Source Year: 1998

The resistance of Hevea rubber tree genotypes to South American leaf blight, caused by M. ulei, was evaluated. Two isolates of M. ulei were used. Seedlings in polyethylene bags were inoculated at the B1/B2 growth stage with 2 x 10 raised to 5 conidia/ml. The plants were incubated in humid chambers for 24 hours at 24 degree C. The latent period (PL), lesion diameter (DL), lesion type (TL) and the reaction type (TR) were determined. Most of the genotypes are completely susceptible to at least 1 isolate, were susceptible to the other. Only the AM/86/271 genotype showed incomplete resistance characterized by a longer PL, small DL and low sporulation. It is concluded that the genotypes tested do not have resistance which could be used in a breeding programme.