brown rot pandemic

[Lmpgs]

One more question on this subject

Recently, I lost 3 plants of these symptoms. 1 Phragm. Olaf Gruss, just bought from Ecuagenera, 1 Paph. delenati vinicolor (bought last summer from Popow, DE) and 1 phragm. Cape Bonanza from Wubben NL (almost dead - 1 growth only still alive but affected). I'm wondering if chemicals can bring good results. Eg. Previcur of Bayer Crop Science Propamocarb hydrochloride 72,2%.

-Can chemicals cause major damages to my plants? (the specific one),
-Could I use it for prevention?

Thank you

 

[Brabantia]

Because we are around the subject "Induced Defense Plant Response". Has somebody tested the effect of the laminarin on our orchids? Laminarin is an elicitor extracted from the brown algae. But maybe this subject can be a title for a new thread.

 

[TyroneGenade]

the molar mass of salysilic acid is 138 g/mol

so 9mM solution is 1.25 g/L which is 4.7 g/gallon

Thanks, Rick. I'm an old biochemist and you saved me some tedious math. :clap:

The CaSO4 top-dress isn't a bad idea. Otherwise, I can just have a slurry in my watering can. It reaches about 0.2 g/ 100 mL so the Ca would be definitely in excess.

Any idea on how this would effect Restrepia and Tolumnia? Everyone gets water out of the same can... Not a lot of time in the morning to specially water everyone.

About my fertilizer regime: Osmocoate around the plants (or for the Paphs, along the inner edge of the pot) and some Kelpack every other week. Most plants are potted in crushed brick and the plants watered daily (unless it rains) in the warm months. There is some fine milled bark among the brick---something organic to hold a little water.

 

[Rick]

I've also been growing some restrepias for several years. I don't think they are a big fan of significant TDS levels. I started seeing some black spotting on the leaves when I boosted Ca for them (in conjunction with everything else), so I upped the Mg sulfate ratio a bit more and this seemed to help.

I believe Osmocoat has a balanced NPK, but it is slow release. You might consider checking some pot conductivity levels for TDS buildup. I was really surprised when I checked one of my semi hydro phrags in Hydroton clay balls how much salt was getting retained in that matrix even though I primarily water with RO.

I've been flushing/replacing the sump water a few times a week since, and brought the conductivity down from around 700 useimens to 350.

 

[TyroneGenade]

Thanks for the advice, Rick. My water is very soft to start with so I will see how it goes when I start adding Ca. If the Restrepia complain then I will have to make a different plan.

Thanks

 

[bullsie]

I always have a bit of a problem with this type rot several months after my plants have been brought in from the outside. Since I windowsill grow I have noticed that my darkest days are my most 'lethal' days. I try to keep a wary eye on the plants then and work to keep air flow good and usually try to spray periodically with Physan to help. And when it strikes to remove plants and peroxide them leaving them in quaranteen. Sometimes I save them sometimes not.

Oh, and the younger my Cattleyas, say 2" pot size for standards (or plants I've acquired that were old, 30+ yrs), the more apt they are to be affected or infected.

I will try the ca mg route as has been suggested. I hate losing plants to this menace. I'm also going to try a cinnamon spray and see if that helps.

 

[TyroneGenade]

I've been growing some Brachy's indoors on the kitchen 'sill and have had no problems with them... It seems this is a summer problem. I wonder if there isn't some fly buzzing about biting the plants and letting the infection in.

I'm going spray everything with asprin and water with CaSO4.

That said, while all the Masdevallia have rotted away the Restrepia and Tolumnia have done the best, chiefly because I keep them drier (yes, the Restrepia are drier in there clay pots) so it could be a moisture issue.

 

[ericst11]

The best thing i have ran across for any rot that works great on my orchids is pageant fungicide .I use it on all my stuff and stops most rot and diseases in its tracks and i grow everything from pleurothallis to Catt's about 300 different species. check it out costly but goes a long way and isn't even close to as bad as most fungicides for you or your plants. Heres a link it took a lot of research to find it. http://betterplants.basf.us/products/pageant-intrinsic-brand-fungicide.html

P.S if you really want to try it i would send you a little to see if it would save your plants.

 

[TyroneGenade]

Well, I have sprayed with asprin twice now. Seems some of the young tender leaves of some of the Oncidium hybrids are still suffering but for the most part the epidemic has stopped. Sadly, my Gege Hughes didn't make it.

 

[SlipperKing]

That's good but bad news at the same time. Sorry about the G. Hughes but sounds like the asprin cleared up your headache as well as the plants.
I tried the aspirn on a few problems as well but wasn't certain it did anything or if the rot had just run its course. Thanks for the update Tyrone.

