Phrag Leaf Tip Spotting

[Dandrobium]

Hey all!

I've had a problem for over a year with my phrags leaves developing small brown spots near the tip of the newest leaf. These spots will eventually coalesce as they gradually move down the leaf. Cutting the leaf tip seems to slow the process down, or at least stop the spotting until a new leaf emerges from the crown. I originally had my phrags in a traditional medium of small-medium bark or CHC, perlite, charcoal. Now, most of them are in semi-hydro, but the problem remains. This affects certain types more than others. The most affected are my pearcei, kovachii, hanne popow. Somewhat affected is kovachii x richteri. No effect (so far) is Don Wimber x 2, Fritz schomburg. I just picked up some nice besseae & crosses from John M, so I'd like to get this solved soon!

I water with rain water (1:5000 physan) and around 150ppm of MSU or Miracle gro 12-4-8 + micros & Cal-Mag. I alternate with just rain water every second watering. Kelp & humic acid every month or so. Fish fertilizer every month or so.

I posted pictures in the link below.

http://s1152.photobucket.com/user/Dandrobium/library/Phrag%20Leaf%20Tip%20Spotting

The only other post I could find with similar pictures on ST was here: http://www.slippertalk.com/forum/showthread.php?t=36125
It was recommended that reduced light and more frequent watering may help. In my case, I top up the s/h reservoirs with rain water every morning.

Currently my phrags are about 1-2ft away from a large east window. No supplemental light. The sunroom faces east, with a small south window. RH is 60-70%, temps are from 68F to 88F in summer, but now dropping 5F or so from season change :sob: . It does get fairly bright in the morning, but thats for about 3 hours a day, then it is bright filtered light afterwards. Tower fan runs 24h a day.

Has anyone seen this type of spotting, and if so, what have you done to rectify it?

Many thanks!

 

[gonewild]

Try not using physan

 

[Dandrobium]

The use of physan was in response to the spotting phenomena. I could stop using it, but the spotting will likely remain as before. I maintain its use to prevent (or reduce) the occurrence of other gremlins.

I should also say that spraying with Thiomyl does keep the spotting at bay, but it inevitably comes back. I think its a fungal infection brought on by some cultural thing I need to fix. I just can't think of what would cause this on some phrags. Even when I flush and just give rain water, it will come back.

 

[NYEric]

Looks like rust. Wipe the leaves or spray with alcohol.

 

[Dandrobium]

If left unchecked, the leaves will eventually look like this (sample image from google):

Is this rust? I've never seen it before. There's nothing to wipe off, or does an alcohol wipe/spray kill the fungus?

 

[TrueNorth]

I get this when the plant doesn't have enough roots. It usually happens when the new growth is too far above the medium. The new roots start to grow but dry up before they can reach the medium.

 

[Dandrobium]

That sounds like a reasonable explanation. So could this just be a physiological response, or is this a fungal infection brought on by a lack of available water?

Perhaps the media I use (mainly semi hydro) is too airy for some of my phrags. This (spotting) has happened to me using other media as well, even when my kovachii was in small CHC, charcoal, perlite, and some growstone, sitting in 1/2" of water. It was growing some great roots when I transferred to S/H, maybe I just needed to give it more time...

The kovachii S/H media also has crushed oyster shell and that synthetic sphag (Synthic?) throughout and down into the reservoir to aid with wicking. I think I'll just give it more time to develop a strong root system and see if the problem goes away.

The pearcei is in straight LECA S/H, and Hanne Popow is in a CHC mix. The newest growth on the HP is slightly above the media though, and it is showing the worst of the spotting.

 

[gego]

If you havent tried it yet, increase your supply of Ca and Mg and make sure your pH is good. Also when you water add Ca/Mg to the rain water and or a few calcium carbonate from tap. Just a suggestion.

Sent from my HTC One using Tapatalk

 

[Dandrobium]

Thanks, yeah I always apply Cal-Mag when I fertilize, but not when I strictly 'water'. I've added additional crushed oyster shell also, in case it is deficiency related. I don't believe thats the case but you never know.

 

[gego]

Shells will take forever to provide the quantity of Ca you expected to get. Much more when you water with rain or RO. The small quantity your solution may have will just be leached out. It was hard for me to believe that Ca/Mg supply was my problem, it just can't be and it doesn't show the typical signs. I noticed that when Ca is deficient, it shows up pretty fast and could show up in any form and will throw you off. My gut feeling is that if it bonds to another nutrient and both will be less available to the plant, you will have two deficient nutrients that will lead to other deficiencies. But maybe my case is just different.

 

[orcoholic]

I think the Physan is causing the spots on the leaves when they are just starting to form. New growth is very tender. That's why it's only on limited areas of the leaves. The spotting happens when you put the Physan on new growth.

I once tried to sterilize the tank that stores my water by adding a quant (RD20) to it and when I watered with the stored water, a lot of new growth was damaged. I don't know what the rate of application was, but it was way less than the recommended rate. Probably less than the 1:5000 you are using.

Also, Isn't the recommended rate for Physan about 1oz/gallon? If it is, a 1:5000 rate probably isn't doing anything except spotting the new growth. It may also allow a resistant fungus or bacteria to develop.

