?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Inhibition+of+the+apple+scab+pathogen+Venturia+inaequalis+and+the+grapewine+downy+mildew+pathogen+Plasmopara+viticola+by+extracts+of+green+waste+compost&rft.creator=Larbi%2C+M.&rft.creator=Gobat%2C+J.-M.&rft.creator=Fuchs%2C+J.+G.&rft.subject=Crop+health%2C+quality%2C+protection&rft.subject=+Composting+and+manuring&rft.description=Extracts+of+green+waste+compost+have+been+shown+to+inhibit+plant+diseases.+In+this+study%2C+the+factors+influencing+the+mechanism+of+inhibition+of+apple+scab+(Venturia+inaequalis)+and+grapevine+downy+mildew+(Plasmopara+viticola)+were+studied.+Extracts+were+prepared+from+samples+of+30+composts+from+commercial+composting+plants.+Composts+were+extracted+with+1%3A2+or+1%3A5+water+for+2+or+7+days.+Extracts+were+applied+to+seedling+of+apple+and+grapevine.+The+seedlings+were+artificially+inoculated+with+V.+inaequalis+or+P.+viticola%2C+respectively+and+incubated+under+controlled+conditions.+After+inoculation%2C+severity+of+diseases+and+lesion+diameter+were+measured.+The+incubation+time+and+the+compost%2Fwater+ratio+did+not+influence+the+capacity+of+the+extracts+to+protect+the+apple+plants.+All+treatments+with+compost+extracts+reduced+disease+severity+in+both+host+pathogen+systems%2C+and+there+was+no+difference+in+efficacy+between+autoclaved%2C+sterile+filtrated+(0.+2+%C3%82%C2%B5m)+and+untreated+extracts.+From+this%2C+we+conclude+that+the+inhibition+by+compost+extracts+is+not+linked+to+their+microbial+activity.+Rinsing+apple+seedling+leaves+1+and+48+hours+after+application+of+the+compost+extracts+did+not+diminish+the+protective+effect+against+V.+inaequalis.+On+the+other+hand%2C+the+severity+of+P.+viticola+increased%2C+when+the+seedlings+were+rinsed+after+the+application+of+compost+extracts%2C+and+was+similar+to+the+untreated+control.+Compost+extracts+enhanced+in+vitro+germination+of+conidia+of+V.+inaequalis+and+showed+no+fungicidal+effect.+Thus%2C+inhibition+apparently+acts+indirectly+in+this+host-pathogen+system.+On+the+other+hand%2C+the+activity+of+zoospores+of+P.+viticola+was+inhibited+by+70+%25+compared+to+the+control.+The+salt+content+of+the+extracts+and+their+effect+on+the+zoospores+were+positively+correlated.+For+this+host-pathogen+system%2C+there+is+thus+evidence+for+a+direct+inhibition+by+compost+extracts.+We+conclude+that+the+active+principle+against+V.+inaequalis+and+P.+viticola+must+be+a+water+soluble%2C+heat-stable+metabolite+produced+in+the+compost+before+its+extraction.+The+mechanism+of+inhibition+in+both+plant-pathogen+systems+is+different.&rft.publisher=Verlag+ORBIT+e.V.%2C+Weimar&rft.contributor=Kraft%2C+Eckhard&rft.contributor=Bidlingmaier%2C+Werner&rft.contributor=de+Bartoldi%2C+Marco&rft.contributor=Diaz%2C+Luis+F.&rft.contributor=Barth%2C+Josef&rft.date=2006&rft.type=Book+chapter&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Forgprints.org%2F10317%2F1%2Flarbi-etal-2006-orbit_conference.pdf&rft.identifier=Larbi%2C+M.%3B+Gobat%2C+J.-M.+and+Fuchs%2C+J.+G.+(2006)+Inhibition+of+the+apple+scab+pathogen+Venturia+inaequalis+and+the+grapewine+downy+mildew+pathogen+Plasmopara+viticola+by+extracts+of+green+waste+compost.+In%3A+Kraft%2C+Eckhard%3B+Bidlingmaier%2C+Werner%3B+de+Bartoldi%2C+Marco%3B+Diaz%2C+Luis+F.+and+Barth%2C+Josef+(Eds.)+ORBIT+2006+%3A+Biological+Waste+Management.+From+Local+to+Global%3B+Proceedings+of+the+International+Conference+ORBIT+2006%2C+Verlag+ORBIT+e.V.%2C+Weimar%2C+chapter+Part+2%2C+pp.+529-537.&rft.relation=http%3A%2F%2Forgprints.org%2F10317%2F