Aqueous extract effects of sorne common weed species against certain plant pathogenic fungi

Résumé

Antifungal effects of 64 common weed species belonging to 29 plant families against Penicillium digitatum Sacc., Sclerotinia sclerotiorum (Lib.) De Hary, and Verticillium dahliae Kleb were investigated under laboratory conditions. Aqueous extracts ofmany weed species were toxic to growth and/or sporulation of one more of the tested fungi, while ceitain weed extracts showed stimulatory effects. Extracts were varied in their antifungal activities and in the persistence oftheir effects. Antifungal effects differ from species to species and from family to another. Among an species tested, the most toxic extracts were those of Chenopodium murale, Crepis aspera and Ranunculus asiaticus to P. digitatum. Erodium cruciatum, Euphorbia helioscopia and R. asiaticus to S. sclerotiorum and E. helioscopia, Galium tricornutum, Sisymbrium irio and R. asiaticus to V dahliae. The extract from R. asiaticus was the most toxic to the three fungal species, and completely prevented their growth and sporulation at an periods of incubation.