The influence of physical factors on growth and development

Abstract

It is necessary, both for research and for practical application of in vitro culture, that a growth room is available in which the light, temperature, etc. can be controlled. In most cases one growth room is insufficient, especially when working with different species having very different temperature requirements, or with one species under different temperature regimes. It should be well insulated, so as not to be effected by external temperature changes. Lighting is usually supplied by fluorescent tubes the chokes (control equipment) of which are (is) mounted outside the growth chamber, since if they are inside the chamber extra cooling is necessary to dissipate the heat given off. When in use the fluorescent tubes produce so much heat that the culture room needs to be cooled, the amount of cooling necessary depending on the number of fluorescent tubes in use. The temperature of a well insulated chamber will certainly remain at the desired temperature during the dark periods and if badly insulated heating may be necessary to maintain the desired temperature. The temperature control (cooling and heating), is achieved with the aid of a thermostat.