the Role of light and temperature in growth and development regulation. Cultivation of plants at artificial light

you are: the Role of light and temperature in growth and development regulation

In dwellings, experimental laboratories and in some branches of gardening of a plant in escalating scale grow up at artificial illumination. Some indoor plants occurring from tropics where they grew at strong zatenenii in jungle, can survive and grow at amazingly low light exposure; other kinds demand additional light if it is necessary to grow up them not in the open air or in a hothouse, and in other places. overall objective of additional illumination consists, of course, in supply by energy for photosynthesis. However we should not lose sight of that light influences and on the plant form (see gl. 11) also that light of appropriate spectral structure is necessary for reception of the healthy, well generated plants.

For cultivation of plants it is possible to use many various light sources. The main thing thus that useful radiation of high intensity without superfluous allocation of heat has been provided. To these requirements is better satisfy luminescent lamps. In hothouses it is possible to apply mercury lamps, but they are great and allocate heat significant amount, and also strongly radiate a near ultraviolet which is absorbed by plants without advantage and can even cause damage. Usual lamps ' a daylight ' or ' cold white ' luminescent lamps they radiate the greatest energy not in the main photosynthetic range - give basically a strip about 560 nanometers with smaller peak of radiation at 475 nanometers. special luminescent lamps ' groljuks ' (Gro-Lux) let out light which structure corresponds to absorption by a chlorophyll, with high peaks of radiation at 440 and 660 nanometers more. These lamps for our eye seem pink. The African violets, gloksinii and other plants under these lamps grow excellently. However both standard luminescent lamps, and lamps ' groljuks ' practically do not give light with lengths of waves more than 700 nanometers; and as light of this area influences as photosynthesis, and especially on morfogenez, many plants receiving light only from fluorescent sources, do not grow optimum. Two decisions of a problem are possible: use of other light sources or addition to luminescent lamps of other lamps. Luminescent lamps ' groljuks ' with a wide spectrum give more balanced illumination with considerable radiation in the field of more than 700 nanometers. Creating conditions for the best growth. however very much, roads, and the same results it is possible to receive these lamps with ready smaller expenses, simply adding to standard fluorescent sources some lamps nakalivanija. There are the special mercury lamps which are letting out light at 660 nanometers or a flowerpot more 700 nanometers, but they are too great and besides operate more likely as a dot light source - do not create a wide homogeneous light field. Value has not only light the basic morfogennoj lengths of a wave of 720 nanometers: there is weighty data in favour of that light in near infra-red area (720-800 nanometers) too promotes growth; the plants receiving additional illumination in this range, are more similar under the form with growing at a sunlight. As lamps nakalivanija allocate a considerable part of energy in this area (even more-in than infra-red area where energy is useless and for our sight, and for fotomorfogeneza), they successfully supplement fluorescent lamps. It is important to shine plants not only one lamps nakalivanija as they have not enough light in dark blue and red areas in comparison with distant red and infra-red zones; These lamps are perceived by plants basically as sources of distant red light at which the plants of an unnatural kind seeming etiolirovannymi are formed.

Now industrial concerns make considerable efforts, aspiring to create lamps, suitable for mass use in gardening. Such lamps should give light of sufficient force and suitable spectral structure, and also to be economic at installation and operation. Lamps let out till now neoptimalny in many respects: lamps ' gro-lux ' on the general radiation of light not so are effective, as fluorescent lamps or ' cold white ' luminescent lamps, and, except that, road whereas lamps nakalivanija radiate the most part of the energy in infra-red area. Now most economically combined application of fluorescent lamps and lamps nakalivanija, but here remains, of course, a wide field of activity for improvement.