29 C.F.R. § 780.146

The inclusion of incidental practices in the definition of agriculture was not intended to include typical factory workers or industrial operations, and the sponsors of the bill made it clear that the erection and operation on a farm by a farmer of a factory, even one using raw materials which he grows, “would not make the manufacturing * * * a farming operation” (see 81 Cong. Rec. 7658; Maneja v. Waialua, 349 U.S. 254). Accordingly, in determining whether a given practice is performed “as an incident to or in conjunction with” farming operations under the intended meaning of section 3(f), the nature of the practice and the circumstances under which it is performed must be considered in the light of the common understanding of what is agricultural and what is not, or the facts indicating whether performance of the practice is in competition with agricultural or with industrial operations, and of the extent to which such a practice is ordinarily performed by farmers incidentally to their farming operations (see Bowie v. Gonzales, 117 F. 2d 11; Calaf v. Gonzalez, 127 F. 2d 934; Vives v. Seralles, 145 F. 2d 552; Mitchell v. Hunt, 263 F. 2d 913; Holtville Alfalfa Mills v. Wyatt, 230 F. 2d 398; Mitchell v. Budd, 350 U.S. 473; Maneja v. Waialua, supra). Such an inquiry would appear to have a direct bearing on whether a practice is an “established” part of agriculture. The fact that farmers raising a commodity on which a given practice is performed do not ordinarily perform such a practice has been considered a significant indication that the practice is not “agriculture” within the secondary meaning of section 3(f) (Mitchell v. Budd, supra; Maneja v. Waialua, supra). The test to be applied is not the proportion of those performing the practice who produce the commodities on which it is performed but the proportion of those producing such commodities who perform the practice (Maneja v. Waialua, supra). In Mitchell v. Budd, supra, the U.S. Supreme Court found that the following two factors tipped the scales so as to take the employees of tobacco bulking plants outside the scope of agriculture: Tobacco farmers do not ordinarily perform the bulking operation; and, the bulking operation is a process which changes tobacco leaf in many ways and turns it into an industrial product.