# Problem with leaves...help..!



## biothanasis (Jul 25, 2011)

Hi all,

Does anyone have an idea why would leaves from vandaceous (and pleurothallidinae) plants fall off without any sign of decay??? Roots are fine and there is no evidence of bacterial rot, yellowing (sometimes there is though...) etc.

Could high temprature cause something like this? Should I start providing epsom salts, to help plants recover or something? What is the dosage in a litre of water? Anything else?? (cooling would be very difficult this period...)

Any help would be appreciated. TYIA


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## paphioboy (Jul 25, 2011)

Pics (of whole plant and fallen leaves)..? I have had problems with vandas, only when the root system is unhappy. They may shed up to several basal leaves and you just have to wait for the roots to recover before they regrow new leaves.


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## biothanasis (Jul 25, 2011)

Thank you for the reply! I have tossed the fallen leaves...  

I cannot provide photos at the moment as my camera's memory card is broken... Ah.... What did you do until they grew new roots?? What if all leaves fell? Was there any opportunity to put new growth or grow roots? TYIA


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## SlipperFan (Jul 25, 2011)

How are the roots on your plant?


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## Rick (Jul 25, 2011)

Vandaceous covers lots of ground for light and temperature tolerance. Low light Phalaenopsis or high light Vandas? Vanda tricolor likes warm temps, but Vanda roebelingii likes cooler temps.

Heat could be an issue for lots of Pleurothallids though.

Heat and low humidity together is even worse. What is the RH?

Yellowing and dropping older leaves in large amounts sounds like the plant may be trying to grow, and reabsorbing nutrients in the old leaves. Epsom salts would probably help, and certainly not hurt.

What is the hardness of your irrigation water?


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## Roth (Jul 26, 2011)

In my experience you can get this from poor root system and heat at the same time, combined with pythium. If the roots are actively growing and the plant is not infected all is fine. Otherwise, when the plant is stressed (poor roots) or when the heat comes, pythium resumes and kills the plant. Pythium usually stays dormant during the cooler months, which does not mean that the plant is not infected. That's why many people see 'bacterial rot' during summer time. It is not bacterial first, and second, the plants most of the time were long time infected by pythium. Leaves of phals, vandaceous, and masdevallias just drop immediately without any warning. For paphs, it makes watery areas and brownish colors. It is the same disease on different plants (paphs do not drop their leaves so the symptoms are different)


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## paphioboy (Jul 26, 2011)

Roth said:


> For paphs, it makes watery areas and brownish colors. It is the same disease on different plants (paphs do not drop their leaves so the symptoms are different)



Interesting you should say that. I thought the common 'soft rot' on paphs was caused by the bacterium Erwinia cypripedii... Pythium infection is obvious on roots (brown and mushy, basically damped off and mostly affects seedlings). If it is Pythium, you will see fine greyish fungal hyphae growing on the base of the bulb, near the rhizome... From my experience, anyway..


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## Roth (Jul 26, 2011)

paphioboy said:


> Interesting you should say that. I thought the common 'soft rot' on paphs was caused by the bacterium Erwinia cypripedii... Pythium infection is obvious on roots (brown and mushy, basically damped off and mostly affects seedlings). If it is Pythium, you will see fine greyish fungal hyphae growing on the base of the bulb, near the rhizome... From my experience, anyway..



No, the soft rot is caused by pythium and sometimes a strain of phytophthora. I made PCR analysis and that was clear.

You have good photos of pythium here:
http://www.hark-orchideen.de/Pflanzenschutz/Phythium/bilder.php?lang=en&navID=99

The tissues are very watery, disease can progress overnight.

The soft rot with mycelium is either rhizoctonia or fusarium.

Got a photo of one of those soft fungal rots here:
http://www.hark-orchideen.de/Pflanzenschutz/Sclerotium/bilder.php?lang=en&navID=99


Real erwinia cypripedii, PCR or microscope confirmed, is what makes a dry brownish color and yellow leaves, but it is never ever 'wet'. There is a picture here:







That looks exactly like that. It is never 'wet'.


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## Bjorn (Jul 26, 2011)

So, how to avoid it? Any cultural practises that would help?


