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The materials required for this science fair project:

-    1 packet of tomato seeds
-    2 garden pots
-    Soil for the 2 garden pots
-    7 liters of milk (the same type/brand)
-    7 liters of distilled water
-    1 measuring cylinder
-    1 ruler
-    1 black marker pen, and writ


1.    For this science fair project, the independent variable is the method of watering the tomato plants –using water or milk. The dependent variable is the height of the tomato plant in the pot. This is determined by measuring the height of the plant with a ruler. The constants (control variables) are the environment the pots are kept in (temperature, humidity, light, etc), the number of seeds used, the type of seeds and the size of the pot and the type of soil.

2.    The 2 garden pots are labeled as “Water” and “Milk”. Each of the 2 pots is filled with the same amount of soil. Poke 10 holes in the soil in each of the pots (about an inch deep) and place 10 tomato seeds in each of the 2 pots. Cover the holes with soil. Additional seeds may be planted in case some of the seeds do not germinate. The extra plants can be removed later.

3.    For the next 14 days, water the first pot daily with  500ml of water and the second with 500ml of milk.

4.    Between days 5 to 14, the height of the tomato plants in the pots are measured. The measurements  are recorded in the table given below.

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Complexity level:
Project cost ($):
Time required:
1 day to prepare, 14 days for observation
Material availability:
Easily found
Safety concerns:

Basic safety requirements