Carbon dioxide enrichment can also be a limiting factor in photosynthesis. Elevated levels Of C02 will not be beneficial at low light intensifies or temperatures. If light intensity or temperature is increased, then higher levels Of C02 can be introduced to stimulate further growth increase. It is worth noting that elevated C02 levels can also be expected to increase fertiliser and water requirements.
Photo: fal.de
The relationship between C02 levels, light intensity and temperature and their interactive effects upon photosynthesis are well illustrated in curves developed by Gaastra (1962) for cucumbers. In the lower curve the rate of photosynthesis begins to plateau at a light intensity of about 40,000 lux (3800 footcandles), independent of the temperature being maintained at either 20°C or 30°C. The 300 ppm level Of C02 became a limiting factor at this point.
When the C02 level was elevated to 1300 ppm at 20°C, the rate of photosynthesis increased. At this point the temperature became the limiting factor. With a temperature increase to 30°C, at the same 1300 ppM Of C02, another increase in photosynthesis was recorded.
by: Steven Carruthers
Carbon dioxide enrichment
7:08 PM
ThanateTan
