The morphological characteristics, root growth potential and flushing response of rooted cuttings compared with transplants of Sitka spruce

The morphological and some physiological attributes of Sitka spruce (Picea sitchensis (Bong.) Carr) rooted cuttings derived from juvenile selections i n the nursery were compared with those of conventional unimproved transplan ts grown in Ireland in 1996 and 1997. A field trial was established in the second year to assess flushing and growth responses of the stock. Although some were highly significant, absolute differences between stock types in m ost morphological characteristics were small. Cuttings had much fewer branc hes/cm shoot, and root dry weights were smaller than in transplants, but th e shoot/root ratio differed little between stock types. The root growth pot ential (RGP) of cuttings was good, but was lower than that of the transplan ts in 1997 but not in 1996. Cuttings flushed 3-5 days earlier than the tran splants in the RGP tests, and up to 10 days earlier in the field trial. The earlier flushing of the cuttings probably occurred largely because the cut tings were derived from material selected for having rapid juvenile growth rates. The height increment of cuttings was greater than that of transplant s after one growing season in the field. ((C) Inra/Elsevier, Paris.).