BSES RSD LABORATORIES--10 YEARS OF SERVICE

BSES established laboratories to screen samples for ratoon stunting disease (RSD) with an enzyme-linked immunosorbent assay (ELISA) in Tully in 1993 and Mackay in 1994. The laboratories have processed more than 380 000 samples during the 10 years of operation. The benefits to the sugar industry have been a greater confidence in the disease-free status of plant sources and quality control programs for approved seed plots. The laboratories were responsible for preventing widespread distribution of RSD-infected plant sources from seed plots on at least three occasions. The two districts that have made most use of the laboratories are Mackay and Harwood. The Mackay district has had a long history of successful control of RSD. The RSD laboratories have enabled this region to maintain RSD below 2% of commercial fields throughout the period. This position was maintained even during the orange rust epidemic when growers were forced to use old ratoons for plant sources. Harwood had a severe RSD problem in the early 1990s. Through the extensive use of the RSD laboratories combined with increased use of approved seed and education of growers and planting contractors of the need for hygiene, Harwood has been able to reduce RSD from 40% of plant sources infected to around 10%. The RSD laboratories have recently expanded to conduct testing of preserved samples from Papua New Guinea, Indonesia, Malaysia and China. The ELISA test for RSD is cost effective and enables intensive sampling that greatly increases the chances of detecting the disease.