RESEARCH UPDATE
Figure 3 . Carina trees on Controller 6 rootstock near Robinvale in November 2021 . Trees were budded in March 2017 and planted in August 2018 at 2m x 4.5m spacing ( 1,111 trees per ha ).
Intensive orchards and new rootstocks This trial near Robinvale is a collaboration with Select Harvests Ltd and compares Nonpareil and Carina trees budded on the new Controller series of rootstocks from California (
ucdavis . edu / rootstocks ). Trees were budded in March 2017 and planted in August 2018 at 2m x 4.5m spacing ( 1,111 trees / ha ) and grown using PFR ’ s minimal pruning system (
Almond-pruning systems ) to create narrow , slender trees suitable for high-density plantings ( Figures 2 and 3 ). Kernel yields for both cultivars were consistently higher on the Controller 9.5 rootstock than either Controller 6 or Controller 7 . Nonpareil and Carina trees budded on Controller 9.5 produced 3.3 and
3.5 t / ha on third-leaf trees . Higher yields were associated with larger tree size , as Nonpareil and Carina trees on Controller 9.5 rootstock were 0.5m taller than on Controller 6 rootstock . Controller 7 rootstock was not suited to the slightly alkaline soils at this trial site near Robinvale , and resulted in smaller tree size and reduced crop compared with trees on the other Controller series rootstocks . Kernel yield from Nonpareil trees increased consistently over the first three years of cropping , with 0.6 , 2.4 and 3.1 t / ha on second- , third- and fourth-leaf trees on Controller 6 rootstock , respectively . Yields from Carina trees on the same rootstock were substantially reduced in 2022 after comparatively high yields in 2021 , with 0.6 , 2.7 and 1.8 t / ha over the three-year period .
Conclusions : Some almond cultivars when planted at high density may produce too much crop on young trees and thus risk creating a cycle of alternate bearing . Is the current irrigation scheduling for high-density blocks providing young trees with sufficient water to support these high crops - i . e . water per tree is less than in low-density blocks ? While precocity is important to the economics of high-density plantings , irrigation scheduling needs to match the needs of the tree and mitigate any effects of high yields in one year on the cropping potential of trees in the following year .
industry . australianalmonds . com . au
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