TRANSFERABILITY OF PLANT REACTION PARAMETERS TO CLIMATE – GROWTH CHAMBERS, GREEHNOUSES, FIELD –

To parameterize the response of radish (Raphanus sativus var. sativus) to temperature and radiation, experiments in growth chambers were conducted.
Considering the problems of transferability of the parameters to practice, later on the response of the same cultivar was tested in greenhouses and in the open field.
By growth analysis , Leaf Area Ratio (LAR), Leaf Weight Ratio (LWR), Specific Leaf Area (SLA), Net Assimilation Rate (NAR) and Relative Growth Rate (RGR) were determined.

LAR (Fig. 1), characterizing plant morphology, reacted significantly to radiation and temperature, but was not specifically affected by the site.
The same was true for LWR and SLA. NAR (Fig. 2), as a physiological component of growth, did not react to temperature in the range of 10° to 20° C, but to radiation and distinctly to the site.
Compared to the growth chamber NAR was somewhat lower in the greenhouses and considerably lower in the open field.
This may be due to less favourable environmental "rest conditions", e.g. air humidity or water supply. RGR (Fig. 3) as a product of LAR and NAR showed corresponding differences.

The response pattern to temperature and radiation was basically comparable in the environments testet.
The absolute values of NAR and RGR, however, were higher in growth chambers, presumedly since other growth factors could be kept closer to the optimum.

International Symposium on Models for Plant Growth, Environmental Control and Farm Management in Protected Cultivation

H. Krug, M. Fink

https://doi.org/10.17660/ActaHortic.1989.248.50