Effects of Pseudomonas fluorescens F113 on ecological functions in the rhizosphere of pea is dependent on pH. D.C. Naseby and J.M. Lynch School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, UK. Abbreviated title: pH and the impact of P. fluorescens. Number of text pages: 20 Number of tables: 3 Number of figures: 3 Proofs and correspondence: Professor J.M. Lynch fax: (0)1483 2597283 e-mail: j.lynch@surrey.ac.uk Key words: pH, Pseudomonas, 2,4 diacetylphloroglucinol, GMM