I wanted to get everyone's advice on this. A few (three or four) of my phrag. besseae hybrids are developing brown patches on some of the new growths. See photos below. I have been advised that this might be related to overfertilizing.

A little background - I grow using S/H medium and use RO water with the Michigan St. fertilizer from First Ray's at 3/4 tablespoon / gallon. I try to at least partially flush out the pot when watering.

About a month ago I started using pure RO water on the phrags in an attempt to get rid of the spots. I also took each phrag to the sink and flushed RO water through them several times. All this flushing of RO water seems to be having little effect on the plants that are having problems at least so far. I wonder if there is any way this could be caused by a fungus or something?

I'd really appreciate any help you can offer.

Thanks,
e-spice

http://forum.theorchidsource.com/attachments/IMG_4663.jpg

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Have you taken a look at the roots? If they are burnt/rotten then even switching over to RO water won't cause immediate reversal of the browning.

Could be too much fertilizer and underwatering - you should cut of the dead parts just below it

That has happened to my besseaes before and it was due to overfertilizing and or overwatering. Once I gave them less water and fertilizer, the problem went away.

Wow you are getting all kinds of advice here, huh? Well, as a certifiable besseae hybrid torturer, let me throw my experience into the pot. These plants are very finicky, and they will complain and moan in dramatic fashion, but are actually difficult to kill. Your second photo looks to me like leaf tip die back caused by something the plant doesn't like in your culture. Be it too much/too little water or fert, or the type of water. You can rule out the type of water since you are using r/o. Just to be safe have you tested your r/o system to make sure it is working properly? Zach makes a good point about the roots. If the roots are in poor shape that could explain the slowness of recovery. But I don't necessarily recommend you unpot and look at the roots because really there's nothing you can do about it except wait for new roots to grow and unpotting will only upset the plant further or just won't help.

Your first photo could be the same problem, but because it is in the middle of the leaf it could also be something else. I don't think it's fungal, I'm thinking maybe insect damage because it looks slightly pitted. It could be mite or thrip damage. These are very tricky pests because they are almost impossible to see. I have just recovered from an infestation of thrips in my garden and they leave damage before you even see the pest itsself. Rubbing the undereside of a leaf will not tell you if you have thrips. They hide in the folds of the leaf and in the medium. They mainly attack my roses but this year they attacked my ochids as well.

All you can do is try some things and see what your plant respond to. I would treat them for insects. I don't know how you feel about pesticides, but there are a couple of things that I use that work very well, are inexpensive, and don't seem to stress the plants. As far as watering...My besseae hybrids love water. I tried drying them out and they did not like it at all. I have Phrag Cape Gold Nugget, Barbara LeAnn, Hanne Popow, and Ruby Slippers. Since you are using the s/h method (which is what I use) it takes some of the guess work out of watering because you can see the water level. Are your plants taking up water at a normal rate? If they are then you can assume the roots are doing ok.

Hope this helps, please keep us posted!

I had similar problems with my Phrags(especially besseae hybrids).
I grow in s/h as well.
3/4 tablespoon per gallon seems high but not sure of the amounts with MSU.
I use a nursery derived crystal fert(26-6-10) for rainwater @ 1 "teaspoon" per 5 gallons.This gives me approx 70 PPM nitrogen .I do add some "guano tea" to my fert mix but keep the overall TDS to about 200 PPM.
I also found that using taller than standard pots seems to really make a difference.
I remove the bottom of a clear plastic 6" pot & sit this in a 4" clear pot & tape them together.I use a 1" deep saucer as a res.
I fert @ the weekend & flush the pots with rainwater during the week.In this hot weather i am flushing the pots every day in the evening to help cool the roots & stop the water in the res going stagnant.

I would say bad water and to much fretilizer. I use 1/2 teaspoon per gallon of the M.S.U. fertilizer in R.O. water. Hope this helps.

Hello e-spice ,

If the leaves get yellowish there is possible temperature (cold), cause I see the tree leaves tips bronw !!! Sometimes get with me when the temperature is bellow 10 Celsius degrees !!!!

Sencond probality, is fungus but particulary I belive is cold , if is fungus try to use dithane just make a past and pass in the leave.

My sincere apologies - I have actually been using 3/4 TEAspoon per gallon, not tablespoon like I incorrectly stated above. This concentration is supposed to yield about 125 ppm of nitrogen in RO water.

The roots on these plants are all very good. The phrags I have in S/H wind the roots all around the pot. Water uptake in the ones that are having a problem is a little bit less than the ones that are doing fine.

I think I will treat the plants for pests and reduce the fertilizer concentration to about half. I will also flush pure RO water through the pots more often.

Thanks for all the suggestions. I really appreciate your help. It's also good to hear that other growers have had similar problems and were able to resolve it.

e-spice

Since everyone else has given you different advice, I will chime in also....
I have seen this problem on occaision with my bessae hybrids and have not been able to nail down the problem. My water is very good, and I fertilize phrags very rarely. I keep the roots wet most of the time, they are in great shape and in the summer the plants grow like weeds. Late winter/early spring is when I see this problem. Repotting seems to help if the mix is starting to go sour, but it looks like you are growing with clay pellets which don't break down.
For what it's worth, the plant do seem to survive and flourish again.....

i hear everyone saying RO water. hmmmm but what is that???????????? i know its prolly so obvious but someone spelling it out would make it all the clearer for me. lol
well hope someone replies. :confused: :confused: :confused: :confused: :confused: :eek: :confused: :confused:

RO is Reverse Osmosis. I have been growing slippers for many years and I have never once used RO water and my plants are doing just fine. Many growers do use RO water and they have great success growing slippers.

I also have that problem with some of my besseae. I have several besseae 'Hidden Agenda X Winter Sun' seedlings. They will do that quicker than the others and I'm not sure why.

Grandma MC

As a long time Phrag. besseae fanatic, I have seen this condition several times - and almost always attributed it to a higher than normal concentration of salts of one kind or another at the root zone. This can be caused by over-fertilization, or correct fertilization coupled with too little watering, or using plain water for irrigation that is itself too high in total dissolved solids even before adding fertilizer. It is also true that some particular clones of besseae seem to be more succeptible to this condition than others.

To prevent this problem in our own collection, we try to limit the conductivity of our fertilizer water to 200 micro-siemens or less, or roughly 100 mg/L total dissolved solids. This gives a very low level of supplimental nitrogen, somewhere in the 20-25 ppm range. If you are measuring out your fertilizer and you have R.O. water, I would anticipate the dose to be somewhat less than 1/8 tsp/gal. Very low - but you have to remember that these are very light feeders (In Ecuadoran P. besseae habitat, I measured the groundwater seepage conductivity to be 18 micro-siemens, or about 10 mg/L - very pure water - and the only source of nitrogen was the small pockets of decaying vegetation around the roots and whatever was absorbed in the rain as it fell through the atmosphere to the ground.) The plants must be flexible to some extent, though, as our maximum feed rate of 200 micro-siemens or 100 mg/L TDS is still about ten times what they would experience in the wild.

Growing your besseae's on the dry side will also tend to magnify the effects of over-fertilization. As the pots dry out, the salts deposited by the fertilizer water will concentrate around the roots and damage them.

Hope this helps!

Best, Tom

hello,
I have the same problem with my besseae, first the new growth was growing well, then this appeared a week ago...

http://img430.imageshack.us/img430/861/dsc04134oo2.jpg

I have been told that it could fusarium, what do you think?

I think I would be sick!

Thanks, Tom. That is very helpful information.

Thanks for the info, Tom!:cool: