For my biology class, I was given a problem that I needed to write a half page r

Question

For my biology class, I was given a problem that I needed to write a half page response on. The problem is as follows:

You're growing black-eyed Susan (Rudbeckia hirta). You hope to sell your flowering plants as soon as possible. In nature, flowering in this variety is initiated when day length exceeds 14 hours. It's now early March, and, although daylength is increasing, its currently only about 11 hours. To ensure that the plants flower in the next several weeks, you need to manipulate the greenhouse light environment, but can't afford to expose plants to artificial (white) light for more than 2 hours per day. Provide a viable strategy for immediately promoting the development of flowers, using, in any manner you choose, the 2 hours of artifical light each day. Also include a mechanistic, physiological rationale for your strategy.
How would I go about solving this problem? My initial thoughts were to increase the red and blue lights which mimic the spectrum of the sun more, and help the plant because they absorb those colors more than other wavelengths. Any thoughts?

Explanation / Answer

Rudbeckia hirta is a long day plant since it requires a photoperiod longer than a certain critical length.

To initiate flowering in a long day plant under unfavorable short day condition, the dark period should be interrupted with flash of light exposure. Exposing the leaves to flash of light will be more effective since the leaves contain phytochrome, the flowering pigment. Absorption of red light by phytochrome converts it into the biologically active Pfr form which promotes flowering.

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