| Short plant dormancy periods in warm regions make the use of dormant plant cuttings for streambank stabilization difficult because the abbreviated time complicates construction scheduling. This study applied three storage treatments (cold storage at 4.4°C, onsite storage in compost and onsite storage in water) to Salix nigra cuttings to explore the possibility of extending the dormant condition of cuttings. Field experiments that involved cutting harvest, storage treatment, planting and monitoring were conducted from February 2001 to March 2002. Cuttings were installed on an embankment of a 33% gradient located in Bryan, Texas. Three installations of the cold-stored cuttings were conducted in March, April and May. Two installations of the onsite-stored cuttings were conducted in April and May.; One year after installation, 56.3% of cold-stored cuttings survived while cuttings of onsite storage in compost and in water had 0% and 2.6% survival, respectively. This result indicates that the cold storage treatment appears to be "applicable." Further, cold stored cuttings planted in March had a significantly higher survival rate (81.3%) than those planted in April (43.6%), and May (43.8%). This may result from the temperature difference between different installation months. The higher the mean monthly temperature of the installation month, the lower the survival rate. Cutting size also affected the survival of cold-stored cuttings. Within the tested diameter range of approximately 10 mm to 29 mm, cuttings of small diameters survived better than those of large diameters.; In this study, cuttings used in cold and onsite storage treatments had to be harvested from Bryan and Texarkana, Texas, respectively, due to dormancy breaking. This represents a selection threat to the study, which makes the identification of the cause of the survival difference among storage treatments impossible. The low survival of cuttings in the onsite storage treatment may result from (1) different physiological conditions nurtured by the climate at the harvest location, (2) different genotype, (3) discrete rather than continuous chilling effect that was applied to the cold storage treatment, (4) excessive soaking applied to cuttings stored in water or lack of pre-planting soaking to cuttings stored in compost, and (5) inevitable root damage during cutting installation. |
