Rockopulco impatiens with darkening stem
Hi everyone,
I have a rockopulco impatiens plant that is currently in quarantine. It’s in a sealed off section of my greenhouse. It has its own grow light (set to the equivalent of bright shade), which is on for 14 hours a day. It’s watered via drip/timer on a regular schedule. There’s a fan circulating the air in the room. It received diluted portion of sea kelp to assist in recovering from transplant shock and root establishment after being shipped from a nursery. It arrived about 1 week ago, and is still in the same soil/pot from the nursery. The ship time was approximately 2 days.
Recently, I noticed it had developed darkening portions of one of the stems. The darkened tissue isn’t soft, has no odor, and maintains the same firmness as the rest of the stems. The roots are not rotting, they are white and appear healthy. It is pushing a few small flower buds, the leaves are turgid and have a nice color. It’s a young plant, and with the exception of the stem darkening, is showing signs of growth/life. But something is obviously very wrong. I haven’t ever seen this type of discoloration on a plant stem that wasn’t some form of rot, but none of the other symptoms of rot are present.
I’m wondering if this can be some form of bruising from mechanical/shipment injury? Or just sadly, the early stages of rot that hasn’t fully set in, but is inevitable? Or is it something else? Can anyone assist me in diagnosing? Again, I have the plant isolated from my other plants, but need to know how/if I should intervene? Is this bruising or is this viral infection? The former means I can intervene and try to rehab it, the later is a different story..thank you in advance for any help you can provide!