RESEARCH & EVENTS
Celebrating 10 years of almond research with Plant & Food Research
UNDERSTANDING tree architecture has been a key component of Plant & Food Research ’ s almond research in Australia over the last 10 years . This began in 2013 when Plant & Food Research appointed Dr Grant Thorp as lead scientist based in Australia to undertake research on tree crop physiology . At that time Australian almond growers were successfully using Californian growing systems and cultivars . But the question from industry was , how could they be more successful ? In 2014 , Plant & Food Research was awarded funding from what is now Hort Innovation for a five-year program : Almond Productivity : Tree architecture and development of new growing systems . The key objectives were to better understand tree architecture and the limitations to traditional growing systems with standard cultivars and rootstocks ; and to investigate options to redesign orchards of the future with new growing systems and new cultivars and rootstocks . Importantly , the research would involve close collaboration with almond breeders to identify architectural traits associated with high productivity and suitability for more intensive growing systems . The first trials were established in 2014 to evaluate previously untested systems to increase yields on commercial orchards . Treatments included a novel , selective limb removal pruning system and reflective ground covers . While these treatments increased light interception and shifted production to low canopy zones , they did not increase total yield or improve kernel quality . They also created problems with mixed maturity . These results led to research on more intensive growing systems with smaller trees , to optimise light distribution and increased yields with more uniform crop maturity . This was tested in 2014 and 2016 trials that showed with palmette style canopies , trees could be easily managed in narrow 5m wide rows without reducing kernel yield per tree . The first of Plant & Food Research ’ s high-density trials were planted in 2018 at the Almond Board of Australia ( ABA ) Centre of Excellence in Loxton ,
From left : Wayne Kiely , Dr Roberta De Bei , Nick Timbs and Dr Jill Stanley representing Plant & Food Research at the Almond Centre of Excellence Open Day in November 2023 .
with trees in 4.5m and 6.5m wide rows and 567 to 1,111 trees / ha . The trials continued in 2020 with a new five-year program funded by Hort Innovation and collaboration with the South Australian Research and Development Institute ( SARDI ). At the same time , a parallel set of trials were planted in California with funding from the Almond Board of California ( ABC ) and collaboration with the University of California ( UC Davis ) and California State University ( Fresno ). The Californian trials effectively enabled two production seasons in one year . Two interesting results came from these trials . Firstly , while cultivars such as Nonpareil and Vela planted as central leader trees and pruned to form a narrow shape soon lost their dominant central leader , there were obvious benefits , with less risk of limb breakage as structural limbs were spread over a longer section of trunk . Of the cultivars included in this research , only Shasta ( Buralmondtwo ( BA2 )) and Independence ( Alm-21 ) trees were regarded as well suited to high-density growing systems . The second result was how closely yield from young trees correlated with irrigation . Yields from higher density plantings were higher only when irrigation was increased so that all trees received the same amount of water . With twice as many trees per hectare , twice as much water needed to be applied . Dr Thorp retired in 2022 and Plant & Food Research appointed Dr Roberta De Bei to lead the almond component of the National Tree Crop Intensification in Horticulture program funded by Hort Innovation . Questions on irrigation , nutrition and pruning strategies for highand ultra high-density orchards still remain , and so in 2022 an ultra-high-density trial in Loxton at the Almond Centre of Excellence was planted . This ongoing trial combines genotypes characterised by architectural features considered to be better suited to high-density growing systems , high productivity , and precocity ( a key element for Australian conditions ) with vigourcontrolling rootstocks . Thanks to the last 10 years of research , Plant & Food Research ’ s expertise in orchard design and tree architecture has increased hugely , but there is still more to investigate to carry on supporting the Australian almond industry . Roberta and her colleagues in Australia ( Nick Timbs and Wayne Kiley ) and New Zealand ( Ken Breen and Jill Stanley ), with continuing support from Dr Thorp , are continuing the orchard productivity research and developing more new research directions for the Australian almond industry .
industry . australianalmonds . com . au
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