|Shields jr, Fletcher|
Submitted to: The Scientific World
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/22/2004
Publication Date: 10/22/2004
Citation: Martin, L.T., Pezeshki, S.R., Shields Jr, F.D. 2004. High oxygen level in a soaking treatment improves early root and shoot development of black willow cuttings. The Scientific World. 4:899-907. Interpretive Summary: Stream channel erosion results in degraded water quality, loss of land, and ecological damage, but willow trees rooted from cuttings, are effective and economical plants for re-establishing woody vegetation to stabilize eroding stream channels. Laboratory and field experiments have shown that soaking cuttings in water for 10 days or more prior to planting increases survival and growth rates, but some workers have suggested that running water, which is likely to be high in dissolved oxygen, is better for soaking than stagnant tanks or ponds. A laboratory experiment was conducted to compare the performance of willow cuttings soaked in water with a high dissolved oxygen concentration with cuttings soaked in water with very low dissolved oxygen concentration and with unsoaked cuttings. Roots and shoots of cuttings soaked in high oxygen water were 63% and 49% longer, respectively than those soaked in low oxygen water. These findings suggest that soaking cuttings in running waters high in oxygen content has potential for improving early growth and survival of willow cuttings planted on eroded streambanks.
Technical Abstract: Black willow (Salix nigra) stem cuttings are commonly used to stabilize eroded streambanks with survival dependent on rapid development of adventitious roots to maintain plant water balance, absorb nutrients, and provide anchorage and support especially during flood and drought events. Soaking cuttings in water prior to planting increases survival and growth rates, but it is not known whether the soaking water oxygen concentration affects the rate of root and shoot initiation and growth. A laboratory experiment tested the hypothesis that cuttings treated with high-oxygen (>95% saturation) soaking exhibit more rapid initiation and growth of roots and shoots than cuttings treated with low-oxygen (<15% saturation) soaking and control (unsoaked). Root initiation was enhanced in both high O2 and low O2 soaking treatments compared to the control (100%, 93%, and 41%, respectively, n=27). High O2 soaking led to greater root length than low O2 soaking during the first three weeks after planting (23.8 cm and 14.6 cm, respectively). Shoot growth was greater in high O2 compared to low O2 soaking (9.3 cm and 6.3 cm on day 36 after planting, 10.7 cm and 7.2 cm on day 56, respectively). Shoot and root biomass production was stimulated in both soaking treatments compared to control. Results of this study demonstrated that a high-oxygen soaking treatment has potential for improving early root and shoot growth, and survival in willow cuttings planted on eroded streambanks.