Any citizen of this state shall have the privilege of submitting to the director of the department of agriculture samples of agriculture and vegetable seeds for test and analysis, subject to such regulations as may be adopted by the director; provided, that the director may by regulations fix the maximum number of samples that may be tested free of charge for any one citizen in a specified period of time, and fix charges for tests on samples submitted in excess of those tested free of charge. The fees collected for testing seed shall be paid to the Missouri department of agriculture and shall be deposited in the state treasury.