The Connection between High Energy and Low Energy Responses to Red and Far-Red Light of Hypocotyl Elongation in Red Cabbage Seedlings (Brassica oleracea var. capitata'Marner Septemberrot')

Growth responses of hypocotyls of Brassica oleracea L. var. capitata caused by diurnal irradiation of various duration (0.5 h/d up to continuous irradiation) and various irradiance (0.3–1.5 W m^?2) with red and far-red light from sources characterized below can be described by the equation: (W= relative effect, I= irradiance, t₁= irradiation time per day, W_s= constant dependent on material and wavelength, α, B and t_s, = constants dependent on wavelength.) On the basis of that equation a possible connection between longtime and short-time irradiation responses is discussed.