Answer:
The sun and the water.
Step-by-step explanation:
In this experiment in which Joey and Elena want to determine which is the best fertilizer to use on pepper plants the independent or controlled variables are the amount of sunlight and the amount of water the plants receive. Identical plants are treated in the same way except for Super Grow fertilizer and Mo' Grow fertilizer. The fertilizers are the independent variable that may or may not show different results on the height of the plants.