Is this Fusarium?-phal

[Egrigby]

Philip,

First, I want to thank you for taking this time with me. I know you do not have to, and I appreciate that. To answer your questions:

Growing environment:
Sun room attached to the kitchen. Window on three sides, for to ceiling. The windows face SE,E, and NE. Humidity is 40-50%. Temp steady 72 degrees.

Media: This phalaenopsis​ was in semihydroponic using First Rays instructions. I have several still in bark because they are not ready to transition. I use a bamboo skewer to check more on those.

Fertilizer: miracle grow orchid fertilizer 1/4 strength in zero tds water. Epsom Salt and calcium in leca soak. Kelpmax used once for all orchids X3 waterings. This phalaenopsis got a good soak in it.

Use of peroxide: at repotting on all plants and on this phalaenopsis at least three other times due to what I thought was stem rot.

Scenario: The phalaenopsis in question had a dear section of stem with what I thought was black rot. The roots on the green living tissue above the "diseased" area had black collars at the base which eventually rotted killing the entire root. New roots would grow only to die at about 2 inches every time. Eventually they started dying shorter, and the past super producing roots.

Here is an image of the roots in better days which shows the black on the roots and some of the black on the stem
Elaine

[King_of_orchid_growing:)]

Hi Elaine. Unfortunately, something happened to your pic. It didn't show up.

I already spot one problem - the relative humidity. It is too low. 40% - 50% is too low a humidity for Phals. It's gotta be at least 60% and up. Preferably the humidity should be closer to 80% - 90% as this is the humidity that many wild Phal species grow in. 80% - 90% is the ideal. 60% - 80% is actually tolerated quite well.

Wild Phals usually grow in pretty wet areas. Some of them are actually found in swamp forests. If you go on YouTube, type in a search for "Phalaenopsis wild", you will find a short video of how Phals actually grow in the wild. They are usually growing on trees that do not have any moss or have very little moss on it, so the roots are exposed to a lot of air and light. The regions they grow in are not only wet, but it is very humid, (80% - 100%). The bark of the trees are usually consistently moist, not sopping wet. The natural range for a Phal are usually in tropical areas, (not always), such as Taiwan, southern parts of China, Vietnam, The Philippines, Laos, Thailand, Cambodia, Malaysia, Indonesia, and Papua New Guinea.

Visiting Phalaenopsis cornucervi (orchid) habitat in the swamp of Borneo-part 1 - YouTube

Visiting Phalaenopsis cornucervi (orchid) habitat in the swamp of Borneo-part 2 - YouTube

Visiting Phalaenopsis cornucervi (orchid) habitat in the swamp of Borneo-part 3 - YouTube

Visiting Phalaenopsis cornucervi (orchid) habitat in the swamp of Borneo-part 4 - YouTube

Visiting Phalaenopsis cornucervi (orchid) habitat in the swamp of Borneo-part 5 - YouTube

The temperature is ok. In order for Phals to bloom, there needs to be a temperature differential of about 10 F - 20 F. It has been scientifically proven that it is a rise in temperatures that triggers the blooming process, not the drop of it. Steady temperatures will not produce blooms. Blooming a plant is reserved for healthy specimens, not sick ones.

This scientific article describes the trigger for Phals blooming:

Temperature during the day, but not during the night, controls flowering of Phalaenopsis orchids | Journal of Experimental Botany | Oxford Academic

This knowledge of temperature differentials initiating bloom spikes is how nurseries seem to get Phals to bloom all year round, when most really only bloom once a year.

Also, Phal hybrids are fine in temperatures of 60 F - 90 F. If you are going for some of the species, (particularly the soft, light-green leafed species such as Phal bellina), the low end temperature of the range has gotta be 65 F - 70 F.

I don't know what to tell you in regards to growing in semi-hydoponics. I do not use such a method. Perhaps when you tried to grow the plant in SH, even as per instructed, it didn't adjust well to it, I'm just not sure what to say about this.

I personally don't think it is necessary to use peroxide on the plant itself during a repotting, but if you want to use peroxide on the pots, that shouldn't be a problem. Peroxide loses its potency minutes after exposure to air, so you should be safe using the pots again shortly. After a while, it just becomes water and releases oxygen (O2). The chemical formula for hydrogen peroxide is H2O2, (2 hydrogen atoms, 2 oxygen atoms bonded together).

Here's the chemistry:

2H2O2 = 2H2O + O2

If you click on this link, you will find a photo of a person's fingers after exposure to the oxidizing effects of hydrogen peroxide. This is why I did not recommend repeated use of hydrogen peroxide on your plants.

