How to prevent erwinia?

[spujr]

I just had a thought for what it might be worth.
I am no Paphiopedilum expert like so many of you are. I am just an old school grower who does not like to use chemicals on anything. I have grown a good number of Paphs in my time and I can honestly say that I never have suspected that I lost a single plant to Erwinia. Not a one. And the only thing I can suggest is that I have always tried to keep water out of the 'crowns' of the slippers. I pot water from above but very carefully. I use a watering wand with a narrow head. And along with that I have always used an abundance of air movement. I like a light breeze blowing right over the tops of the plants. Now that I am 6 years under lights here in Michigan, the fans are on the same timers with the lights. I too water early in the day.
The only other thing I can add is plant spacing. Good air movement over plants that are spaced too tightly, too close together might hinder or block what you might think is good air movement. In Florida out of doors where the Paphs' got water in the crowns all of the time from rain showers, I did not lose any there either. I was there 9 years. Why do I think that was? Very good air movement and plant spacing.

I completely agree with you on these points. In principal, air movement and proper watering should greatly help reduce rot problems.

However, consider a moment this video from Paph Paradise on "how to water Paphiopedilums": How to Water Orchids

As you can see here, the plants are quite close and for sure water is getting into the crown of most of these. Yet this does not seem to cause erwinia problems for them. Is it the solar radiation, pH, or something else?

As I mentioned earlier, I'm watering first thing in the morning with a lot of air movement shortly after. I live pretty close to Paph Paradise so relative humidity is similar and my plants are not as crowded as seen in this video. I feel like there is something more than just avoid getting the foliage/crown wet.

I'm curious about the oxygen levels in the water. I recently added a bubbler to the water tank thinking that the extra oxygen might help reduce erwinia problems. I have doubts it will help but pretty sure it won't hurt to try!

 

[spujr]

The biological product that works best for me is called Actinovate. It's Streptomyces lydicus.

Erwinia is not one of the diseases listed on its label. But, it does list many other problematic species like Botrytis and Fusarium as well as various leaf spotting diseases so it's a useful product just from that standpoint. Despite not being officially listed, I've found Actinovate to be very effective for control of Erwinia in my collection. It doesn't mean I don't still get the occaisonal Erwinia rot on susceptible plants, but I have seen a dramatic improvement.

Actinovate has one (in my opinion) major advantage over Serenade and the stuff that Ray sells (both of which I have tried multiple times): I can use it more preventatively on my indoor collection than the other products, which might explain why I have more success with this product than the others.

Actinovate is completely odorless (it's a powder you mix with water), whereas the awful smell of the other products I've tried make them unsuitable for me to use. I can handle the stench, but the other members of my household cannot, and it's frankly embarassing to have guests over when my house smells like stinky athletic sneakers (Serenade) or putrid garbage funk (Ray's product).

The main downsides to Actinovate for me, are the fact that it's expensive and it can sometimes be hard to find for sale, as many vendors run out of stock on a somewhat frequent basis. As for the expense, it's actually not terrible when you consider it on a per dose / per application level, but the stuff is fairly expensive to buy by the packet.

The reason I tried Actinovate (whether scientifically solid or not): Agricultural streptomycin (antibiotic) is very effective at controlling Erwinia. I have used it in very limited quantities in my collection as a last resort, but I was not really comfortable using an antibiotic indoors like this. My theory was, since Actinovate contains a species of Streptomyces (the genus for which streptomycin is named), there was a chance that it would provide more targeted and "natural" antibiotic control of gram negative bacteria like Eriwnia.

I'm going to investigate this. Thanks for the suggestion!

 

[spujr]

Hello,
I am a retired dentist. I have found Chlorohexadine to be very effectine in the human. I was wondering how it might be for plant diseases??? Just a curious thought.
George

I did some googling on this and it seems to have come up as an option to help control plant diseases but it is still unknown if toxic (and at what level) to plants.

 

[mrhappyrotter]

I'm going to investigate this. Thanks for the suggestion!

You're welcome, hope it helps!

I use it at a rate of 0.5 to 1 tsp per gallon (lower rate for preventative, higher rate if there's been some confirmed Erwinia or other disease recently and/or if I'm spot treating a plant with troubling symptoms). I also periodically soak it into the potting mix, since it can be used as a foliar spray as well as a drench.

I try to treat once a month or once every other month with Actinovate as a general preventative. I do also sometimes rotate in Serenade, but it really does have a gross and lingering odor, so I make limited use of that product indoors.

I have mentioned my use of Actinovate before on Slippertalk and elsewhere, but I don't recall anybody else responding that they are using it. So, if you do decide to get some and try it out, I'll be interested to see how it works for you. Keep me in mind, whether it works or not for you, I'm interested to know.

 

[SuperPaph]

My experience here shows a big relation between watering and days with more than 80 % humedity. Usually during the transit of winter to spring (march-april). Now I apply Phyton when high humedity, mustly during rainy nights.
My conditions are different maybe to all yours, I grow my Paphs out there, under ceiling. And I do control the watering, been sometimes more than five days without doing it (usually I water em each two days). Hope this help.

 

[awesomei]

My experience here shows a big relation between watering and days with more than 80 % humedity. Usually during the transit of winter to spring (march-april). Now I apply Phyton when high humedity, mustly during rainy nights.
My conditions are different maybe to all yours, I grow my Paphs out there, under ceiling. And I do control the watering, been sometimes more than five days without doing it (usually I water em each two days). Hope this help.

Which Phyton???
I use Pyton 27 to combat Erwinia and other resistant fungal infections.

 

[Ray]

Try regular use of probiotics…

 

[awesomei]

Try regular use of probiotics…

Such as???

 

[spujr]

My experience here shows a big relation between watering and days with more than 80 % humedity. Usually during the transit of winter to spring (march-april). Now I apply Phyton when high humedity, mustly during rainy nights.
My conditions are different maybe to all yours, I grow my Paphs out there, under ceiling. And I do control the watering, been sometimes more than five days without doing it (usually I water em each two days). Hope this help.

I think you are right.

And it is interesting to think what is going on in the spring versus other times of the year:
1. Large day- night temperature differentials.
2. Flush of growth from plants.

The increase growth probably means certain nutrients that are less mobile are deficient in the new leaves, such as calcium. This might make the new cells more susceptible to pathogen invasion.

 

[Ray]

Such as???

I think any formulation can help, and the greater number of species in the formulation, the better.

I have used both Inocucor Garden Solution (a.k.a Synergro) and Quantum-Total (which contains both species mentioned earlier, Bacillus subtilis and B. amyloliquefaciens, among several others).

 

[Joost]

iodoine will help as well

 

[spujr]

iodoine will help as well

Is there a recommended dosage?

 

[Ray]

I would think iodine would be a curative treatment, not preventive, and honestly, have no idea of its phytotoxicity.

However, I would think it would effectively wipe out all microbes in the rhizosphere, good and bad.

 

[SuperPaph]

I use Phyton 27.
Would like to have experience using probiotics, but those doesnt exist here!!!! Lol!!!