Flash,

It wouldn't be easy to control the G's on a growing radish. Like, for example, how would you grow a radish in ½ G? You couldn't do that in a centrifuge on earth, so you would need a rather slow centrifuge in space.

Some people grow tomatoes upside down, so I guess you could call that minus one G. If you alternated it between upside down half the time and right side up half the time, the average of +1 and -1 G would be 0 G, but I doubt that the effect on the tomato would be the same as growing it in space in zero G.

If you wanted to experiment with growing plants in higher than normal gravity, you could build a centrifuge.

I wouldn't hazard a guess as to the effects of G-force on a radish.

MM

There may be some information on this in NASA publications since plant growth has been the subject of several shuttle experiments.

A Google search on ~ "plant growth" nasa gravity ~ shows quite a bit of interest but I don't find too much news on practical results. Much of the research is on finding the chemicals that gravity uses e.g. some chemicals have been found that facilitate or confound auxins.

I don't know the answer to your question, but a classic demonstration of geotropism was to grow seedlings on a spinning disc (record player) to show that they leaned inwards. As MaineMan suggested you could build such a centrifuge.

You can also experiment with low G. The February, 1996 Scientific American, in the Amateur Scientist column by Shawn Carlson described a device built from two bicycle wheels that could be adjusted to simulate lower gravities, such as the moon or Mars. Naturally, it's not really low gravity, but the idea is that slowly turning the plant in all directions does not give it time to adapt.

Apparently these columns were once online, but no longer. This page has a link to Amazon where you can get the entire collection on a $30 CD-ROM.

This page has an article by Shawn Carlson that gives the background of the original idea, which came from his grandfather and was printed in the same column in June 1970 by C.L. Strong.

The name for this type of device is clinostat.

Here is a good picture of a similar device called a "Random Positioning Machine."