Answer:
Independent variable: the concentrations of the chemical product used.
Dependent variable: the productivity rate of tomato plants.
Control variable: irrigation, intensity of sunlight, number of seeds, tomato plants, number of tomato plants, tomato species.
Step-by-step explanation:
The independent variable is one that presents an element that stimulates the visualization of a result and that acts on the dependent variable influencing it to behave in a certain way that will be evaluated for the formulation of the results. In the text above, we can see that the concentrations of the chemical product have the ability to influence the productivity of the tomato, therefore, the concentrations of the product are the independent variables.
Dependent variables, on the other hand, are those that do not provide influence, but are influenced. In the text above, we can see that the productivity of the tomato is influenced by the concentrations of the chemical product, therefore, the productivity of the tomato is the dependent variable.
The control variables are all the experimental elements that remain the same, without changes throughout the experiment. In the case of the experiment quote: irrigation, intensity of sunlight, number of seeds, tomato plants, number of tomato plants, tomato species.