Influence of treatment on rooting of arctic Salix species cuttings for revegetation

Increased northern exploration and resource extraction highlight a need for effective revegetation techniques to restore disturbed environments. This study assessed effects of indole-3-butyric acid (IBA), water extracts of Salix and smoke, soaking time, and collection time on adventitious and lateral root development of Salix species cuttings collected from Diavik Diamond Mine Inc., Northwest Territories. Over 80 percent of fall and spring cuttings developed adventitious roots, yet only 30 percent of summer cuttings rooted, indicating strong seasonal influences. Many cuttings developed extensive root system architecture in 60 days; some developed up to six orders of roots. Root length decreased with increasing root order in all seasons, and season influenced length within root orders. Application of IBA increased number of primary roots per cutting per season and number of cuttings with less than fifty secondary roots per primary root. Longer soaking times increased number of primary roots per cutting in different seasons, and soaking up to ten days increased longest root length. Salix and smoke water extract applications increased number of cuttings with twenty-five to seventy-four secondary roots. This research highlights the importance of treatment effects on adventitious and lateral root development to optimize root system architecture of cuttings from northern shrub species.