Phalaenopsis leaf disease - thinning, veinging and clearing?

[OzPhal]

Hi Everybody,

How are you all? My name is Dan and i'm comparatively new to the world of Phalaenopsis culture - although not new to Orchids in general. I have been growing Sarcochilus spp here in Australia since a young age. Sadly over time my collections has dwindled and i made the mistake of purchasing a Phalaenopsis spp a few months ago. Needless to say i'm now looking at importing species from Thailand etc and breeding my own (I'm a microbiologist by trade so do all my own flasking etc - i really enjoy it). In any case i have a hybrid, i'm not sure of it's name, and it has developed some clearing on some of its leaves, the veins are showing through and it almost looks like it's being dissolved from the inside. There are no mites or anything on the leaves, no fungus, any ideas what it might be and how to treat it? I've attached a picture for you to see what i mean...

Any thoughts?

I look forward to talking with you all more about the lovely Phalaenopsis...

[Blueszz]

Hi Dan, welcom to OB.
can you post a larger picture or a link to a large picture? You can choose to "insert image", enter the image link and OB will resize for you, but we are able to click the image and see the origal size.

I wonder if it's leaf burn, or cell collapse but I would love to see a larger picture from this leaf. Maybe also a picture from the under side from the leaf would be helpful identifying the problem.

Nicole

[Bird Song Farm]

From what I can see in the small picture I would guess sun burn.
But, as Nicole says, would like to see more.

Al

[OzPhal]

Thanks Guys for your replies and thank you also for your welcome... do i need to upload my photos to a website before i provide the URL?

Kind regards

Dan

[OzPhal]

I think i have it sussed:

[Blueszz]

Hi Dan,
I still think it's sunburn. Am I right that the affected spots are dry (not soft, mushy)?
If it's sunburn it should be OK and it will be a cosmetic 'problem' until the leaf sheds by age.
Where I live, some sun in the winter is OK, but I'm not sure as it comes to Australia. If you want to know if the Phal can take the sun, feel the leafs when the sun shines on them. When they feel warm you risk sunburn.

Nicole

[OzPhal]

Thanks Nicole, I appreciate your reply... yeah, it is dry, definitely not mushy... What are your thoughts on the dry black tips on the end of the leaves? also does the leaf colour look good? i'm not 100% certain on where best to position it to get the best possible light...

I'll give the leaf/sun thing a shot... it can be prety intense at times though (although not overly hot) so i prefer indirect sunlight

[Blueszz]

My opinion is that the dry black tips are caused by mechanical damage. I think it's nothing to worry about.
Leaf color might be good, hard to say. Some Phal's naturally have darker leafs than others.
Too bad I don't have an idea how intense the light in Australia can be, but behind a window it's not only the light intensity you have to deal with, also the heat build up behind the window and probably stagnant air.
Running a fan towards the plant can help (for instance a small computer fan - a old cell phone charger can provide the fan power).

I only have North and South faced windows. During the winter the windowsills get too cold during the nights, during the summer the South window gets way too hot and even the morning and evening sun is too hot for the Phal's, despite they are about 2 ft way from the windowsill. Currently it's summer here
I make sure they only get indirect light during this part of the year and they seem to do fine in a corner close to the South faced window. The most intense light is during the late afternoon when the sun hits the white wall behind the Phal's.

OK, now I have to admit that this was the old situation as I started growing under lights a few months ago - as had to many low lights plants and got enough from moving plants around all the time (closer to the window, back from the window etc) - and one of my cats that threatenend me to bite the orchids whenever it wanted to be fed LOL

If you only have one Phal. you can use a fluorescent desk lamp if you are afraid it gets not enough light. For instance, during our winters we only have about 8 hours of day light and because my windowsills are so cold I had to keep them away from the windows. Fluorescent desk lamps will give you some extra light for the plant and you can increase day lenght with it. Don't know if that is an issue where you live.

I used desklamps with 4000 K lamps and maybe not optimal, my plants did well under them last winter. Other winters they stopped growing, this winter they kept going.

Currently I grow under 600 fc (growing fase, none are spiking) and newest leafs always turn a bit reddish, once they mature they turn normal green. Plants with white flowers don't show this reddish pigment in the leafs (at least not mine).

Nicole