The sunburnt country... an apple story

• State-supported, water-efficient overhead misting system saves sensitive fruits from the harsh Australian sun
• Losses from sunburnt apples reduced by 80 %, saving € 30 430 a year 

Spread over five sites and 250 hectares, Oakmoor Orchards produces apples, pears, peaches, nectarines, apricots and plums. Around 8 000 tonnes, including 2 000 tonnes of Granny Smith and Pinklady apples, are produced every year.

The fruit is easily damaged, especially during heatwaves which are common in many parts of Australia. According to the Department of Environment and Primary Industries, up to 30 % of overall apple and pear losses, and 40 % of Granny Smith apples in particular, are due to heat stress. In 2013 alone, 30 % of Granny Smiths were lost due to sunburn.

Consumers demand that these products are fresh when they are sold at the supermarkets. Climate change could result in more intense and frequent heatwaves, requiring better protection for the fruit. So Oakmoor installed an overhead evaporative cooling irrigation system (by DEPI) that sprays a low-volume mist of water during high temperatures, which cools the surrounding air and fruit.

To help finance this measure, the orchard received a grant of € 27 646 (AU$ 42 700) from Sustainability Victoria, which went towards the cost of installing the evaporative cooling system over a 16.5 hectares trial block of Granny Smith trees.

Key benefits

Thanks to the misting sprinklers, Oakmoor estimates that sunburn loss is reduced from 10 % to 2 % per year, which is an 80 % improvement that saves the company € 30 430 (AU$ 47 000) annually. The 16.5 hectares section of the orchard produces around 620 tonnes of fruit, equating to € 384 580 (AU$ 594 000) gross income. Without the evaporative cooling, Oakmoor would expect heat stress losses of about 10 % or € 38 200 (AU$ 59 000). The payback time of the measure is therefore estimated at less than 2 years.