Final answer:
The hypothesis may state that the color of light affects radish seedling growth, with blue light being most effective due to its absorption by chlorophyll, affecting plant growth and germination. Exposure to red light followed by far-red light suggests a light modulation mechanism affecting seed germination.
Step-by-step explanation:
A possible hypothesis for the experiment in which radish seedlings were grown in different light conditions (red, blue, green, and white) could be: "The color of the light under which radish seedlings are grown will affect their growth, with blue light resulting in the tallest plants due to the higher absorption by chlorophyll a and b, followed by red light, with green and white light resulting in less growth." This hypothesis is informed by the knowledge that plants absorb primarily blue and red wavelengths of light for photosynthesis, and that green light is reflected more than absorbed, which might result in less plant growth.
Considering the data presented in the various seed germination and growth experiments mentioned, the red light seems to play a crucial role in the germination process and the subsequent plant growth. When red light exposure is followed by far-red light, the effect of red light seems to be reversed, indicating a red/far-red light modulation mechanism. Also, the absence of light seems to result in less or no germination, as illustrated by the control plates and dishes wrapped in an opaque cover.