Submitted to: American Society of Sugar Cane Technologists
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/1997
Publication Date: N/A
Interpretive Summary: Evidence is provided that ratoon stunting disease (RSD) of sugarcane, a disease that is estimated to cause a five percent yield loss in Florida, can be controlled by planting resistant cultivars alone. No other control practices such as hot water treatment of seedcane were necessary. When fields were planted with non-hot-water-treated seedcane, the disease incidence was related to the cultivar's reaction to RSD. A level of resistance based on the number of colonized vascular bundles was determined that restricted the RSD incidence in commercial sugarcane fields. Knowing the level of resistance required to control RSD will aid in the development of resistant cultivars and the control of this economically import sugarcane disease.
Technical Abstract: The incidence of ratoon stunting disease (RSD), caused by Clavibacter xyli subsp. xyli Davis et al. (1984), varied in commercial sugarcane fields that lacked a RSD control program. RSD incidence in sugarcane fields varied by resistance of cultivar as determined by the number of colonized vascular bundles (CVB). Resistant cultivars had a low incidence of RSD and also had a low number of CVB. Susceptible cultivars, CP 70-1133 and CP 72-1210, had an incidence of greater than 90 percent stalks infected and averaged more than 6 CVB per 1 cm diameter standard stalk sample. In contrast, resistant cultivars, CL 73-239 and CP 72-2086, had 2.7 and 1.4 percent stalks infected in the fields surveyed and averaged less than 0.5 CVB per stalk. Since these cultivars have been grown for several years without a RSD control program, resistance appears to have limited the spread of the disease.