The Plant Mass of Tomatoes Grown in Different Environments

May 8, 2008

Soda Bottle Hydroponics for Kids

PURPOSE

In the first phase of the experiment, the purpose was to measure the mass of tomato plants grown in different temperatures. In the second phase of this experiment the purpose was to measure the mass of the tomato plants grown in different soil moisture levels.

I became interested in this idea when my grandma complained about how her plants had trouble growing in our environment since it is so hot and dry.

The information gained from this experiment would help farmers and/or gardeners know the best environment for growing tomatoes, and how much water to add to them.

HYPOTHESIS

My hypothesis for the first phase was that the tomatoes would have greatest plant mass in the environment with high temperatures. My hypothesis for the second phase was that the tomatoes would have greatest plant mass in the environment with high soil moisture.

I based my hypothesis on a book called Tropical Rain Forests by April Sayer? Pulley. She indicates, “Rain forests get a lot of rain. ” She added, “The humidity is extremely high, because of the heat from the sun. ” Since plants need a lot of water, but not too much, the fact that it rains a lot is good. Since it is hot if it rains too much than the heat will make some of the extra water evaporate.

EXPERIMENT DESIGN

The constants in this study were:
* Growing temperature for all of one group
* Seed age
* Type of seed (steak tomatoes)
* Brand of seed
* Size of pot
* Potting depth
* Shape of pot
* Amount of soil
* Type of soil
* Lighting
* Type of grow light
* Type of plant
* Scale used to weigh tomatoes
* Time tomato plants are picked at conclusion of experiment
* Length of time tomato plants are allowed to grow
* Size of the tent
* Material made for tent (PVC pipes, black plastic, clear tape)
* Time of day plants are watered

Variables:

The first manipulated variable was the temperature of the three “tents”. The second manipulated variable was the amount of water added to the two test groups in each of the three “tents”.

The responding variable was the mass of the tomato plants after they have grown for four weeks.

To measure the responding variable the tomato plants are pulled, roots and all, and weighed on a triple beam balance.

MATERIALS

8 packs of seeds
3 "Tents" (PVC pipes, Black Plastic, Clear Tape)
3 Bags of soil
3 Heat lamps
12 Pots
1 triple beam balance
1 Measuring cup

PROCEDURES

1. for two weeks to allow plants to start.
2. Design an accurate drawing of the tent fame and build three “tents”:
A) Cut PVC according to design and put together.
B) Tape black plastic around PVC pipes so that the heat is held in and it makes a tent like structure.
C) Put a thermometer inside each of the tents so that the temperature can be monitored.
D) Put grow light in each tent.
3. Put “tent 1” in my garage (coldest environment).
4. Put “tent 2” in my living room, nearest to the home heating vent (warmest environment).
5. Put “tent 3” in my living room (away from home heating vent). Cut slits in the top of the “tent” to allow heat to rise out of the “tent” (close to room temperature).
6. Get twelve little pots (four per tent) and put them on the plastic covered floor.
7. Open up the bag of soil.
8. Put soil in each pot 8 cm above rim.
9. Germinated starts are placed into pots.
10. Put four planted pots in each tent directly under grow light.
11. Label two pots “A” and two pots “B” in each tent. Pots “A” receive 360 ml water and Pots “B” receive 120 ml water.
12. Water pots “A” and “B” in each of the tents every four days at 5:30pm.
13. Make sure that the tent in my garage is approximately 10 C*.
14. Make sure that the tent in my living room next to the heater is approximately 27 C*.
15. Make sure that the tent in my room is approximately 24 C*.
16. Document temperature and amount of water of pots in each tent every time they are watered.
17. At conclusion of experiment, weigh the plant mass with a triple beam balance.
A) Pick all of the tomato plants from the “tent 1” and weigh them.
B) Repeat above for “tent 2” and “tent3. ”
18. Record data in science notebook.

RESULTS

The original purpose of the first phase of the experiment was to measure the plant mass of the tomato plant grown in different temperatures. In the second phase the purpose was to measure the plant mass of the tomato plants grown in different soil moisture levels.

The results of the experiment were that the tomato plants in the 25°C that were given 120 ml of water weighed the most.

CONCLUSION

My hypothesis for the first phase was that the tomatoes would have greatest plant mass in the environment with high temperatures.

The results indicate that this hypothesis should be accepted.

My hypothesis for the second phase was that the tomatoes would have greatest plant mass in the environment with high soil moisture.

The results indicate that this hypothesis should be accepted

Because of the results of this experiment, I wonder if tomato plants would grow better in even warmer temperatures.

If I were to conduct this project again I would have started growing my tomato plans earlier so that they would have more time to grow and I would have but more plants per group.

Researched by Whitney K.2003-04

Written by Mike · Filed Under Hydroponics Experiments