Host specificity of a brazilian isolate ofAlternaria cassiae (Cenargen CG593) under greenhouse conditions

SeveralAlternaria cassiae isolates were recovered from diseased sicklepod plants (Senna obtusifolia) in the southern regions of Brazil. A representative isolate (Cenargen CG593) was tested for its host range under greenhouse conditions. The fungus promoted symptoms in sicklepod, cassava (Manihot dulce), tomato (Lycopersicon esculentum) and eggplant (Solanum melongena) when tested at a spore concentration of 10⁶ spores ml⁻¹. When the plants were inoculated with a suspension of 10⁵ spores ml⁻¹ and held at a dew period of 12 h (cassava) or 18 h (tomato and eggplant), the plants showed symptoms of the disease, but they recovered and continued their normal vegetative growth. These results show that the fungusA. cassiae is safe to use for the control ofS. obtusifolia under Brazilian conditions, because it did not cause excessive damage in the three plants tested. http://www.phytoparasitica.org posting Jan. 14, 2007.