Originally Posted by redchigh
the warm light bulbs could probably trigger algae, so only do it if you remove the emersed plant to a bucket or something...
With indoor gardening, "redder" bulbs with a shorter day triggers flowering and seed/fruit production- It only makes sense it would apply to emersed (and only emersed) aquarium plants too.
(Be careful when trying to research this- 90% of the articles that come up are related to illegal drugs. Still, plants are plants (for the most part) right?
I doubt there are many emersed plants that set viable seed as the primary reproduction method... most you can probably use plantlets or cuttings. This info might be useful for some hard-to-propogate plants like madagascar lace leaf and banana plants though...
in the natural world, the difference in lighting spectrum, reds are more prevalent in the autumn, blues more prevalent in the spring. guessing this may be more of a tendency towards a 60/40 split, or less
"shorter days" - yes, but unfortunately 8 hours of light and most plants are in the dead of winter.
autumn and even spring lighting hours can be used to flower, typically these seasons have 12/12 (day/night) and plants enter their flowering stage very well. as you notice flowers in spring and plants producing seeds and fruit in the autumn.
16/8 (day/night) is used to grow terrestrial plants to ensure they don't flower, and this logic may ring true for all germinating plants
our aquarium 8/16 (day/night) tends to come out of a minimum light to avoid algae. but i doubt it's enough light to cause flowering or seed production.
for flowering the light spectrum has a tendency towards red (natural world) but plants will take what they can get, if it's not enough the plants get sick & die. if they're getting the right amount of light and the spectrum is off, the plants will still flower (why spring also works to bring plants to flower)
plenty of emersed plants produce seeds and even flowers, true aquatic plants i'm guessing not so much. emersed plants that do flower generally don't let the water stop them from flowering, ... the flower just tends to rot off very soon.
and some it's more temperature related, i only know of one, the cherry tree. the cherry tree flowers when the temperatures rise as winter ends
for specific lighting to promote algae, actinic would be your best bet, dark blues tending towards UV
yet these same lights hit some key specific spikes on the light spectrum for all photosynthesis in general (all in the blue ranges and towards UV)