Phalaenopsis Leaf tip/edge turn black

[kenngks]

Hi,

One of my Phalaenopsis leaf's edge turned black and started spreading, so I decided to cut the infected portion off early this month to stop the problem.

I just noticed that the tip of the same leaf started to turn black again, as shown in the attached photos. Could someone please advise what I should do to permanentely solve this problem?

It doesn't look like a fungus infection as it is not waterly when I touched it. I followed the weekly weakly rule to fertilise my plants and I did flash them using water only every month end. So it shouldn't have caused by excessive salt built up right?

What should I do now? Can't keep cutting back the inefected leaf.....

Regards
Ken.....

[Ray]

In what condition is the potting medium?

[JennS]

Am I just seeing things, because the leaf tip looks more brown then black to me. Don't know how much that matters, but generally rot is black, so if it is brown you can probably rule out rot. Have you tried anything like Physan20 to treat it? Also, Ray probably has some ideas if you respond to him. He is very helpful!

[kenngks]

Hi Ray,

The potting medium seems ok with me. I am using Sphagnum Moss for all of my 7 phalaenopsis plants. I am using the same watering and fertilise routing for all of them but this is the only one have this problem (second time. First one starting from the edge about 4 weeks back). I water my plant usually once a week. I did ensure one inch top from the moss surface is dry before watering again. The roots are green and firm too.

Thanks.
Regards
Ken..

[kenngks]

Hi JennS,

I used Captan 50% W.P. every once a month as a preventive meaure for fungus. The other leave of this plant and the roots seems ok with me Please see the attached photos.

I suspect it could be because this plant is more sensitive to fertilise althought the other 6 plants that gone through the same "weakly weekly" application don't have same problem. Maybe I should cut down to fertilise this plant only once a month but still using "weakly weekly" rule.

[Sandy4453]

Originally Posted by JennS

Am I just seeing things, because the leaf tip looks more brown then black to me. Don't know how much that matters, but generally rot is black, so if it is brown you can probably rule out rot.

This is exactly what I'm thinking, as well. Assuming that it is black though and not brown, I had this happen to one of my Phals this past spring, pic attached. I also cut away all the affected area on the leaf, treated it and was doing fine for about a week and then overnight, another black spot on the same leaf began. Since I had unpotted and cleaned it the first time this happened (and new medium added), I didn't want to stress it out further so what I did was give it a heavy dose of hydrogen peroxide down the crown and on the new cut area, and sealed it with cinnamon. It's been growing great ever since.

If your spot is looking anything like mine did, I'd then recommend the treatment I used.

[kenngks]

Hi Sandy4453,

I have cut off that small portion of the infected brown looking area and treated with hydrogen peroxide. I will consider to re-pot the medium only if the problem come back again as the roots of my plant just look too healthy to be disturbed.

[Dollgoldii]

kenngks
First of all, I would not worry too much about the 'browning' problem because you have already taken precautionary measures. In fact, I totally agree with Sandy(?). I had a few Cat seedlings (Bc Mrs J Leeman) that displayed the same symptom and I thought it was result of bad (disintegrating) bark and overwatering. There was just insufficient air flow to the root. The sad news is that they all failed to make it even after repotting with fresh medium size bark (as shown in picture). I heard about the hydrogen peroxide / cinnamon trick but had never given it a try. With your successes, if need be, I'll try this First Aid! By the way, I like the slitted pots, is it possible to get those in USA?

[kenngks]

Hi Dollgoldii,

I still worry about this problem. If I don't cut off the infected area, it will spread and grow bigger. This is why I am seeking the expert's advice from this forum to permanently resolve this problem.

For the slitted pot, sorry that I am not sure if you can get it in the state. This is provided free of charge from one of the big orchid nursery in Singapore when I purchased the phalaenopsis from them.

[JennS]

My other thought is that sometimes you can underestimate how far the infection has gotten in the leaf. I usually cut back a little behind the discoloration to be sure to get everything then you can pour on some hydrogen peroxide and after lettting it dry a bit then you can seal it with cinnamon. The cinnamon will dry it out and prevent anything new from entering the wound.