Final answer:
Plants perform best under blue light due to the absorption characteristics of chlorophyll a and b; thus, Plant A under blue light would grow the most, followed by Plant C under orange light, and Plant B under green light will have the least growth. Lighting periods that extend daylight in red and blue wavelengths are effective for flowering long-day plants in nurseries.
Step-by-step explanation:
When considering the optimal growth conditions for plants under artificial lighting, it is important to understand that plants utilise light primarily in the red and blue wavelengths for the process of photosynthesis. With regard to plants that harbor only chlorophyll a and chlorophyll b, which are key pigments in photosynthesis, blue light is quite effective for their growth. Chlorophyll a absorbs well in the red and violet-blue regions, while chlorophyll b absorbs light in the blue range.
Given this information, Plant A grown under blue light would likely exhibit the most growth, as blue light supports both chlorophyll a and b. Plant C grown under orange light would be next, because orange light is closer to red light that also supports photosynthesis, but to a lesser extent than blue light. Plant B grown under green light would likely show the least growth because green light is not efficiently absorbed by chlorophyll and is mostly reflected, which is why plants appear green to the eye.
Throughout these experiments, the effectiveness of light on plant growth can also be understood in terms of flowering, where long-day plants require sufficient periods of light to flower. To induce flowering in February, nurseries would need to mimic the long-day conditions by providing extended hours of light that fall within the effective red and blue ranges of the spectrum.
In summary, the plants under blue, orange, and green lights would be predicted to grow from most to least growth in that respective order. A combination of the right duration and quality of light influences both the vegetative and reproductive success of plants.