How does light affect plant growth?

[take-ahike]

I already know that different colors of the light affect the plant growth in different ways. but I need to know what happens when the light hits the leaf and by that how does it grow??? would anyone be kind enough to explain the thing above with the colors:red blue green yellow and full spectrum.also the factors that contribute to plant growth besides light.

[ChrisG]

Hi take-ahike,
Welcome to the Ask an Expert forums. I think this web site will address your questions about light and plant growth:
http://biol1114.okstate.edu/study_guide ... 7/lab7.htm
You can also try an internet search for "colored light photosynthesis" or similar terms.
For info about what affects plant growth, try a search for "plant growth factors". You'll find many pages like this: http://www.buzzle.com/articles/plant-gr ... ctors.html
Good luck!
Chris

[take-ahike]

what would be a good method of measuring plant growth?
mass,height,area of leaf???

[ChrisG]

Hi,
I am combining your new topic with your old one. Please keep future posts related to this project in this topic, so that Experts can follow your progress and see what help has already been given.

All of those would be acceptable measurements of plant growth. Wny not measure all of them?

Chris

[michellebayefsky]

Here is a bit of information about measuring plant growth:

https://www.sciencebuddies.org/science- ... owth.shtml

This might help explain the relationship between color and plant growth:

http://74.125.93.104/search?q=cache:yq2 ... clnk&gl=us

Hope this helps!

Michelle

[take-ahike]

I've started the experiment on the 5th of april . when should I stop and write about it?

[HeatherL]

Hi take-ahike,

That depends! First, when is your project due? You want to allow enough time to analyze your data and organize the results and conclusions. It also depends on how quickly you get measurable results. You don't want to stop your experiment before you've had the chance to observe any changes!

My advice would be to continue your experiment as long as possible. However, you may be able to start writing about things before you are totally finished. Do you need to write an Introduction with background information? That is something you can do before you are finished with the experiment. You can also start writing the Methods, since you know what methods you have used. (You can always edit them if you have to change things along the way.) That will get you going with the writing, so you don't have to do everything at the last minute.

Let us know if you have further questions!

Cheers,
Heather

[michellebayefsky]

What I have learned from working on my own projects is that it makes writing the final report a lot easier if you are analyzing data throughout. You are measuring your plants at a set interval, I imagine? Every few days or so? Perhaps you could chart or graph your data while the experiment is still going on. This could help you visualize any changes taking place. Also, as Heather suggested, you could research your topic and write your introduction before the experiment is finished. If you think that you have obtained the results you hypothesized or clearly disproved your hypothesis, and carried on the experiment for a reasonable amount of time, I don't think it is necessary to keep it running. You can ask your teacher or mentor what they think about how long the experiment should be. But even while it is still going on you can research the results you are finding and this will help build the discussion section of your paper - why you saw those results.

Good luck!

Michelle

[take-ahike]

sadly I'm not getting the results I wanted. the plant growing in the blue light is dying and the one in green is doing the best. Also I forgot to measure the height of the plant in regular intervals... what should I do?

[davidkallman]

Hi take-ahike,

Re blue vs. green: the results are the results. One needs to report on what happened.

It's best if you have the measurements. When is the Project Due Date? It's listed as 1/5/2009, but your Project Status is I am just starting.

[take-ahike]

the plant has multiple shoots and I've only measure one of each(the tallest ones),can I just record the growth of those tall ones and exclude all the small ones??

[davidkallman]

Hi take-ahike,

It sounds like you decided to run the experiment again so that you could collect data. Is that true? If so, that's great!

The goal of the measurement is to quantify the plant's growth.

What do the plants look like?

Is the tallest shoot representative of the plant's growth?

Two other measurements are:
1. counting the number of shoots
2. measuring all the shoots adding them together

So, if you're in a new data collection mode, you can collect the two measurements above plus the length of the tallest shoot to see which measure is the most representative of overall growth.

[take-ahike]

For my background info, I need to write about all the different types of plant growth, but I cant find the info in the web.
Does anybody know

[HeatherL]

Hi take-ahike,

I'm not sure what you mean by "types of plant growth." Do you mean different growth patterns in different types of plants, or different ways to measure growth on the same type of plant? You might try doing a web search with a more specific phrase that best identifies your goal.

If you want to know about different ways to measure growth on the same type of plant, you've had some good suggestions by other experts. Measuring the number of shoots, counting leaves, measuring leaf size, and measuring plant height, are all ways to quantify (put a number to) plant growth. Another way is to measure the wet and dry mass of the plant; but you will have to kill the plant to do that, so that measurement can only be taken at the end of your experiment.

I hope this information helps you focus your efforts for your background search. Let us know if you have more questions.

Cheers,
Heather