Ideas for Student Experiments

Our hope is that as students work with plants they will develop questions of their own that they'd like to find answers to.

Ideas for Tropism Experiments:

We did a series of "tropism" experiments that we hope will inspire students. Here are two slideshows that include information about "tropism" and the results of our experiments. One slideshow is more student-friendly; the other is more detailed:

Gravitropism
Gravitropism - Students

Ideas for Seedling Density Experiments


Any vegetable gardener knows that plants need space if they are going to produce a good crop. We did a simple experiment to see the effect of seedling density on the mass of the radishes that grown. The results were very clear. What related experiments could be tried? Other types of seeds? Other densities? Other dependent variables? Here is a summary of what we did and our results:


The Effect of Seed Density on Radish plant Growth

Ideas for Germination Experiments

Exposure to Smoke on Germination Rate

Plants that evolve in fire prone environments have seeds that respond to smoke from fire by germinating quickly to take advantage of reduced competition and increased nutrients. Without smoke exposure seeds germinate at different times in order to increase chances of some surviving.

Purple Coneflower is one such plant.

Seeds have evolved to germinate under the right conditions. For some seeds, they are protected from germinating too early with a strong seed coat that inhibits the absorption of water that is the first step of germination.

These seeds depend on freeze thaw cycles, traveling through the digestion system of an animal, or age to weaken the seed coat. For some, long soaking in water will work as well.

Scarification and Germination rate

Ideas for Germinating Fast Plant Seeds

We tried germinating Fast Plant seeds under different conditions. Our control was 100 seeds in a petri dish on wet paper towel sitting on a lab bench with normal classroom light.

We realized Fast Plant seeds are successful germinators and so think we might direct students toward conditions to avoid if you are growing Fast Plants. We think they will be motivated to see if they can slow the germination rate of these seeds.

We repeated our germination experiments with a slightly different combination of conditions and with only 30 seeds per petri dish this time.