The interaction between phosphate-dissolving bacteria and Zea mays plants
was investigated. Results showed that: Highly variation in the ability of phosphate-
solubilizing bacteria in bringing down the pH of the media and consequently varied in
their ability in releasing soluble phosphorus. The highest level of soluble-P (421.9
ppm) was released by isolate No. 15. Greatest amount of maize dry weight and Qrain
yield was obtained with the Inoculation at 10 and 20 days after planting. The
inoculation at 10 and 20 days with cell suspension was more active than its
application as cell suspension to the grains one hour before sowing. P and N content
in maize plants and their grain were increased signiflcanUy with the treatments of
grain slurry plus supplementary inoculation of cell suspension at 10 or at 10 an~20
days after planting and those inoculated with cell suspension at 10 and 20 days rom
planting. There are a positive correlation between Inoculation with phosp ate
dissolvers and N-content in the plant during the two seasons. Results also sho ed
maximum counts of phosphate dissolving bacteria in rhizosphere soil of maize hfter
60 days from sowing in all treatment, which gradualty increased up to 60 days,
thereafter decreased. The inoculation of maize plants with phosphate dissolving
bacteria increased the amount of soluble phosphorus in the rhizosphere soil of maize
compared to the non-inoculated soil. The increase of phosphorus content was
significant with the treatment of seed slurry plus supplementary cell suspension Jt 10
and 20 days after planting. Therefore, the application of rock phosphate and
inoculation with efficient phosphate-dissolving bacteria produced more amount of
soluble phosphorus In the soil. which plays an important role in metabolic pathways
in living organisms and thus increased the yield of plant.