Effect of Light Conditions and Temperature on Fresh Yield of Some Spice Plants Grown in Containers

The aim of this work was to study the effect of quantity of light, length of day and temperature on yield of five species of spice plants. Another purpose of the study was to determine the correlation between the climatic factors mentioned above and to find the optimum coefficient of growth for the individual species. Three levels of temperature during the day were determined: 15, 20 and 25°C (at night the temperature was by 5°C lower). Two daily light integrals (2.9 and 3.8 mol·m^-2·d^-1) and three levels of photoperiod (12, 14 and 16-h) were chosen.

Photon flux and temperature had the greatest influence on yield. A higher yield of fresh mass was obtained for all species in the condition of 3,8 mol·m^-2·^d-1. Yield depended linearly on amount of photon absorbed by plants in the growth time. Dry weight was directly connected with RRT (the ratio of radiant energy to thermal energy) and increased linearly as RRT increased.