A Far North Queensland cocoa grower says new harvest research will help boost yields in the industry.
Gerard Puglisi grows two hectares of cocoa on his property at Mossman.
He participated in research trials conducted by James Cook University’s Centre for Terrestrial Environmental and Sustainability Science, which found rotten cacao fruit husks (cacao is the bean that produces cocoa) left over from processing, dramatically improved the bean harvest.
“It will help to increase our yields with very little input costs because we are using byproducts of the cocoa trees,” Mr Puglisi said.
“It’s putting husks from the cocoa process back under our trees which can increase our yield without as much financial output; perhaps a little bit more physical work.”
The centre’s graduate Samantha Forbes said the addition of cacao husks below trees, which normally would be discarded, dramatically increased pollination rates and increased the abundance of predators that may help control pests.
The transformation from cacao flowers to fruit pods containing beans used for chocolate production relies on small midges that develop in decomposing organic matter.
“This simple change tripled the number of fruits, and quadrupled the yield harvested per tree,” she said.
Mr Puglisi estimated the research could double commercial yields.
A cane grower first and foremost – he grow 188 hectares – Gerard and wife Theresa decided to grow cocoa on a small patch of land that was proving unproductive for cane.
Ten years on, they are part of the successful Daintree Estates Co-Operative – the first company to make chocolate from single origin cocoa beans grown in Australia. The average 15 tonnes per hectare.
“That block of land use to be cane but it wasn’t 100 per cent suitable,” Mr Puglisi said. “We have better production under cocoa and this is better utlilisation for our farm.
“A lot of cane farmers have these fields that are a pain for sugar but ideally suited to cocoa.
“If every cane farmer put in one or two hectares we could have a good cocoa industry and a good sugar industry.”
The research team also investigated how native insect predators, including green ants, spiders and skinks, helped to control pests on the farm.
Ms Forbes showed that green ants didn’t deter midge pollinators away from the cacao flowers and, by hand-pollinating some trees, she demonstrated that the main benefit of adding cacao husks was through increased pollination.
Team leader Dr Tobin Northfield said it was a simple and effective technique.
“There are many other insects using the rotting cacao husks as habitat, that likely serve as prey for larger predators like spiders and skinks,” Mr Northfield said.
“So, adding cacao husks is a simple management technique that simultaneously improves pollination and pest control, while practising species conservation.”
The scientists said their research showed a simple habitat manipulation can enhance both species conservation and pollination in cacao plantations.
But multiple-year studies would be useful to evaluate whether the ‘win-win’ combination could be sustained long term.