FACT SHEET
Influence of rootstock on hull rot severity
Agriculture Victoria Tonya Wiechel , Peta Faulkner and Simone Kreidl Agriculture Victoria Research , AgriBio Centre for AgriBiosciences , Bundoora , Victoria . Agriculture Victoria Research , Irymple Centre , Mildura , Victoria .
● Rootstock selection can influence hull rot by affecting hull split timing , nutrient and water usage .
● Peach Almond ( P . kansuensis x P . dulcis ), Peach Plum ( P . persica x P . cerasifera ) and Peach ( P . persica x P . davidiana ) generally are less affected by hull rot .
Introduction Rootstock selection is an important factor for tree productivity . Rootstock interacts with scion , influencing stomatal conductance , shoot growth , fruit growth and ultimately fruit yield and quality . Rootstock selection also affects the timing of phenological stages and nutrient and water usage , all of which affect hull rot susceptibility . To investigate whether rootstock choice influences hull rot susceptibility , we used an established ABA rootstock trial ( AL11012 ) planted in 2013 at Lacton Farms , Lindsay Point , to examine rootstock influences on hull rot severity .
Trial site Conducted in the Riverland over 2 consecutive seasons from 2021-22 , this trial evaluated 12 rootstocks in four replicated blocks ( Table 1 ). Replications consisted of four tree rows of five trees with 7.5 m between-row spacing with alternate plantings of Nonpareil , Carmel and Peerless . Trees were maintained according to commercial standards .
Disease assessment Three trees per replicate of Nonpareil scion were assessed for hull rot strikes in the second week of February over 2 consecutive seasons . Disease severity was determined by counting total hull rot strikes per tree .
Results and discussion Hull rot severity varied considerably between seasons and rootstocks . In 2021 , hull rot severity ranged from 90 strikes per tree on GF557 to < 30 strikes per tree on GF749 and Bright ’ s Hybrid , significantly less than the industry standard Nemaguard with 47 strikes . Garnem , Monegro and GF557 had significantly more strikes than Nemaguard ; Adafuel , GF677 , Krymsk , Felinem , Cornerstone and Hansen were not significantly different . In 2022 , hull rot severity ranged from 129 strikes per tree on Monegro to < 30 strikes per tree on GF749 , Krymsk and GF677 . Monegro , Garnem , Hansen and Felinem had significantly more strikes than Nemaguard ; GF749 , Krymsk , GF677 , GF557 , Cornerstone , Adafuel and Bright ’ s Hybrid were not significantly different to Nemaguard ( Figure 1 ). Analysis of two seasons data of
hull rot incidence on Nonpareil scions across 12 rootstocks found GF749 Peach Almond ( P . kansuensis x P . dulcis ), Krymsk Peach Plum ( P . persica x P . cerasifera ) and Nemaguard Peach ( P . persica x P . davidiana ) generally had less hull rot than Peach Almond ( P . persica x P . dulcis ) rootstocks particularly Monegro , Garnem , Hansen and Felinem .
industry . australianalmonds . com . au
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