Section 75. The commissioner may prescribe and enforce such rules and regulations as to the sale of commercial fertilizers, soil conditioners, or agricultural liming materials as he deems necessary to enforce sections sixty-four to seventy-eight, inclusive, and may prosecute or cause to be prosecuted any person who violates any provisions of said sections; provided, however, that the effective date of regulations pertaining to ”guaranteed analysis” shall be not less than six months following the issuance thereof, and that for a period of two years following the effective date of said regulations the equivalent of phosphorus and potassium may also be shown in the form of phosphoric acid and potash; and, provided further, that after the effective date of a regulation issued under the provisions of this section, requiring that phosphorus and potassium be shown in the elemental form, the guaranteed analysis for nitrogen, phosphorus and potassium shall constitute the grade. Regulations prescribed in this section shall contain the accepted definitions and official fertilizer terms issued by the Association of American Plant Food Control Officials. No complaint based upon analysis of samples shall be made if samples are taken otherwise than as provided in section seventy.