Wirkung von Lichtintensität und Lichtqualität auf die Entwicklung der Schattenpflanze Lamium galeobdolon (L.) Crantz und der Halbschattenpflanze Stellaria holostea L.

Abstract

Summary 1. Lamium galeobdolon (L.) Crantz (shadow plant) and Stellaria holoatea L. (half· shadow plant) have been cultivated in the open air at 100 % (full day light) and 1.8 % (shadow) relative light intensity, and likewise in climatic chambers under red light (2.7%), blue light (6.3 %) and red and blue light comprising a small portion of white light (4.6 % relative light intensity). There have been measured number and length of shoots, leaf area per plant, per soil surface (leaf area index) and per leaf weight (specific leaf area), plant dry weight, contents of chlorophyll, protein nitrogen and soluble nitrogen. 2. Stellaria utilized very well higher light intensity for dry matter production. There was a rather low increase (1.5 times) of chlorophyll and nitrogen content in the shadow. 3. Lamium did not show the same rate of dry matter increase with light, because it reached light saturation just above 20 % of relative light intensity. In the shadow chlorophyll and nitrogen content were 2 – 4 times higher than in the full day light. 4. Only Lamium showed differences between the cultures of red and blue light. In blue light the contents of chlorophyll and nitrogen were significantly higher (about 1.2 times) than in red light. Lamium is obviously adapted to both, shadow and high proportion of blue light. The influence with light intensity was much more distinct than the influence with light quality. 5. The results are discussed with respect to the habitat conditions of the two species.