These lesions also often “coalesce and progress to severe leaf blight under favorable conditions for the bacterium.”[8] When the infected leaves become dry, the spots often look brittle and crack.

[9] After favorable conditions allow colonization of the pathogen, it can spread via rain, splashing, wind, movement of debris, insects and of course, via human agricultural practices.

Entry into host tissue can be accomplished via wounds or natural openings such as stomata, epidermal hairs,[12] or hydathodes.

Large populations of Pseudomonas are known to release an array of phytotoxins, and this is the cause of the observed spotting symptoms on the leaf.

[14] Plants growing outside exposed to rain exhibit dark brown to black spots on their leaf surface.

When the plants are exposed to a limited amount of water and moisture, they exhibit sunken in lesions on both the upper and lower leaf surface.

[15] Little is known about the biochemical pathways of Pseudomonas cichorii, but linear lipoproteins are believed to contribute to virulence, motility, and biofilm formation.

[17] These discoveries give an insight to potential phytotoxins and virulence factors, and also illustrate how large the knowledge gap is in our understanding of P.

These infected cuttings and seedlings should not be planted or kept near uninfected fields as the pathogen is able to survive on the host's seeds.

[26] The wide range of hosts and presence on every continent besides Antarctica[27] has contributed to its notoriety in many greenhouses and agricultural fields across the world.