Browning Leaf Tips

[richard.feldman48]

Hoping someone can help me identify a problem with a phrag. It's labeled QF Angel wings (Phrag. Grande x Phrag. Incan Treasure). It's growing in LECA, fertilizing with K-Lite at very low concentrations (25 ppm), RO water. (Also, Kelpmax and Quantum Total. i.e, Ray's method.) I looked at the photos at the St. Augustine Orchid Society site. It looks something like the images of anthracnose, but also a little like those of calcium deficiency. But, of course, it could be something else entirely. I have a hard time with these identifications. Advice appreciated.

Rich

 

[Happypaphy7]

I would rule out calcium deficiency unless you have a good reason to think it is calcium related.
One thing I'd like to say about Phrags is that this issue seems fairly common when I visited some nurseries with good number of phrags. Almost all the phrags they had with very few exceptions, looked pretty much the same as shown in your photo or had their leaves heavily trimmed off. The commercial nurseries feed their plants on a regular basis. So, it can't be calcium deficiency and honestly, they don't look typical of calcium deficiency to me.
Anthracnose is a high possibility as I had one phrag that had this same symptom which stopped progressing further when I applied antifungal agent on the affected area. Fungus is everywhere and some plants especially under less-than-ideal conditions fall easy victim to fungal diseases.
Another phrag, my very first phrag, also showed similar issue, but it was due to dehydration. I was keeping the plant too dry. I switched the plant to wet feet condition as suggested and ta da! The plant just took off growing like a weed.
So, I would check first to see if you are watering your plant enough at all times. I saw Phrag Grande being grown in the bucket full of water. Some of these phrags really do like to have a lot of water always available at their roots.
Then, try spraying the antifungal and see if that stops any further damage on the leaves.

 

[Ray]

Rich, there are a number of things that can result in leaf-flip dieback.

• How long has it been in that pot?
• Was the LECA thoroughly cleaned prior to use? (If it’s only been a short time.)
• Does “in LECA” mean semi-hydro, or just as an inert medium? (I see leaf-tip die back if I get lazy and they get too dry.)
• How often are you watering and feeding it?

Of course, it could be a disease, but I usually blame such things on slips in my own culture, more than anything else.

 

[richard.feldman48]

Thanks for the replies.

Ray - it has been in the pot for about 9 months. Yes, the LECA was cleaned well. It is semi-hydro. I water twice a week, with the very low concentration K-Lite. I’ve assumed the problem was in what I was doing rather than a disease, but the photos made me question that assumption.

One thing that I don’t do is to flush it with water w/o fertilizer. I thought that filling it with low concentration fertilizer solution was good enough. Maybe not?

Rich

 

[big923cattleya]

I have been growing Phrags for years and judging them on a regular basis. In my opinion pure Leca as a media is not a good idea.
They require to grow fairly moist and Leca dries out too much. Leaf tip die back can come from too much water but in Leca, I doubt that is the issue. I grow mine in 50% seedling bark, 10% charcoal, 10% perlite, 10% medium bark and 20% Leca. I use Hydroton buts it is basically the same.
I fertilize only one a month at 1/2 strength and water every 5 days or so under lights and every three days when they are outside for the summer. All are in plastic pots.
Too much fertilizer can burn leaf tips!

 

[Ray]

One thing that I don’t do is to flush it with water w/o fertilizer. I thought that filling it with low concentration fertilizer solution was good enough. Maybe not?

That depends upon whether your irrigation technique is flooding the pot with a large volume of solution, or something closer to wetting the LECA and refilling the reservoir.

I have been growing Phrags for years and judging them on a regular basis. In my opinion pure Leca as a media is not a good idea.
They require to grow fairly moist and Leca dries out too much. Leaf tip die back can come from too much water but in Leca, I doubt that is the issue. I grow mine in 50% seedling bark, 10% charcoal, 10% perlite, 10% medium bark and 20% Leca. I use Hydroton buts it is basically the same.
I fertilize only one a month at 1/2 strength and water every 5 days or so under lights and every three days when they are outside for the summer. All are in plastic pots.
Too much fertilizer can burn leaf tips!

All of my phrags are in 100% LECA in semi-hydro culture, so only get dry when I have been extremely lazy. Some have been in it for 20 years.

In a semi-hydro pot environment, the well-saturated LECA can stay moist enough to sustain a plant for several weeks after the reservoir is dry by keeping the root zone humidity elevated (not that I recommend that).

 

[richard.feldman48]

I flood the pot - filling it to the top and letting the water run out the holes an inch above the bottom.

Rich

 

[Ray]

Rich,

It sounds like you an I are doing about the same things and I’m not seeing that, so maybe it’s not cultural.

I just noticed a subtle (?) difference in the browning pattern: when I neglect my plants, whether that be letting them get too dry or letting the LECA accumulate to much waste (it happens), the leaf tips have a more gradual green to yellow to brown “fading”, and not a distinct green/brown “line” as that appears.