Fungicidal Activity of Some Common Weed Extracts Against Different Plant Pathogenic Fungi

Aqueous extract effects of 64 weed species on growth and development of Alternaria solani Sorauer, Helminthosporium sativum King & Bakke and Rhizoctonia solani Kuhn, plant pathogenic fungi were studied in vitro. Extracts varied in the strength and persistence of their antifungal effects against the three fungi species. Some stimulated, others inhibited or had no effect. Among all species tested, extracts of Chenopodium murale, Falcaria vulgaris, Ranunculus asiaticus and Sisymbrium irio were the most toxic to A. solani. Anagallis arvensis, Atriplex leucoclada, Crepis aspera, Notobasis syriaca, R. asiaticus, Rumex crispus, S. irio, Sonchus oleraceous and Vicia narbonensis to H.sativum and R. asiaticus, S. oleraceous and Mercurialis annua to R. solani. However, R. asiaticus extract was the most effective and completely inhibited growth and sporulation of the three fungi species at all incubation periods.