Biological control of the predominant seed-borne fungi of tomato by using plant extracts

Résumé

Aqueous extracts from five wild traditional medicinal plants (Achillea fragrantissima, Balanites aegyptiaca, Peganum harmala, Rumex vesicarius, and Urtica urens) which were collected from different locations in Egypt were tested against the predominant fungal pathogens (Alternaria alternata f. sp. lycopersici,  A.  solani, Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani) infested tomato seeds . All the aqueous plant extracts significantly inhibited the mycelial growth and spore germination of these fungi, but the extract of A. fragrantissima exhibited the strongest antifungal activity. The maximum seed germination, plant emergence and seedling vigor was detected after the treatment of tomato seeds with 10% A. fragrantissima extract. Pathogenicity testing of tomato seeds by predominant fungi indicated positive infection of tomato seeds but A. solani had the most aggressive infection. In greenhouse experiment, the aqueous A. fragrantissima extract reduced disease severity but increased total pigments, total phenolics and fruit yield.