Effect of spectral quality on horticultural plant propagation in a greenhouse

A greenhouse of semi-circular shape was employed to study the effect of spe ctral light response on the stem-cutting propagation of horticultural plant s. The number of days taken for the root formation were noted and it was ob served that the stem cuttings showed earlier root formation under a red-tin ged greenhouse followed by a blue-tinged greenhouse. The UV-stabilised shee t prolonged the formation of well-formed roots by an additional three days over that for the control system. The study shows that the temperature grad ient is not only a minimum at canopy level but also negative throughout in blue cladded greenhouse and a maximum vertical heat flux of zero is noticed . (C) 1999 Elsevier Science Ltd. All rights reserved.