Explanation:

E.A. Mitscherlich (1909) was among the first to quantify the relationship between plant growth response and the addition of a growth factor. He developed two laws from his research works which are as follows:

 (i) Mitscherlich’s Law of Physiological Relationships: “Yield can be increased by each single factor even when it is not present in the minimum as long as it is not present in the optimum.”

(ii) Mitscherlich’s Growth Law and Equation: Growth Law: “Increase in yield of a crop as a result of increasing a single growth factor is proportional to the decrement from the maximum yield obtainable by increasing the particular growth factor.”