Need help please - Orchid Board

OOAJ · #1 07-07-2012, 09:16 PM

I have 2 paphs that I have been growing semi hydro, they have bother been about 6-8ft apart, and have never shared the same water or anything else I can think of that would be a direct source of contamination other than air; however, they both have something that has been attacking their new growth.

My first thought was fertilizer burn since it has started primarily at the very tips of the leaf and I flushed them with clean water. However, whatever the problem is continues to eat down the leaves and has recently begun spreading to some of the older growth as well.

I sprayed all three, (leaves and a soak for the roots), with an anti fungal/anti microbial chemical but there continues to be an issue. The first two paphs are the most infected, and the 3rd is questionable. I have included pictures. Please help so that I can save these plants, or at the very least, dispose of them before they infect my other plants.

As far as conditions, I have pretty good air movement, and have been watering independently. I did cut the damaged leaves off a couple days after treating with anti bacterial/antifungal chemical. I did use the same shears, but only after holding them directly in the flame of my gas stove for over 30 sec. Prior to their infection they had no direct contact through the shears or otherwise.

So far, the problem seems limited to my paphs, and has not affected the other surrounding plants. Until recently it was only affecting the new growth, however, within the last several days I have noticed it creeping down from the tips of the old growth on the first plant I noticed had an issue.

Please let me know what you think this is and what your suggestions for cure are.
Thanks in advance.

Wynn Dee13 · #2 07-07-2012, 09:58 PM

Are they actually growing semi-hydro or are they just potted in LECA? Some people think growing in LECA is growing semi-hydro. Are they in containers with no drainage holes in the bottom of the pot and only a couple holes about an inch or so up the side of the pot? The pots they are in look like regular pots with saucers under them.

The only thing I can think of is that it is rot from water sitting in the leaves or fertilizer burn. Also did you clean the LECA well before using it?

I hope someone can help you. Good luck.

OOAJ · #3 07-07-2012, 10:38 PM

The pots do have holes, I put them there at a similar hight and size to what is available through other vendors since I wanted something that was nicer looking than a Chinese take out container but would serve the same purpose.

I flushed some water through them. I typically spray them several times a week with water and then once a week or so I do a proper flush from the top, filling the pot until I can see water at the surface and then letting it drain out the bottom. The only fertilizer I've been using on them is the time release MSU fertilizer for well and tap water (13-3-15).

The pots are 5" wide x6.5" tall and I used about 1.5 tsp of fertilizer per pot about 5 months ago, so from my understanding they should be due for fresh fertilizer, rather than being burned by it. I have used the same fertilizer in the same proportion with other plants without any problem. For clarification, I am using Boston municipal water.

I know the second plant has had water sit on the leaf that is currently being affected in the past, but it never sat on the leaf that has been removed prior to this.

If it is just a watet/fertilizer problem that would be great, but I, in my unexperienced opinion, don't believe that that is the case at this point. I would love to be wrong though, since naturally the plants in paid the most for are the ones infected...

Wynn Dee13 · #4 07-07-2012, 10:48 PM

I have never heard of anyone using timed release fertilizer with semi-hydro. I don't know much about how they work but I would think if the time release pebbles are constantly wet they would release the fertilizer faster. I also thought Paphs are light feeders but I only have one so I don't know much about them. I hope someone else has some ideas for you. Good luck.

Wynn Dee13 · #5 07-07-2012, 10:50 PM

Do you know if you have good tap water? It might be a water issue.

OOAJ · #6 07-07-2012, 11:14 PM

As I understand Boston has well above average quality tap water and none of my other orchids have had an issue with it.

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billc · #7 07-08-2012, 06:01 AM

It does look like fertilizer burn, but if I'm reading your post correctly you've only fed it once in the last 5 months with 1 1/2 tps of MSU. That's more than I would give a paph at a single feeding, but that shouldn't be causing a burn.
MSU is not a time release fertilizer, and growing in s/h requires continual feeding in small doses. I would try watering at least 2X a week alternating plain water and 1/2 tsp MSU per gallon. Watering once a week and spraying at other times is probably not keeping enough moisture at the roots unless you are spraying the heck out of it.

Bill

Leafmite · #8 07-08-2012, 09:43 AM

Problems with new growth is said to often be a calcium issue. When my cattleyas (and a few others) lost their new growths (and, for many of them, their lives when it spread), I was told to add more calcium. The new growths are perfect so I think I will keep doing this. I have been adding extra calcium with all my orchids.
When I did have Black Rot (the black plague, as I think of it), nothing seemed to stop it so at the end I just cut away infected parts and swabbed the plants down (not the roots) with isopropyl alcohol, very well, a twice a day, for about a week. The orchids that recieved this treatment survived and are doing well.
I hope this helps.

OOAJ · #9 07-08-2012, 12:13 PM

The fertilizer isn't a powder that's added with the water, it's in pellets and the instructions on the packaging say to refresh the fertilizer every 4 to 7 months bases on the average temp. In terms of spraying, I was spraying until I could see water coming out of the holes at the bottom. My other orchids have been all right on this regimen, but I will concede that the others in S/How that are doing well are a brassia, oncidiums and a couple phals.

Now that you mention it, the calcium could be it. I was told that it can help in my area with the paphs, but may or may not be necessary and to just try and see. Maybe it's going to be necessary.

If more water and Ca are the solution that would be great since those will be easy fixes. I would like to mention though, since it may not be apparent in the pictures, that in addition to the browning that usually started at the leaf tip and crept down towards the base, there appear to be lesions that appear ahead of the browning/dying of the leaf. In paphs is that consistent with a calcium/water deficiency? Or is it as I fear, something a bit more insidious? I'm hoping the first since as I said, I treated them with a chemical that another member of my local society was willing to lend me. I can't remember the name of it, but it's expensive and supposed to be very potent, but the issue doesn't seem to have gone away. The other thing that is slightly odd to me is that both plants started having an issue at very similar times, I don't know if that's significant or not.

Thank you for all of your responses so far, please keep them coming so I can save my plants!

Wynn Dee13 · #10 07-08-2012, 04:26 PM

Quote:

Originally Posted by billc

It does look like fertilizer burn, but if I'm reading your post correctly you've only fed it once in the last 5 months with 1 1/2 tps of MSU. That's more than I would give a paph at a single feeding, but that shouldn't be causing a burn.
MSU is not a time release fertilizer, and growing in s/h requires continual feeding in small doses. I would try watering at least 2X a week alternating plain water and 1/2 tsp MSU per gallon. Watering once a week and spraying at other times is probably not keeping enough moisture at the roots unless you are spraying the heck out of it.

Bill

MSU does come in a time release fertilizer. Ray sells it on his site.