FUNGAL METABOLITE EXTRACTS ACTIVE AGAINST PHYTOPATHOGENS

The effectiveness of some genetically engineered microorganisms in the control of plant disease pathogens is widely acknowledged. These biop esticides, so far, pose less danger to the environment. However, littl e attention has been paid to the potential benefit of the use of exome tabolites of some microorganisms in spite of their known activity and high biodegradability. A total of 1108 fungal metabolite extracts obta ined from different strains of micromycetes cultured in two different liquid media (malt extract and yeast saccharose) were tested for antif ungal activity. The target organisms were Colletotrichum musae, Drechs lera spicifera, Fusarium oxysporum, Geotrichum candidum, Pyricularia o ryzae, Drechslera oryzae and Gerlachia oryzae. Percentage mycelial gro wth inhibition activities varied widely with the different taxonomic g roups. Extracts from Aspergillus and Penicillium spp. consistently sho wed the highest activity. A greater number of micromycetes produced ac tive extracts in a liquid yeast extract saccharose medium than in a li quid malt extract medium. Mycelial growth inhibition diameters were al so greater in assays with extracts from the yeast extract saccharose m edium. The results generally demonstrated fungal metabolite extracts a s potential sources of agricultural chemical input.