Phalaenopsis new leaves stress or pest?

[Yourneedfulthings]

All my Phals. new leaves are growing damaged near or at the crown.
My greenhouse has been hot and humid for several weeks. Around high 90's and at time above 70% humidity.
During winter these plants suffer a cold spell, thermometer indoors register 30 degrees but no damaged observed, nothing died.

My gut guess is that the plants are stress due to heat, combined with high humidity and dehydration. I have a hard time deciding when they need water when very hot and humid.
Please comment. Do I need to worry about pests or fungus?

[jcec1]

I'm not sure what the cause of the leaf distortion is, but the plants look like they are in huge pots compared to the size of the plants. It also looks like there are multiple plants in a pot. I would pot individually, into much smaller pots to get watering correct.

[lepetitmartien]

I'd explore the carrency/excess route in fertilizer/water couple.

It won't solve on its own and wil get worse.

For more details see on the STAUG website, the Sue Bottom section, she made a little pdf about ferts with an extensive chapter on this.

[Istra]

I know my oncidium leaves will grow in crinkled up and distorted (almost accordion-type folds) if they don't get enough fertilizer and have an irregular watering schedule. I've never had it happen to my phals but it may be something similar.

[Yourneedfulthings]

Do you mean that it could be too much fertilizer?
I just recently start using a zyphon vs. a container pump. Same product, just relaying on zyphon to deliver correct ratio.
I still think I am not watering frequently enough during the summer heat.

---------- Post added at 03:50 PM ---------- Previous post was at 03:40 PM ----------

Originally Posted by jcec1

I'm not sure what the cause of the leaf distortion is, but the plants look like they are in huge pots compared to the size of the plants. It also looks like there are multiple plants in a pot. I would pot individually, into much smaller pots to get watering correct.

I do have several plants in a pot, but they are shallow and with open spaces all around. In a 6" round x 2.5 deep I have beteen 4 to 6 plants depending on the size. I consider removing the ones that lost leaves to individual but, plenty of roots twine in the pot I am not sure what is best.
Thank for your advice, I do tent to use larger than needed pots and slowly learning to correct.

[NYCorchidman]

Heat you described is not going to stress phalaenopsis. Plus you have a good humidity. I grow indoor and they grow wild!

Distortion is not caused by fertilizers.
It may be caused by severe drought while the plant is in active growth and insect damage at the crown.
One less common case, it could just be the crappy genes. lol

I do see one plant is diseased. The one with the black sunken mark. While this is not a fatal disease, it is unsightly and will spread slowly. best to cut that part off and do not water on the plant where the black mark is. You will be spreading the spores all over.

The last picture looks like the leaf had mechanical damage or insect bite?
Did you accidently drop something on the crown or pinched? or do you have cockroaches or other pests in the growing area?

Also, one of the plants have chlorosys or color streak its newest leaf. That could be just nothing, but that could also be manifestation of some virus.

[Yourneedfulthings]

Thank you for detail comments.
I think the most possible reason of damage is dehydration. I was a absent for few days when temp change drastically and plants got stress.
I took your advice and inspected, trim and spray physan 20/ cinnamon.
Can't leave my greenhouse alone during summer,
Thank you.