You know that plants need light to grow. How much, do you think, does the amount or type of light plants receive affect how well they grow? In the Caphter 2 Project, you will design and carry out an experiment to determine the effect of light on plant growth. The project rules outline the major steps you must take to complete the project. The project hints will give you useful tips to help ensure project success.

Project Rules

- Decide what type of plants you will use in your experiment.
- Decide how many plants you will grow.
- Decide how you will vary the lightning conditions.
- Decide how you will measure plant growth.
- Set up a data table for recording your data.
- At the end of this experiment ,graph the data in your table and analyze your results.
- Display your graph and explain your results in an oral or written report.

Project Hints

- If your teacher does not suggest a type of plant to use, choose a plant that will help grow quickly.Generally, leafty houseplants such as coleus or geranium grow quickly under bright light. Bean plants will also work well for this investigation. Avoid chooseing cactus plants or succulent plants, because most are slow-growing.

- Give each plant an identifying number or letter. Use a permanent marker to write the numbers or letters on the plants pots.

- Try to vary the two lighting conditions as much as possible. For example, place bright-light plantsin the brightest light available-under plant growth lights, in a greenhouse, or on a sunny windowsill. Place low-light plants in very dim light, such as on a shelf in an unlighted room away from windows. Alternatively, you can keep low-light plants in a dark cupboard or closet most of the time, and place them in bright light for just an hour or two each day.

- The best way to control the variable water is to keep the soil slightly moist in each pot at all times. However, all plants should receive the same amount of water.

- You may choose to use one,some,or all of the following measures of plant growth: plant height, plant diameter, number of leaves, and average size of leaves. If plants are in bloom during the project, you may wish to add number or size of folwers as a measure of plant growth. Use more then one measure, at least at the beginning of the project. As the project continues, you may find that one measure provides better information than others and decide to rely on it alone.

- Unless plant growth if very rapid, you may need to measure plant growth only every two or three days. However, be sure to keep checking your plant's soil for water every day.

- Record your data on growth for each plant as soon as you measure it. Record the data in the table in worksheet 1 or in table like it. The table must be filled in for each plant each time you measure it, so be sure to leave room in the table for enough rows (number of plants X number of times measure= number of rows needed).

- At the end of two weeks, graph your data using the graph to make comparisons of their growth easier. Indicaticate on the X-axis how the plant growth was measured (for example, by height in millimeters or by number of leaves). If you grow more than one plant under each lighting condition, you can plot the average values for all the plants growth under that condition. If you keep records on more than one useful measure of plant growth, create a seperate graph for each measure.