Hello everybody !

I would like to have your opinion about the following photo.

It is a paph lowii leaf.
Indeed, this symptom appears gradually. The top end of the leaves becomes yellow / dark.

I don't think it’s virus or bacterium. I think of a deprive or toxicity. In addition, that paph is under fluorescent lamps and that the leaves are relatively close to them.

What do u think about ?

Thank you for advices, Philippe

http://cjoint.com/data/iEntQAhPVJ_3.jpg

Heat damage! Believe me, I know what this looks like. I just finished moving several of my plants inside and they all look like this. Some of my plants were not even in direct sunlight, but the 100 degree temps outside were literally baking them. Try moving it further from the light and it should stop the yellowing. :D

It could be a number of reasons but most commonly extreme bright light, intense heat and over fertilization. In nature, Paph lowii grows on tree branches where they get direct filtered light through the leaves of the trees.

Thank you Nynaeve and Paphraguy. So, maybe it is due to heat wave in france and fluo lampes.
I fertilize about 0,5 EC. Do you think it's ok ?

I rarely fertilize my paphs because I have many minerals and lots of calcium in my tap water. I think the amount of fertilizer depends on if you are using tap water or distilled or rain water. But usually when I see browning at the tips I think it is an over fertilization.

I would take care to flush out the mineral salts from fertilization at least once a month. It could be root burn from the salt deposits.

FYI In the March/06 issue of ORCHIDS Frank Smith from Krull-Smith Orchids said that he gives his paphs no fertilizer at all from June through September because the high temperatures during this period result in a too rapid uptake of fertilizer which results in leaf burn.

FYI In the March/06 issue of ORCHIDS Frank Smith from Krull-Smith Orchids said that he gives his paphs no fertilizer at all from June through September because the high temperatures during this period result in a too rapid uptake of fertilizer which results in leaf burn.

Very interesting info! That makes perfect sense to me. I basically stopped fertilizing mine. They seem to grow fine without any fert. Then again I water with tap water that contains much calcium and other salts, so maybe I just don't need fert.

I took photos. We can see the yellow area on leaves...

http://cjoint.com/data/iFs0k7DEXy_lowii.jpg

http://cjoint.com/data/iFs0SonhT2_lowii-dessus.jpg

Are you sure it is a Paph lowii? The leaves look too narrow. Mine has broader leaves. Anyway, your plant looks nice and healthy. My tigrinum also has yellowish green tips and that was due to very high light to induce spiking and now it has a sheath.

To be precise it is a paph lowii var lynniae.

To be precise it is a paph lowii var lynniae.

Aha! No wonder it looked very different from my lowii. Paph lynniae is a smaller species related to the larger lowii.