In vitro efficacy fungicides against causal agents of twister disease of onion

Abstract

Twister disease of onion has become epidemic in coastal tract and other onion growing\rdistricts of Karnataka which caused heavy loss and its causal agents are C.\rgloeosporioides and F. oxysporum. Efforts were made to screen fungicides to know\rtheir efficacy of different fungicides at different concentrations under In vitro by\rpoisoned food technique. Among the four non-systemic fungicides evaluated against\rC. gloeosporioides maximum inhibition was observed in chlorothalonil (42.60%).\rAmong the seven systemic fungicides against F. oxysporum evaluated, hundred per\rcent inhibition of mycelial growth of C. gloeosporioides at all tested concentrations\rwas observed in propiconazole, hexaconazole, tebuconazole and tricyclazole. Among\rthe seven combi product fungicides evaluated carbendazim 12 per cent + iprodione 63\rper cent (Quintal) inhibited maximum mycelial growth (95.43%). In vitro evaluation\rof fungicides revealed that among the four non-systemic fungicides evaluated, maximum\rinhibition of mycelial growth of F.oxysporum was observed in copper oxychloride\r(64.84%). Among six systemic fungicides evaluated, maximum inhibition of mycelial\rgrowth of F. oxysporum was observed in propiconazole (93.52%). Among the six combiproduct\rfungicides evaluated, hundred per cent inhibition of mycelial growth was\robserved in Saaf, Sprint and Vitavax power at all tested concentrations.