Hi to all.
I had recently the same problem with my H. neblinae. it was very big (43 centimeters tall pitcers) and with H. tatei ( the same size, more or less).
I found that all the plant was starting to dry out. But knowing the problem (it occourred to one plant some year ago) I'm succeded in saving some part of both the plants.
These plants were big (with a stem, expecially H.tatei) and I had enougth "plants" to cut away the rooting part of them and (the part of the rhizome with roots, I cut the stem looking for the live tissue) and I kept some piece of these plants in sphagnum moss...some of the cuttings died, but some staied alive for many time, untill one cutting of H. tatei succeded in rooting...with 3 beautiful and fat white roots....I'm so happy, I've not lost the whole plants.
So, I can say: it is a fungus (I think something as Pythium or Fusarium). this appened after I used trichoderma. It occourred in december, so the period when I have cool temperatures...It seems to be non related with high temperatures...and it occourred after I repotted H. neblinae and after I brought the H. tatei to an exposition...so both had a stress.
I succeded in saving a part of them only because the plants were big ( both flowered 2 or 3 time). Whith smallest plants there would not be anything to do.
I think this is a fungus normally present in the coltural mix. It coexist with the plant, without any trouble. but when the plant is stressed for some reason, it takes over.
I think trichoderma it will help. but it is not the total solution to this problem.
I think my mistake was also keeping plants too wet ( however always without standing water). with big pots it occours also the problem that there is more standing water on the bottom ot the substrate, because of fisical reason (if you use a wet sponge you'll know exactly what I'm sayng). So I recently started using large pieces of polystyrene. I put them into the pot before starting to fill it with the substrate, in order to have a very high drainage. Plants seem to like it. Roots tend to stick to polystyrene. I think they like it!
Excuse me for my imperfect english, but I just wanted to write you my experience with this problem. I think it's mainly caused by too wet conditions.
I think these problems are more frequent in winter or in indoor, because of a lack of sun means a lack of uv radiation, that are the most efficient antidotes against fungi and molds. So winter has better temperatures than summer (an high temperature can also cause this problem, surely) but in summer the stronger uv radiation fights against it.
instead, in case of indoor, the worst period should be just the summer, because of higher temperatures and the lack of direct sun (in this case plants never grow on direct sun, so they have no advantages of uv radiation) and the best period for their groth is in winter, with can allow lower temperatures.
Edited by kribbio, 27 March 2011 - 16:55 PM.