((a)) Whenever the Secretary of Agriculture has reason to believe that any article or articles are being or are practically certain to be imported into the United States under such conditions and in such quantities as to render or tend to render ineffective, or materially interfere with, any program or operation undertaken under this chapter or the Soil Conservation and Domestic Allotment Act, as amended [ et seq.], or , or any loan, purchase, or other program or operation undertaken by the Department of Agriculture, or any agency operating under its direction, with respect to any agricultural commodity or product thereof, or to reduce substantially the amount of any product processed in the United States from any agricultural commodity or product thereof with respect to which any such program or operation is being undertaken, he shall so advise the President, and, if the President agrees that there is reason for such belief, the President shall cause an immediate investigation to be made by the United States International Trade Commission, which shall give precedence to investigations under this section to determine such facts. Such investigation shall be made after due notice and opportunity for hearing to interested parties, and shall be conducted subject to such regulations as the President shall specify.

((b)) If, on the basis of such investigation and report to him of findings and recommendations made in connection therewith, the President finds the existence of such facts, he shall by proclamation impose such fees not in excess of 50 per centum ad valorem or such quantitative limitations on any article or articles which may be entered, or withdrawn from warehouse, for consumption as he finds and declares shown by such investigation to be necessary in order that the entry of such article or articles will not render or tend to render ineffective, or materially interfere with, any program or operation referred to in subsection (a) of this section, or reduce substantially the amount of any product processed in the United States from any such agricultural commodity or product thereof with respect to which any such program or operation is being undertaken: , That no proclamation under this section shall impose any limitation on the total quantity of any article or articles which may be entered, or withdrawn from warehouse, for consumption which reduces such permissible total quantity to proportionately less than 50 per centum of the total quantity of such article or articles which was entered, or withdrawn from warehouse, for consumption during a representative period as determined by the President: , That in designating any article or articles, the President may describe them by physical qualities, value, use, or upon such other bases as he shall determine.

((c)) The fees and limitations imposed by the President by proclamation under this section and any revocation, suspension, or modification thereof, shall become effective on such date as shall be therein specified, and such fees shall be treated for administrative purposes and for the purposes of , as duties imposed by the Tariff Act of 1930 [ et seq.], but such fees shall not be considered as duties for the purpose of granting any preferential concession under any international obligation of the United States.

((d)) After investigation, report, finding, and declaration in the manner provided in the case of a proclamation issued pursuant to subsection (b) of this section, any proclamation or provision of such proclamation may be suspended or terminated by the President whenever he finds and proclaims that the circumstances requiring the proclamation or provision thereof no longer exist or may be modified by the President whenever he finds and proclaims that changed circumstances require such modification to carry out the purposes of this section.

((e)) Any decision of the President as to facts under this section shall be final.

((f)) No quantitative limitation or fee shall be imposed under this section with respect to any article that is the product of a WTO member (as defined in ).