BLC Ports of Paradise issue - need disease ID help

[Roberta]

Keeping out of the grow chamber (so that it does not have a chance to infect other plants) is important - in a confined space, think of an airplane or a kindergarten classroom - petri dishes. Catts are not fragile with regard to humidity, so the ambient house humidity should be no problem. Just put it near a window where it can get some light, and see what it does. If it is doing new growth, it might be a good idea to unpot it and get a good look at the rhizome, cut away any growth that has evidence of rot, since this sort of infection can spread rapidly into the rest of the plant. Cut back to clean tissue, and you will greatly improve your odds of saving the plant. Even if you have to cut away the new growth, eyes on the older p-bulbs may pop out new leads - you really do want to get rid of any part that shows signs of the infection.

[smokinjoe1952]

Thanks Roberta, that sounds like good advice. I will re-pot in the next few days, as I assume if not all infected tissue is not removed, it will possibly spread.

SJ

[Roberta]

Originally Posted by smokinjoe1952

Thanks Roberta, that sounds like good advice. I will re-pot in the next few days, as I assume if not all infected tissue is not removed, it will possibly spread.

SJ

Definitely - if it gets into the rhizome, it can take down the otherwise healthy part of the plant rather quickly. After you have cut to clean tissue, you can dust the cut with cinnamon, which is a natural fungicide.

[Fernando]

I wouldn't touch it, for the infestation rarely goes into old - matured and strong - tissues, but if you do, be careful to clean your instruments after every cut.

[Selmo]

Looks like pythium or black rot. If it is, it can move fast. It is caused by high temps and high humidity and stale air. Increase air movement and spray with Subdue, Subdue Maxx, Aliette, Signature or Banrot, these fungicides are only labeled for pythium and powdery mildew. Most other fungicides will not help against pythium. These fungicides work on contact and will knock down any pythium instantly. Respray in 7-10 days and good luck with this

[estación seca]

Most Cattleya hybrids do not need super high humidity. The higher the humidity, the greater the chance of bacterial or fungal infection. I wouldn't keep them at 70%+ unless there were no other option.

[smokinjoe1952]

I recently increased the humidity from 45% day/60% night, to 65%d/77%n and the Phals are looking WAY better, but it may have caused this 1 Catt. to develop a problem.

I have four 12v fans providing circ. so I don't think that needs to be increased. It is a 4'x 18"x 5' high chamber.

I will try to reduce the night time humidity to the 60-65% range instead of the current 77%. Hopefully the Phals will stay happy and the Catts will be less suseptable to these issues. They have been in the chamber for 6 months with no issues until I raised the humidity.

I raised the humidity by putting my humidity tray back in the chamber, and putting a 12v IP55, 80mm fan face down, blowing air directly onto the water surface. It has been running 24/7 for about 3 weeks now. Hopefully lowering the night time humidity will be a matter of switching the fan off with the lights.

Also, I looked for all the fungicides mentioned, and they are $150+ on Amazon. Is some of this stuff really $160/quart? Is there a reasonable source for smaller/less expensive quantities?

SJ

[Roberta]

I think that you could try something less robust, like PHysan (which is not very expensive) If you reduce humidity, you may solve the problem and not have to go for the big expensive guns.Phyton 27 (copper based) may also be a reasonably priced solution, but some species may be sensitive to copper, so do your research first

[smokinjoe1952]

I already have Physan 20 and have treated the plant. Fingers crossed with a reduction in night time humidity.

SJ

[estación seca]

What are your home temperatures and relative humidity outside the enclosure?