Images of experimental design and procedure. (A) Lindera benzoin stock plant on a bench with varying banding and indole-3-butyric acid treatments applied to the shoots. (B) Shoot with band removed showing successful blanching of underlying tissue. (C) Cuttings under intermittent mist. (Photo courtesy of the author)
Ithaca, NY The variability among woody plants in their responses to asexual propagation techniques poses challenges and severe limits for commercial production. While some species readily root from stem cuttings, others are more difficult to propagate despite their desirable traits
A new study investigated the efficacy of various methods to stimulate rooting on stem cuttings of northern spicebush (Lindera benzoin), a difficult-to-root woody plant.
Studies have proven evidence that etiolation (growing plants without light or under heavy shade) and the application of growth regulators stimulate root formation. Etiolation, especially when combined with synthetic auxins like IBA or NAA, has shown positive effects on rooting in various plant species.
Banding, a method of localized etiolation where an opaque band is used to exclude light from the base of the cutting, has also been effective, especially when combined with IBA application. Research on northern spicebush (Lindera benzoin) suggests that these techniques can improve rooting success, thus facilitating commercial production. Optimal results are often achieved with a combination of full etiolation and banding.
The objective of this research was to determine the most successful combination of lighting and banding treatments for increased rooting of L. benzoin stem cuttings, making rapid commercial production of this species more feasible. Observed average number of roots per stem cutting of Lindera benzoin seven weeks post treatment under intermittent mist are on the chart below:
Observed percent rooting of Lindera benzoin stem cuttings 7 weeks post treatment under intermittent mist.
The study demonstrates that rooting percentage and root quantity in Lindera benzoin can be notably enhanced through etiolation, shading, and banding methods. Etiolation alone or combined with banding (without IBA) shows the most promising results with minimal effort. However, banding and IBA treatments also significantly boost rooting in both shaded and light-grown cuttings. This allows commercial growers to choose the most suitable propagation method based on their resources and constraints.
Improved understanding of asexual propagation techniques will allow the horticulture industry to make more clonal selections for desirable ornamental traits and bring L. benzoin and other underused woody plants to a wider market. The propagation methods implemented in this experiment have been widely used across numerous genera and species and further investigations should be undertaken to study their effectiveness in new taxa.
The full study can be read on the ASHS HortScience electronic journal website at: https://doi.org/10.21273/HORTSCI17022-22
Established in 1903, the American Society for Horticultural Science is recognized around the world as one of the most respected and influential professional societies for horticultural scientists. ASHS is committed to promoting and encouraging national and international interest in scientific research and education in all branches of horticulture.
Comprised of thousands of members worldwide, ASHS represents a broad cross-section of the horticultural community - scientists, educators, students, landscape and turf managers, government, extension agents and industry professionals. ASHS members focus on practices and problems in horticulture: breeding, propagation, production and management, harvesting, handling and storage, processing, marketing and use of horticultural plants and products. To learn more, visit ashs.org
