The Development of an Improved Method for Evaluating Sugarcane for Resistance to Smut

The isolation from bud scales and partial characterisation of highly active, low molecular weight, germination inhibitors, in concentrations correlated quantitively with resistance of N52/219, N11, NCo376, and NCo293, holds promise for the development of a rapid, quantitative, chemical assay for evaluating sugarcane for pre-infectional resistance to smut. Histopathological studies on stalk and meristem colonization by Ustilago scitaminea did show, however, that there are postinfectional forms of resistance that may be independent of pre-infection resistance. The two forms of resistance may be the basis of differential varietal response to smut races.