Nitrogen is required in the greatest amounts. It is a major constituent of many plant components including amino acids, proteins, and nucleic acids. Deficiency rapidly inhibits plant growth causing chlorosis – yellowing of older leaves.
Sulfur is required for the synthesis of chlorophyll. It is contained in the amino acids cysteine, cystine, and methionine. These are essential components of proteins, responsible for the formation of disulfide bonds which cause proteins to fold and contribute to the configuration, catalytic, and/or structural properties of the protein. Sulfur Deficiency symptoms often first occur in younger leaves, as Sulfur is not easily translocated within the plant. Characteristic signs of deficiencies include uniformed chlorotic tissue and stunted, thin stemmed growth.