(4) in handling, planting, drying, packing, packaging, processing, freezing, grading, storing or delivery to storage or to market or to a carrier for transportation to market any agricultural or horticultural commodity but only if the service is performed as an incident to ordinary farming operations. The provisions of this paragraph shall not be deemed to be applicable with respect to service performed in connection with commercial canning or commercial freezing or in connection with any agricultural or horticultural commodity after its delivery to a terminal market for distribution for consumption. As used in this subsection, the term "farm" includes stock, dairy, poultry, fruit, fur-bearing animal and truck farms, plantations, ranches, nurseries, greenhouses, ranges and orchards;