Tomato Experiment
Ages 4 and up (one 45 minute session)
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Objectives:
- To introduce children to the scientific method
- To stimulate curiosity
- To learn prediction, observation and data collection
- To learn to interpret data
Materials:
- 10 overgrown tomato plants about 2 feet tall in 4 inch pots
- Shovel
- 10 Stakes
- Small log book and a pencil
- A scale
- Measuring tape
Set up:
Dig two trenches 12 feet long approximately 12” deep. Space the trenches 36” apart.
Part One:
Talk to the children about root growth and nutrient and water uptake. Pull one of the tomato plants out of its pot and show them how crowded the roots are. Explain how if the plants are buried in the ground ½ way up the plant that roots will grow from the buried stem. Encourage them to speculate on whether that plant will grow better or worse if they planted it that way. Encourage them to think about how they might tell which planting way would be better. Maybe weighing the fruit? Write down their predictions and ideas in the log book and explain it is their experiment data book. Create two groups of tomato plants (5 and 5). Plant one group by just covering the root ball. The second group will be planted with the root ball and half the shoot underground. Put a stake in for each tomato plant. The ones planted to just cover the root ball will need to be tied to the stake immediately so they won’t fall over and breal. Large twist ties work well but leave lots of room for the diameter of the stem to expand without being constriction.
Part Two:
After two or three weeks, sacrifice the end plant from each trench and look at the root growth along the stem and at what happened to the root ball. Count the roots or observe which plant has the most. Throughout the summer keep track of how the plants are doing. Every fruit that is picked should be weighed and the weight recorded. Plant height should be taken periodically and recorded. Is there a noticeable difference?
Revisit the predictions the children made, and discuss which were more accurate.
Questions to ask:
- Everything about roots.
- Everything about tomato culture.
- How big were the tomatoes?
- How many grew on each plant?
- Why did the shoot grow roots?
- Were you right in your prediction?
- Was your reason right?
- Why do scientists do experiments?
