phal infestation needs your help

[Shirley]

Originally Posted by silken

None of mine that looked like that were subject to any strange temp. changes and the odd thing was it spread from one plant to another by being on the same growing table. I hope you segregate them till you figure it out.

It may not be a spread from plant to plant so much as that the plants were all subject to the same conditions that caused the cell collapse. I believe that once the cells collapse bacterial infections are then able to take hold. Do you have phals in other parts of your growing space that are OK? Incidentally, the thread on Mesophyll cell collapse, referred to by Gin, was originated by myself some time ago but this problem continues for me without affecting any other genera and I'm aware that my night temperatures in winter will at times unexpectedly drop too low.

[Shirley]

I should mention that I've given virus tests to several of these plants and they have tested clear!

[silken]

I had other Phals in the same growing conditions but just on another shelf and far enough away not to be affected. They were all subject to the same light and temperature conditions. It started with one plant that was fairly new. Those on the same table then became affected within a few months if I remember. I inadvertently moved a healthy phal from the other area to that table and it too was soon affected. I waited for about a total of a year to see if they would recover, but as each new healthy looking leaf grew, it developed the same problem. Since I tossed these and disinfected, I haven't had the problem again and I have a number of phals.

[silken]

Shirley, as an experiment I suggest you buy a new phal and keep it seperate but in the same conditions as the other ones and see what happens. My greenhouse in winter goes down to 55F at night but my Phals are all fine with that. I have heard that the problem I had has caused a lot of Phal loss in the last couple of years.

[Shirley]

It's certainly all very puzzling! My phals seem to be recovering nicely at the moment but who knows come winter? My growing area is a small sunroom where the temperature can change dramatically and we do get occasional power outages. I have an emergency kerosene heater but don't always catch it in time so this is where I've placed the blame since my tests show no virus. I'll be following this thread with much interest!

[Leisurely]

I have about seventy five Phals. A few years ago, the same thing happened to some of mine. Do you grow indoors or out? I once read that stink bugs are predator bugs. I had this giant one in my greenhouse that I did not remove because I was going to let him do his predator thing. One day I saw him at work on one of the Phals. It was a scraping effect which resulted in the leaf damage.

[Orchid126]

What do the underside of the leaves look like?