groffralph
Sapling
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Any suggestions on the DLI for Brazilian Raintree's and Jabotica? (12hrs daily)
Any suggestions on the DLI for Brazilian Raintree's and Jabotica? (12hrs daily)
That sounds like good advice, thanks a bunch! I have them in various positions. I should be receiving my PAR meter soon, I will keep you all posted.You could use a map as a benchmark (as in if you were to live in a region where you could grow a tropical outdoors, what DLI could you expect there?). https://news.clemson.edu/new-national-light-maps-help-greenhouse-growers-manage-plant-growth/
But it sounds very difficult to match tropical sun in output especially if you're only doing 12 hours. For overwintering my tropicals/cacti/succulents, I think 25-30 is OK. Looking at the map I linked, the winter levels for Florida are around 25-30 anyway.
That is awesome food for thought, thank you! I'm getting my PAR Meter and Tent soon. I will post my findings as I have plants in various positions ie. Windows supplemented w/ lights, shelving w/out much natural light, basement w/little natural light, and soon a grow tent!You don't mention if under lights or natural lighting...but I assume lighting??
DLI can be misleading under lights. What people don't often realize is light intensity falls as the square of the distance. 4000 lumens at 6" from a light panel falls to 1000 lumens at 12". The sun is 93 million miles away. The intensity drop from 93 million miles to 93 million miles + 6" is negligible
In practice, this means that under lights you can burn the upper canopy while freezing the lower one For example:
View attachment 463927 View attachment 463928
The top of this tiger bark ficus was receiving in the neighborhood of 30K lux for 16 hours while the bottom was receiving ~10K lux. The tree is just shy of 24" tall. What does DLI mean if the top of the tree gets 4x more than the bottom? There is more foliage at the wider base...but it gets less intensity.
Some of my trees I illuminate from the side to get a wider area of foliage under a more uniform intensity. But even then, the back is shaded and I need to rotate to avoid phototropic effects.
I haven't yet seriously measured my new setup...I had to buy new hard to find batteries for my PPFD meter! But here is some data from my previous setup in a former home:
PPFD from where one of my willow leafs summered:
View attachment 463930
PPFD at mid canopy from where that same tree wintered:
View attachment 463931 View attachment 463929
The first plot is without the lights on...just window light. The second is with the lights on...this was in a living space so I had lower output supplemental lighting in an already bright window. The "shoulders" on the second plot are the artificial light. The sun, even through a window, dwarfed the artificial light output!
That ficus was about 18" tall at the time. These measurements were about mid canopy. 12 PPFD was enough to keep the tree full and healthy looking. No growth...but too cold in that window for much growth anyway.
I can't find the plots right now, but I did similar for my BRTs...which are a little taller than 24" I kept the upper canopy at about 15 PPFD and it did well...even grew some once it got warm enough.
But, honestly, all that is just fun numbers to entertain me. In practice, all that is really needed is some basic familiarity and some rules of thumb. Most trees...especially tropicals...have a "tell" when they are receiving an acceptable amount of light. The ficus picture above is telling me that the upper canopy is receiving about the right amount of light because that lightish green color is what I would expect from a health ficus kept outdoors. The color of the lower canopy is too dark...it's not getting an optimal amount of light down there.
BRT's tell is that they tend to grow larger leaflets in dimmer light. Sorry, I don't have pictures, but mine grow leaflets that are about 2x larger when inside for the winter than when outside for the summer. They are also darker in shade. Mine drops all its leaves when moved inside to out or outside to in so there are rarely both styles of leaf on it at the same time.
As a rule of thumb, you can often get away with this: hold your hand at canopy height and observe the shadow below. For a "full sun" plant, if the light source casts a sharp shadow...you can count the fingers...it's "bright enough" and a 10-12 hour day should be plenty. If the shadow is diffuse...a noticably darker patch but can't count fingers...then increase the duration to closer to 14-16 hours. If there is no noticable dimming, the light is too dim and no amount of increased duration will "catch up" to bright light.
NOTE: if your light source is a panel or long tube or some other extended form you might not get a shadow even under very bright light.
If it works keep on rolling!Wow! That is a lot of stuff I would need to make room for in my head.
I think I'll just do what I have been doing for decades. It seems to work.
Wow! That is a lot of stuff I would need to make room for in my head.
I think I'll just do what I have been doing for decades. It seems to work.
A strikingly scientific answer!Wow! That is a lot of stuff I would need to make room for in my head.
Agree Totally! Love the BT's, they look amazing.I have shop lights with daylight bulbs over my trees. I use one 3 bulb fixture for one table and 2 of those for another table
15 hours per day.
Trees grow most of the winter so if it works, dont fix it is my thoughts
View attachment 463961
I have shop lights with daylight bulbs over my trees. I use one 3 bulb fixture for one table and 2 of those for another table
15 hours per day.
What is you fertilizing regime for the Brazilian's. What type of fertilizers do you use?I have shop lights with daylight bulbs over my trees. I use one 3 bulb fixture for one table and 2 of those for another table
15 hours per day.
Trees grow most of the winter so if it works, dont fix it is my thoughts
View attachment 463961
Trees grow most of the winter so if it works, dont fix it is my thoughts
View attachment 463961
I have shop lights with daylight bulbs over my trees. I use one 3 bulb fixture for one table and 2 of those for another table
15 hours per day.
What is you fertilizing regime for the Brazilian's. What type of fertilizers do you useI have shop lights with daylight bulbs over my trees. I use one 3 bulb fixture for one table and 2 of those for another table
15 hours per day.
Trees grow most of the winter so if it works, dont fix it is my thoughts
View attachment 463961
Trees grow most of the winter so if it works, dont fix it is my thoughts
View attachment 463961
What is your Fertilizing regime for the BT's(Fert types, timing, etc.)? They look amazing, any recommendations would be greatly appreciated.I have shop lights with daylight bulbs over my trees. I use one 3 bulb fixture for one table and 2 of those for another table
15 hours per day.
Trees grow most of the winter so if it works, dont fix it is my thoughts
View attachment 463961