GROWTH AND PHOTOSYNTHETIC RATE OF JAPANESE MINT (MENTHA ARVENSIS) GROWN UNDER CONTROLLED ENVIRONMENT

Cultivation of plants using a controlled environment facility provides the possibility of manipulating different environmental factors in favor of plant optimum growth.
The objective of this study was to investigate the effects of different levels of light intensity, light period and CO₂ concentration on photosynthetic rate and growth in leaves of Japanese mint at different ontogenic stages.
In experiment I by combining three different light periods (8, 16 and 24 h d^-1) and two levels of light intensity (100 and 200 µmol m^-2 s^-1) provided by white fluorescent lamps, six treatments were applied on plants growing in chambers.
After 4 weeks, growth parameters were measured destructively.
In experiment Π, plants were grown in a controlled environment using white fluorescent lamps, providing 12 h d^-1 light period and PPF of 100 µmol m^-2 s^-1. At the end of the 5^th week, photosynthetic rate of three leaves in different ontogenic stages was measured under combination of three levels of CO₂ concentration and six PPF levels using a portable photosynthesis measurement system.
The results showed that changing light period, light intensity and CO₂ concentration can alter the photosynthetic rate and the consequent growth of Japanese mint.
Results imply that increasing light intensity and CO₂ concentration would raise photosynthetic rate of Japanese mint.
Moreover, our findings suggest that leaves age as well as the DLI value affects the growth and final yield and should be considered in cultivation management in order to maximize the yield.

VI International Symposium on Light in Horticulture

S.H. Malayeri, S. Hikosaka, Y. Ishigami, E. Goto

fluorescent lamp, PPF, light period, DLI, medicinal plant, CO₂ concentration

https://doi.org/10.17660/ActaHortic.2011.907.6