RESEARCH UPDATE
Are almond rootstocks making a difference ?
Grant Thorp , Ann Smith , Michael Coates and Roberta De Bei Plant & Food Research Australia Pty Ltd
THE performance of new almond rootstocks is being evaluated as part of orchard intensification trials led by Plant & Food Research ( PFR ). Field trials , first established in 2016 under the previous AL14007 Almond Productivity program (
Almond-AL14007 ) and continued in the new AS18000 National Tree Crop Intensification in Horticulture Program (
Almond-AS18000 ), are providing new insights into the interactions between tree vigour , productivity and the ability of young trees to carry heavy crops . While the earlier projects were restricted to traditional planting densities of < 400 trees / ha producing up to 3.6 t / ha on sixth-leaf trees , we now have high-density blocks with 1,100 trees / ha , planted with new cultivars and new rootstocks producing 3.5 t / ha on third-leaf trees . In this research update we provide information on a traditional and a high-density planting trial comparing different scion / rootstock combinations .
Figure 1 . Kernel yield and cumulative yield ( t / ha ) of Nonpareil and Price almonds on four different rootstocks at Lindsay Point . Trees were budded in March 2015 and planted in July 2016 at 6.85m x 3m spacing ( 487 trees / ha ).
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Traditional orchard and rootstocks In this project at Lindsay Point , we compared Nonpareil , Monterey and Price budded on Nemaguard , Cornerstone , Garnem and Bright ’ s Hybrid rootstock . Trees were budded in March 2015 and planted in July 2016 at 6.85m x 3m spacing ( 487 trees / ha ) ( Figure 1 ). After six years , there is no difference in annual or cumulative yield of Nonpareil almonds budded on the different rootstocks . Trees produced on average 3.6 t / ha in 2022 . Similar results were found with Monterey . Price trees produce higher yields when grafted on Bright ’ s Hybrid rootstock than on the other rootstocks . Tree heights were generally similar , with no substantial differences in tree size between rootstock treatments . On these Riverland soils , the clonal rootstocks Bright ’ s Hybrid , Garnem and Cornerstone when budded with Nonpareil are showing no advantage or disadvantage over the traditional seedling Nemaguard rootstock .
In A Nutshell - Summer 2022 Vol 23 Issue 4
Figure 2 . Kernel yield and cumulative yield ( t / ha ) of Nonpareil and Carina almonds budded on Controller™ 6 , Controller™ 7 and Controller™ 9.5 rootstocks at Robinvale . Trees were budded in March 2017 and planted in August 2018 at 2m x 4.5m spacing ( 1,111 trees per ha ).