The commissioner may comply with the request of any person for official inspection of agricultural products and he or his agents shall have authority to inspect and determine the grade and quality of agricultural products at public markets, concentration points, packing, grading, and processing plants and other places where agricultural products are assembled for distribution; the commissioner shall establish and publish a schedule of charges for such inspection and grading service; and it shall be his duty and he shall have authority to collect such charges for such inspection and grading services, which moneys shall be paid into the state Treasury and reappropriated to the Department of Agriculture for the administration of this article.