S08 - Session P4 - Nutritional value of Asian herbaceous plants under different light conditions suitable for indoor cultivation

Authors: Kerstin Paschko, Nikolina Grabovac, Michael Böhme *

Asian herbaceous plants were cultivated in climate chambers in order to simulate an indoor cultivation with following conditions light: day/night 16 h/8h, temperature: 24°C/19°C and humidity: 64%/56% RH. Four plants emerged as most suitable under adjusted conditions: beefsteak plant ( Perilla frutescens var. ciliata ), Vietnamese coriander ( Persicaria odorata ) , Vietnamese balm ( Elsholtzia ciliata ) and Thai basil ( Ocimum basilicum var. thyrsiflora ), of which Perilla and Persicaria were selected for further studies: with the purpose to optimize yield and nutritional value of indoor cultivated plants, as effect of different light conditions by modifying light intensity (81.17-190.06 µmol m -2 s -1 for Persicaria and 177.33-223.4 µmol m -2 s -1 for Perilla ) and adding monochromatic LEDs (443 nm, 515 nm, 629 nm) have been studied. Enhancement of the light intensity correlated positively with biomass accumulation of both plants (+0.56% by 1% increased light intensity for Persicaria +1.92% for Perilla ) and led to higher contents of flavonoids. Contents of polyphenols and anthocyanins (detectable only in P. frutescens) decreased. Modifying light spectrum by adding LEDs led to different results: Blue LEDs (443 nm) increased biomass and decreased polyphenol content of both plants. Red LEDs (629 nm) decreased biomass accumulation in Persicaria and increased flavonoid content in Perilla . Green LEDs (515 nm, only applicated on Persicaria ) affected polyphenol and flavonoid contents positively (although not significantly).The study proved Asian herbaceous plants to be suitable for indoor cultivation. By adjusting light conditions (intensity and spectrum), significant increases of yield and nutritional value can be achieved. However, none of the undertaken modifications had positive impacts on all considered parameters. Therefore, light conditions should be chosen carefully under consideration of all relevant quality parameters.