RESEARCH & EVENTS
Phase 1 of integrated disease management research completed and Phase 2 continuing
Tonya Wiechel ( Agriculture Victoria , Agribio Centre , Bundoora , Victoria ); Brittany Oswald ( South Australian Research and Development Institute , Plant Research Centre , Urrbrae , SA ); Simone Kreidl ( Agriculture Victoria , Agribio Centre , Bundoora , Victoria ); Peta Faulkner ( Agriculture Victoria , Mildura , Victoria ); Khageswor Giri ( Agriculture Victoria , Agribio Centre , Bundoora , Victoria ); Len Tesoriero ( NSW Department of Primary Industries , Ourimbah , New South Wales ); Suzanne Mckay ( South Australian Research and Development Institute , Plant Research Centre , Urrbrae , SA ); Mark Sosnowski ( Agriculture Victoria , Mildura , Victoria and School of Agriculture , Food and Wine , Waite Research Institute , The University of Adelaide , SA ); and Jacky Edwards ( Agriculture Victoria , AgriBio Centre , Bundoora , Victoria )
34
IN response to the rapid expansion of almond production in Australia , project ‘ AL16005 : An integrated disease management program for the Australian almond industry ’ was established to provide a better understanding of disease prevalence , causes and management to develop a robust integrated disease management system for Australian almond production . Led by Agriculture Victoria , in collaboration with SARDI and DPI NSW , this Hort Innovation project has provided accurate , up-to-date knowledge on the diseases of economic importance in Australian almond orchards from 2017 to 2022 . The project team carried out extensive surveys during 2018-2020 in the major almond production regions to identify the prevalence and impact of endemic diseases of almonds . The most important were hull rot , trunk and Phytophthora diseases and lower limb dieback ( LLD ). Significant correlations were found between these diseases , agronomic practices , and weather conditions .
Field trials Field trials were conducted investigating the factors affecting hull rot . Scion and rootstock selection were found to have a significant effect , as well as water availability . Contrary to expectations , mummy
In A Nutshell - Autumn 2023 Vol 24 Issue 1
Almond IDM team 2017-2022 , from left , Tonya Wiechel , Mark Sosnowski , Jacky Edwards , Len Tesoriero , Peta Faulkner , Suzanne Mckay , Simone Kreidl , Brittany Oswald .
nuts only had a weak association with hull rot . A prediction tool based on thermal and multispectral imaging showed promise for identifying locations with high disease risk . It was found that the fungal toxin , which leads to hull rot strikes , was influenced by water and nitrogen treatments . In field trials , currently used fungicides reduced hull rot but did not eliminate it . The product diKap , previously investigated in California , had a similar success rate .
Three-year study Along with the surveys , a 3-year study showed that LLD is unlikely to be caused by trunk disease pathogens alone . Other factors , including tree age , light interception , cultivar and management practices , appear to influence symptom severity .
Seven different trunk disease pathogens were tested for pathogenicity in glasshouse trials . All species were found to cause disease . It is also likely that factors such as water , nutrition and temperature affect canker development . Phytophthora and
Phytopythium species were also tested , with many found to be aggressive pathogens . There was no effect of cultivar on susceptibility to trunk disease pathogens among the six cultivars tested .
Fungicide testing Twenty-three fungicides were tested in the laboratory against trunk disease pathogens , and nine products were progressed to orchard trials . Results from the field trials indicated that four fungicides were potential wound protectants , effectively reducing infection rates .