Electricity in horticulture

British horticulture has developed from a way of life to an industry run on factory lines, where all facets of growing, from seed sowing to marketing, depend on precise control of the environment and maximum operating efficiency. The need to improve the output and quality of greenhouse crops has demanded a strict control of plant climate; the increasing cost of labour, the drift of workers to factories and the restriction of the working week to five days has forced growers to adopt mechanised and automatic methods from seed sowing to harvesting. In 20 years the industry has progressed from using practically no electricity to being completely reliant upon it. A grower without a standby generator could face serious financial loss. Although electricity is not used as a source of heat except in very small holdings, it is essential for ancillary equipment and for the close control of the plant climate, with automatically operated heating, ventilating and watering systems. Concentrating the heat where it is wanted (e.g. in the soil or on the bench) with soil-warming cables can effect economies. There are spectacular results being obtained by using supplementary lighting and propagating plants in a completely controlled environment (i.e. a growing room where heating, ventilating, watering and lighting are provided). The increasing use of ?nightbreak? and ?dusk-to-dawn? lighting enable crops to be produced all the year round to meet market requirements. There are improved methods of rooting cuttings and germinating seeds under intermittent mist, and also of germinating seeds in a germinating cabinet. The grower relies on electric power to shred and mix composts, fill pots, make soil blocks, plant and gather many crops, move material about the holding, and to pump water for irrigation and frost protection of field crops. There is an increasing use of cool stores to hold cuttings until the propagating benches are ready, to store fruit, vegetables and flowers for a favourable - - market, and to remove quickly field heat from greenhouse and field crops as the first step of a cool chain from grower to consumer. Air-supported plastics houses are an alternative to rigid structures, one such experimental ?house? having rigid sides and an inflated roof. Mushrooms are a crop with considerable potential here as air conditioning in the growing sheds is now essential for maximum crop output. The British horticulture industry still needs extensive research and development to be done, particularly in the full and economic use of all forms of lighting for plant production.