ISHS Acta Horticulturae 197: Working-party on Greenhouse Chrysanthemum
INFLUENCE OF TEMPERATURE, PHOTOSYNTHETIC PHOTON FLUX AND PLANT AGE ON LIGHT UTILIZATION EFFICIENCY IN CHRYSANTHEMUM. |
| Authors: | M.G. Karlsson, R.D. Heins, E.J. Holcomb |
| Abstract:
Dry weight production and plant quality as a function of light energy, and day and night temperature were studied in Chrysanthemum morifolium ‘Bright Golden Anne’. Light utilization efficiency (LUE) was determined as the ratio between measured dry weight production and potential dry weight production. Changes in LUE and dry weight gain were determined from the start of short days (SD) through flowering under 15 climatic combinations of photosynthetic photon flux (PPF), day temperature (DT) and night temperature (NT) arranged in a central composite design. The PPF levels ranged from 50 to 600 μmol s-1m-2 and DT and NT from 10°C to 30°C. LUE was most strongly influenced by the PPF under which the plants were grown. In general, as PPF increased, LUE decreased. Within a common PPF level, LUE was greater with a 26°C DT or NT compared with a 14°C DT or NT. DT only had a small effect on LUE except at 10°C where LUE was markedly depressed. Dry weight gain of plants during development was primarily a function of PPF. Temperature had a smaller influence on dry weight gain. Highest plant quality occurred on plants grown under high PPF levels (greater than 10 mol d-1) and day and night temperatures of 14°C to 20°C. The ability to increase LUE by temperature was small within a PPF level. Highest LUE or dry weight did not correlate with highest plant quality. | |
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