Little update:
Still no alkaloids present in extraction attempts- All Acuminata/Floribunda plants are well over a year old now. I had an interesting theory however, which I am now testing:
Are alkaloids produced as a coating on phyllodes/bark?
I have noticed many posts about floribunda variants/growing conditions resulting in different yields (with people complaining none at all for grown floribundas), and also the often mentioned "harvest when dry" to get max yields.
So I got to thinking, what if the alkaloids are a form of pest deterrent (as in other plants/cacti), and unless grown under a canopy of sorts, the alkaloid "coating" on phyllodes/bark washes off? This could go from an external protective coating to becoming internal in phyllodes/bark as the plants grow and new growth envelopes these alkaloids which were a coating previously? This could explain why acuminatas grown in a dry region have a phyllode yield fairly high, compared to say floribunda which appears on the east coast in areas with comparatively far higher rainfall.
I never had pest problems while growing under cover and watering daily. When I moved the young plants to an area with zero protection from rain, I had a huge pest problem. Multiple types of little bugs have decimated new growth ever since. I have since moved a few floribundas under cover again (transparent cover, they still experience most of the sunlight as before) and pests are still an issue.
I have not innoculated with any nitrogen fixing bacteria, unless they were present in the native potting mix that formed part of my soil mix.
I also put a floribinda over a tub with "fruit and veg" hydroponic liquid, with the roots growing out the bottom of the pot into the solution, kratky style. This plant has pests too.
All this has gotten me thinking, maybe the wild acacias have a much better chance at producing alkaloids? For instance, acuminatas would have to be not ideal for mammals to eat, or insects, and need to withstand a dry environment. So potentially, all new growth could have a small alkaloid content which over time accumulates throughout most of the actual plant, whereas I get rain often and I live in a somewhat humid area. (Coastal NSW).
To further test this theory, I would need data on successfully grown floribunda/acuminatas that have an alkaloid yield. I'll keep growing mine for now, but after failing at moving 2 acuminatas into PVC piping, I am left with only a half dozen from the nearly 300 i sprouted originally (quite saddening for me).
Maybe growing acuminatas in a low humidity grow tent with strong lighting could produce a reliable yield, but I am not keen on going down that route. I was hoping to be able to trim a few plants every few months for some experiences, but that is looking less and less likely.
I will post another update if I successfully convert an acuminata to kratky as i did to a single floribunda. The main issue is the NPK makeup of almost all hydroponic concentrates is not ideal at all for aussie natives, so I need a workaround for that too...
I will also look out for an innoculant for nitrogen fixing bacteria and see if that has any effect (I will use it on only half of the pots for experimental validity).
Always keen to be PM'd if anyone has advice or has experimented growing acacias!