TRELLISES may be the answer to protecting north Queensland horticultural crops from severe cyclones.
Agriculture Minister John McVeigh said his department would investigate trellises and other techniques as a possible solution to the damage caused to tree crops by severe tropical storms.
“Some northern producers are already looking at trellising, chemical defoliants, windbreaks and strategic pruning of tree canopies to better protect their crops and livelihoods,” Mr McVeigh said in a statement.
“I recently visited Tully district producers Peter and Alison Salleras along with the Minister for Natural Resources and Mines, and local Member for Hinchinbrook, Mr Andrew Cripps.
“Peter and Alison lost their crops in Cyclone Larry in 2006, but their use of trellises saved them a lot of grief during Yasi in 2011.”
Mr Salleras said 95 per cent of his family’s soursop trees were lost in Cyclone Larry.
“Afterwards, we replanted a range of tropical fruit species, including soursop, mangosteen, durian, jackfruit, rollinia, abiu and Malay apple on a modified Tatura trellis system,” Mr Salleras said.
“We were in the eye of Yasi and we didn’t lose any of the 450 soursop trees we had replanted after Larry.”
Mr McVeigh said the Rural Industries Research and Development Corporation (RIRDC) had granted around $500,000 over the next four years for the department to work with producers to develop ways of better protecting tropical primary industries such as fruit, beef, dairy, forestry and aquaculture.
Yan Diczbalis from the department’s research team said modified trellis structures were effective for some producers during Yasi.
“We especially want to look at how we can build on this for wider industry adoption,” Mr Diczbalis said.
“We will assess a range of trellis designs for their effectiveness and determine which designs are the best for specific tree species. We’ll also trial the designs on custard apple, rollinia, durian, rambutan, jackfruit and possibly mangosteen.
“If we can design trellises more suitable for netting, we may be able to protect crops from birds, flying foxes and fruit flies as well. If plastic covers can be used, they could reduce rain damage and help induce flowering.
“We want systems that allow for the rapid removal of nets to reduce damage to both them and trees during cyclones.”
Mr Diczbalis said trees with small canopies and sparse foliage survived better in Larry and Yasi because they had less wind resistance.
“Using heavy machinery to prune trees would be impractical if a cyclone is on the way, so we will test different defoliants to assess their impact on leaf fall and wind resistance of trees,” he said.
Mr and Mrs Salleras had a “light bulb moment” when they saw pear trees growing on Tatura trellis systems in southern Queensland.
“We trialled poles and wires in our trees and it saved our orchard when category 4 Yasi struck last year, only five years after Larry,” Mr Salleras said.
“We had some problems with our permanent netting which acted like a huge sail in the strong winds and caused some damage. We won’t make that mistake again and I’m pleased the project will look at alternatives.”
The Sallerras’ Tully property will be one of the trial sites for the DAFF/RIRDC project, which will also look at windbreaks as another possible resilience measure.
Other horticulture production and risk-mitigation techniques to be studied include -
* Nursery techniques that promote healthier plants with stronger root systems.
* Pruning techniques and timing.
* potential amendments to crop insurance policies due to adoption of improved crop management practices on farms.
* Fencing strategies, animal identification and welfare issues to potentially benefit beef producers and other stock owners.