Hydrogen peroxide - Wikipedia

In the photo, the person's fingers were treated with 35% hydrogen peroxide, which is admittedly very powerful compared to the over-the-counter 1% or 3% solutions, but they all do the same thing, just at different potencies - they kill cells through oxidative stress.

The efficacy of H2O2 depends not only on the concentration of the hydrogen peroxide solution, but also on the organisms being affected and the contact time that these organisms have with the chemical. To put it simply, different "bugs", different contact times, depending on concentration of the peroxide.

This is an easy to read article talking about how hydrogen peroxide kills cells.

Why Does Hydrogen Peroxide Fizz On Cuts?

H2O2 does not discriminate between fungi, bacteria, or cells belonging to your orchids, it just kills cells through oxidative stress.

I'm going to keep it simple for as many people as possible to understand the process of oxidative stress...

Reactive oxygen atoms steal electrons from the atoms from the cells when they come into contact with each other. Because oxygen stole electrons to satisfy its electron needs, the oxygen atom is happy, but the atoms belonging to the cells are not. This loss of electrons causes cellular damage, and eventually the death of the cell.

Here's a video that I think describes oxidative stress simply.

Oxidative stress explained - YouTube

This video shows what oxidative stress does to a cell:

What is Free Radical Damage? - YouTube

[Egrigby]

I can not do anything to raise the humidity in the house because of health issues. I do have several that are doing well, one putting out about ten new roots currently. Would keeping them on the heating mat and turning it off in the evening create the appropriate temperature change? I currently use it for adjustment to semihydroponic. It raises the temp inside the pot to about 85 degrees F. It should drop to about 72 degrees F. by morning. I imagine I could also move them outside in the evening, but that does increase the risk of insects. I have a covered Lanai on the east side of the house and live in Raleigh,NC, USA.

I have some questions?
At what point do you sanitize the roots of an orchid when repotting? Would I be better not to sanitize them at all?

My local orchid shop advised me not to repot orchids I buy from them for one to two years, most advice in books, blogs and posts tells me the opposite.?

I am reading the cultures for general phalaenopsis, and Oncidium and Oncidium Intergenetics. I am scared, and tentative. I want to learn to properly take care of these beautiful plants. My ability to change the environment is limited as my husband and I both have autoimmune disease. It is possible that phalaenopsis are not the right orchid for me, and another would be a better fit culturally.

---------- Post added at 10:49 AM ---------- Previous post was at 10:38 AM ----------

Originally Posted by King_of_orchid_growing:)

The efficacy of H2O2 depends not only on the concentration of the hydrogen peroxide solution, but also on the organisms being affected and the contact time that these organisms have with the chemical. To put it simply, different "bugs", different contact times, depending on concentration of the peroxide.

This is an easy to read article talking about how hydrogen peroxide kills cells.

Why Does Hydrogen Peroxide Fizz On Cuts?

H2O2 does not discriminate between fungi, bacteria, or cells belonging to your orchids, it

I'm going to keep it simple for as many people as possible to understand the process of oxidative stress...

Reactive oxygen atoms steals electrons from the atoms from the cells when they come into contact with each other. Because oxygen stole electrons to satisfy its electron needs, the oxygen atom is happy, but the atoms belonging to the cells are not. This loss of electrons causes cellular damage, and eventually the death of the cell.

Philip,
What a great explanation! If I'm understanding correctly, as we would titrate medication for age, weight, and state of health, so the strength of the peroxide must be titrated for the organism it is being applied to, not just intended to kill.

As well, your description of the electrons is an excellent demonstration of the molecular damage done, physics can not be denied.

Thank you

[King_of_orchid_growing:)]

Originally Posted by Egrigby

I can not do anything to raise the humidity in the house because of health issues. I do have several that are doing well, one putting out about ten new roots currently. Would keeping them on the heating mat and turning it off in the evening create the appropriate temperature change? I currently use it for adjustment to semihydroponic. It raises the temp inside the pot to about 85 degrees F. It should drop to about 72 degrees F. by morning. I imagine I could also move them outside in the evening, but that does increase the risk of insects. I have a covered Lanai on the east side of the house and live in Raleigh,NC, USA.

That temperature change sounds adequate enough. Try it out.

If your other orchids are not suffering from root problems, then continue on. There must be something to their liking the way they are grown.

Originally Posted by Egrigby

I have some questions?
At what point do you sanitize the roots of an orchid when repotting? Would I be better not to sanitize them at all?

It is really not necessary to sanitize orchid roots. They have an immune system to deal with disease organisms when they are healthy.

