The commissioner of agriculture, markets, and food shall adopt rules, pursuant to RSA 541-A, establishing official grades of apples packed or repacked within the state, and may from time to time by rule amend or modify such grades. Before establishing, amending or modifying any such grades, the commissioner shall consult with growers and shippers of apples relative to proposed grades, or, upon written petition of 10 or more growers producing annually an aggregate of not less than 100,000 bushels of apples, the commissioner shall, after reasonable notice specifying the date, place and purpose of the proposed hearing, hold a public hearing for the purpose of obtaining information with a view to establishing or amending or modifying as the case may be, such official grades. The grades so established shall include grades identical in name and requirements with all grades or standards of apples as promulgated from time to time by the Secretary of Agriculture of the United States and commonly known as the United States grades. The commissioner may, in an emergency and after consultation with representative growers, establish temporary grades, without holding a public hearing, but he shall indicate the period for which such temporary grades will be in effect. Apples not conforming to official grades, or, if conforming, not branded in accordance therewith, shall be considered “unclassified” and so branded. Each package shall be packed so that the apples in the shown face shall be reasonably representative in size, color and quality of the contents of the package.