Effect of Citrus Aurantifolia Leaf Extract on Mycelial Growth and Spore Germination of Different Plant Pathogenic Fungi

The effect of cold water extract of leaves of Citrus aurantifolia (Christm.) swingle (lime) at 10%, 20%, 30% and 40% concentration on the in vitro growth and germination of Botryodiplodia theobromae Pat., Aspergillus niger Van Tiegh, Aspergillus flavus Link. and Penicillium oxalicum currie Thom. was investigated. Phytochemical studies on the pulverized leaves of the medicinal plant revealed the presence of flavonoids, glycosides, tannins and phlobatannins. The leaf extract of the plant significantly (P < 0.05) reduced the mycelial growth and spore germination of all the test pathogens at the different levels of concentration. The inhibitory action of the extract on mycelia growth and spore germination increased with increasing concentration, giving a toxicity profile of 40% > 30% > 20% > 10%. Penicillium oxalicum was the most sensitive fungi to C. aurantifolia extract, while Aspergillus flavus was the least. These findings indicate a promising potential of C. aurantifolia in controlling the test pathogens in plants. Keywords: Citrus aurantifolia, mycelial inhibition, spore inhibition, fungitoxic, pathogenic fungi