Still looking for the book with the table I am thinking of, but I found some info in
Peppers: Vegetable and Spice Capsicums. Keep in mind this is a book targeted at commercial production of peppers
"Flowers drop when night temperatures are above 24C." 24C = 76F
"When the night air temperature is lower than 16-21C there is a marked increase in fruit setting." 21C = 69F
"The optimal temperature for pollen germination is 20-25C." 68-77F
There is also a section on growth regulators that talks about GA.
"Young pepper plants treated with gibberellic acid (GA3) before the initiation of floral organs produced abnormalities in subsequently formed flowers."
There is no mention of the effect of GA on mature plants. There are brief discussions of uniconazole and ethephon (effects vary depending on does and timing of application). Indoleacetic acid and benzyladenine (both for lateral growth) were not effective even at high concentrations.
Finally, while looking around for the magical table (that I now think I may have just imagined) I found a very recent paper on the use of growth regulators specifically to increase yield. The most effective substances in that study were triacontanol at 5 ppm and 2,4-D at 2 ppm. See
http://www.nepjol.in...viewArticle/697 for the full results.