Is Erwinia preventable?

[MateoinLosAngeles]

I was away for two weeks and when I came back I had Covid, which knocked me out for another week or so. My plants have been tremendously underwatered during this time but no signs of diseases.

Then today, I noticed one of my polychilos Phalaenopsis had grown a giant Erwinia blister on one of the leaves. I immediately isolated it and cut away the leaf.

The plant was doing fine; it needs to stay warm so it's on a heat mat with all the other polychilos. Temperatures measured at the canopy height fluctuate between 68 and 80 degrees. Humidity between 45-55%. Computer fans continually run on the grow shelf. No other plant seemed infected.

What struck me was this infection had shown up seemingly overnight. I know Erwinia does this, but the blister covered almost the entire leaf, which was a new leaf that was still growing.

The plant wasn't showing dehydration damage but I can assume that going 3 weeks with barely more than a splash might've been stressful. The only other difference is that today my grow light timer got desynchronized and didn't turn on, so the plants didn't get any light for 24h. Not sure if Erwinia can be photosensitive.

So, this is the background, what do you think could've been the trigger for this Erwinia attack and what could be done to prevent it?

Should I assume not sustaining the plants to water stress should help...?

[Ray]

Assuming you’re right about the diagnosis, it seems to me the more likely scenario was that an insect - even a housefly - transmitted the bacteria.

[estación seca]

Are you sure it's not sunburn or heat damage? Erwinia is a disease of high temperatures, very high humidity and poor air circulation. It would be very unusual for it to attack just one plant.