HOST-RANGE ALTERATION OF THE BIOHERBICIDAL FUNGUS ALTERNARIA-CRASSA WITH FRUIT PECTIN AND PLANT FILTRATES

In greenhouse tests, the host specificity of Alternaria crassa (Sacc.) Rands, a mycoherbicide for jimsonweed was altered by the addition of water-soluble filtrates of jimsonweed and hemp sesbania or fruit pectin to fungal conidia suspensions. Several crop and weed species that were resistant to the fungus alone exhibited various degrees of susceptibility following these amendments, with 100% mortality occurring to the weeds hemp sesbania, showy crotalaria, and eastern black nightshade when treated with the fungus/pectin mixture. Nonhost plants that were inoculated with conidial mixtures amended with sucrose or cellulose were not affected. Modification of host specificity of this pathogen could have an influence on its bioherbicidal potential.