 

[Dandrobium]

So I've still got this problem with my kovachii

Its no longer in SH, now potted and well established in CHC, growstone, charcoal, and crushed oyster shells. It sits in a small saucer of water that is changed every few days. It gets watered at least once a day, usually twice. Watered with RO or rain water and added fert or Cal-Mag, fairly dilute. Same as all my other phrags get. Haven't added physan to water for a long time.

It does have a couple roots near the top of the media, but they are healthy, and lots of roots going down below the water level.

It seems to be growing well, just that the leaves emerge from the crown already browned like this. I don't get water in the crown, I'm fairly careful to avoid that.

 

[John M]

When you water a Phrag, always water from the top and put copious amounts of water through the pot. Phrags HATE mix that has any mineral salts building up....even if it's not enough for you to see. While I find that they grow much better with frequent feeding, they must not have a build up of nutrients in the mix. If you water by allowing the plants to drink up water from a reservoir, you're asking for trouble. You can get mineral build up even if you use rain water...it just takes longer. When I see new leaves doing that, I repot and water more often....from the top and allowing all the excess to flow out and away. Then, new growth comes up clean. My best grown Phrags have been the ones that get watered so often they never really stop being wet; but, I water from the top, using copious amounts of water and allowing all the excess to drain out of the pot and away. Lots of FRESH water and air in the root zone seems to be the trick to keep this issue from cropping up.

Also, beware of using too much Calcium. I did a lot of damage last year when I was using Calcium Nitrate even though I stopped using R.O. water and switched to water from a nearby stream. Plants were dying! I realized my mistake and simply stopped adding ANY calcium, relying on whatever was disolved in the water from the stream. All my plants greened up again and the leaf tip death stopped.

BTW: When I water, I deliberataly water the WHOLE plant including allowing the water to wash over all the foliage and fill up the crowns. On sunny days that I don't water a particular bench, I still use a coarse spray to wet all the foliage thoroughly. I NEVER, EVER worry about water in the crowns of plants. Crown rot only happens if other cultural conditions are not right and the plant is stressing. It has nothing to do with getting water in the crown. If it did, nothing in the wild would survive.

 

[Brabantia]

Cut the brown parts of the leaves and apply an alcoholic extract of cinnamon on the few centimeters from the top of the leaves. The top surface of your potting seems to me a little to dry. I am also watering and fertilysing from the top with a copious amounts of water or fertilyser solution. The pots are not in a water level. I don't like this method because air can't reach the bottom of the substrate.

 

[Dandrobium]

Ok, thanks John/Brabantia. Yes, I always water from the top. I'll try repotting this into a slightly bigger pot, and maybe add some sphagnum on top. The mix is always wet, as I typically water 2x a day with this one. I'll remove the saucer and hopefully that will solve my problems. My water is rain/RO so there is no (or very little) existing calcium in the water.
This is definitely my fussiest phrag :crazy:

 

[John M]

You seem to be doing everything right. However, since you do need to add calcium, perhaps you're a bit heavy handed? It doesn't take much to keep these plants satisfied.

I find with Phrags that if a plant has a curious health issue that I just can't seem to figure out, if I repot, the problem will usually resolve itself anyway, even though I did not actually know what was the issue in the first place. My experience is that Phrags (which are basically healthy with live roots), love repotting. They always seem to have a flurry of new, healthy, fresh growth after being repotted and given a bit of time to re-establish. My theory for this is that fresh mix is highly beneficial because there is NO mineral, fertilizer or chemical residue in it. The longer a plant is in a mix, the higher chance that there is a build-up of something that will begin to make the plant unhappy. This is why I water frequently and copiously from the top. Lots of water rushing through the mix frequently helps to wash out and remove deposites left from previous waterings. Also, as the water drains out the bottom holes in the pot, a vacuum is created in the pot which causes fresh air to be drawn in. So, very frequent watering with copious amounts of water also causes more FRESH air to be in the root zone.

 

[Stone]

So I've still got this problem with my kovachii

Its no longer in SH, now potted and well established in CHC, growstone, charcoal, and crushed oyster shells. It sits in a small saucer of water that is changed every few days. It gets watered at least once a day, usually twice. Watered with RO or rain water and added fert or Cal-Mag, fairly dilute. Same as all my other phrags get. Haven't added physan to water for a long time.

It does have a couple roots near the top of the media, but they are healthy, and lots of roots going down below the water level.

It seems to be growing well, just that the leaves emerge from the crown already browned like this. I don't get water in the crown, I'm fairly careful to avoid that.

If you can, get hold of some Prochloraz and get that on to them. This is a fungal infection IMO. Probably colletotrichum or something like that. ( the little brown spot under the main die back on the leaf tip is a bit of a give away). If it is salt burn which is also possible, (or a combination) you are not flushing the crap out of it as John says. You can fertilize straight after flushing but you must flush to bring the EC of the mix back down again at least one per week I'd say. To flush, water the plant with about 3 pot volumes of water 3 times in a row 1 hour apart. That re-sets your EC and your good to go again. I have found all my paphs and phrags doing much better now that I do this regularly. You can do it as often as you like as long as you feed again soon after.