Climate change: Aussie fruit growers deal with heats, storms and pests

Australian scientists and growers are teaming up to protect crops from storms and heatwaves triggered by rising global temperatures.

University of Adelaide researchers say mobile polliniser units could be the key to making netting viable for crops like apples that need to be pollinated. Picture: Katja Hogendoorn

Australian growers are finding ways to protect their crops from climate extremes as the United States tallies the fallout from its devastating June “heat dome”.

In its latest horticulture report, the United States Department of Agriculture said the full impact of the heat dome remained to be seen, but many growers expected to see “lower production, smaller sizes, more sunburn damage, and/or internal fruit damage” as a result of this year’s unprecedented heat across the US North West.

Nicky Mann, chair of Australian Protected Cropping, said Australian growers were increasingly turning to netting and other protective infrastructure to shield their crops from the elements as they experienced more frequent extreme weather events.

Hort Innovation research and development manager Ashley Zamek said new research from Australian universities was now helping to expand netting to crops that haven’t traditionally been protected.

Historically, protections like greenhouses and tunnels have “been favoured by the berry and tomato industry and vegetables such as cucumbers, eggplants, capsicums, leafy vegetables and herbs,” Ms Zamek said.

But there was now an increasing demand for netting and shade protection for tropical and temperate trees like apples, cherries and lychees, she said.

Growers have faced natural disasters with creativity in recent years, rolling out marketing campaigns to encourage people to buy hail and sun-damaged produce, but Ms Zamek said “growers tend to want to avoid that having to think of new marketing ploys to get consumers to be accepting of damaged fruit. They really want to be able to give consumers what they want, which is consistent quality.”

Over the past 14 months, scientists from the University of Adelaide have been working with apple growers in the Adelaide Hills to solve one of the challenges of netting apple crops by using honey bees to cross-pollinate in undercover settings, with “promising” results, said University of Adelaide project lead Dr Katja Hogendoorn.

In another trial, the NSW Department of Primary Industries has installed humidity sensors in a soon-to-be-netted cherry orchard at Orange to understand how netting the crop affects humidity.

Ms Zamek said the research will give more growers the chance to better control their growing environment as climate change bites.

Some companies, like Nutrano Produce Group, which has invested in 74 hectares of netting over one of its citrus crops in Sunraysia, are considering expanding their area under netting.

“Every time we look at redevelopment, we consider netting,” Nutrano general manager Tania Chapman said.

The netting at the Sunraysia crop has helped protect the fruit from extreme heat, hail and pest pressure, and was also reducing the amount of water the crop required, she said, but installing it was “not a cheap exercise”.