Experiments on crop yields

Have a look in Basics - Plants and climate - Plants and the environment and see how high temperatures and water logged soils affect the growth of important crops.

Experiment

Try this simple experiment and see just how important water, warmth, and light are to the growth of plants.

What you need:

- 1 pack of cress seeds 
- 3 plastic boxes  
- a piece of filter paper (e.g. a coffee filter) 
- 1 ruler

1. The equipment you will need. 
Photo: Sarah Ancot.

Sowing:

- Mark the plastic boxes 1, 2 and 3.

- Cut the filter paper to fit.
   Put a piece in each box.

- Sow the cress seeds in each box.

2. Sowing
Photo: Sarah Ancot

Box No. 1: Keep the filter paper wet and place the box near a south facing window.

Box No. 2: Place the box near a south facing window but don't water it

Box No. 3: Keep the filter paper wet and store the box in a dark cupboard. 

Water boxes 1 and 3 once a day!

Once the seeds have germinated (this will take several days) measure the height of the cress at the same time everyday using a ruler.   

Record the results in the table below.

Keep an eye on what happens in the boxes and don't forget to water boxes 1 and 3 once a day.

3. Experiment set up
Photo: Sarah Ancot

Download: Worksheet --> Solution

...And if you want a quick experiment:

What you need:

- 3 boxes of water cress from the supermarket

- 1 ruler

- a set of kitchen scales

4. Set up for the quick experiment
Photo: Sarah Ancot

Instructions:

- Mark the plastic boxes with the numbers 1, 2 and 3.
- Weigh each box and record the results in the table below!
- Measure the height of the cress and record this in the table as well.
- Put the boxes of cress in different places:

Box No. 1: Place the box near a south facing window but don't water it.

Box No. 2: Water the box regularly and place it near a south facing window.

Box No. 3: Make sure the box is wet and then put it in the freezer for 24 hours.

Water Box 2 regularly!

After 24 hours weigh and measure the cress boxes again.  Record the results in the table below. 
Keep an eye on cress box number 3 after you take it out of the freezer.

Download: Worksheet --> Solution

About this page:
author: Sarah Ancot - University of Nürnberg, Nürnberg, Germany
educational reviewing: Dr. Helmut Schrettenbrunner and Julia Heres - University of Nürnberg, Nürnberg, Germany
last update: 2003-09-15