Vol. 11, Issue 11 (2022)

Investigations on in vitro bioassay of different fungicides for their bioefficacy against Plasmopara viticola (downy mildew) and Erysiphe necator (powdery mildew) of grapes was carried out at the Department of Plant Pathology, College of Agriculture, Vijayapur during 2020-22. The study revealed that among the different systemic fungicides across different concentrations maximum inhibition of sporangial germination (zoospore release) (95.00%) and zoospore germination (99.00%) of P. viticola was observed in famoxadone 16.6% + cymoxanil 22.1% (Equation Pro). Among the different combi-fungicides; significantly highest inhibition (91.33%) of sporangial germination (zoospore release) was recorded in fenamidone 10% + mancozeb 50% (Sectin) while highest zoospore inhibition (99.66%) was observed in fluopicolide 4.44% + fosetyl-Al 66.67% (Profiler). Similarly, maximum inhibition 99.66 and 98.04 per cent of conidial germination of E. necator was noticed in azoxystrobin 11% + tebuconazole 18.3% (Custodia) and tricyclazole 18% + mancozeb 62% (Merger) respectively.