Employees engaged in building terraces or threshing wheat and other grain, employees engaged in the erection of silos and granaries, employees engaged in digging wells or building dams for farm ponds, employees engaged in inspecting and culling flocks of poultry, and pilots and flagmen engaged in the aerial dusting and spraying of crops are examples of the types of employees of independent contractors who may be considered employed in practices performed “on a farm.” Whether such employees are engaged in “agriculture” depends, of course, on whether the practices are performed as an incident to or in conjunction with the farming operations on the particular farm, as discussed in §§ 780.141 through 780.147; that is, whether they are carried on as a part of the agricultural function or as a separately organized productive activity (§§ 780.104 through 780.144). Even though an employee may work on several farms during a workweek, he is regarded as employed “on a farm” for the entire workweek if his work on each farm pertains solely to farming operations on that farm. The fact that a minor and incidental part of the work of such an employee occurs off the farm will not affect this conclusion. Thus, an employee may spend a small amount of time within the workweek in transporting necessary equipment for work to be done on farms. Field employees of a canner or processor of farm products who work on farms during the planting and growing season where they supervise the planting operations and consult with the grower on problems of cultivation are employed in practices performed “on a farm” so long as such work is done entirely on farms save for an incidental amount of reporting to their employer's plant. Other employees of the above employers employed away from the farm would not come within section 3(f). For example, airport employees such as mechanics, loaders, and office workers employed by a crop dusting firm would not be agriculture employees (Wirtz v. Boyls dba Boyls Dusting and Spraying Service 230 F. Supp. 246, aff'd per curiam 352 F. 2d 63; Tobin v. Wenatchee Air Service, 10 WH Cases 680, 21 CCH Lab Cas. Paragraph 67,019 (E.D. Wash.)).