Blackening Stem - Shld I be Worried?

[eBeyonder]

Hi, I have a thor x aristo which has been growing slowly for the past few months. It came as a long stem with two basals. The two basals have since grown large and are pitchering, but the main stem is dying away.

Today, I spotted what is apparently blackening on the stem of the two basals. First, is this really troublesome blackening or is it just the stem becoming old?

This is the main stem dying. There is a brown colouration creeping up and the leaves are becoming limp:

This is the whole plant:

If the blackening is trouble, should I take cuttings or persist with fungicide? Thanks.

 

[glider14]

happened to me too... root rot i think. i would repot your basals(should have a root system by now) into a more airy mix. my ventrata was in pure LFS when it got root rot. but a week earlier a big storm came through and ripped off all of its roots and didnt grow at all. so i got 3 cuttings from it so far nothin but its still early.
Alex

 

[agustinfranco]

Hi There:

Basal growth delays the growth of the main stem. I have seen blackening of stem from some neps, it does not necessarily mean root rot, especially when the blackened section involves onely one internode (between two leaves). The best way to find out, please pick up the plant from the pot and check the roots. If these are missing, then yes, you have root rot, if not, please put the plant back and enjoy growing it further.

Gus

 

[Tony Paroubek]

I would take a cutting from one of the basal shoots pronto. Make sure you cut well above the dark stem and when you do cut, make sure that you dont see any offcolor tissue inside the stem. What you are seeing is not the normal 'rot' that comes from the roots. That disease causes soft black mushy tissue and travels to the growth tips even before you notice it on the stem/lower leaves.

What you have is the fungus that causes leaf spot (Cercospora) that has infected the stem. It is very slow moving and infects the stem from the leaf junction. Hence it takes a while to girdle the stem and cause the effect you are seeing on the main shoot. That dehydrated look from lack of water. The roots are probably still somewhat ok or you would see severe wilting in the basal shoots as well. The other characteristic is the black dry woody stem with the lighter colored dots and the reddish area between the dry part and the green tissue. If you have some Clearys3336 I would deffinately spray and drench the plant and proceed with a cutting.

T

 

[agustinfranco]

very interesting indeed. I always thought cercospora produces leafspots. Unfortunately, i can't see any there. If it's a fungal infection, then a fungicide must be used.

Gus