Spatial recovery and persistence of Pseudomonas chlororaphis M71 and Trichoderma atroviride SC1 in grapevine following stem injection.

Pseudomonas chlororaphis M71 persisted up to 56 days after stem injection in grapevine but stayed predominantly near the injection site, unlike broader dye transport.

• Why it matters: Internal establishment of biocontrol agents after vascular delivery is poorly understood, including how long they persist and whether the graft union limits distribution.
• What they did: Rooted and grafted grapevine plants received controlled stem injections of P. chlororaphis M71, with xylem-mobile dye as a passive transport reference and viable recovery tracked over time using quantitative isolation and microscopy.
• The result: M71 remained detectable for up to 56 days yet was mainly associated with tissues close to the injection site, indicating spatial confinement that depends on microbial identity and inoculation position.