Canadian Forest Service Publications
Short- and long-term responses of yellow cypress cuttings to different environmental regimes in the nursery. 1992. Arnott, J.T.; Puttonen, P.; Mitchell, A.K. Acta Horticulturae 319: 377-382.
Issued by: Pacific Forestry Centre
Catalog ID: 3269
To stop shoot growth, induce dormancy and prepare yellow cypress (Chamaecyparis nootkatensis (D. Don) Spach for transplanting, rooted cuttings were grown from 16 July to 31 August 1990 under one of the following environmental regimes: short days and long days (9 h and 18 h) and three levels of water stress (pre-dawn xylem water potentials of -0.4, -1.0 and -1.8 MPa). During this period (the short term), short day and water stress treatments significantly reduced shoot growth. Photosynthetic responses indicated transitory changes in stomatal sensitivity to water stress. Height growth resumed in all cuttings immediately after the treatment period, indicating that a true resting phase had not occurred. Short days increased cold hardiness but water stress did not. After transplanting (the long term), cuttings that had been exposed to short days in the nursery photosynthesized at significantly higher rates during hot weather than cuttings that had been exposed to long day treatments. One year after planting, there were no survival differences among treatments but small additional growth increases were detected on those cuttings that had been treated with -1.0 MPa stress levels in the nursery.