Effect of TFX production and inoculum ratio on gall formation. Legend: Nicotiana glauca stems were wounded with a dissecting needle, and 5 ul of inoculum (mixtures noted at left) was placed on the wounds. The top stem was inoculated with CG435 as a positive control. Stems 2 and 3 were inoculated with mixtures of biological control test strains and CG435 at either a 1:1 (left three inoculation sites on each stem) or 10:1 (right three inoculation sites) biological control:pathogen ratios. The photograph was taken approximately 2 months post-inoculation. pT2TFXK confers biological control on F2/5 at the 10:1 ratio, but not at the 1:1 ratio.