Webinar Review: Netting
Research & Extension
APAL’s webinar series has been a major hit, with almost 250 people tuning in to listen to the latest in research from subject matter experts from around the world.
That trend continued with last week’s webinar on that critical element of orchard protection: netting.
In recent years, Australia’s apple industry has been hit hard by a range of environmental elements, with netting forming one of the key forces in the fight against these factors.
Hail has decimated orchards in South Australia and Western Australia in particular, while sunburn is an issue nation-wide. Similar to our Australian apple and pear industry, netting is being increasingly adopted to mitigate sunburn and hail risk in Washington State, particularly for high-valued cultivars.
Dr. Lee Kalcsits, Associate Professor of Tree Fruit Physiology at the Washington State University Tree Fruit Research and Extension Center, has been conducting trials to assess the effects of netting on the light and temperature in the orchard and the implications for tree growth, productivity, and quality.
Risk of sunburn
Sunburn is the biggest cause of loss of fruit in Washington State, at around 10%.
Lee noted that given the impact of global warming, as most of the world’s apple growing regions grow hotter by the year, mitigating sunburn risk may prove to be one of the most important factors in the future of apple growing.
He also spoke about the way fruit can physiologically be primed to better withstand damage caused by high temperatures.
Colouring
While there were smaller improvements in colour development in uncovered trees in comparison to covered trees, the size of fruit, bins picked and quality of fruit in covered trees far outweighed the benefits of the colour development. Reflective fabrics underneath the netting also proved to mitigate some of the negative impacts on red colour development.
In the use of blue vs black or red netting, Lee noted in discussion later that the colour that was right for each orchard was largely dependent on the variety.
Different netting types
Drape Netting is noted as being the easiest to deploy and lowest cost, but the most difficult to work under.
Lourve Netting is seen to be the most effective in a North-South tree row orientation, protecting the West side of the tree that is exposed to the sun.
Exclusion netting offers the most protection, including against insect pests, and can be used on sites where wind damage is a bigger factor.
Costs
While the benefits of netting are undoubted and well documented, the primary negative is of course the cost – both to purchase and the labour cost of applying it.
APAL are continuing to work in this space, with the National Netting Program continuing to progress, albeit at a slower rate due to COVID-19, bushfires and other factors.
The South Australian Government recently announced $14.6 million worth of funding to the state’s horticulture industry as part of Netting Infrastructure Grants, helping protect growers from damaging weather and pests.
APAL is now awaiting announcements from other State Governments as to the guidelines for the program for those states.
Join us for the final installment of our current webinar series, as we discuss the benefits of sourcing clean, high quality nursery tree stock, why the Australian Plant Production Standards (APPS) are so important, and more.
As always, the webinar is free, but registration is required – click here for more information.
