ABSTRACT
Introduction Leaf scald disease of sugarcane caused by Xanthomonas albilineans, Ashby 1928, Dowson 1943, has been known to man since the earlier part of the previous century. The disease was first reported to be caused by a bacterium in Java (Wtlbrink, 1920) and has since been reported in most sugarcane growing regions. It is now known to occur in at least 66 countries (Rott and Davis, 2000). In the 1940s, severe losses caused by the disease were encountered in the noble canes, Saccharum officinarum, when they were commercially exploited. The disease was brought under control with the cultivation of interspecific hybrid varieties. However, several disruptive outbreaks occurred and prompted the replacement of a number of clones by resistant ones. In the late 1980s, new outbreaks were recorded in several places including Cuba (Diaz et al., 2001), Florida (Comstock and Shine, 1992), Guadeloupe (Rott and Feldmann, 1991), Guatemala (Ovalle et al., 1995), Louisiana (Grisham et al., 1993), Mauritius (Autrey et al., 1995b), Mexico (Irvine et al., 1993), Taiwan (Chen et al., 1993) and Texas (Isakeit and Irvine, 1995). All of these manifestations of leaf scald were attributed possibly to new strains of the pathogen. The disease assumes importance particularly under stress conditions such as drought, waterlogging, and high and low temperatures (Persley, 1973). As leaf scald can be severe under various environmental conditions, the disease is one of the most threatening among those affecting sugarcane.