 

[Erythrone]

I tried aspirin too and I did not see any evidence that it did anything too. I had better results trying to find the best growing conditions for my plants

 

[TyroneGenade]

Curses! I spoke too soon. Checked on some new growths from my mini Catts and the new growths had rotted back. Even of my Trick or Treat which is as tough as nails (I roasted it in the noon day sun last year and still just carried on). Seems it is mostly new growth which is affected. Again, the Restrepia seem fine as is the Masd. tovarensis (the sole survivor of my Masdi collection). I'm told the tovarensis prefers to be dryier... but the Restrepia want humidity so I can't see this as a humidity problem or being too wet.

So much for the asprin. And the Catts are in crushed brick which is heavy on the lime and drains very freely so it can't be a Ca/Mg problem either.

I thought that maybe my old spray bottle or watering can was carrying the pathogen (darn organic fertilizer rubbish!) but I have replaced either and switched fertilizer. I don't think this is Erwinia. Maybe it is a fungus?

 

[cnycharles]

an induced response from aspirin may not work right away, just thinking... also are you sure there hasn't been any change to your water supply, like it's getting saltier or more chlorine, or the chlorine has been changed to chloramine? (or just some other previously non-present water condition that has now changed)
I read here or somewhere where a water supply had changed their disinfectant to chloramine from chlorine, and it had a detrimental affect on their plants. also there may have been some contamination to a chemical that you used previously (like the benlate contamination years ago) that has messed up your plants

although thinking back on your posts if some of the above I listed was the case, it would affect the restrepias as well or worse (just trying to think around corners a bit)

 

[Rick]

an induced response from aspirin may not work right away, just thinking...

Yes

Erwinia rots are something very difficult to "cure", and with orchids it may take a year or so to get the foliage tough enough to withstand the assaults.

The K/Ca balance in tissue is not something that can be fixed after the growth has been developed.

So often the plant will need to turn over a bunch of growths under a different growing regime before you get resistant growths.

 

[Rick]

And the Catts are in crushed brick which is heavy on the lime and drains very freely so it can't be a Ca/Mg problem either.

I don't think this is Erwinia. Maybe it is a fungus?

Brick is typically fired clay, so not sure what this has to do with lime/Ca

Erwinia is pretty obvious with its sickly/sweet/fermenting like smell. Actually I've never seen it on a Catt before.

I've had black rots (also bacterial) taking out new growths on Catts. Generally new ones that were just acquired. The last time was for a newly obtained and potted Portia (in plain bark, but with styrofoam peanuts to make the growth shallow). After getting a bunch of new growths rot off I added a liberal top dressing of "Cichlid Sand". It put out a flush of new roots over the surface of the bark, and then all subsequent new growths came out fine.

 

[SlipperFan]

Yes

Erwinia rots are something very difficult to "cure", and with orchids it may take a year or so to get the foliage tough enough to withstand the assaults.

The K/Ca balance in tissue is not something that can be fixed after the growth has been developed.

So often the plant will need to turn over a bunch of growths under a different growing regime before you get resistant growths.

I'm glad you posted this because, although I've been using K-lite for several months now, I still have battles with erwinia. Not as bad, I must say, but still fighting it.

 

[Rick]

I'm glad you posted this because, although I've been using K-lite for several months now, I still have battles with erwinia. Not as bad, I must say, but still fighting it.

Yup

The biggest problem is calcium uptake. K will generally trump the uptake of Ca and Mg when present, and once Ca is really hard/slow to get into plants in the first place. Once a leaf is matured, it can't Ca anyway (although K and Mg are still mobile). So you are kind of stuck waiting for the new leaves and growths to dominate the plants.

The asprin may help toughen up the older leaves and growths in the meantime. Since it seems to be pretty mobile in the plant.

 

[TyroneGenade]

Brick is typically fired clay, so not sure what this has to do with lime/Ca

We have lovely white clay rich in lime so the bricks tend to be very alkaline. I must admit that maybe this is still a problem and a top dress with CaSO4 is still a good idea. It surely can't do any harm now.

Thanks

 

[keithrs]

I personally dont think that Ca/Mg or aspirin will fix the problem if it already in the plant(s). I think a more aggressive approach is going to have to be taken. I think you'll need to use a systemic fungicide several times if your going to have any chance. Spray everything around your grow area. After you have fixed your rot problem(fingers crossed) than you can use a preventer like physan 20 or what I like is trichoderma and bacterial products like Sub Culture B. I had rot problems for a long time and these is how I have pretty much solved it. I tried using the high Ca/Mg rout without use SubC and I started to see problems come back.

I feel your pain and wish you luck!!!

 

[Erythrone]

keithrs, why use a fungicide if it is bacterial rot?