Growth abortion and size issues in Lepanthes.

[Flowers]

Good day everyone,
Almost all the Lepanthes I have seem to be aborting 95% of new growths. In addition to the abortion, the growths that make it to maturity are always substantially smaller than those that preceded them. Plants with these problems are L. imbricans, L. ophelma, L. pastoensis, and L. caprimulgus. The bizarre thing is that they are all flowering profusely. I mean a lot of flowers, sometimes on multiple spikes.
The three Lepanthes I have that are not experiencing problems are L. gargoyla, L. telipogoniflora and L. tsubotae. They are doing astonishingly well.
They are all growing in a terrarium (Exoterra XL high terrarium) with two small 9v PC fans(will upgrade soon), humidity is maintained above 88%, temp (F) is at roughly 72 degrees day, and 65 night, fertilized weekly with 1/4 strength Grow More 20-20-20.

There are several other plants growing with them, including Masd. caesia, Pleuro. teaguei, and Pleuro restrepioides, with the two former having the same size decrease as the lepanthes, and the latter having no problems what so ever.

The abortion is obnoxious, but the decrease in size of successful growths is down right depressing. Anyone have any ideas? I'm willing to try anything at this point.

[Kyle]

I have same problem sometimes, not so much with lepanthes, but with masd. Your humidity is really good, but I suspect a fungus is the problem. Does your terrarium have a fresh air intake? Otherwise you are just circulating stale air and the pathogins in it. Fungus loves high humidity and new growths a more susseptable to fungal attacks.

Try a once a month spray with a systemic fungicide. Funginex works well for me. I spray the base of the plants.

I notice a difference in new growths when I miss a month of spraying.

Kyle

[Restrepia]

I agree with Kyle - Circulating stale air results in problems and you really need to change the air often especially with high humidity and small enclosures.

I use Exoterra for all of my growing cases and love them! Perfect for Pleurothallids however I am aware that some growers adapt the top mesh by covering it with glass. I do not do this and keep the mesh, as this provides my growing cases with plenty of new fresh air. Yes you loose humidity however I have automatic misting set up in my growing cases so that compensates for keeping the mesh. Humidity is always around 70 - 100%.

Flowers, have you adapted your Exoterra by replacing the mesh with glass?

When growing in any type of enclosed case it is always advisable to spray the case and plants on a monthly basis with a fungicide preventative. I use Physan.

[Flowers]

The terrarium has an intake running along the entire front. Most of the top is covered with lexan, with a one inch wide, whole length space in the back for intake/exhaust.

I'll try the fungicide. A fungus makes sense, as now there seems to be a white substance (kind of resembles a mineral deposit) forming on the leaves of the L. imbricans, and on the tree fern mount of the L. telipogoniflora (who isn't experiencing a problem for some reason).

Thanks for the tip.

[Restrepia]

Do you use RO/Dist water? If you are using mains water from the tap I would also advise testing it or using RO/Dist water only!

[Flowers]

I only use distilled. I'm thinking about putting bigger fans in as well. What size do you use with your guys?

[Kyle]

I don't grow in a terrarium, so I don't know about fans. But it might be wise to point one fan to suck air into or blow air out of the terrarium. Again, I don't know much about terrariums, but I don't think you can rely on a passive air exchange.

Physan is good, but I have the best luck with a systemic. The action last longer too.

You should pat yourself on the back concerning the L. telipogonaflora. I have a hard time keeping those alive.

Kyle

[Flowers]

Originally Posted by Kyle

You should pat yourself on the back concerning the L. telipogonaflora. I have a hard time keeping those alive.

Thanks. Right now she has one open bloom and 5 buds on different spikes. Don't know why that one's so happy, but I'm glad it is.

Pics are up in the Miniature show & tell section. In pic #4, you can see the white creep on the leaves.

[Mahon]

If you have new growths aborting, I can only think of three things. One was already said (fungal, or even bacterial issues), another is too much heat, and the last is gases being emitted inside your tank.

-Pat

[Flowers]

To what concentration should, if any, the fungicide be diluted?