AN ABRASIVE PAD RUBBING METHOD FOR INOCULATING SUGARCANE WITH SUGARCANE MOSAIC-VIRUS

An abrasive pad rubbing method was developed for inoculating sugarcane plants with sugarcane mosaic virus (SCMV). This method involved moist ening an abrasive pad with sap extract containing SCMV and carborundum , folding the pad around the base of the youngest fully expanded leaf, and pulling the pad towards the tip of the leaf. The abrasive pad met hod was as effective as, and much less laborious than, inoculating the spindle leaf by Sein's pricking method. Differentiation of resistant and susceptible sugarcane varieties was better when plants were inocul ated at the advanced tillering stage than at either the 2-3 leaf or th e tillering stages. In SCMV resistance trials done over 4 years with a set of eight 'standard' varieties, correlation coefficients of 0.92 t o 0.99 were obtained for level of infection and disease ratings, indic ating a high level of reliability of the rub inoculation method.