EFFECTS OF CO₂ AND PLANT DENSITY ON GROWTH AND YIELD OF GLASSHOUSE GROWN FREESIAS

It has been demonstrated for many glasshouse crops that increasing the CO₂ concentration leads to improved quality and yield, while concentrations below the ambient level lead to loss of quality and yield.
Relatively few experimental data are known for freesia in this area and on freesia holdings CO₂ enrichment is applied only to a limited extent.

For this reason in an experiment 4 CO₂ concentrations were combined with 4 plant densities to investigate the effect of CO₂ on quality and yield of the cultivar ‘Blue Heaven’. The CO₂ concentrations realised were 265, 360, 560 and 860 ppm.
Plant densities were 57, 78, 100 and 121 corms per net square metre.
The concentration of 265 ppm resulted in a 20% lower yield of stems, corms and cormlets and a reduction of stem quality as compared to 360 ppm.
Increasing the concentration to 560 ppm resulted in a 20% higher yield and an improved quality as compared to 360 ppm.
Levels exceeding 560 ppm did not improve yield and/or quality.
Higher plant densities did not give higher yields but evidently reduced quality.
Vase life was not affected by differences in CO₂ concentrations or plant densities.

IV International Symposium on CO2 in Protected Cultivation

J.C. Doorduin

https://doi.org/10.17660/ActaHortic.1990.268.16