Fire-affected fruit – even if it wasn’t directly touched by flames – needs special handling and storage according to a study currently being conducted by the NSW Department of Primary Industries with partnership from the Government of South Australia and Hort Frontiers.
Representatives from the state agency presented their post-fire observations to Batlow growers at the Batlow RSL Club last Tuesday (February 16) in a forum titled ‘Orchard Recovery Research Update’. Scientists and officers with the DPI shared early results from some of their tree recovery and fruit quality studies.
Project Leader Dr Bruno Holzapfel, a DPI Senior Research Scientist, explained that the purpose of the study was to help growers maximise their harvests after fires like the recent Dunns Road fire.
“[We’re looking at] the impact and how to get through that phase of recovery and what to do if that event happens again,” said Dr Holzapfel.
“There [are some who say] that whatever is damaged, just pull it up and replace it, but of course, that is a large cost.
“The alternative is to see what is there and what is saveable and, of course, that is a better economic option.”
The study is the first of its kind in Australia, using fruit grown on three Batlow orchards during and after the Dunns Road fire, Royal Galas from Warren Duffy’s ‘Dufruits’ in Willigobung, Rosy Glow from Batlow Fruit Company’s Vanzella orchard in Batlow and Kanzi from Greg Mouat’s orchard.
“It’s a challenging project and I’ve never done anything like this before,” said Dr Holzapfel.
Dr John Golding, also with the DPI, said that his Postharvest and Fruit Quality studies showed that even if a tree didn’t suffer flame damage, its fruit still needs special attention in order to make it to market.
“There was a significant difference between severely affected fruit and slightly affected,” he said, explaining that severely affected trees were those which had browning damage on their leaves, while slightly affected trees might not appear to have any damage.
“They look like common trees, but they were close to the fire front,” he said.
“There might be some minor signs that something had happened to the tree.”
Dr Golding studied two varieties of apples, the Rosy Glow and Kanzi, storing them for up to eight months to observe how they aged.
“It’s too early [to draw any conclusions], but they do behave differently,” he said, “So you do need to store and market them differently.
“They might look the same on the tree, and the trees might look similar, but there is a significant difference in how they behave.”
Mount View orchard owner John Robson said his property on Old Tumbarumba Road suffered ‘minimal’ damage compared to others, but he felt it was important to learn how far the effects of the fire travelled and how to best respond in the future.
“Immediately after the fires, people ask you the question, ‘Do you think these trees will survive? If so, what’s their crop potential?’ I think it’s something that with this research we’ll certainly have some indicators there for future events.”
After the presentations, the group toured one of the research sites.
“I just want to go out now and see the damage that happened over 12 months ago and see for myself what trees have survived and how well they’re going,” said Mr Robson.
“You get degrees of damage and some people think you see green leaves, so things are okay, but in many instances, you’re better off to take your line back further, push all that orchard out and re-start.
“These are the decisions that are difficult to make at times.”
Mr Robson said he was hopeful that the study would provide guidance for growers in the future to get back on their feet as quickly and economically as possible after a bushfire.
“They said at the start [of today] there’s been nothing documented that people can pick up a paper and say, ‘Okay, I’m at this level of damage, push the orchard out and start again,’ or ‘There’s part of it I can work with and go forward,’” he said.
Mr Robson said he was also dealing with secondary effects from the fire, with birds targeting his orchard for food now that the nearby forests have been burnt and logged.
“We’ve had to be much more vigilant this year,” he said, “We’ve had to put curtains in around the side to stop birds coming in and feeding.”
The birds had been coming in under fire damaged netting in 2020, but Mr Robson said they’re increasingly active as their usual food sources disappear.
To keep up with the challenges of modern apple growing, Mr Robson said his orchard is investigating methods of ‘mechanizing’. Overall, he remained optimistic about the future of Batlow’s apples.
“As far as this district goes, it grows very nice fruit and there’ll always be a place for it in the market,” he said.
DPI Temperate Fruit Development Officer Kevin Dodds helped to open and close the event, sharing Post-fire observations. He said the meeting had a dual purpose: to share the DPI research and to launch a new booklet which documents the initial observations of bushfire damage in Batlow’s orchards.
“[This is] something that wasn’t previously in the public record anywhere in the world before, so this now documents captures visually and also in some text, some of the meaningful impacts of those orchards affected by fire,” he said.
He highlighted the two different types of effects impacting the trees: direct flame or hot air damage – “we call that the blow torch effect,” he said – and the indirect “slow cooker” damage caused as dry materials around the base of trees caught fire and burnt.
“The impact of fires in Batlow Orchards was very significant,” he said. “When the fire was actually happening, people were following the fire and on the RFS maps you can see basically the whole Batlow district – bar two small areas – were directly impacted by fires, which meant that every orchard in the district had some fire impact and some quite severely – we are talking entire orchard blocks lost.”
Mr Dodds said that he was also optimistic about Batlow’s future being “bigger and stronger than ever”, since the area “is one of only a few areas in Australia that have the right soils, climate, elevation and winter chilling in particular to grow the best apple they can, so Batlow is always going to be a premium apple growing area.”
Mr Dodds said the region is seeing investment coming in from “outside”, with growers from other regions buying land in the area.
“What we’re hearing about climate change is that the winter chilling, particularly here in Batlow, is critical and the scientists tell us we have got quite a buffer against reduction in winter chilling, so Batlow is going to remain a good place to grow apples for quite some time, and that’s what is going to make it attractive to others.”
The informational booklet, titled ‘Bushfires in apple orchards: observations from the 2019-20 season” focuses entirely on Batlow and Bilpin (in the Blue Mountains) and is available through the DPI website. Use the search function to find ‘Bushfires in apple orchards’.