The effect of radiation of LED modules on the growth of dill (Anethum graveolens L.)

Abstract

Light quality is thought to affect the growth and development of plants. We examined how light influences the growth and content of some chemical compounds in dill (Anethum graveolens L.). The plants were grown under different light quality. The share of orange and green light in the spectrum was constant and amounted to 10% for either colour. In the first combination (A, 70/10), there was 70% of red light and 10% of blue light. Other combinations had the following proportions: B 60/20, C 50/30, D 40/40 and E 30/50 of red and blue light. The PPFD was about 155 μmol m-2 s-1. Blue light inhibited the elongation growth as well as leaf area. It had positive influence on the accumulation of dry mass, glucose and fructose in the herb. In the combinations with higher percentage of red light the plants were characterised by higher content of essential oils, macronutrients and zinc. To sum up, we can say that the proportion of red and blue light has significant influence on the morphological qualities, chemical composition and dynamics of photosynthesis in these plants. On the other hand, the selection of spectral composition of LEDs will depend on the result we want to achieve.