Preliminary evaluation of Septoria urticae Rob. et Desm. as a biological control agent of Urtica urens L.
Plants of U. urens (annual nettle) showing symptoms of severe foliar necrosis were collected in the horticultural belt of La Plata, in the province of Buenos Aires, Argentina. The agent causing disease was identified as S. urticae. Routine phytopathological techniques were used to evaluate the bioherbicidal potential of S. urticae in the greenhouse on U. urens and other species of Urticaceae (Boehmeria nivea, Pilea cadierei and Parietaria officinalis). Using variance analysis, it was shown that the pathogen caused a high percentage of defoliation, reduction of DW and seed production of U. urens. B. nivea and P. cadierei did not show disease symptoms, and P. officinalis was slightly affected. It is suggested that the pathogen could play an important role as a biocontrol agent of U. urens.