This paper describes a survey of the Ratoon Stunting Disease (RSD) prevalence in 108 sugarcane multiplication areas (558 ha) of seven municipalities of the Espírito Santo, western of Minas Gerais and southern Bahia States, during 2003 and 2004. The diagnostic method of RSD is mainly based on detection of the pathogenic bacterium Leifsonia xyli subsp. xyli (Lxx) in xylem sap extracts, which is important on sugarcane propagation material to direct the control of disease. The Dot Blot Enzyme Immunoassay (Dot Blot-EIA) was used as diagnostic method of RSD on this work. The pathogen was detected in 67.6% of the sampled areas (67,7% of the whole area). In 2003, the average incidence of infected stalks (canes) was correlated with the crop age, being 4.8% for first harvested (one year) areas and 10.3% for two six harvested (six years) areas. In 2004, highest average IC (18%) was observed for one year areas. Twenty eight cultivars were infected by Lxx of a total of 34 sampled. The IC varied from 0.6 to 42% for infected cultivars. The highest IC of 59,5% was observed for RB855113 in an one year area. All the uninfected cultivars were poorly sampled (one area per cultivar only). Despite cultivars RB72454, SP711406 and SP813250 were susceptible to RSD they presented IC values lowers than 10% in general, being considerate intermediate resistant to RSD. We concluded that RSD was found largely disseminated in the studied regions and the propagations materials used for replanting were highly contaminated by Lxx. Additional studies have to be taken to characterize the cultivar resistance or tolerance to RSD and to improve the cultivar manage and the sanity of the seedcane nurseries in the studied regions.
Sacharum; Serology; Ratoon Stunting Disease; seedcane sanity
