Leaves splitting

[james mickelso]

In pics I've seen of catts in the wild, I've seen this numerous times. Probably 20% of mine have some leaf or two that shows some degree of splitting. I'd love to find out the answer.

[Oskar]

Originally Posted by NYCorchidman

That is definitely a possibility and called micro fissure, especially on the orchid roots. One reason not to let orchids (especially the terrestrials) bone dry too long, as micro fissure gives easy access for pathogens to enter the broken tissues.

However, I don't think it would cause such massive scale split as the one that the original poster described.

I have had a phal that got ignored and the leaves got all wrinkly a bit, then after I soaked it well and there were no split of any kind developed.
The same goes with my oncidiums and dendrobiums and cattleyas on their pseudobulbs.

I believe the cuticle layer is somewhat flexible in that once the plant tissues shrinks a little bit due to dehydration, it has no problem shrinking a little and then plump back up when the internal pressure returns.

Tissues that developed under low water condition may mature "hard" and smaller than ideal, but then once mature, they will not increase in size even when there is enough water supplied later on.

Even within the same leaf that is still growing for example like an onsidium leaf, the part that grew while being underwatered may crinkle up a bit, then when the watering is done properly, the crinkled up part won't get fixed but stay that way while the new part of that same leaf will grow out normally.

Ah, i see. That's probably true and don't i think that the cellulosa in the cell membrane would over exceed it's own matured size and in response split the leaf. If not very over watered.(?)

Wild guess: I do remember from my earlier biology studies in school about osmosis (I think this is the correct translation - where the water travels in and out of the cell depending on the salt levels inside and outside of the cell) and if this process is happening a bit to fast maybe it could in response split the leaf. Again, wild guess.

I have a similar crack in one of my newer phal, one split is almost down to the middle but i also have another leaf that's vertically splitting (seen from a cross-view angle) - i wonder what may have caused that, might have been a mechanical damage before i got it.

[jeremyinsf]

I have a suggestion for everyone - try to grow Paph's in your shower. Your significant other or whoever you are dating may find them 'inspiring'. The added benefit is that you will learn about leaf splitting due to humidity changes.

[TracyLee9]

Wow, nice to see I got quite the little debate going!

[jeremyinsf]

For the record, I think there is more than one reason this happens. I was just trying to add some light humor to the topic. My post, however, is very true in my experience :-)

[OCRC_Dir_China]

Just; some general information that might help.

Air pollution; this is a Worldwide problem indoor or outdoor air pollution; (Form our own unpublished study). We have found in areas like Beijing many Cattleya, Cymbidiums have this unanswered problem in the flower markets. And I have seen this same problem in other areas of China that have high rates of pollution. And I have seen many indoor growers have this problem. The Cattleya I purchased in Beijing was affected by leaf splitting; but all new leafs are unaffected so far one and a half years now.
See; Northen, 1970, Arditti, 1979, OCRC unpublished work.

Light photoperiods; leaves turn yellow when plants are given too much light. This is due to the fact that under excessive light chlorophyll is destroyed faster than it is synthesized. Plants grown under insufficient illumination are dark green, soft, and susceptible to diseases (those given no light at all or very poor lighting become yellow). Flower production is also reduced. Physiological functions vary among orchids so will their photoperiods.
Inappropriate Humidity; ether too high or too low; under excessive humidity plants may be soft and subject to infections. When humidity is suboptimal the plants and potting medium may dry too quickly.
See; Northen, 1970.

Watering, inappropriately; excessive watering inhibits growth and predisposes the plant to many diseases. Insufficient water causes plants to shrivel and lose vigor.
See; Northen, 1970.

Salinity damage; all orchids, though genera and species may vary in susceptibility “Burned” areas consisting of dead cells.
See; Northen, 1970, Birk, 1983.

Mineral deficiencies; a shortage of different minerals in potting mixes and/or fertilizers, the deficiency of each mineral can produces a specific symptom. These symptoms may be modified by climate, species, growing conditions, and other deficiency of a single element.
Boron- Terminal leaves are necrotic, apical meristems blacken and die, roots are short, and plants are stunted.
Calcium- Distorted and stunted new growth leaves chlorotic and curled, poorly developed roots.
Chlorine- Leaf tips wilt, leaves become bronzed.
Cooper- Terminal shoots wilted, faded leaf color.
Iron- A condition commonly known as chlorosis in which leaves especially new growth turn yellow or nearly white particularly between the veins.

A detailed study is needed to accurately determine this problem.

[NYCorchidman]

Originally Posted by Oskar

Ah, i see. That's probably true and don't i think that the cellulosa in the cell membrane would over exceed it's own matured size and in response split the leaf. If not very over watered.(?)

Wild guess: I do remember from my earlier biology studies in school about osmosis (I think this is the correct translation - where the water travels in and out of the cell depending on the salt levels inside and outside of the cell) and if this process is happening a bit to fast maybe it could in response split the leaf. Again, wild guess.

I have a similar crack in one of my newer phal, one split is almost down to the middle but i also have another leaf that's vertically splitting (seen from a cross-view angle) - i wonder what may have caused that, might have been a mechanical damage before i got it.

I don't think the rate of water movement will cause damage. When cells shrink due to osmotic pressure, they won't break. no splits.
When cells swell up due to osmotic pressure, they could burst, although this is also not likely as the result was seen in the lab on individual cell basis, and these cells were forced to go beyond unnaturally high pressure.

Your phal cracking or any other plants is most likely due to mechanical damage.
Often when the leaves are bent due to careless handling, the center will split open or split without opening. These turn brownish sooner or later.

Again, this is not the same on the cattleyas I see.
I have cattleyas that show small splits on areas where it cannot have suffered being bent, but rather being scratched almost. no idea what happened there.

---------- Post added at 12:52 PM ---------- Previous post was at 12:50 PM ----------

Originally Posted by jeremyinsf

I have a suggestion for everyone - try to grow Paph's in your shower. Your significant other or whoever you are dating may find them 'inspiring'. The added benefit is that you will learn about leaf splitting due to humidity changes.

I'm not sure if it is good for everyone as it may bring the end of the relationship as well.

Most of my female friends hate the look of lady slipper orchids flower if that gives any idea.