Troubles with sect. Pardalopetalum

[bulolo]

Hi everyone,
It seems that I have the most troubles with section Pardalopetalum rotting. I think it's Erwinia. The rot is smelly moist looking and starts at the bottom of leaves and if not caught quick enough it will take the whole growth/plant quickly. I've had this on my lowii, richardianum, haynaldianum, and now my parishii. These were all blooming size plants. I hand water all my paphs so that I know that no water gets in the leaves. These plants also get fairly dry before I water. I have them planted in fir bark, coarse perlite, charcoal, and a little NZ Sphag moss. I also grow under flourescent lights in the basement where it's about roughly 75F for a high and have an oscillating fan that runs 24/7. Can anyone else give me direction on growing these guys or at least keeping Erwinia at bay? Thanks!!!

 

[troy]

Do you have daily air exchange? sphagum moss holds alot of moisture, you need to let your plants almost dry before watering, also your high temp is my night time low, overfertilising also causes rot, usually rot sets in from some kind of stress, hope that helps

 

[abax]

I suggest you obtain some Dragon's Blood to stop the rot/
erwinia while you figure out what's causing the rot and
correct whatever it might be. As an after thought, I think I'd
drop the sphagnum in the potting mix. Maybe the mix is staying
too wet down in the pot

 

[Stone]

I think bacterial rot (are you sure that's what it is? Could be pythium) is not really a product of excess moisture in the medium. And if you let them dry a bit I would say it definitely is not in your case.
Sounds like you just have the pathogen ''set'' up and spreading around.
I would drench the roots in a fungicide specific to Pythium and Phytophthora.
I'm sure you can get you hands on something. Also, if you can get it, a good thorough spray of Chlorothalonil on the leaves will help with bacteria. You could have brought in the disease from the bark (most likely) or the sphag or the charcoal. How about the water?

If you don't want to use chems.....good luck!

 

[dodidoki]

I noticed that in the past when I used RO water for waterings , Erwinia rot was more frequent. I changed to RO+hard water 2/1 for 2 years and rot is extermely rare.(1 or maybe 2 plants/ year). Another -sad- observation about Erwinia that this state is incurable, all plants infected by Erw., died, despite of many efforts. ( cinammon, dragon's blood, merbromine)

 

[Justin]

Do you use RO water? My problems stopped when i upped the Calcium by going back to tapwater.

 

[Gilda]

I noticed that in the past when I used RO water for waterings , Erwinia rot was more frequent. I changed to RO+hard water 2/1 for 2 years and rot is extermely rare.(1 or maybe 2 plants/ year). Another -sad- observation about Erwinia that this state is incurable, all plants infected by Erw., died, despite of many efforts. ( cinammon, dragon's blood, merbromine)

I changed to half rain, half tap. A grower told me that he saw more rot with rain water . He switched back to city or well, and had no rot problems.

Since we've been under the heat wave, I've done NO fertilizing and am watching things like a hawk. I've seen more rot this year with the heat..only on new growths on some phrags.

 

[dodidoki]

I changed to half rain, half tap. A grower told me that he saw more rot with rain water . He switched back to city or well, and had no rot problems.

Since we've been under the heat wave, I've done NO fertilizing and am watching things like a hawk. I've seen more rot this year with the heat..only on new growths on some phrags.

Tap water is very hard here, cca 14 German degrees ( ppm is cca 450 ) so I use only 1/3 part with 2/3 part RO.

 

[Brabantia]

Tap water is very hard here, cca 14 German degrees ( ppm is cca 450 ) so I use only 1/3 part with 2/3 part RO.

With this quantity of tap water add how many fertilyser can you put in this mix taking into account to keep an acceptable range of conductivity for Paph and Phragmipedium ?

 

[dodidoki]

With this quantity of tap water add how many fertilyser can you put in this mix taking into account to keep an acceptable range of conductivity for Paph and Phragmipedium ?

Eg.: if I'd like to get 40 ppm N, I add 60 ppm N to 66 L RO water than I dilute this with 33 L tap water. There are CaHCO3 and MgHCO3 here in tap water.

 

[gego]

Do you use RO water? My problems stopped when i upped the Calcium by going back to tapwater.

Are you positive the lack of calcium is the cause?

 

[Stone]

This is what I think happens (or at least can happen) with rain water. Birds pick up pathogens from the ground land on the roof, deposit them there, you collect the water and water your plants. Bingo, you have introduced them.
I got a problem with rain water but it was not erwinia it was anthracnose which is very common in the environment. (It's the brown patches on your apricots) Now it's either tap water or
rain water heated to 70C first. The more I think about using rainwater, the more I think it's too much of a pain to worry about! (Unless your tap water is complete crap of course)

It's easy enough to add lime to your water or you p/mix if you're worried about the lack of Ca in rain water.

 

[Brabantia]

Eg.: if I'd like to get 40 ppm N, I add 60 ppm N to 66 L RO water than I dilute this with 33 L tap water. There are CaHCO3 and MgHCO3 here in tap water.

Have you data for of your final dilution ? Conductivity (micro siemens) or TDS ?