W. Mann, H. Krug
Following the approach of Krug and Liebig (1979 a, b), outlined in the lecture of Liebig and poster 17, the CO2 factor was integrated into the planning model for radiation and temperature. The response surface for autumn plantings of lettuce (fig. 1), graphs for the growth periods (100 g) as a function of temperature set point and CO2 -concentration (fig. 2 and 3) as well as corresponding input factor costs (energy + CO2 , fig. 4 and 5) are presented.

CO2 -enrichment results in remarkable increases of growth rates, particularly in combination with high irriadiances and favourable temperatures. Therewith the growth period will be shortened, especially if due to better growth in favourable environments unfavourable conditions will be avoided. This can be achieved in autumn by enhancing growth to finish the crop before winter, in spring by later plantings and enhancing growth to finish at the time scheduled.

Mann, W. and Krug, H. (1989). PRODUCTION PLANNING - CO2 ENRICHMENT. Acta Hortic. 248, 201-206
DOI: 10.17660/ActaHortic.1989.248.23

Acta Horticulturae