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## paphioboy (Jul 26, 2011)

Thanks for the clarification, roth. This is interesting (I am interested in plant diseases ). Does that mean the common soft rot on Phalaenopsis leaves is also caused by Pythium instead of Erwinia, as stated in several books I have read? I know Pythium sp. grow very fast in vitro (fills a petri dish in 1-2 days) and also in soil, which may explain the overnight progress of disease observed... I just didn't think it would grow on 'dry' surfaces like leaf tissue, unless damage has occurred or water has pooled at the axils.


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## biothanasis (Jul 26, 2011)

Hi all,

Thank you for the nice answers... From what Roth says it must be pythium.... But how do we treat plants with it??

Also Rick has a point there... But unfortunatelly I have no idea what TDS my water has. I use tap water, which has at least stayed overnight to let the chlorine evaporate.

The problem has occured on a phal, a stereochilus (recently arrived) and all the pleurothallis I had (in the pleurothallis the symptoms are the same as described by Roth). [Let's say the pleurothallidinae are more succeptible to stress...]. The phal has silvery-white roots and almost the same are the roots of one remaining pleurothallis. The stereochilus has a couple of roots that are hiden in a thin layer of sphagnum moss, which I mounted on a piece of cork. The stereochilus lost most of its leaves in 2-3days. There is only one left on the top...What could I do to save it???

Roth, I have also lost some paphs from the same disease seen on the photos you provided. Thank you! If you know any easy to apply treatment, please let me know! TYVMIA.


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## NYEric (Jul 26, 2011)

Treat them, cool them down, and improve air flow.


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## biothanasis (Jul 26, 2011)

Unfortunatelly I do not have a way to cool them down...  So I think I will loose them and then buy others... LOL


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## Paphman910 (Jul 26, 2011)

You think it is bad to get diease on your plants. In Canada, the government have banned all systemic pesticide and fungicide for non-commercial use! It really sucks if your prized collection gets infected by rust!

Paphman910


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## biothanasis (Jul 26, 2011)

Eeemmm.... I do not think it is bad... it is the way it is... but if I can save a plant with a homemade treatment of jst improve the conditions I could offer to the plant then I think it would be nice both for me and the plant ...

Do you happen to have any problem at present with your plants?


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## Paphman910 (Jul 26, 2011)

biothanasis said:


> Eeemmm.... I do not think it is bad... it is the way it is... but if I can save a plant with a homemade treatment of jst improve the conditions I could offer to the plant then I think it would be nice both for me and the plant ...
> 
> Do you happen to have any problem at present with your plants?



Last year I had problems with losing lower leaves to rot and the rot smelled nasty. It seems to occur when the temperature got over 90 F and humidity of 95% plus just watered the plants the day before. I think lack of air flow and light caused it.

This year I don't have problem as I added a fan to circulate the air but the plants need to be watered every two days!

I think the fungi and bacterial occurs naturally in the air and around us and when the conditions are right they will thrive and destroy your orchids. 

My plants seems to be getting alot of algae growth in the last two years and the weather has been strange.

Paphman910


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## paphioboy (Jul 26, 2011)

Paphman910 said:


> You think it is bad to get diease on your plants. In Canada, the government have banned all systemic pesticide and fungicide for non-commercial use! It really sucks if your prized collection gets infected by rust!
> 
> Paphman910



Interesting. So what do you use for treating plants? Any of the organic mixtures? Neem oil? I agree with you that airflow is very important in preventing rots and other nasty things, especially in a humid climate where I live...


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## Marc (Jul 27, 2011)

paphioboy said:


> Interesting. So what do you use for treating plants? Any of the organic mixtures? Neem oil? I agree with you that airflow is very important in preventing rots and other nasty things, especially in a humid climate where I live...



Politics making the world a better place again, sigh................ :S


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## Rick (Jul 27, 2011)

biothanasis said:


> Hi all,
> 
> Also Rick has a point there... But unfortunatelly I have no idea what TDS my water has. I use tap water, which has at least stayed overnight to let the chlorine evaporate.



