Abstract:
Colletotrichum gloeosporioides f sp. manihotis, the causal agent of cassava (Manihot spp) anthracnose
disease produces toxic metabolites in culture. Symptoms induced on cassava leaves and stem cuttings by
the toxic metabolites are similar to those induced by the pathogen. Twenty one M. esculenta clones were
screened under field conditions using natural infection and with the phytotoxic metabolites of the
pathogen. Results indicated that 8 cassava clones were resistant while the other 13 clones were susceptible
at varying degrees. Results from in vitro screening of cassava using phytotoxic metabolites compared
favorably with field screening based on natural infection. Use of toxic metabolites appears to be a more
effective assay for screening cassava clones for resistance to anthracnose disease than those based on
natural disease infection.
