In Farmers Irrigation Co. v. McComb (1949) 337 U.S. 755, the issue was whether certain employees of a farmer-owned mutual ditch company, the sole purpose of which was to distribute irrigation water to its owners, were exempt from the provisions of the Fair Labor Standards Act (29 U.S.C. 201 et seq.). The company claimed that the employees were exempt under 29 United States Code section 213 (a)(6) as employees "employed in agriculture." The court held that the exemption did not apply, although it conceded that the work performed by the company's employees was necessary to agricultural production. "Functions which are necessary to the total economic process of supplying an agricultural product become, in the process of economic development and specialization, separate and independent productive functions operated in conjunction with the agricultural function but no longer a part of it. Thus, the question as to whether a particular type of activity is agricultural is not determined by the necessity of the activity to agriculture nor by the physical similarity of the activity to that done by farmers in other situations. The question is whether the activity in the particular case is carried on as part of the agricultural function or is separately organized as an independent productive activity. The farmhand who cares for the farmer's mules or prepares his fertilizer is engaged in agriculture. But the maintenance man in a power plant and the packer in a fertilizer factory fn. omitted are not employed in agriculture, even if their activity is necessary to farmers and replaces work previously done by farmers. The production of power and the manufacture of fertilizer are independent productive functions, not agriculture." (337 U.S. at pp. 761-762.)