In the US you could go to your local health department or municipal water regulator and ask for a report. I couldn't tell you about getting reports in Greece would be like (or if you are on a well, then you would be on your own anyway).

Conductivity (TDS) meters are pretty cheap from garden centers too.

I have a pretty good paper that for agricultural plants demonstrating that disease agents are often the result of poor or imbalance nutrition (generally the ratio of K, Ca, and Mg. You could probably find a bacteria or fungus if you look for it, and might even get some positive effects with a treatment for such disease agents. But without providing the plants with the proper nutrition, you would only be providing a short term, topical, aid without fixing the underlying problem. Ultimately it would happen again farther down the line.

Check through this thread too.
http://www.slippertalk.com/forum/showthread.php?t=21871


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## biothanasis (Jul 27, 2011)

Thank you Rick!!!


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## biothanasis (Jul 28, 2011)

OK!! I found a TDS meter I purhased some years ago and found out that the water I use has 300ppm TDS. I think it is too much, isn't it? Since I cannot get a R.O. system (and I think it is wate of water), I can purchase pure water and mix it with the tap water. Any other tips?


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## Roth (Jul 28, 2011)

biothanasis said:


> OK!! I found a TDS meter I purhased some years ago and found out that the water I use has 300ppm TDS. I think it is too much, isn't it? Since I cannot get a R.O. system (and I think it is wate of water), I can purchase pure water and mix it with the tap water. Any other tips?



Well, I measured myself the water at Vacherot and Lecoufle over 15 years ago, when the plants were at the peak of their glory, and the EC was around 800. They used nitric acid ( with a pH meter that was fucked up, they fired their old lab director and nursery manager, because he was too expensive, and asked his worker to do the job, however he had no idea that the pHmeter should be calibrated, so they did everything for about 5 years with an uncalibrated pHmeter...), to get the pH to 5.7, and 1g/L Hakaphos blue (15-10-15, nitrogen nearly only ammoniacal, a bit of urea if I remember too and trace of nitrate). So the TDS apparently is not that important, at the end of the day.


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## NYEric (Jul 28, 2011)

Paphman910 said:


> You think it is bad to get diease on your plants. In Canada, the government have banned all systemic pesticide and fungicide for non-commercial use! It really sucks if your prized collection gets infected by rust!
> 
> Paphman910



Oh, I could make such a killing..:ninja:


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## biothanasis (Jul 28, 2011)

OK! I'll check the ph too...!


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## Rick (Jul 28, 2011)

biothanasis said:


> OK!! I found a TDS meter I purhased some years ago and found out that the water I use has 300ppm TDS. I think it is too much, isn't it? Since I cannot get a R.O. system (and I think it is wate of water), I can purchase pure water and mix it with the tap water. Any other tips?




300 ppm is not out of the range of what I know some succesful growers use. I would prefer about 50 - 100 (but not 0). I wasn't trying to determine if you had toxic levels of salt as opposed to getting a rough idea of the amount of calcium or magnesium in your water. Your water is probably in the "average" hardness range. Maybe around 25-40 ppm of calcium. Maybe 5 or so ppm of Mg.

So if you use a standard balanced fertilizer shooting for 100 or so ppm of N you would also be getting 100 or so ppm of K. You could afford to add more calcium and magnesium to your system to help offset those large doses of K. 

Wild plants (orchids and non orchids) rarely see environmental conditions when potassium exceeds calcium and magnesium. But it is apparent they have become very efficient at extracting K from the environment. So when we make it easy for them its easy for plants to suck up excess K which blocks out uptake of Ca and Mg. Plants then become imbalanced and susceptible to disease.


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## biothanasis (Jul 29, 2011)

Nice input Rick!!! Thank you for the advice and info...I did not had this in mind when watering and it is very crucial!!!!!!! As for fertiliser, I use 20-20-20 all year round, about every 2-3 weeks...(if I remember to...)

Epsom salts are a good source of magnesium, but is there any similar material to supplement my plants with Ca? I have both mounted and potted plants, so I would like to add something to the water to do the work..!


