FUNGICIDAL ACTIVITY OF SOME COMMON WEED EXTRACTS AGAINST DIFFERENT PLANT-PATHOGENIC FUNGI

Aqueous extract effects of 64 weed species on growth and development o f 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 inhib ited or had no effect. Among all species tested, extracts of Chenopodi um murale, Falcaria vulgaris, Ranunculus asiaticus and Sisymbrium irio were the most toxic to A. solani. Anagallis arvensis, Atriplex leucoc lada, Crepis aspera, Notobasis syriaca, R. asiaticus, Rumex crispus, S . irio, Sonchus oleraceous and Vicia narbonensis to H.sativum and R. a siaticus, S. oleraceous and Mercurialis annua to R. solani. However, R . asiaticus extract was the most effective and completely inhibited gr owth and sporulation of the three fungi species at all incubation peri ods.