Australian-bred almond varieties are set to make their mark across the globe as growers look for ways to combat the danger of declining bee colonies.
Six new varieties developed at the University of Adelaide in South Australia have been released in Australia in the past two years, four of which are self-fertilising.
Budwood cuttings have been sent to California and South Africa with a shipment expected to leave for Spain in the coming weeks.
The United States is the dominant almond producing nation, growing about 80 per cent of the world’s almonds followed by Australia, Spain, Iran and Italy.
More than $400 million of Australian almonds are exported to 46 countries every year with Europe and India the biggest markets.
However, concerns about declining bee colonies overseas, particularly in the US, have nurseries looking to new varieties – including those bred in SA – that do not require bees for pollination.
The decline in bee numbers in recent years has been blamed on a variety of factors including pesticides, climate change and parasites.
This has coincided with a rise in global almond consumption and increased plantings that led to record production of 1.3 million tonnes in 2017-18.
They are very keen to trial our self-fertile varieties because they don’t have anything on their books that is self-fertile
- Dr Michelle Wirthensohn, University of Adelaide
The University of Adelaide has run the national almond breeding program for two decades, leading to the commercial release in Australia of five new varieties of almond trees in 2016 and a sixth in 2017.
Cuttings of all six were sent to the US in August 2016 where they will remain in quarantine until November.
Some of them will go into USDA trials along with trees from other parts of the world.
Program leader of the breeding program Dr Michelle Wirthensohn received an Australian Government grant last month.
This has allowed the University of Adelaide to partner with Californian company Varieties International, which will send the trial varieties to Yuba City nursery Sierra Gold.
“They’re a large nursery and they are very keen to trial our self-fertile varieties because they don’t have anything on their books that is self-fertile,” Dr Wirthensohn said .
“It’s a fairly new thing, there’s a few varieties out … Sierra Gold has told me they will test for 10 years before they release them commercially.”
The six varieties have also been sent to South Africa in the past year and will be trialled when they are released from quarantine from next year.
Three of the varieties – Carina, Mira and Maxima – have semi-hard shells while Vela is a soft shell, Rhea a paper shell and Capella is a hard shell. Maxima and Rhea are not self-fertilising but Maxima is proving popular among some Australian growers because of its large kernel.
Nonpareil, also known as Californian Paper Shell, is the main commercial variety in the world.
Dr Wirthensohn said a key factor with the new Australian varieties was their similarities in kernel properties to Nonpareil.
She said all of the varieties out-yielded Nonpareil in Australia by more than 10 per cent, producing more almonds per tree with the same amount of water.
“So if the time came when for some reason Nonpareil collapsed then we would have an almond that looked really similar and was either the same size or bigger,” Dr Wirthensohn said.
“The main attraction is the self-fertilising and I guess in the US they are also curious to see how our almonds are going to perform over there – they’ll probably perform differently but hopefully they will do at least as well as they do here.
“They’re probably not going to be interested in Capella but the Spanish will probably like it because they do like a hard shell.”
It can take decades to breed a new almond cultivar from the initial crossbreeding through to commercial release.
Dr Wirthensohn said the next pipeline of trees in the Australian breeding program were currently going through secondary and tertiary evaluation with a projected commercial release of another five varieties – some self-fertile and some not – by 2023.
“The next lot of breeding I’ll be beginning next year,” she said.
I’m only going to focus on self-fertile varieties because that’s what the industry says it is aiming for – self-fertilising trees that minimize the need for bees and filling up the orchard with a variety that doesn’t need a pollinator.
“The lack of bees will be a concern in the future.
“No one has trialled a solid block of self-fertile trees in Australia yet – they have in Spain and they said it worked fine – but not here yet, which will be interesting.”
The Almond Board of Australia is also testing high and medium density plantings at the Almond Centre of Excellence Orchard in SA’s Riverland, one of Australia’s main almond, grape and citrus growing areas.
The medium density trial was planted in 2017 at three-metre spacings between trees with 6.5m between rows using Nonpareil, Carina, Maxima and Vela.
The high-density plantings will go in this year at one-metre and two metre spacings.
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