Today the population centers of industrial North America are increasingly supplied with fresh vegetables from the southern and western states, Mexico, and the Caribbean Islands. Similarly, the cities of central and northern Europe receive fresh vegetables from the Mediterranean countries. Due to the perishability of vegetables, their production was formerly limited to about one day's trip from market. However, with the development of modern refrigeration methods and modern transportation, production has spread to more distant areas. This production, often limited to a single crop, is usually called truck farming. Since the term truck farming has various meanings, extensive vegetable production is sometimes specified as vegetable farming.
In adverse climates perishable vegetables of relatively high value, such as tomatoes, cucumbers, lettuce, mushrooms, and rhubarb, are produced in greenhouses, hotbeds, or forcing structures. This is called vegetable forcing. Production in greenhouses (also called hothouses or glasshouses) is common in the colder areas of Europe and the United States. Greenhouse farming may function on a relatively small scale for a local market or on a large scale for distant markets. Low-cost, transparent plastic film used as a glass substitute has stimulated this type of production.
Vegetable Production in the United States
Vegetable production occurs on farms of various sizes where an assortment of vegetables is the chief or only enterprise, on general farms where a vegetable crop is grown in rotation with agronomic crops, and on large-scale, factory-like farms specializing in one or, at most, a few vegetables. In the United States production on relatively small acreages is concentrated in the states around the Great Lakes; along the Atlantic Seaboard, particularly New Jersey and the Delmarva peninsula; and in the Mississippi Valley. Large-scale, specialized vegetable farms are located in many production areas but are concentrated in the Imperial, San Joaquin, and Salinas valleys of California, the Salt River valley of Arizona, the Rio Grande valley of Texas, and in southern Florida.
Extensive farming of vegetables adapted to storage is also concentrated in favorable growing areas. Potato production in Maine, Long Island (N.Y.), Idaho, and the maritime provinces of Canada and sweet potato production in Louisiana illustrate this practice. Similarly, crops for canning, freezing, pickling, or dehydration are raised in areas favoring dependable quality and production. For this purpose tomatoes, asparagus, and lima beans are grown in California, sweet corn in Wisconsin, green peas in Washington state, snap beans in Oregon, and pickling cucumbers in Michigan.
Business Aspects of Vegetable Production
Vegetable production involves integrated operations of scheduled plantings, scientific growing, precise pest control, efficient harvesting and handling, quality maintenance after harvest, and orderly marketing. Large growers often handle their own packing and shipping and are referred to as grower-shippers. Valuable land resources, heavy capital investments in equipment, and large seasonal expenditures for supplies, labor, and services are required. A given company may operate in more than one production area in order to reduce overhead costs and maintain its products in the market throughout the year. Although these operations are highly mechanized, large numbers of workers are required, and they are often housed and fed on the ranch and transported to work by bus. Special crews perform specific operations, and communications may be maintained by the use of a two-way radio. Highly specialized operations such as fertilizer application, disease control, and harvesting are often performed under contract by agencies specializing in these services.
Large-scale vegetable farming in areas of favorable climate that are distant from areas of consumption has developed as methods have been devised for producing throughout the year, as the economics of volume production have been realized, and as many operations have been mechanized. This type of farming has also resulted from the spread of supermarkets that require a large and dependable supply of vegetables and, perhaps above all, from the development of rapid, refrigerated transportation to carry the vegetables to the markets.
Harvesting and Marketing
All vegetables are perishable and deteriorate after harvest unless processed, as by canning or freezing. Ideally, vegetables to be delivered fresh to the market are harvested carefully at desirable maturity, packaged and cooled without delay, and transported and marketed under continuous refrigeration. Many vegetables deteriorate six to eight times as rapidly at room temperature as at 32° F (0° C). Railway cars and trucks refrigerated by ice or by mechanical units rush the vegetables to terminal markets where refrigerated warehouses, refrigerated delivery trucks, refrigerated display cases, and finally, home refrigerators continue to protect the vegetables against unfavorable temperatures. Only the leafy, vegetative commodities and sweet corn should be kept near 32° F in general; the warm-season vegetables should be held at about 50° F (10° C).
Technological developments in packaging and processing coupled with consumer demands for convenience and the widespread use of self-service supermarkets have caused revolutionary changes in vegetable marketing. The total per capita consumption of commercially produced vegetables remains nearly constant, but processed vegetables have increased significantly at the expense of the fresh. For example, fresh lima beans and peas are disappearing from the market. Furthermore, those vegetables marketed fresh are increasingly packaged in preweighed, prepriced, consumer-sized units and in kitchen-ready condition.
