Black marks on Psychopsis spike

[Susie11]

I have had a Psychopsis Mariposa GV for about four months now and I got it with a 10 inch spike. Since it has been with me it has grown really well and is now about two feet tall. Unfortunately I have recently noticed that the spike is turning black at the base. I thought that it could be sunburn as I left it facing an unfiltered window on a hot day a few weeks ago but now that it has spread I really don't know what it could be.







Does anyone know what this is?

[Leafmite]

It looks like black rot.

[-k-]

Hmm... At first glance it looked like a dried sheath but then I see the yellow just below the black.. is the spot in question soft at all? How is the bud development?

[Susie11]

Originally Posted by -k-

Hmm... At first glance it looked like a dried sheath but then I see the yellow just below the black.. is the spot in question soft at all? How is the bud development?

There are no buds yet as the plant is only about two feet tall however, the formation of new ??? -I don't know what to call them- papery sheafs has slowed down somewhat. As for the black itself, it is hard and dry not soft at all. It started at the base of the spike and I have just seen that it is quite well advanced actually. There is also a secretion coming from the blackness which is like tiny drops of clear honey.

[-k-]

Just seems strange if it is some type of bacterial rot that it is only affecting the base of the spike? I wouldn't do anything rash quite yet aside from keep it seperate from any other plants for now until a diagnosis is met... There are several folks here that grow these so lets see what they have to say about it...

Also, have you treated it with anything yet? And do you know how the rest of the plant condition is... ie: roots?

[Susie11]

Originally Posted by -k-

Just seems strange if it is some type of bacterial rot that it is only affecting the base of the spike? I wouldn't do anything rash quite yet aside from keep it seperate from any other plants for now until a diagnosis is met... There are several folks here that grow these so lets see what they have to say about it...

Also, have you treated it with anything yet? And do you know how the rest of the plant condition is... ie: roots?

Yes I have -just as a precaution, rubbed it with Hydrogen Peroxide as we can't use Physan over here. I have not checked on the roots but I think they are fine as they are still a nice healthy greeny white colour. I have isloated it and hopefully this is not a rot of some kind. I will await the advice of the others though just incase. Thanks for your help K.

[Leafmite]

Try isopropyl alcohol. I think it is black rot because it looks just like the black rot that affected many of my cattleyas. You need to be very careful that this doesn't infect the main plant. Here is a good site (if the link I post works): Orchid Pests, Orchid Diseases

[katrina]

Like -k-, I wouldn't be so quick to diagnose rot if the tissue is not mushy and/or watery. I have various dark/black spots and dots on some plants and it's not harmful at all.

I would keep an eye on it...watch and wait. Keep it isolated and use good hygiene between this one and your other plants until you feel confident you know what is going on (if anything) w/that one.


here's a great article on Black Rot...
Black Rot

[Susie11]

Originally Posted by katrina

Like -k-, I wouldn't be so quick to diagnose rot if the tissue is not mushy and/or watery. I have various dark/black spots and dots on some plants and it's not harmful at all.

I would keep an eye on it...watch and wait. Keep it isolated and use good hygiene between this one and your other plants until you feel confident you know what is going on (if anything) w/that one.


here's a great article on Black Rot...
Black Rot

Thanks for the advice katrina. I am keeping it isolated for now and I will keep a close eye on it too. I have just liberally applied another coat of hydrogen peroxide so maybe it will do something good for it. The spike is still growing but not as vigorously as before but it is still getting taller so :/. I will keep my fingers crossed and keep you all informed.

[Susie11]

Originally Posted by Leafmite

Try isopropyl alcohol. I think it is black rot because it looks just like the black rot that affected many of my cattleyas. You need to be very careful that this doesn't infect the main plant. Here is a good site (if the link I post works): Orchid Pests, Orchid Diseases

Thanks for the link.

I will amputate the spike and repot.

[Leafmite]

I'm sorry about the spike. I had hoped it would be something else. I lost a few cattleyas and a brassavola to this before I figured out what was happening. That's why I was concerned when I saw your picture.

[Brooke]

Please don't cut off the spike just yet. If you have the dreaded rot the black spot will continue to grow. Take a black marker and circle just outside the perimeter of the spot. If the black on the spike grows beyond your line, then you have a problem. If the spot doesn't grow then it is harmless.

Black rot grows quite fast and is soft to the touch.

Brooke

[Susie11]

Originally Posted by Brooke

Please don't cut off the spike just yet. If you have the dreaded rot the black spot will continue to grow. Take a black marker and circle just outside the perimeter of the spot. If the black on the spike grows beyond your line, then you have a problem. If the spot doesn't grow then it is harmless.

Black rot grows quite fast and is soft to the touch.

Brooke

Oh my! I was just about to cut the spike today!! Thank God I saw this message in time - I got no notification this time so I am happy that I was browsing the site!!

As far as I can tell there is no softness at all infact it is dry and hard.

I will do as suggested and cirlce and see. Many thanks for your suggestion Brooke.