How to prevent erwinia?

[dodidoki]

I treat with orchids for about 30 years.With slippers for about ten.I think the most devastating danger for slippers is Erwinia.I have not had it for 2 years.Now i noticed it in early stage on 2 of my plants.It begins the outest and lowerest leaf at the base as a brownish orange wet spot and spreading rapidly not just toward the affected leaf but inside the base of the crown( to the heart of plant).I know it can be stopped maybe with dragoon blood.I tried it without succes.My experience is that if a plant got erwinia, will die.Can be treated and maybe stopped disease for a while, but this beast will kill plant with time.My question to growers who never had it: how to do?

 

[Ozpaph]

All I can add is that it seems to occur mostly after a particularly hot weather period. I assume the excessive heat either weakens the plant to allow infection or 'supercharges' the pathogen.
I strip off all the infected parts ASAP - dragons blood and cinnamon and then spray all the plants with systemic fungicide +/- Physan. Some of them do survive.....

 

[Duck Slipper]

When I have had rot, I think it could have been prevented. Some of the rot issues are when I am out of town, and someone is taking care of the orchids. Plants are indiscriminately watered, late in the day. If I have to water late in the day, pot water only, no water on foliage. I normally water first thing in the morning, by evening there is no water left on the foliage. Duck

 

[dodidoki]

Plants get sometimes heavy rain day by day, all the day and night in nature and they have no rot problem.I use Ro water.It does not contain bacteria, theoretically.I use 400 uS fertilizer solution, always been measured.Rot affects not only weak plants but sometimes srtong healthy plants and new leading growths get sick more frequently.

 

[Ray]

The bacterium does not necessarily have to be in the irrigation water; it can come in as an airborne disease too, but water splashing from one plant to the next is a "great" way to spread it! A droplet of water just sitting there can become an incubator.

Increasing air movement to dry the plants can certainly help, as can the use of a disinfectant spray.

 

[NYEric]

I use Dragon's Blood, distillate of croton lechleri, topically. If it doesn't stop it, because I found it too late, I pull the affected leaf off and put DB or Captan on the wound. Also, keep drier and increase air flow.

 

[tomkalina]

I agree with Ozpaph on this one. The few times we've had to deal with erwinia, the infection always seemed to coincide with a prolonged hot spell, with day temps in the mid to upper 80's F (60-62 C) and night temps between 75F and 80F (54-57 C). The combination of Dragon's Blood and Cinnamon seems to work best after removing the infected part. If the disease has spread to the crown of the plant it's probably not savable.

 

[Carper]

I did use to get erwinia most years but through a few adjustments to the culture, very rarely does it raise up. I also lessened my food strength to around 400 u/S and do not foliar feed. The strength also gets adjusted, ie weakened during the winter periods to around 200 u/S or less to compensate for the low light/short days as do not supplement lighting. I also ensure that there is no excess water/feed in the lower leaf axles overnight. My humidity is also lower at around 50% most of the time, with good air circulation and have seen no negative effects on any of my plants. I also add a small amount of physan to my RO tanks periodically. I have worked on prevention as opposed to a cure. I do have Dragon's Blood and cinnamen but never really had success in saving a plant affected by it, so just use them when any signs of infection appear anywhere on the plant however small. My plants get inspected every day, which also helps in keeping them healthy. I understand everyone's culture is different and mine is obviously different to match our climate in the UK. These are simple adjustments brought into my existing culture over time as no one wants to lose a growth or plant, especially how long they take to mature or the amount of care given.

Gary

 

[SuperPaph]

Erwinia usually appears in my collection during april-may, so I avoid it apling Phaysan, but if any plant surprises me with the typical dark spot, I apply Phyton quickly.

 

[Ray]

I had erwinia on an expensive phal clone once. I unpotted it and soaked it overnight in a 1:50 Inocucor solution then sprayed it with that a couple times a day. Within 3-4 days, it was stopped cold.

 

[Elite Orchids]

we spray hydrogen peroxide at either 3 or 9% and find it is fantastic at killing Erwinia. Unless it is in the crown - we then treat with a 40% solution and we find a side growth often starts.

 

[SuperPaph]

we spray hydrogen peroxide at either 3 or 9% and find it is fantastic at killing Erwinia. Unless it is in the crown - we then treat with a 40% solution and we find a side growth often starts.

I will keep this procedure in mind!!!!

 

[troy]

It pops up during prolonged heat spells

 

[My Green Pets]

Erwinia usually appears in my collection during april-may, so I avoid it apling Phaysan, but if any plant surprises me with the typical dark spot, I apply Phyton quickly.

Wow, same! I just found a nasty streak of brown wetness halfway up the bottommost leaf of my dear Paph Michael Koopowitz. I pulled the leaf off and sprayed rubbing alcohol on the wound and surrounding leaves. I would like to try the hydrogen peroxide spray but unfortunately, all such disinfectants are all sold out in stores at the moment!

 

[Upfeng]

we spray hydrogen peroxide at either 3 or 9% and find it is fantastic at killing Erwinia. Unless it is in the crown - we then treat with a 40% solution and we find a side growth often starts.

Hi Marc,
a 40% solution of hydrogen peroxide is not available on the market because Hydrogen peroxide is a very unstable compound at this concentration. Could it be that you mean a 4% solution?

 

[Ray]

40% hydrogen peroxide is available, is stabilized differently than the 3% stuff sold in drug stores, and is corrosive as hell! It would kill any plant it was applied to.

I used to work with 50% grade routinely.

Look into Biosafe Disease Control. It is about 0.3% hydrogen peroxide that is stabilized with peroxyacetic acid. Drugstore peroxide is stabilized with stannous chloride, and decomposes instantly upon contact, leave a pool of water. The Biosafe product stays chemically active until it is dry, so is much more effective, even at its lower concentration.

I know that regular treatment of your collection with probiotics is a reliable way to prevent such diseases from happening in the first place. I was a big fan of the Inocucor product, but the Quantum ones seem to offer similar protection.

 

[Phaladdict]

I use bacillus subtilis and amyloliquefaciens, first one commercial name is serenade it works also against pseudomonas and other bacteria as well as fungi always as preventative

 

[Elite Orchids]

Hi Marc,
a 40% solution of hydrogen peroxide is not available on the market because Hydrogen peroxide is a very unstable compound at this concentration. Could it be that you mean a 4% solution?

hi, it is actually 50% solution we use - it is stabilized with silver. it requires extreme caution and we only use it in specific situations with gloves and goggles - we simply use a pipette and drop single drops into the crown - should erwinia have got that far. it saves approx 75% of the plants with rot in the crown.

 

[gego]

This was mentioned in the AOS magazine before but I have been using this and most of the time if caught early when small you may even save the infected leaf. I use Neutrogena for stubborn Acne. It is basically a benzoyl peroxide. Just use a cotton bud and apply around the infected part. If it is already inside the tissue creeping up, i just cut the leaf then apply alcohol,,dry, then apply this cream. Some infection does start from within specially with specimen plants. I just cut that growth to the base and apply the cream on the cut and let it sip in. Let it dry for at least three days.

 

[awesomei]

Thank you all very much! I have gotten erwina a few times and have always lost my plant. I am go to follow your advice.