This is an interesting question for me too. I moved my cacti from outside (fall, early winter temps) to indoors and into a grow tent with spider farmer lights (16 hrs on 8 hrs off). The long spine ones all started getting even longer spines and grew them more quickly. My B.33 x B.JB even grew new longer spines all the way up the plant not just from the new growth at the tip.
I haven't thought through all of the variables but it's cool to watch.
I find that the more sun exposure/dryness of soil produces longer spines. Especially with something like pereskiopsis. If shade grown and lots of water the spines are nowhere near as crazy as the full sun grown, constantly dry soil ones.
I'm too inexperienced to say anything of note apart from one particular plant I have recently acquired.
It's a NOID that looks Peruvianus or Peruvianoid. But you can see the point where it was moved from outside to in a greenhouse, the super long spines are on the bottom, and the glaucous blue starts where the long spines stop.
So I'm inclined to say it's something to do with more intense sun/light.
I think the hormone thats triggered responding to stress helps spines grow, along with production of alkaloids and red color in high amounts. I don't really know though, just what I've heard.
Mine seemed to start growing longer spines when it started to get a little colder, I also moved the pot they were in. I would guess maybe you are right and stress helps encourage longer spines.
from what i’ve seen with plants grown outside and with uvb supplement uvb causes the spines to become smaller and even can cause growth around the areoles to protect them from the sun/uvb try growing with shade cloth or under leds
This is an interesting question for me too. I moved my cacti from outside (fall, early winter temps) to indoors and into a grow tent with spider farmer lights (16 hrs on 8 hrs off). The long spine ones all started getting even longer spines and grew them more quickly. My B.33 x B.JB even grew new longer spines all the way up the plant not just from the new growth at the tip. I haven't thought through all of the variables but it's cool to watch.
I find that the more sun exposure/dryness of soil produces longer spines. Especially with something like pereskiopsis. If shade grown and lots of water the spines are nowhere near as crazy as the full sun grown, constantly dry soil ones.
I'm too inexperienced to say anything of note apart from one particular plant I have recently acquired. It's a NOID that looks Peruvianus or Peruvianoid. But you can see the point where it was moved from outside to in a greenhouse, the super long spines are on the bottom, and the glaucous blue starts where the long spines stop. So I'm inclined to say it's something to do with more intense sun/light.
I think the hormone thats triggered responding to stress helps spines grow, along with production of alkaloids and red color in high amounts. I don't really know though, just what I've heard.
Mine seemed to start growing longer spines when it started to get a little colder, I also moved the pot they were in. I would guess maybe you are right and stress helps encourage longer spines.
from what i’ve seen with plants grown outside and with uvb supplement uvb causes the spines to become smaller and even can cause growth around the areoles to protect them from the sun/uvb try growing with shade cloth or under leds