Phal Bellina and black spots
 

Hi, I have 3 small bellina's and they all seem to exclusively develop black spots that my other Phal species (basitani, deliciosa, parishii, stuartianii) don't encounter. One leaf was lost 12 months back but the plant recovered though seems an ongoing issue. Violacea has some wet spot issues but no black spots.

I'm assuming they're fungus related so am doing my best with hygiene and circulation, but right now am trying to determine the best treatment. I've tried mancozeb but not convinced it's helped, next is a Physan equivalent or Phosacid.

Alternatively I'm unsure if it's a result of cooler conditions than it appreciates (12-13c) that's exposing it to fungus.

Has anyone encountered this on this specific species and an effective treatment, or is it just my batch.

Cheers
Fred

Two suggestions that might help:
1) Water from the bottom instead of the top
2) Give your orchid extra Calcium

I have my bellina in NZ sphagnum moss/basket pot and, to water, I set the pot in a bowl of water and let it soak up the water. I actually have mine hanging from the side so that the leaves can hang downward as I love the look of these mounted but this works better with my lower humidity. Having it growing this way allows quite nice air-flow around the leaves which would help prevent fungus issues.

Ok thanks for that, I don't have the courage to soak them right now as are also growing in sphagnum but is mid Winter so tends not to dry out for weeks.

I'll give that a go in Summer and avoid wetting the upper portions, currently my watering is a direct squirt on the roots once a week to be on the safe side. You're right though the wet upper media may result in more opportunity for fungus growth.

12-13C/52-55 F is far too cold for bellina. That is the cause of the spots. People try not to let it go below 20C and much warmer is even better.

yes temps need to be 20 C at night and warmer during the day.
You can achieve this with a reptile heat mat.

Colder temps will weaken the plant. The roots look very dry also - I can understand why as in such low temps any more moisture would cause problems but that is the problem, you want warmer temps and more water around the roots.

Missed the temperatures somehow but I agree that they need to be kept warmer. Those temperatures are much too cold for bellina.

Thanks for the replies, that gives me some insight on my issue. I will start keeping it in a warmer part of the house as is currently 6c at night outside so I have a bit of a challenge for the next month at least.

Yes I'm scared to water but inadvertently dehydrate the plant in the process compounding my issues.

I'll invest in a heat mat, I have vacant aquarium I can try but have never grown under artificial light - it came with a blue & red spectrum light but I think combined may be too strong for a phal.