Abstrakt

Study of Effect of Artificial Light and Percentage of CO2 on Plant Growth of TriticumTurgidumand Aristida Purpurea in Artificial Ecosystem

Krishna Mohan CVT, Murali Krishna MPS, Murali Krishna KVSG and Sreenivas VVS

Crop growth experiments in the soil-based closed ecological facility, Laboratory Biosphere, were conducted in artificial ecosystem. Wheat (Triticum Turgidum) and a perennial plant i.e Indian wild grass (Aristida Purpurea) are allowed to grow in the plant trays. The required optimum light intensity is obtained by planning and executing a batch of multivariate experiments. The duration of the exposure of the plant to the artificial light radiation is followed as per natural schedule of the day. The growth rate for the grain crop plant is observed over a period of 87 days during tillering, jointing, booting and heading, anthesis,milk, dough and ripening stages respectively and the growth rate for the perennial plant is observed over a period of 30 days under various experimental conditions. A series of multi-factorial experiments are planned and conducted by considering the following conditions. 1) 0.4%CO₂ is maintained with Artificial light 2) 0.04% CO₂ ismaintained with Artificial light 3) 0.4%CO₂ is maintained with Natural light and 4) 0.04%CO2 is maintained with Natural light. On comparing the growth rates of grain crop plant under different physical conditions it is found that the growth rate is high under artificial lighting when 0.4% of CO₂ is maintained. The next high value of growth rate is observed for the same light with 0.04% of CO2. However the growth rate under natural light is found to be more when 0.4% CO2 is maintained than 0.04% of CO2. On considering the growth rate under the artificial light with 0.4%CO2 as 100 then the growth rate of the same plant when 0.04%CO₂ used is found to be 17%less. Similarly the growth rate under natural light and 0.4% CO₂ is found to be 32% less. On comparing the same with natural light at 0.04%of CO₂, it is observed 40%less. The growth rate under natural light at 0.4% CO₂ decreases by 11.8% when the concentration reduces to 0.04%. Under lowpressure conditions the growth rate under artificial light is 27.7% high compared to the rate using natural light.