I grow indoors and outdoors, I find that for CFL or other fluorescent lighting, you need more than the usual 12 hours, I go with 15-16 hours a day.
For vegative growth (early life) the temperatures dont matter unless you dont want to water periodically.
A plant can fruit as soon as a flower appears, but generally you want to pinch off the first month or so of flower development because this will slow the growth down. Also, use a Fertilizer higher in Nitrogen during this growth stage.
When the plant gets to the size you want, you can switch to Tomato food which is high in P and K and less N. I use that and Epsom Salt + Bloom Booster.
For container plants, water deeply so water leaks out the bottom, this is to flush out salt buildup which can be very bad for your plants.
Never water them if the top inch or so of soil is wet, I water when my plants start to wilt.
Anyway, getting back on topic, the biggest killer of fruitset are
temperature and
light! Not enough light and you get
few or
no fruit set, too much light means too much heat, and too much heat means few or no fruit set!
You have to strike a ballence between light and heat, when using High Intensity Lighting this is less of a problem because you can place the lights farther away without reducing light intensity while reducing radiated heat. This is most of a problem when using CFL or other Florescent lighting which isnt very bright and must be placed real close to the foliage. Although Florescent lights dont put out as much heat as HID lighting or Incandescent lights, you have to place them so close to the leaves that the heat they do put out can become a problem.
CFL and other fluorescent lights, while they may appear bright to the human eye, are not very bright at all, and you need to bring them as close as you can to the leaves and use a longer photo period (15 to 16 hours a day) then other types of lights to make up for the lack of intensity.
This presents a problem though, while they are not very bright, they emit a lot of heat and this radates onto the plants which wreaks all kinds of havoc on the flowers and fruitset in general. So you are faced with the challenge of keeping the lights close enough to the plants for adequate light, while keeping them far away as to not cause the temperatures to get out of control.
Here are some temperature numbers I pulled out of a book on Chilis and have worked great for me, these are based on Annums and it is to my understanding that Chinenses are more picky about temperatures than Annums.
No Fruit Set (Assuming Flower hasnt dropped or been aborted):
Mean temps lower than 16'C (60.8F) or greater than 32'C (89.6F)
Flower Drop:
Nighttime temps greater than 24'C (75.2F)
Maxiumum Flower Set:
Day and Night temps between 16'C (60.8F) and 21'C (69.8F)
Pollen Germination:
Optimal temps between 20'C (68F) and 25'C (77F)
Pollen is harmed at temperatures above 30'C (86F)
Pollen is sterile if temps are above 30'C (86F) 15 days prior to anthesis (bloom)
Fruit Set:
Pollen tube growth (pollen travel) from stigma to egg (fruit) takes between 6 to 42 hours.
Now what all that means is, if the nighttime temperatures are too high the flowers tend to abort, even if they have only been open for a short period of time. Aborted flowers turn yellow or pinkish in the stems while the petals tend to fold inward and look wrinkled in appearence. At the 'stem-node end' (the part where the stem meets the plant) it will shrink to a tip and the flower may or may not wilt, falling off easily.
If the young flower buds experience temperatures in excess of 30'C (86F) 15 days prior to blooming, the pollen may be less viable or sterile. I noticed this when bringing plants outdoors that were under hot lights in a hot grow room... The first week of young flowers would not set at all or very few of them would set, however after those had been aborted the next set would set just fine.
So there are three things that can prevent a flower from setting.
#1: High nighttime temps cause flowers to abort and fall off regardless of whether or not they were pollinated.
#2: High mean temps cause problems in pollen viability or reduced fertility.
#3: High day-time temps can interupt
pollen tube growth in a negative way, causing pollinated flowers to abort or reduced seed count which can reduce pod size.
My advice to you is, place your growing area near a window and put a fan in the window to let cool nighttime air in, and other fans around the room to remove hot air from the lights and circulate air.
As for Light Color temperature, unlike other plants that tend to fruit in red light and less so in blue light, it is to my understanding that chilis like a mixed spectrum. I use 50/50 mix of Red (Warm, 2600K) and Blue (Daylight, 6500K) lights. Time of light does NOT effect fruiting like other plants.
For Pot Size, 10-inch or larger, but you can grow them in pots smaller than 10-inch but the plant may not get very large (which could be a good thing if your growing area is small).
You can grow them all year under lights, some people (me included) will cut the plants down to a 4 inch stump and wax the top at the end of the growing season. The next years growth will be very bushy, and yeilds will be higher, though pod size may suffer.
A tip on pod heat, if you let a plant with fruit on it wilt from lack of water, the pods will tend to be much hotter. Any plant stress will do this, but wilting from lack of water is the safest way, as the plant will recover quickly after being watered.
However, stressing a plant with no fruit will NOT make the future pods hot!
Also, if growing outdoors, it's best to start plants early, like late December, early January indoors under lights. This way your plants are ready or just about ready to hold a decent fruit set by the time the weather outside becomes favorable for growing.
I hope this info helps you, good luck!
). If it turns out to be Rainbow Thai, I'll send some pics. 