Effect of Plant Growth Regulators on White Mould (Sclerotinia sclerotiorum) on Bean and Cucumber

The effect of plant growth regulators on thepathogenic fungus Sclerotinia sclerotiorum (white mould) was investigated under in vitro and in vivo conditions. Naphthalene acetic acid inhibits the fungus in vitro and in vivo. It reduced white mould disease severity on bean and cucumber plants at concentrations of 200–400 μg/ml. Gibberellic acid (GA3) promoted both mycelium and white mould disease severity on plants at concentrations of 50–250 μg/ml. Methyl jasmonate (MeJa), and abscisic acid (ABA) decreased mycelium growth of S. sclerotiorum in vitro. MeJa decreased bean and cucumber white mould disease at concentrations of 75–250 μg/ml.ABA increased disease development on bean and cucumber plants at concentrations of 100–300 μg/ml.