RESEARCH & EVENTS
SARDI at ACE – 2024 season review
SARDI Almond Production Research Team South Australian Research and Development Institute ( SARDI ), the research division of the Department of Primary Industries and Regions
SARDI progressed a range of field-based research activities at the Almond Centre of Excellence ( ACE ) through 2023 / 24 . These included rootstock drought response studies , the commissioning of whole tree weighing lysimeters and the collection of various canopy and yield metrics from more than 580 experimental plots . This article briefly updates some of these activities , with more information available through SARDI factsheets at the ABA website .
Planting density effect on yield and kernel quality SARDI manages two density optimisation experiments examining the interaction between genotype and planting densities ranging from low ( Horizon 1 or H1 ) to high ( H2 ) to ultra-high density ( H3 ). Background , trial designs and earlier results can be found at H1-H2 Density and H2-H3 Density . range , the average sixth leaf cumulative yields for these varieties were 14 t / ha ( Vela ) 13 t / ha ( Carina ) and 11 t / ha ( Shasta ). H2 to H3 yields ( fifth leaf / planar canopy ): In 2024 the Shasta trees had their best yield to date , averaging > 3.7 t / ha across all density and rootstock combinations . Whilst the 2024 Vela crop was suppressed (< 3 t / ha ) its average fifth leaf cumulative yields remained higher overall at 7.5 t / ha ( Vela ) compared to 7 t / ha ( Shasta ). Trees grafted to Rootpac-40 and Controller-6 outperformed those on Controller-7 and showed the greatest fifth leaf cumulative yields at the higher densities . Kernel Quality : Over the last three seasons , Carina has consistently produced a smaller kernel (~ 1.1 g ) than Nonpareil (~ 1.3 g ), Shasta (~ 1.3 g ) and Vela (> 1.5 g ). Shasta continues to present with a higher proportion of shrivelled kernel ( although the 2024 incidence was lower than previous ) and Vela exhibits more pepper spotting . SARDI are yet to identify a connection between density and the incidence of shrivel or pepper spotting , but the economic implications of total yields , piece weights and kernel defects are being explored .
Rootstock – Scion compatibility screens SARDI have two rootstock screening trials assessing over 140 graft combinations for compatibility , phenology , disease susceptibility and growth habits suited to higher density production systems . A section of these screens currently hosts an ongoing drought response experiment , discussed in the following article on page 30 . SARDI are integrating 2024 observations into rootstockscion factsheets to be made available through the ABA website in season 2024 / 25 .
Soil amendment experiment ( established 2018 ) This experiment demonstrates almond response to both pre-plant and annual applications of organic matter to the soil . Whilst early benefits have been measured in soil metrics ( increased carbon , improved friability , greater biological activity , enhanced water infiltration ) treatments are yet to produce consistently positive impacts on canopy size or yield . Learnings to date are summarised in the factsheet Soil amendments . Annual yield and canopy measures continue to be collected and longer-term soil metrics will be assessed in the orchard ’ s eighth leaf ( 2025 postharvest ).
Annual and cumulative kernel yield for Nonpareil x Garnem , 2021 to 2024 ( 3rd to 6th leaf ) at densities ranging from 308 ( H1 ) to 615 ( H2 ).
H1 to H2 yields ( sixth leaf / free-standing trees ): The 2024 Nonpareil crop was strong , and the variety ’ s upright canopy continued to demonstrate a density response with sixth leaf cumulative yields ranging from 9 t / ha at 308 trees / ha to 12.5 t / ha at 500-600 trees / ha . The other , less upright but self-fertile varieties yielded well in their early years but did not present such a clear density response . Across the same density
For further information about any of the trials , or to arrange a visit to the ACE orchard , call SARDI ( 08 8595 9100 ) or ABA ( 08 8584 7053 ).
Acknowledgment SARDI projects at the ACE experimental orchard have been funded by Hort Innovation using the almond research and development levy and the Hort Frontiers Advanced Production Systems Fund with co-investment from the South Australian Government and contributions from the Australian Government . For more information on these funds and strategic levy investments visit horticulture . com . au .
industry . australianalmonds . com . au
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