INFLUENCE OF PACHYMETRA ROOT ROT RESISTANCE ON YIELD LOSSES IN CENTRAL QUEENSLAND

Pachymetra root rot is a major disease of sugarcane in Queensland and varietal resistance is the disease control strategy favoured by the Australian sugar industry. To ensure both productivity and profitability are optimised, it is important that an appropriate level of disease resistance is incorporated into commercial varieties. In this paper, the yields of varieties growing under low and high disease levels were compared and the relationship between Pachymetra root rot resistance and yield differences compared. It was found that yield losses (tonnes cane/ha) attributed to Pachymetra were around 20% in susceptible varieties declining to near zero in resistant varieties. Similar but slightly smaller percentage losses were seen in tonnes sugar per hectare. These results confirm that Pachymetra root rot may have an important influence on yield in the central Queensland cane-growing district. Appropriate management strategies need to be applied to avoid industry losses.