Discoloration of Lc. Casitas Spring Linden Leaves

[OrchidFun]

Hi All, hopefully someone can help me. I bought a mature Lc. Casitas Spring Linden Orchid about a year ago. It has bloomed and started to sprout new leaves. Lately, however, all of a sudden a few of the mature leaves have started to turn yellow. The discoloration starts at the base of the leaves and moves upward. I have lost three of the large leaves all ready. Does anyone know what I am doing wrong? Is it an issue of too much/not enough water maybe?

Any help is appreciated!

[seamonkey]

Pics would be helpful.

[OrchidFun]

[tuvoc]

Looks to me like the older bulb dieing, which is perfectly normal.

Kim

[seamonkey]

Older bulbs shrivel up and lose their leaves entirely. As long as it's not mushy I wouldn't worry.

[OrchidFun]

Alright, thanks guys

[orchidsamore]

Unfortunately this can be fusarium fungus. The brown coloration at the base of the medium is an indication that it has spread into the rhizome.

Fusarium exists all over the world and can attack plants at any time. It is a major disease of grass lawns.

If the bulbs start to become soft when you squeeze them, you have problems.

Commercially we destroy these plants. I have sent a number to the burn pile this year.

The only recourse if it is a special plant is to remove it from the pot and keep cutting out the rot until you get to good green growth. You may find the rhizome is infected throughout the plant.

Thiophanate methyl and iprodione based fungicides have been the recommended fungicides to prevent spread, but they have been used for so many years they are pretty much ineffective against fusarium now.

Removal and destruction of diseased material is your only recourse.

The fungus will spread right through the entire plant.

This fungus is highly contagious and should be keep quarantined fro your other orchids (and plants not only orchids get infected). It spreads from splashing water and can even go airborne.

Your hands and tools are a major source of spreading the fungus.