Also, there's no connection with ammonium/ammonia, as all farmers (incl. submerged rice) worldwide know. They don't fear to fertilize with manure, urea and ammonia, but no matter what nitrogen fertilizer they use, they still spend enormous sums for fungicides.
I am not interested in this particular quarrel, but fertilizer burn from too much nitrogen and ammonia specifically is definitely a thing farmers are concerned about. I am not sure if or how all the mechanisms translate to submerged plants, but ammonium toxicity in plants is a well documented phenomenon and not an invention of this hobby.Never heard of, never seen... What are the symptoms? Who and how has analyzed the connection between supposed damage & ammonia?
Well, I can contribute myself. This one is a good summary: https://kronzucker.org › wp-content › uploads › 2019 › 08 › amtox.pdfammonium toxicity in plants is a well documented phenomenon and not an invention of this hobby
I'm pretty sure that some of the problems people have had with the dry starts have been due to Pythium, or similar, causing "damping off". <"Hemianthus Callitrichoides - problem during DSM">.
Ammonia burn is really common in terrestrial plants. The usual mechanism is via osmotic effects. In vitro plants would be particularly vulnerable to osmotic issues.Never heard of, never seen... What are the symptoms?
The point about ABA as a phytohormone is that it could potentially be added as a preservative. This would keep the in-vitro plant in a dormant state and avoid wilting until opened, but conversely could cause existing plants to shut their stomata and suffer stress if it is released locally into the water column in high concentrations, because in-vitro plants could be positively laced with ABA for all we know.
From <this publication in 2011>:This does sound like a crazy conspiracy, so I apologise, because it is exactly that.
Interesting article about ABA. Direct-to-consummer TC cups are a unique and kind of strange product, but I guess it would make sense for producers to ship out their cups with media that would support the longest shelf life, whatever that takes. I wish I had better insight, but it's out of my wheelhouse.From <this publication in 2011>:
"During the last 20–30 years, ABA has attracted the interest of many plant tissue culture specialists... ...ABA can act as anti-transpirant during the acclimatization of tissue culture-raised plantlets and reduces relative water loss of leaves during the ex vitro transfer of plantlets even when non-functional stomata are present. ...[ABA is] used as a growth retardant in plant tissue culture....ABA has also received much attention for their involvement in abiotic tolerance and disease resistance."I did kind of expect something like this, because being lazy, I have often left them in their tubs for weeks in reasonable lighting, and noticed negligible new growth.
I don't really see how producers can avoid them bursting out of tubs when they are distributed and put on sale without something like ABA added.
Lots of the producers I that favoured actually sent them in packets directly to my door, probably without any ABA, and they tended to do really well.
Oh yeah, those things make the magic possible.I think it is fairly inevitable that they are grown with a selection of different PGRs, nutrients, biocides, and other additives.
I've just read through this thread and some of your posts could be interpreted as a little confrontational. It's not really in the spirit of the forum. Please take a look at the forum rules and guidelines for guidance.Never heard of, never seen... What are the symptoms? Who and how has analyzed the connection between supposed damage & ammonia?
My fault, I apologize. I should have posted the question more narrowly, referring to my recent problem. If I described the situation and development, I think ammonia/ium would not appear in the discussion as a possible cause.I've just read through this thread and some of your posts could be interpreted as a little confrontational.
In "The Ecology of the Planted Aquarium, 2nd Ed", Diana Walstad (2003), she states that ammonia toxicity can reduce growth or kill plants, but species vary in tolerance. Sensitive species would be harmed by about 1 mg/1 NH4. For instance, Stratiotes aloides showed decay and destruction of plant tissue when exposed to only 0.9 mg/l NH4
<"Google scholar"> is your friend.1) I don't know of any evidence (or at least reasonable indications) that melting of in-vitro plants is regularly or at least occasionally caused by elevated ammonium,
2) I've never heard of 'ammonia burn' in connection with plants.
I've tried potassium sorbate 1 mg/L. It didn't help.Recently, I've got a cup of in-vitro Rotala indica (aka Ammannia Bonsai). They looked like healthy. I've divided that batch between one of my aquaria and a paludarium. In both of them, the Rotalas started to melt, and from them the melting spread further, to unrelated plants which were healthy until then.
A very interesting take on chlorine. I doubt if any hobbyist would decide to omit the water conditioner when seeing their precious plants struggle. Maybe we need to experiment more!This <study> suggested that 30 seconds of exposure to 0.5 ppm chlorine can kill 100% of Phythium aphanidermatum zoospores (Oxidation reduction potential (ORP) 748-790 mV and pH 6.3) - lower pH levels in that study appeared to be more effective. Presumably this would be true for most Oomycetes (water moulds), and anecdotally this method is already employed successfully by many hydroponic growers. Tap water contains around 4 ppm chlorine, so it is a rather handy source of chlorine. One <publication> from the 1980s suggested that Spiked water milfoil Myriophyllum spicatum growth was unaffected by intermittent residual chlorine concentrations below 1 ppm (for three 2 hour periods daily, up to 4 days). Obviously, you would need to check for more recent research in order to validate these findings.
If you think about how we typically do a wet start - we plant the in-vitro plants, but will be changing the water every couple of days for about a week, before gradually dropping off to once per week in order to avoid high ammonium levels, only adding livestock when we are certain the ammonia and nitrite levels are safe. It does strike me that most die-back seems to occur during this initial period. Perhaps that is because water mould zoospore levels are reduced by each water change, and at that point in time they are not so much of a problem for in-vitro plants. If during that initial period, we simply avoided water conditioners and applied a suitable chlorine concentration, perhaps the instances die-back would reduce.
In the UK we have <"less than 0.5 ppm">. 0.5 ppm is about the level of chlorine at which you get an obvious taste and smell.How much chlorine do you guys have in your tap water?