Evaluation of microorganisms for biocontrol of grey mould on lettuce

Abstract

A range of microorganisms including saprophytic yeasts bacteria and fungi were evaluated for control of Botrytis grey mould on whole lettuce plants In a controlled environment (1822C 8590 relative humidity and 12 h photoperiod) lettuce leaves were spray inoculated with antagonists (10⁷ fungal spores/cells/ml or 10⁸ bacterial cells/ml) allowed to dry and challenged by spray inoculation with the pathogen (10⁶ spores/ml) After 7 days the mean Botrytis lesion areas were assessed Four fluorescent Pseudomonas spp (isolates LC8 PF13 PF14 and PF15) significantly reduced lesion areas by an average of 79 on whole lettuce plants in two experiments An Ulocladium sp (U13) significantly reduced lesion areas by 94 in one of two experiments