Vegetables – Entomology & Pathology 197 New Zealand Plant Protection 55:197-201 (2002) EVALUATION OF MICRO-ORGANISMS FOR BIOCONTROL OF GREY MOULD

A range of micro-organisms, including saprophytic yeasts, bacteria and fungi, were evaluated for control of Botrytis grey mould on whole lettuce plants. In a controlled environment (18-22 ° C, 85-90 % 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