Management of ratoon stunting disease by hot water treatment to provide healthy cane seed

Ratoon stunting disease (RSD) is one of major sugarcane diseases in Indonesia. The causal agent of the disease is Leifsonia xyli subsp xyli. The pathogen systemically infects xylem vessel. Providing healthy seed cane is the most important management of the disease. This study aimed to determine the best Hot Water Treatment (HWT) method for reducing RSD incidence of sett cane. There were eight treatments arranged in randomized blocked design, ie: Bud setts were (1) soaked in running water (RW) for 48 h and then treated with 50°C HWT for 2 h; (2) RW for 5 h and 50°C HWT for 2 h; (3) directly 50°C HWT for 2 h; (4) directly 45°C HWT for 30 m; (5) soaked in bactericide suspension for 2 h; (6) directly planted without any treatment; (7) RW for 48 h; (8) RW for 5 h. Results of the study showed that germination was only 23-27% when treated with 50°C HWT, but incidence of RSD was only 3-6%. Germination increased when soaked in running water for 5 h before HWT. The fastest bud germination occurred at 45°C HWT for 30 m with the highest percentage of germination (83%) but incidence of RSD was high.