensively reduce the entire pest population.