Having previously confirmed dieback is resistant to chemical control on crops such as avocados, stone fruits and pines, Curtin University researchers have gained new insights into how phosphite works against the fungus-like disease, in a potentially major breakthrough for growers.<\/p>\n\n\n\n
Researchers from Curtin\u2019s Centre for Crop and Disease Management (CCDM) and Proteomics International<\/a> will use the new findings to develop a detection tool to help limit the spread of dieback caused by the pathogen Phytophthora cinnamomi<\/em>, which can lead to huge economic losses in the horticultural industry as well as devastate native flora.<\/p>\n\n\n\n Lead author and recent CCDM PhD graduate Dr Christina Andronis, along with her CCDM supervisor Associate Professor Kar-Chun Tan and CCDM fungicide resistance expert Associate Professor Fran Lopez-Ruiz, found phosphite works in three ways to control dieback.<\/p>\n\n\n\n \u201cFirstly, phosphite targets the pathogen directly and inhibits its growth. Secondly, it can act through the plant and increase its natural defence against dieback, and thirdly, it can cause a \u2018greening effect\u2019 on the plant by amping up the production of proteins that are associated with photosynthesis,\u201d Dr Andronis said.<\/p>\n\n\n\n \u201cBefore now, how this compound worked was a bit of a mystery, with many believing phosphite only improved the plant\u2019s defence system against the disease and its interaction with pathogen was not understood.<\/p>\n\n\n\n \u201cWe\u2019ve been able to show this chemical is extremely valuable for horticulture production due to its three modes of action. One of these modes involves enhancing photosynthesis, potentially leading to improved yields but further studies are needed to confirm this.<\/p>\n\n\n\n \u201cAs phosphite is the only chemical used to control dieback commercially, we need to ensure it remains useful for producers for the long term.\u201d<\/p>\n\n\n\n Associate Professor Tan said the next step of the research is to work out the genetic basis for resistance and pinpoint the gene within the dieback pathogen that has enabled it to survive chemical applications.<\/p>\n\n\n\n \u201cIf we discover the gene responsible, which we are confident we can do here at CCDM, we can then develop molecular detection tools for the rapid and accurate detection of resistant dieback, and we can help producers make the relevant management changes needed in a timely manner,\u201d Associate Professor Tan said.<\/p>\n\n\n\n \u201cWe\u2019ve seen in the grains and grape industries, when fungicide resistance gets out of hand, it can be devastating, costing industries hundreds of millions of dollars in reduced yield, with limited control options.<\/p>\n\n\n\n \u201cBut we\u2019re optimistic this won\u2019t happen in the horticultural industry, because at CCDM we have many years of fungicide resistance research we can draw upon to help prevent such an epidemic.\u201d<\/p>\n\n\n\n