If any provision of this chapter, or the application thereof to any person or circumstance, is held invalid, the validity of the remainder of the chapter and the application of such provision to other persons or circumstances, and the provisions of chapter 3B of title 16, shall not be affected thereby. Without limiting the generality of the foregoing, if any provision of this chapter should be held not to be within the power of the Congress to regulate interstate and foreign commerce, such provision shall not be held invalid if it is within the power of the Congress to provide for the general welfare or any other power of the Congress. If any provision of this chapter for marketing quotas with respect to any commodity should be held invalid, no provision of this chapter for marketing quotas with respect to any other commodity shall be affected thereby. If the application of any provision for a referendum should be held invalid, the application of other provisions shall not be affected thereby. If by reason of any provision for a referendum the application of any such other provision to any person or circumstance is held invalid, the application of such other provision to other persons or circumstances shall not be affected thereby.