Effect of short-term exposure to red and blue light on dill plants growth.

Effect of the end-of-day and the end-of-night red and blue light in dill growth was investigated. Ambrozja dill ( Anethum graveolens L.) cvs were grown in vegetation chambers in completely controlled conditions exposed to white diode light. Red and blue light was employed for 30 min before the initiation or after the end of the lighting period. The values of plant fresh mass, area and height parameters were the highest for plants treated with red light at the end of night. The application of red light at the end of day exerted a similar effect on plants as the exposure of plants to blue light at the end of night. Plants treated with blue light at the end of the lighting period were characterised by the poorest growth rate. Plants additionally lighted with blue light were found to have both distinctly smaller mass as well as area in comparison with plants exposed to red light. Both methods are useful to control the plants growth depending on the phase of plant development and growers' requirements.