When international borders were open and planes were thick in the sky, it would take a matter of hours, not days, for highly perishable food grown in Queensland to reach the nearby export markets of Asia and New Zealand.

As the coronavirus pandemic wrought havoc on international passenger air travel, it also caused chaos for global supply chain networks, particularly those reliant on airfreight.

The disruption in some cases has seen exporters turn back to sea freight as a more reliable option, although the extended time that produce needs to spend on water is presenting a different set of problems.

The key question for exporters is how to keep that same produce in pristine condition for the end consumer when it is spending days, and sometimes weeks, traveling by boat, rather than travelling by plane?

For some, the challenge has proved impossible to resolve. It’s why, according to one of the nation’s peak horticulture groups, Ausveg, exports of vegetables to markets only accessible by air, declined in 2020.

The drop was part of a wider dip of 6.3 per cent overall for national fresh vegetable exports, according to the group’s export development manager Michael Coote.

“While exports of some vegetable crops increased despite the disruptions caused by COVID-19, exports of highly perishable vegetables that have historically only been exported by air freight declined,” Coote says.

“Capacity in the air freight network may take a number of years to return to pre-COVID levels, and it is anticipated that air freight prices won’t return to pre-pandemic rates in the foreseeable future.”

There is much at stake, according to Agriculture Minister Mark Furner, as the industry pushes to achieve $400 million in export earnings from fresh vegetables out of Queensland by 2025.

Rather than conducting trials in real-time in real-world conditions on the high seas, researchers are simulating supply chain operations in global sea channels a long way from the coast at Gatton and Nambour.

With Ausveg and the Department of Agriculture and Fisheries as lead partners, the research project is aimed at providing vegetable exporters with additional insights into which export markets are technically viable by sea freight, while striving to underpin short and longer-term export growth for the industry.

DAF director of vegetables Ian Layden said researchers were working with leading Queensland producers of selected vegetable lines including broccoli, green beans, sweet corn and iceberg lettuce.

“We’re testing a range of temperatures and atmospheric conditions over time in our purpose-built postharvest facilities and a range of packaging options that will better suit sea freight conditions,” he said.

Layden said preliminary results from the studies were promising.

“The quality and shelf life of broccoli for shipment to Japan and Taiwan can be improved using modified atmosphere bags where ice does not directly contact the broccoli,” he said.

“We’ve demonstrated that sweet corn can be successfully exported by sea with the husk on which is preferred by Japanese customers and using controlled atmosphere containers to retain a fresh appearance.

“Selecting the right variety of iceberg lettuce is critical to maximising quality and shelf for the voyage to Asia, while robust varieties and packaging is important for mixed loads of sweet corn and green beans bound for New Zealand.”