This ripe tropical fruit, popular in South America, is ready to be picked and eaten, but it won't be. It will be allowed to fall to the ground and rot.

Because in Australia they are only valued for the strange looking object on the end. The cashew nut.

Cashews are a popular delicacy. Australia imports over 20 million dollars worth a year. The international market is worth 650 million dollars.

"At the moment, the world's demand for cashews is well above the world's supply and the demand is increasing by 7 to 10 per cent each year"

And this is why CSIRO scientists are helping Australian farmers develop the crop. But the reason they are so expensive is because they're not easy to produce and also they're labour intensive to prepare for market.

The kidney shaped cashew fruit sits at the end of a stalk which enlarges into a fleshy pear shaped structure, that turns yellow or red, becoming fragrant in the process.

The greyish brown hard shell at the end, encloses a single seed... or cashew nut.

And although the fleshy part of the fruit can be eaten, it's the nut which is popular.

Growers wait for the fruit to fall to the ground, then the cashews seeds are scooped up and sorted, before being sent overseas, where the nuts are roasted to get rid of cardol and anacardic acid, which are not only irritating, they can be poisonous. Then each shell is opened by hand.

The cashew nut tree, native to Brazil, is found in tropical countries around the world, and they do grow well in tropical areas of Australia. But, despite the demand, at the moment, they are not necessarily highly profitable.

"Because of the high labour costs we have to produce about a 10 fold more yield per tree than they do overseas and we can only achieve this by better irrigation and by better fertiliser and that's the whole crux of the cashew multi-divisonal project"

Cashew nut plantations take a long time to develop and Australian growers are seeking to fill the high quality end of the market.

Science is helping this industry which has the potential to fulfill a valuable local demand while creating a highly profitable export.