Folia Horticulturae

Current issue content   Search      

CO2 balance in tomato production in a plastic tunnel of the "Skierniewicki" type

Jerzy Mydlarz

The Franciszek Górski Department of Plant Physiology
Polish Academy of Sciences
Sławkowska 17, 31-016 Kraków, Poland

Changes in CO2 concentration in a plastic tunnel with a tomato crops of cv Ostona were investigated, directional changes of the concentration being determined in the diel cycle. Owing to CO2 consumption in the photosynthetical process and to the limited CO2 exchange with the outdoor atmosphere the concentration of this gas in the stand decreases to about 200 μmol (CO2) mol-1 (of air) during the day. In the zone near the soil only is the concentration higher owing to CO2 evolution in the respiration process of the soil and of the root system of the plants. At night the participation of whole plants in the respiartion process associated with metabolic changes of the soil increase the concentration to about 500 μmol (CO2) mol-1 (of air), this being reflected in the intensification of photosynthesis in the morning hours when the utilization of CO2 accumulated during the night occurs.

The calculation of the amount of CO2 fixed by the crop and of the level of its evolution from the soil shows that, depending on the weather conditions, the CO2 requirement of the photosynthetic process exceed 2.5-3.5 times the amount of CO2 derived from soil respiration.

In long plastic tunnels the recorded decreases in CO2 concentration in a plant stand of great density lead to inhibition of the photosynthesis process and hence the limitation of yield.

Mydlarz J., 1997. CO2 balance in tomato production in a plastic tunnel of the "Skierniewicki" type. Folia Horticulturae 9/1: 113-124.