If I put a potted sunflower on a clock-driven turntable near a sunlamp, so it turns, say, every 2 or 3 hours,?

Question

will the plant be able to keep up? This may go a little beyond what heliotropism is capable of keeping up with, but that's what I'm trying to find out.

(I'll reset it every so often, so it is not trying to rotate in a complete circle.)

Will it give up in disgust and die? Will it harm the plant? Or strengthen it?

How might these conditions affect subsequent generations of sunflowers grown continuously under them? Assuming five or six generations of sunflowers per year, seed to next seed. What changes would you expect in the plants over the course of years?

I'm particularly wondering about the effects on the stalks. How tough are the stalks, anyway? Are they woody or pulpy? Could I break them by hand? Do they secrete anything that might provoke a severe allergic reaction, like poison ivy, o.s.l.t...?

You probably get the impression I don' t know much about plants, but that's why I'm asking! No wisecracks, plase. Thanks for all serious answers.

1 AUG 07, 1920 hrs, GM

oh yeah, I've already checked all sorts of sites on line and asked people in gardening shops where they sell sunflowers and seed. They don't know.

Thanks for the suggestion that I perform the experiment; and I would, but I don't actually have the room or resources to be able to try it, or I would. (Also that it would take years.)

I'm wondering whether the need to change positon faster would stress the plants beyond their ability to keep up. I'm talking maybe five times its usual rate of movement. (from a 12 hour daylight to a three hour daylight, moving the same arc in the same time.) Poeple that have to change too much, too quickly, usually are susceptible to heart and digestive problems, etc.

Even without selecting the plants that react quickly, do you think some would die of not being able to keep up...?

Does the movement came from the whole stalk, or just the part below the flower?

I've also heard that the stalks contain some latex. How would that be harvested? Could it be tapped while the flower was growing, or wait until the seeds are havested?

PS, I don't have the facilities to do the experiment, or I would have; and then I would not have needed to ask this Question.

Answer 1

I assume you mean it's rotating in a horizontal plane if so it will just grow straight up and be otherwise normal, how often does it turn? You should be clear with your queries! Hold on I see now you're trying to twist it, I guess it will 'roll' the flower as it turns so not to twist, make a good sped up film!

Answer 2

Firstly, I recommend that you do the experiment. Do it will a few different varieties (one at a time) and keep a log of the progress every 15 minutes for each type. It sounds like a very interesting experiment.

Now for the prediction. Since the sunflower can easily move its "face" almost 180 degrees in as little as 8 hours, I predict that your sunflowers will easily keep up with the rotation of the turntable. Your artificial light may need to be quite bright, and you may need to keep them hydrated, but I think that the average sunflower (one flower head on the end of an elongated stem) should have the ability.

I am not sure if all of these gymnastics will affect the ability of the sunflower to produce seeds. That would be one of the things you would want to document in your experiment.

Your activities will not affect the next generation of sunflower plants, unless you artificially select the breeding plants based on your experimental results. For example, you may only allow plants that can keep up with the turntable when it is turning once every 3 hours, and destroy all of the other plants. You would then be artificially selecting your breeding stock based on the ability to turn around every 3 hours. The next generation of plants would then be more likely to keep up with the quick rotation of the turntable. If you continued the experiment generation after generation, always selecting the fastest plants to breed, you would see an increase in the ability of the plants to keep up with the turntable.

If you do not select the plants based on any criteria, and just allow all of the plants to reproduce then you will not see any increased ability to keep up with the rotation of the turntable.

Sunflower plants are very safe to work with. Unless you are allergic to the oil in the seeds, you will not experience any ill effects from the plants. Note that some of them do have tough hairs on the stems that can cause little slivers if not handled with gloves, and many of the giant varieties have very-very tough stems.

Hope this helps,
Lorax

Answer 3

I think the plant would just act as though it was lit equally on all sides. I should think the rate of heliotropism varies and some fast-growing plants might try to stay with the light. it's an interesting thought and I'd like to know the answer.