Brown patches under leaves: Phal. amabilis sick?

[Roberta]

Mealies are actually quite easy to kill with 70% isopropyl alcohol (ordinary rubbing alcohol) on a cotton swab, or sprayed. I just put a sprayer in the alcohol bottle, and hit the mealies as needed. It doesn't harm any part of the plant (even flowers), evaporating harmlessly away after stripping the mealies of their waxy coat and killing them on the spot. If you want to put a few drops of dish detergent in the bottle, you hit them two ways, even better.

[bil]

I actually found a couple of mealies on one of my D nobile the other day. My solution is simple.

CHEMICAL MEGADEATH.

I always have acaricide, a systemic pesticide (imacloporid) and a fungicide (Mancozeb) to hand, as well as cinnamon as a wound desiccant.

I know it is lovely to be in touch with nature, but here if you work like that there is very little you can grow here.

One piece of advice that is most important. Mealies are a swine to eradicate, unless you realise that they are superb hide and seek artists. They will be in every crevice you can imagine, so every part of the plant needs drenching with imacloporid, and then, if you forget to wet the medium well with it, there will be a couple hiding in there to repopulate the place.

I really don't like the idea of oils on the roots. As you saw, they can devastate the roots. Much better to me to hit the plant hard with something devastating and eradicate the problem.

[Dragonar]

Hi guys,
I've purchased my second Phal amabilis as the first one had died, and now the second one seems to be in trouble.

A little background:
Both Phals came from a nursery and they were mounted outdoors receiving dappled sunlight and direct rain when I purchased it. They receive rainfall that may last for less than an hour to a few hours daily, and sunlight that could be rather bright to cloudy days. Day time lasts roughly around from 7am to 7pm. There is a little moss underneath the center of the phal but most of it has been degraded. The roots of the phal has spread across the mount, and the mount is about 20 x 8 cm.

At home:
I have added sphagnum moss around the roots (thinly covered across almost the whole front surface of the mount) and I'm watering it daily. The phal is currently indoors receiving morning sun from an east-north-east window, and occasionally evening sunlight reflected from flats opposite me. When it rains, the moss would be soft but the roots will be silvery after 24 hours. When it is sunny, the moss will be crisp instead. I am currently watering once per day every ~24 hrs

Issue:
The roots that trails off below the mount are starting to desiccate (lower left of pic no. 2 & 3). I'm guessing this is because there isn't any moss covered over them although I make sure they do get wet when I water the phal. Some of the roots that are being covered by the moss however, are turning yellow and some even have turned hollow (Right of pic 2). Thus far, I've checked that the roots that turned hollow are most likely roots that have snapped while removing the mount from the fence that it was attached on. Roughly 80% of the roots still seems healthy so I'm unsure if I am over watering the phal. Maybe because while mounted, it did not stay wet for such long periods and dried off pretty fast as well?

Solution:
I'm considering removing all of the sphagnum and instead, I'll water it twice per day. Not sure how this will turn out but hopefully it won't be too dry (Roots currently not covered by moss turn silvery after 24 hours)!
This is my first phal that came directly mounted and is actually my favourite phal species that I have been searching for long periods. My other phals came from pots and some of them eventually got mounted and adapted well

Do give me some advice please! Thanks guys!

[Dollythehun]

How reputable is this grower? Have you talked to him? I think those spots look bacterial.

[Dragonar]

Hmm I would say he's quite good. But yea the first one died and I'm sure it has some disease as it just deteriorated too fast.

My focus now is one my second one in the new post though, as the first one is already gone.

If you meant the spots on my second amabilis, well I'm not sure what it is but I'm suspecting its from direct sunlight as most of his orchids that were regrown from his supplier does have this. For this particular one that I have, the spots are on the keiki and not on the parent.

[Sharon's Sheepdogs]

My first question is, how much humidity are you able to provide this Phal indoors? The phal appears to be a mature plant previously grown outdoors in a very wet & humid environment. I suspect the phal is experiencing difficulty acclimating to the indoors where it is now experiencing a much lower level of humidity. A mature plant will have greater difficulty adapting to a new environment than a younger plant will.

Perhaps you should try watering twice a day instead of once or try growing the phal in a pot with sphagnum on a tray of gravel until it shows improvement. If you can coax some new growth out of the phal, that growth will acclimate more readily than the original growth and then you can remount it.

If you leave it on the mount & the roots continue to dessicate, you will probably lose the orchid unless you can provide a more wet, humid environment in the meantime.

However, as 'dolly the hun' previously noted, there could be symptoms of something else going on from the looks of the marks seen on the lower leaf of the mature plant, not the keiki, which are visible in your first photo. I definitely don't like the way they look but I am unable to determine if that might be contributing to the root dessication.

Hopefully someone else can jump in with another opinion.

[Dragonar]

Hi Sharon,

I would be able to provide humidity at 75-90% depending on the weather outside. My house is pretty much open to the surroundings and the orchid is situated near the window on the 7th storey.

