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close this bookCERES No. 074 (FAO Ceres, 1980, 50 p.)
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Cost factors limit potential value of vegetable ''factories''

- energy, investment needs high

Is it possible to "manufacture" vegetables at will? Companies such as General Mills and General Electric seem to think so. General Mills is about to invest $4 million in a "factory" for lettuce and spinach, on the outskirts of Chicago. General Electric, a vast and complex transnational that numbers among its varied interests electronics, computers and jet planes, is planning a similar operation in conjunction with Quaker Oats and Campbell's Soup. Other giants of the food industry, such as Ralston Purina and Castle Cooke, have cornered most of the US market in edible mushrooms. This has been made possible by using advanced techniques, which they began adopting five years ago.

These new produce factories do not resemble hothouses, for they are win dowless metal constructions. Inside, optimum conditions for growing plants are reproduced in an artificially controlled atmosphere. No drought, no unseasonable or heavy rain, no pale winter sun or cloudy sky can affect these crops.

The useful part of solar light is reproduced by means of incandescent or halogen lamps. Special systems produce and maintain the required temperature, humidity and the nutritive composition of the atmosphere. The vegetables, whose roots are submerged in chemically enriched nutritive baths, are adapted to photosynthesis by means of artificial light. Exposure to light in the factories is more prolonged than it would be on a farm. Experts from General Mills calculate that with these techniques lettuces can be grown from seed in only one month, instead of the two or three months that are normally required.

The method has obvious advantages. Many more crops can be produced during the year, crops that cannot be affected by unforeseen weather conditions. Productivity is higher: it is estimated that the factories will produce from 20 to 25 kg of tomatoes per m2 as compared to the 10 kg and 5 kg yielded respectively in hothouses and on farms. Factories can be located close to cities, thus facilitating supplies of fresh vegetables, without any extra transport charges being incurred.

The method, however, has drawbacks. Highly skilled technicians are needed to supervise the various systems used for reproducing climatic conditions, for recycling residual heat from the lamps (which is recovered to heat the buildings in winter), for the re-utilization of water vapour and carbon dioxide given off by the plants, as well as for the electronic control of the environmental temperature and of the nutritive chemical solutions. However, the most serious problem is the cost, estimated to be in the nature of $300 000 per ha. Furthermore, the various systems consume a great deal of energy, which can only be partly recovered.

All this affects prices. These vary according to the product. Mushrooms are relatively cheap, but tomatoes are expensive. The system is based on high prices, since the market does not seem to be elastic and demand is always increasing. Partisans of the method maintain that prices may drop when the market is saturated or when production costs are lowered by means of the research that is constantly under way. It is a technique that holds out many possibilities.

H. von Hulst, Chief of FAO's Agricultural Engineering Service, considers the system to be "very interesting, but one that requires huge investments and which consumes a great deal of energy. At present, it is only feasible in developed or oil-producing countries." Such as, for example, Saudi Arabia, where tomatoes are imported by air from Kenya and the Sudan, or the United Arab Emirates, where they are flown in from India and Lebanon.

The need for fresh vegetables in these desert countries can easily be understood. And, since they are also oilproducers, the price of products from atmospherically controlled factories can compete with air imports. But this is not the case with most developing countries, nor with the greater part of the world's deserts, the latter of which cover 12 percent of the globe. However, how many technical products, which were initially expensive, have ended by becoming much cheaper and being distributed on a worldwide scale?