Effect of light intensity and water flow rate of hydroponic unit on thyme (thymus vulgaris l.) production

Hydroponics is a style of cultivation without soil or with growing media, the main aim of the present research is to study the effect of using three different supplemental light intensity treatments (LED light) and four treatments of nutrient (NPK) water flow rates on the Properties of Thymus vulgaris L. plant. The results obtained were compared also with the control (with no supplemental LED light). The light intensities of LED light sources In addition to natural sunlight were: 30, 25 and 20 μmol m -2 s -1 . The four water flow rates were 20, 15, 10 and 5 l/h. Some properties of Thyme plant were determined as plant length (cm) and the dry weight) g) was measured after measuring fresh weight) g). Also the amount of Photosynthetic pigments and accumulation of essential oil in leaves were determined. The results showed that, the highest values recorded in thyme plant growth of fresh weight, dry weight and height were 28.7g, 8.4g and 36 cm respectively, at highest light intensity 30 μmol m -2 s -1 (L1.) and middle flow rate 10 l/h (F3.) the maximum amount of Photosynthetic pigments in leaves were at the middle light intensity 25 μmol m -2 s -1 (L2.) and middle flow rate 10 l/h (F3.) where chlorophyll A, B, total chlorophyll and carotenoids were 4.55,2,6.57 and 2.32 mg/g respectively. It is clearly observed that the highest accumulate of essential oil was4.66 % at the highest light intensity 30 μmol m -2 s -1 (L1.) and middle flow rate 10 l/h (F3.), when compared with the rest of treatments. Conclusively, from these results it could be concluded that light intensity and water flow rate have great effect on productivity of thyme plant under Hydroponic system.