Controlled-Environment Facility

a chamber or complex of chambers for growing plants under regulated artificial conditions. The simplest controlled-environment facilities are reach-in growth chambers, the bottoms of which measure approximately 1 sq m; plants are cared for and observed through a special opening on the side. Small walk-in growth chambers, the floors of which usually measure approximately 5 sq m, are equipped with shelves; a person may enter the chamber to care for the plants.

The most sophisticated controlled-environment facility is the phytotron, an entire building consisting of regulated chambers that permit the simulation of various climates. A modern phytotron is usually equipped to regulate air and soil temperature, relative atmospheric humidity, and intensity of radiation (illumination). Powerful incandescent, xenon, mercury, and luminescent lamps are used as sources of radiation. In some chambers the regime of air temperature and humidity is kept constant, while in others it is varied to simulate conditions of day and night.

The first phytotron was built in 1949 in the USA (California) by F. W. Went. The first in the USSR was built between 1949 and 1957 at the K. A. Timiriazev Institute of Plant Physiology of the Academy of Sciences of the USSR in Moscow. A similar phytotron was constructed later at the biology department of the Lomonosov Moscow State University. A phytotron has been operating since 1969 at the Siberian Institute of Biochemistry and Plant Physiology.

The phytotron is used mainly to study the effect of environmental factors on plant organisms, a subject of great significance for the development of hybrids and varieties.