A research program has been launched to try and get to the bottom of a mystery disorder which has been wrecking mangoes in Australia's north.
Known as resin canal disorder (RCD), it effects mangoes as they ripen, and although they're still fine to eat, it causes a number of aesthetic problems for the fruit.
The number of mangoes effected by RCD has risen over the last couple of years, especially in the Northern Territory.
Senior horticulturist Andrew Macnish says growers have a range of theories on what causes RCD, and he hopes many of them will get involved in the research project, so industry can solve the 'mystery' as soon as possible.
"We don't have any silver bullets yet, but we certainly understand the disorder better and we're hoping to use that knowledge and leads to continue our research and hopefully in another year or two we'll have some recommendations on how to manage it better."
Mr Macnish says the disorder has become a 'major issue' for early-season fruit coming out of the Northern Territory.
"It has also been found in the Burdekin (Qld), Mareeba area (Qld) and a little bit in south-east Queensland, but unfortunately Darwin seems to be the epicentre of this disorder at the moment."
President of the Australian Mango Industry Association (AMIA), Gavin Scurr, says the RCD research is a crucial project for the industry.
"It was a significant issue for the Darwin region during the last season, and unfortunately the mango industry's season starts in Darwin, so if it gets off to a bad start, then it impacts on the rest of the season because consumers lose confidence in mangoes," he said.
"It would appear with mangoes from the Darwin region, it would be 10 maybe 20 per cent of fruit (last season) had some symptoms of resin canal, and for those growers impacted directly it was devastating.
"So it's obviously a major issue for growers who have it, and it's just as big an issue for those who don't have it, because the supply chain and more importantly the consumer loses confidence once mangoes start turning up in retail looking less than perfect."
Preliminary conclusions from RCD research
* RCD can sometimes be found in green fruit with severe physical injury or pathogen infection
* RCD increases as fruit develop from firm ripe to overripe
* RCD incidence can vary between different farms in a close geographic area and for different harvest dates
* RCD incidence is higher in fruit exposed to commercial handling as compared to fruit ripened directly off the tree
* RCD can be present in the flesh without symptoms in the skin
* RCD can be higher in fruit picked immature than of advanced maturity
* RCD incidence can be higher in fruit harvested within 12 hours of rain relative to fruit picked 60 hours after rainfall