Has anyone been using CFL's on stock rather than incadescent. If so, what Kelvin and CRI has been effective.

A follow up question. If CFL's have been used, what cycling time schedule works with them. We currently use 3 minutes on, 9 off for our incandescents.

Hi Mikael, Erik Runkle at Michigan State has probably done the most work on CFL's for photoperiod control. The Ecke folks may have done some of this and may have the details you are asking. Look at this http://www.flor.hrt.msu.edu/as...vidingLDwithCFLs.pdf and do a Google search for “Erik Runkle fluorescent lights”. Their work focuses on long day spring crops. Maybe someone using CFL's will indicate what is working for them on poinsettias. Jim

Thanks Dr. Barrett. I am in discussion with Dr. Runkle currently and have also sent an email to Dr. Erwin as well. I am going to try and contact some growers over in europe, as they seem to be a step ahead in these areas. I am just very surprised about the lack of information out there as the money savings can add up to big $$$ over time (bulbs and power). I guess the old adage of if it ain't broke, don't fix it, must apply to lighting, or is it just that us southern growers that don't require supplemental lighting during the winter for growing, are just using the cheap lighting?!

Mikael,

From the data that I've seen on promoting flowering on Long day plants, or conversely stopping flowering on short day plants, you can use 25 to 33 of the compact fluorescent bulbs combined with the 67 to 75% of the incandescent bulbs. The CWF bulbs don't give off very much far red light so you would need to use 3 times as many bulbs of only CWF to get the same effect--therefore about the same electricity and much more money to install.

Everything I am hearing from everyone else, is that it is fine with just cfl's. Several breeders have actually switched to cfl's on Kalanchoe stock plants in their locations in off shore locations and in vietnam. I am waiting back on the specifics. They are seeing success with about 2 watts per square meter. I would think Poinsettias would be the same. All that stated, there can be a huge difference in the spectrum, and cri of bulbs, so one can not just assume they all work.