A tomato farmer is comparing a new kind of fertilizer "SuperGrow" with two fertilizers "MagicGrow and "ExtraGrow." To test the the effect of the different fertilizers on the growth of his tomatoes, they use 3 plots of land, 200 square feet each. On each plot they plant 1-foot apart, 150, 2-week old, Sungold tomato seedlings. Every Monday and Thursday they turn on the watering sprinklers on his plots with equal amounts of fertilizer. At the end of the growing season they compare the yield of the plots by weighing all the tomatoes grown in each plot.
What is the responding/ dependent variable?