Journal of Applied Horticulture. 2001: 3(2): 71-74

Use of photoselective plastic films to control growth of three perennial salvias

Wilson, S B; Rajapakse, N C

Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945, USA.

Plant response to a photoselective plastic film with a red (R)- or far-red- (FR)-absorbing property was tested using the three perennial salvias: Indigo Spires sage (Salvia longispicata x Salvia farinacea), wine sage (Salvia splendens 'Van Houttei'), and Mexican sage (Salvia leucantha). Films were designated AFR (FR-light-absorbing film), AR (R-light-absorbing film), and control (clear plastic film). Solar light transmitted through the AFR film reduced plant height by 17-36%, depending on the species. This correlated with a reduction in internode length and stem dry weight. Light transmitted through the AR film did not significantly affect plant height, regardless of species. Leaf area was not significantly affected by the AFR or AR film compared to the control film, regardless of species. Leaf dry weight under AFR was reduced in Indigo Spires sage and Mexican sage, but not in wine sage. Flower development (days to flower and flower number) was not significantly affected by the AFR or AR film compared to the control film, except that flower number of indigo spires sage was reduced when grown under AFR film. These results indicate that the compactness of three perennial sage species can be achieved by selective reduction of the far-red wavelengths from the sunlight.