Interesting observation re: CFL lighting
About six weeks ago, I transplanted two cucumber seeds, Tasty Jade and Holland Hothouse. These plants are mostly similar to other cucumbers except for being parthenocarpic (they self-pollinate). Jade is rated as 54 DTM, Holland 64. Both prefer trellising to encourage straight cukes.
I used my own mix, pretty much loose dirt from the garden along with some used potting mix and a bit of compost. They are in four-gallon black nursery pots that are filled about 2/3 of the way. No extra fertilizers have been added. The two plants have been placed side-by-side under a 5000K, 105-watt CFL bulb that is on ~16 hours a day.
My intention was to move them to the greenhouse once the vines attained a little length, as the bottom foot or so of the GH is wood and does not allow any sun. I have been somewhat disappointed in their lack of growth - neither plant is much more than six inches tall - after about 42 days. I grew these in a grow cabinet a couple years ago and in six week the vines were five feet long, although I did grow them in a DWC hydro system.
I checked the plants yesterday and was shocked to see both, but especially the Jade has several blooms on it. (Being about ten days longer in DTM, I would not expect the Holland to have as many).
This is what the Jade looks like:
Here is the flower:
I had posted this picture in another thread, but again, it is under the same type of bulb:
The common theme is the very compact growth but lush foliage of the plants, something that is suppose to happen under Blue Lighting. And then throw in the blooms, which is suppose to be largely controlled by Red light. The intensity of the light is not that great, (30,000 Lux for the tom, 13,000 for the cukes), one could even say a little low for the latter. In theory, they should be stretching a bit. Moreover, especially the cukes, have not been watered much. The pots were soaked to excess when first transplanted, but yesterday was the second time I had watered them since. They never wilted or showed signs of being thirsty, and the dirt seemed to be moist, so I saw no reason to give them a drink.
That's all the pertinent info I can think of, but none of it explains the growth pattern, especially the blooms. Those vines ought to be much, much longer. I wonder if the CFL bulb somehow filters out some of the longer (far) red wavelengths yet allows more blue through? But they are rated as 5000K Full Spectrum.
I e-mailed Eiko, who makes the bulbs and asked for some tech info; whether they will replay or not I do not know.