I do believe magnetic fields do indeed have an effect on light since there seems to be a relationship between luminosity and magnetic activity.

Moreover, while the following effects may not affect luminosity they do show interaction between magnetism and light: the Faraday effect and the Magneto-optic Kerr effect.

The polarization of light through a magnetic field may also play a role in the properties of the light reaching the plant.

It's only a theory, and quite possibly incorrect since my Ph.D. in astrophysics is a perfect example of the "null" effect. :P

Most plants are more sensitive to the blue-violet side of the spectrum for photosynthesis, with a few exception having increased sensitivity to the red side.

My theory is that since humans tend to have peak sensitivity in the green portion of the spectrum and our perception of brightness is near zero in the blue-violet-ultra-violet range it is possible that the brightness of the sun has limited or no effect on plant growth.

Moreover, the solar wind is directly porportional to the strength of the Earth's magnetic field and the Earth's magnetic field blocks less blue-violet-uv then when the magnetic field is weaker so more blue-violet-uv frequencies make it to the plants and hence increase a plant's photosynthetic rate thus contributing to higher growth.

Maybe GCR is to photosynthesis what steroids are to muscles.

Try going to the Canadian news site, www.canoe.ca, they have this annoying scrolling tabbed configuration that just brings my Firefox to a crawl.

You don't work in the aircraft, spacecraft, power industry or telecommunications do you? There's no way to test everything economically. Look at the construction industry. It is considered quite mature compared to the software industry. Even the best construction crew in the world, nay the universe, will build a house that has or will develop issues. There's no such thing as perfect software: testing isn't done to fix bugs, but to find some them. Now considering the length of time Duke Nuke'Em Forever is taking to release, it should be the most bug free piece of software this side of a pace maker!