Seaweeds may drastically lower PH to dangerous levels?

[Ray]

Originally Posted by DavTom

OK, Ray. Sorry I could have stopped this conversation earlier, but this did not come clear to me from your previous posts. I wrongly thought you had checked only the PH and not also the H3O+ concentration.

One last point still related to PH. What do you think about low PH and micronutrients toxicity? Some microelements (in particular iron and manganese) become drastically more available for plants uptake at lower PH and this may easily lead to toxicity. Frankly speaking, I do not know if this has a dependency with H3O+ concentration.

What are your thoughts about this? Did you do any tests, or you simply assumed there is no problem because your plants are doing fine since a long time?

Dav

I rely mostly on my observation of healthy growth, but it is my understanding that 1) micronutrient toxicity occurs at extreme pH levels only, 2) solution pH is quickly “adjusted” in the rhizosphere, and probably most importantly, 3) the concentration of those elements are included in fertilizers in trace amounts to provide the necessary masses without overdosing them.

Most of the time, when trace element toxicity is encountered, it is when they are applied excessively via soluble trace element mixture, in addition to what is provided in the “base” fertilizer.

[DavTom]

Yes, makes sense to me. After all, with the flushing you get rid of any salt accumulation. So, I tend to agree that PH alone, i.e., without salt accumulation and overdose, should not let to any toxicity.

---------- Post added at 10:09 PM ---------- Previous post was at 09:46 PM ----------

Originally Posted by Ray

Most of my collection is paphs and phrags - they get a monthly Kelpak treatment all year.

I will be potting up some deflasked paph seedlings tomorrow. They are currently submerged in a Kelpak + probiotic bath overnight.

Good to know Ray. Since about 3 months I have all my orchids (1 Paph (warm type), 4 Phal, 2 Bulbs, 1 Dendr and 1 Cattl.) in s/h and they are all doing great with nice roots growth and nice leaves growth. Leaving aside the Phals that are already massively blooming, the only other orcgid that has already bloomed is the Pahp. Despite it grew a lot, it is still quite small (I bought it as a young plant). Do you think it is usual for such a small plant to have already bloomed in these 3 months? See pictures.

Thx

Dav

[Ray]

Originally Posted by DavTom

Do you think it is usual for such a small plant to have already bloomed in these 3 months?

In my opinion, there are two reasons a relatively small plant will bloom:

1) It has developed sufficient reserves to do so, based upon the quality of conditions. (That is, a plant grown under less-favorable conditions will want to build up a great deal more reserves before it is willing to "risk it" by blooming.)

2) It is near death and blooming is a last-ditch attempt to carry on its genetics.

I certainly feel the former is the case. Besides, mottled-leaved paphs don't get particularly big, anyway.

[Shadeflower]

congrats davtom.

Do you know what variety. It might just be a cross with a small variety so might be more mature than it seems. Still a good accomplishment at that size I think.

I'm just suprised it grew that fast. I have heard others say it takes their paphiopidelum spikes 6 months to develop so the fast growth rate is surely a good thing.

[DavTom]

Originally Posted by Shadeflower

congrats davtom.

Do you know what variety. It might just be a cross with a small variety so might be more mature than it seems. Still a good accomplishment at that size I think.

I'm just suprised it grew that fast. I have heard others say it takes their paphiopidelum spikes 6 months to develop so the fast growth rate is surely a good thing.

Sorry SF, I missed your question. Here it is
Schöne von Kaunitz x Hamana Clover

Dav

[DavTom]

Originally Posted by Ray

In my opinion, there are two reasons a relatively small plant will bloom:

1) It has developed sufficient reserves to do so, based upon the quality of conditions. (That is, a plant grown under less-favorable conditions will want to build up a great deal more reserves before it is willing to "risk it" by blooming.)

2) It is near death and blooming is a last-ditch attempt to carry on its genetics.

I certainly feel the former is the case. Besides, mottled-leaved paphs don't get particularly big, anyway.

Thanks Ray, I googled and indeed I found many pictures of relatively small mottled leaves Paphs with flowers. But still, they all seem significantly bigger than mine. The biggest leave in the picture is just 10 cm long...
We'll see how it will grow in the future.

By the way, it has already started two new growths. I have read that after blooming Pahps do start developng new growth and let die the growth that bloomed. I am curious to see that...

Dav

[Ray]

Originally Posted by DavTom

By the way, it has already started two new growths. I have read that after blooming Pahps do start developng new growth and let die the growth that bloomed. I am curious to see that...

Dav

I have found the longevity of old growths to be a pretty good indicator of the quality of culture you’re providing.

Paphs are sympodial plants, connected to each other by a rhizome, albeit often quite short. That affords the colony the ability to store and share resources - fuel produced through photosynthesis, absorbed water, and nutrients.

If your culture is good, those old growth will “hang in there” for a long time, contributing and being an active participant in the support of the colony. If not, it’s reserves will be consumed by the other plants and it will die in relatively short order.

[Shadeflower]

that is true Ray but you are possibly making it sound like DavTom should provide better care when I think he seems to be doing really well.
Young plants flowering for the first time will never flower as long as an older more mature plant..

[Ray]

Originally Posted by Shadeflower

that is true Ray but you are possibly making it sound like DavTom should provide better care when I think he seems to be doing really well.
Young plants flowering for the first time will never flower as long as an older more mature plant..

Well…. That certainly wasn’t meant as a criticism of Davide’s cultural practices, but as an observation of the progression of my own! (I may have been growing orchids for 50 years, it that doesn’t mean I don’t know how to do it wrong sometimes!). Davide and I have had enough direct conversations that I expect he understands that.

I’m going to disagree with your second statement, though.

It seems to me that in basic terms, a plant has three primary areas of resource needs - (1) overall health (i.e., staying alive), (2) growth, and (3) reproduction - in that order of priority. Additionally, it’s not just “it has enough” that matters, but I think how easily they can be accumulated also plays a role, as it takes both for the plant to answer the internal question, “can I expend what I have and expect to regain it without putting myself at risk?”.

Everything’s a matter of degree, but consider this scenario: An immature plant simply doesn’t have the mass to store a great deal of expendable resources, so while it might be healthy and growing, the amount available for reproduction
might be marginal. If the growing conditions are favorable, it might risk it, but the flower will likely not be as large as it genetics might allow, and the plant just might not carry it for very long, before the plant “empties the tank”.

In a mature colony, on the other hand, there is a great deal more shared “resource storage capacity”, so the plant can more comfortably afford to grow the blossom and carry it longer in its reproductive efforts.

[DavTom]

Thanks, good to know.

Dav