A PATHOLOGY-BASED INVESTIGATION INTO THE CAUSE OF YELLOW CANOPY SYNDROME

PLANT SAMPLES SHOWING signs of Yellow Canopy Syndrome (YCS) collected since 2013 were subjected to various traditional and molecular pathology tests. The samples were screened with specific tests for known sugarcane pathogens and a range of generic tests for unknown viruses, bacteria and fungi, with an emphasis on pathogens that cause yellowing symptoms, such as luteoviruses and phytoplasmas. Traditional aseptic pathogen isolation and culturing and light microscopy were also performed. The pathology investigations found that both YCS and asymptomatic cane can contain viruses, bacteria and fungi. However, no obvious and consistent organism was found to be associated with YCS. Several new and uncharacterised viruses were found during the investigation and their significance and possible effect on sugarcane production need further investigation.