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## Rick (Jul 29, 2011)

biothanasis said:


> Nice input Rick!!! Thank you for the advice and info...I did not had this in mind when watering and it is very crucial!!!!!!! As for fertiliser, I use 20-20-20 all year round, about every 2-3 weeks...(if I remember to...)
> 
> Epsom salts are a good source of magnesium, but is there any similar material to supplement my plants with Ca? I have both mounted and potted plants, so I would like to add something to the water to do the work..!



Calcium nitrate.

If you kept up with that thread on Paph concolor (I think John M started it), QuietAustralian had a much different application rate for his fertilizing, which I think is appropriate for all. This cuts back the cold season feeding rate to 0. He only fertilizes during the spring summer when growth is high.

You might also consider, when you make up fertilizer use 1/3 fertilizer, 1/3 calcium nitrate, 1/3 epsom salts in the same volume of water that you would normally dilute in.

So for instance if you normally add 1 tsp per gal of dry fert then go 1/4 tsp / 1/4 tsp Calcium nitrate / 1/4 tsp of epsom salts. Not sure how easy it would be to find calcium nitrate

Something else I recently did was to disolve a small amount (1/4 tsp per gal) of EPSOMA peletized lime (that has both Ca and Mg) stabilize the dissolved in kelp extract, and then add that to a 1/2 strength batch of fertilizer. 

My strategy is still evolving for myself, and depends on my observations of plant health, but I'm thinking of eliminating my regular fertilizer during winter and just use calcium nitrate and mag sulfate sparingly during the slow time of year.


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## biothanasis (Jul 29, 2011)

Hi Rick,

Thank you fro the helpful advice!!! I supose that I will be able to find calcium nitrate (do not know if easily or difficultly...hehe..). About feeding rate during cold period, I had read this somewhere too, as the plants do not need the surplus of nutrients..they do not even use... especially urea cannot be broken down from plants during cold months (I read this somewhere here too...).


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## Paphman910 (Jul 29, 2011)

If you get Calcium nitrate, keep it in a ziploc bag to keep moisture out as it absorbs moisture readily.

I have been fertilizing with 1 teaspoon of 20-20-20 with 1 tablespoon of calcium nitrate or 1 tablespoon of epsom salt to 4 litres of water.

Paphman910


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## koshki (Jul 29, 2011)

Where do you find calcium nitrate?


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## Rick (Jul 29, 2011)

koshki said:


> Where do you find calcium nitrate?



I can think of some chemical supply places, but they don't have retail outlets. I work in a commercial lab so I can get it from work.

However, there are a couple fertilizer companies that make "Cal Mag" supplements which are usually just various combinations of calcium nitrate and magnesium sulfate. Usually they have a lot more Ca than Mg, but you could beef up with a bit more epsom salt if you feel like you need to.

Maybe DynaGrow to start. Google "Cal Mag fertilizer" and see what you come up with.

The Advanced Nutrition Micro formula was heavy on Calcium Nitrate. I'm sure it won't be too hard to find something.


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## biothanasis (Jul 30, 2011)

Paphman thank you for the recipie. It is very usefull!!! Lets hope for the best... 

(Maybe I could alternate the formula putting half tbs of each..)


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## Ozpaph (Jul 30, 2011)

koshki said:


> Where do you find calcium nitrate?


Its on EBay


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## SlipperFan (Jul 30, 2011)

koshki said:


> Where do you find calcium nitrate?



http://www.google.com/products/cata...a=X&ei=Xqk0TpO1DsrV0QGEgIHzCw&ved=0CFgQ8wIwAg


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## koshki (Jul 30, 2011)

Thanks everyone!


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## biothanasis (Aug 4, 2011)

Hi again, 

So I managed to get a pH indication for the water I use. It is 7.05. And reminding you that the TDS is 300ppm. Could I use some lemon juice to decrease the pH or what else do you suggest??? TYIA

Also supposing that I will construct a small gh for my orchids, I will use automated misting system. Do you suggest that I use water collected in a container and then watering the plants with is with the misting system (more difficult to construct...), or just use the water directly from the water supply (easier to install...)? I am thinking the first one, as I could mix in the water several necessary compounds (fertiliser, epsom salts, calcium nitrate), but could I use these on the plants with manual supplemental watering on specific time periods per month??? TYIA


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