PACHYMETRA SEVERITY IN QUEENSLAND CANE FIELDS ASSESSED THROUGH DATA FROM THE TULLY ASSAY LABORATORY

BSES Tully provides a commercial Pachymetra soil assay service for the Queensland sugar industry. Assays have been conducted in the laboratory for more than five years. Data have been recorded for these samples on variety, crop class, region, sub-district and soil type. This paper reports on the relationship between Pachymetra inoculum density and some of these other parameters to provide information on severity of the disease by region, variety and, in some cases, by subdistrict within the region. Also revealed is information on regional commercial assay laboratory use patterns. More samples were assayed for the central Queensland and Bundaberg areas than for other areas. Highest spore counts were recorded in some parts of Mackay and the Babinda mill area; surprisingly few soil samples came from northern Queensland. There were strong relationships between varietal resistance and spore count, emphasising the influence of resistance on Pachymetra root rot.