Antifungal activity of aqueous extracts of spices against bean rust (Uromyces appendiculatus)

This pot culture study done under controlled conditions, evaluated the antifungal activity of aqueous extracts [1, 2 and 3% (w/v)] of 8 spices [basil (Ocimum basilicum L.), black cumin (Nigella sativa L.), black pepper (Piper nigrum L.), celery (Apium graveolens L.) fennel (Foeniculum vulgare Mill.), laurel (Laurus nobilis L.), parsley (Petroselinum crispum Mill.) and rosemary (Rosmarinus officinalis L.)] against bean rust. All spice extracts except parsley, when applied 2 h before pathogen inoculation significantly controlled (26.5 – 96.1%) the rust development. Black cumin extract was most effective followed by laurel. Black cumin extracts at 2 and 3% concentrations provided rust control similar to mancozeb fungicide. There was no synergistic effect, when black cumin and laurel extracts were combined. None of the tested spice extracts were phytotoxic to bean leaves.