The in vitro chemical control of <i>Pythium aphanidermatum</i>, an agent of tomato root rots in the north central, Nigeria

Abstract

The fungicides benlate (benomyl), ridomil and mancozeb significantly reduced in vitro mycelial growth of Pythium aphanidermatum at all concentrations tested. The research which was carried out between 2005 and 2008 saw ridomil as the most effective compound at low concentrations as complete inhibition of mycelia growth at 50 ppm in vitro was recorded. The in vitro bioassay of fungicides showed that benlate and mancozeb inhibited linear growth of the fungus at 150 ppm and 200 ppm active ingredient (a. i) respectively. The fungicides equally exhibited inhibition of sporangia production and mycelia dry weight of the fungus. All three fungicides tested were effective against P. aphanidermatum and could be used alternatively to reduce the development of fungicide resistance. Furthermore, the fungicides, except mancozeb, could be applied at low concentrations.

Key words: Fungicides, in vitro treatment, P. aphanidermatum, tomato, root rot.