[Doctor Stochastic]

My proposal could be checked by placing sunlamps below some plants and water above. (In a greenhouse.) The plants could even be placed sideways to see which way things extend.

Sunflowers (and others) follow the light by differential growth. Root tips do tend to grow larger where there's moisture.

There's probably something published about this somewhere.

[Alamo-Girl]

Thank you for your reply!

I am very sure that you are correct about such research! However, they have also determined that gravity is a factor. There is not as much on that particular aspect as I had hoped, but when I read articles tied directly to NASA and space biology, it made sense why that would be so.

[js1138]

Root tips do tend to grow larger where there's moisture.

You should see what I pulled out of my gutter drains yesterday.