The problem arises when their immune system is down, and they get an infection from disease organisms. That is when you can try to help the orchid out.

Cinnamon is not recommended to be put on roots because it chemically contains a desiccating compound called cinnamaldehyde. Incidentally, cinnamaldehyde is also the chemical that has the anti-fungal or anti-bacterial properties. The problem with cinnamaldehyde coming into contact with roots is mostly because of the desiccation properties of the chemical. A plant's roots are sensitive to this kind of chemical desiccation.

Usually the best method of removing diseased roots to prevent further spread of disease, (other than correcting for environmental factors causing the orchid stress), is to make a sterilized cut at least 1/2" into healthy tissue above the line of infection. You may choose to seal the wound with heat or peroxide. I prefer heat to seal a wound. Others may have their own opinions.

Continual use of peroxide for preventative measures is not encouraged. Like I said, peroxide doesn't discriminate between disease organisms and the cells of your orchids. Oxidative stress only cares about what happens chemically, it doesn't care about the organism.

Again, if they are healthy, it is not necessary to treat the orchids.

Originally Posted by Egrigby

My local orchid shop advised me not to repot orchids I buy from them for one to two years, most advice in books, blogs and posts tells me the opposite.?

Trust me, you should repot your orchids as soon as you purchase them. I used to work at a large scale nursery that primarily dealt with Phals, (they shipped orchids to other nurseries in bulk). I know what they go through before they get to the consumer, (hobbyists like us). If you knew, you'd be bothered by the standard practices as a hobbyist.

Originally Posted by Egrigby

I am reading the cultures for general phalaenopsis, and Oncidium and Oncidium Intergenetics. I am scared, and tentative. I want to learn to properly take care of these beautiful plants. My ability to change the environment is limited as my husband and I both have autoimmune disease. It is possible that phalaenopsis are not the right orchid for me, and another would be a better fit culturally.

There is no need to be tentative or scared. Orchids are not that delicate. When grown right, many can be quite "weedy". Orchids are also far more resilient than people give them credit for. This is why I spent the time with you. I'm trying to spread the word to dispel the myth that they are delicate. No, they're not!

You just need to get back to basics.

The basics are:

Phals grow in intermediate to warm temperatures, (60 F - 90F).

They grow in moderate to high humidity, (60% - 100%).

If you cannot provide for the higher end of the humidity range, it is ok. Like I mentioned before, 60% - 80% is tolerated pretty well. 60% - 80% humidity is easily achievable. You can get a warm mist humidifier and put it around your orchids. The whole house does not need to be 60% - 80% humidity. If you cannot use a humidifier, just buy as large a pre-made terrarium as possible, (I like Exo-Terra brand terrariums), and put some coconut coir as bottom material and keep that moist. Then grow orchids inside. It should be pretty humid inside. If you guys want to build your own terrarium, that's up to you as well.

I also recommend purchasing something that measures for relative humidity if you haven't gotten one already.

Lighting is bright shade.

Water the orchid when media goes damp or dry. It is easier to help an under watered orchid recover than it is to help an orchid to recover from being over watered.

There is no need to do too much extra other than fertilize every week or two, and to repot every year or two if you're using organic materials such as bark chips or moss.

Only treat the plant when they are diseased or have pest insects or arachnids infesting them.

---------- Post added at 08:41 AM ---------- Previous post was at 08:22 AM ----------

Originally Posted by Egrigby

...If I'm understanding correctly, as we would titrate medication for age, weight, and state of health, so the strength of the peroxide must be titrated for the organism it is being applied to, not just intended to kill.

Yes, it is similar to what you describe.

Another way to put it would be for a doctor to dose an antibiotic for a patient. There is a recommended dosage, for a recommended duration, for a particular type of infection.

[estación seca]

Most hybrid Phals sold in markets in the US do fine in homes with relative humidity 30% and up. They are less susceptible to fungal and bacterial rots in this humidty range.

[Egrigby]

Esatción,

I really have no way of knowing on some of the phalaenopsis. I have this wonderful quirky mother in law who loves orchids and it's very lucky with them. She is also a bit of a shopaholic.

When I expressed an interest the orchids started coming and I didn't have to do anything at all. I have purchased 4 of the orchids I own, the rest are gifts. I'm very lucky.

Our local orchid shop has a $5 table for orchids that are done flowering or have a defect of some kind. They seem to be without their tags most often. If you are careful to check the roots,stems, and leaves really well, you can get a good deal, and my mother in law often does. You just never know what plant you have, at all. It is possible I've got species of species type, it's more likely they are all hybrid. I'll have to put together an album.

Elaine