I'm would actually too prefer growing this phal on a pot but the roots seems to be very firmly attached. Also, if I manage to remove the roots, I would need to find a pot that is wide (20x4cm) enough to house the roots as they have spread out all over the mount. Any suggestions to go about doing this?

I removed the sphag yesterday and it seems the sphag is actually causing root rot. Look at the amount of yellow roots and wiry roots left behind (Pic 2, 3, 4). Seems like I have a case of desiccation with roots that are not covered in sphag and rot with roots that are covered in sphag? I've only left the sphag under the core of the phal.

Should I just go with watering twice per day or even more to see if desiccation continues? Because I am sure root rot is also occurring if I place sphagnum. I would move the whole plant to LECA if I'm able to find a pot to house those roots for sure!

With regards to the leaf (Pic 1), the lower leaves of both the keiki and the mother plant does seem to have gone through something and I'm guessing it was some insect infestation at the nursery (It's open air not in a closed greenhouse hence bugs would be common). I would be more worried about the keiki though the new leaf that it has grown seems to be doing fine for now.

[Sharon's Sheepdogs]

Dragonar, I first have to apologize. Your location is not showing up on your posts. In your last post you indicated you could provide 75% to 90% humidity. I just checked your public profile and see you are located in Singapore which experiences a tropical climate with high temps, rain and humidity year round. However, your humidity can vary throughout the day because of solar heat. I thought you were growing indoors in a closed environment.

That being said, it is my understanding the phal is located indoors out of direct sun and your doors and windows are open around the clock allowing the phal to be exposed to high humidity levels at all times.

I am unsure why your phal roots would show dessication at that level of humidity. You can try watering the roots more often. I'm going to assume you are providing some type of air movement around your orchids. This should allow you to water more without increasing the possibility of disease developing. If you are seeing rot develop in the roots covered in sphag, remove it. If you have some physan 20, add 1/2 tsp. of it per gallon of water to your watering routine.

We really need a member who grows in a greenhouse who is experienced growing at these high levels of humidity to assist you.
Or, you can call the business where you purchased the orchid and describe the problems the phal is experiencing. I would suggest you go ahead and do this because they are experienced with the conditions you are growing in.

One of the things I would definitely ask the seller is how they prevent rots occurring in their orchids. At those humidity levels, even if you provide all of the other cultural requirements, your orchids will be predisposed to disease. Ask the seller if they are using any preventative methods to decrease the risk that you can use on your own orchids.

Hopefully another member will jump in with additional suggestions. After you speak with the seller, let us know what they told you.

P.S. If you need to remove the phal from the post, soak the entire plant in room temperature water with a little physan 20 for 15 min. to 30 min. This will usually soften the roots enough so you can peel them off with minimal damage. I'm no longer sure sphagnum would be a good potting material with such high humidity though.

[Dragonar]

Hey Sharon, no apologies needed haha In fact, thanks for the effort of going through my profile and checking the weather Singapore has!

Yes the phal is indoors and out of direct sunlight. Humidity levels would be the same as the surroundings and wind would be rather soft but rather constant as it is being filtered by all the surrounding flats around me.

I doubt the growers use chemicals, even fertilisers. They rely more on the natural rain water, with more wind (their nursery is located at a rather open area hence stronger wind flow) and stronger but filtered sunlight hence rot does not occur at all. The orchids need not rely on much sphagnum and is able to receive hours of rain to soak up water, as compared to my 1-2 mins of watering.

Yes I'll water twice per day and monitor to see how the phal fares for now. Sadly all his amabilis are on mounts or I would've bought one in a pot already.

Thanks for all the inputs Sharon

[Sharon's Sheepdogs]

Dragonar,

I just had a discussion with my husband who has a background in programming air conditioning units which operate in commercial buildings.

Apparently, it doesn't matter how high your humidity is, unless you reach the dew point, the humidity is not adding water to your roots. All high humidity does is slow the rate of evaporation of water. If you are interested, he told me he would teach me how to read something called a psychometric chart which I could teach you to read. This chart tells you, based on the current temperature and humidity levels, the amount of temperature drop you would need to reach the dewpoint. This would allow you to determine daily whether that level might be reached and you could water less when that occurs. As we know, too much water causes problems as much as too little water.

However, he also told me you may never reach a dewpoint in Singapore because of your consistently high temperatures but the chart is an easy way to determine when and if that might happen.

Apparently, if you live in an environment where the dewpoint is never reached and your plant is not exposed to the daily rains, your orchid is probably not receiving enough water. I believe in one of your prior posts you mentioned that the seller had the phal exposed to these rains.This might be the change in environment leading to the poor acclimation of the phal into your home.

I would think the solution would be to water more often during the day and to make sure you have good air movement around the orchid. I know people soak their vanda roots too make sure they absorb enough water but I'm not sure if it is a good idea to soak phal roots.

Hope someone else can jump in here. Let me know if you are interested in learning how to read a psychometric chart. I also found a very good article which describes condensation and dew at:

What Does the Condensation Process Require? | Sciencing