More than 96% of cucumber seedlings were diseased in the
infested control with a mean disease severity rating value
of >3.5 (Fig. 2). Seeds treated with noninoculated peat and talc did
not provide any protection to cucumber seedlings from dampingoff
and root rot. As a seed-soak treatment, all 3 bacterial isolates
and the metalaxyl treatment were equally effective in protecting
cucumber seedlings from damping-off and root rot. There was a
27-fold increase in the percentage of healthy seedlings with the
metalaxyl treatment and a 21- to 24-fold increase with the bacterial
isolates as compared with the inoculated control (Fig. 2A).
Seed treatment with antagonistic bacteria P. fluorescens 9A-14 and
B. subtilis 8B-1 as peat (31- and 30-fold increase in the percentage of
healthy seedlings, respectively) and talc (30- and 27-fold increase
in the percentage of healthy seedlings, respectively) formulations
provided significantly better protection of cucumber seedlings
from damping-off and root rot than seed-soaking treatment with
cell suspension of these bacteria (Fig. 2A). All seed treatments
significantly reduced damping-off and root rot severity by 53.1%–
69.4% (Fig. 2B) and significantly increased the mean plant fresh
masses by 3.8- to 5.6-fold (Fig. 2C) compared with the infested
controls. The talc and peat formulations of the P. fluorescens 9A-14
significantly increased the mean plant fresh masses compared
with all other treatments (Fig. 2C).