Protocol Information

John T. Harrington
Professor
New Mexico State University-Mora Research Center
P. O. Box 359
Mora, New Mexico 87732-0359
575-387-2319
575-387-9012 Fax
joharrin@nmsu.edu

Family Scientific Name: Salicaceae

Family Common Name: Willow or Poplar Family

Scientific Name: Salix amygdaloides Anderss.

Common Name: Peachleaf willow

Species Code: SAAM

Ecotype: Valencia County, New Mexico

General Distribution: Widespread throughout North America. In New Mexico, this species is found statewide within riparian areas. (Carter 1997).

Propagation Goal: Cuttings

Propagation Method: Seed

Product Type: Container (plug)

Stock Type: 164 ml conetainer

Target Specifications: Height: 30 to 45 cm Caliper: 3 to 5 mm Root System: Firm root plug.

Propagule Collection: Stem cuttings are taken from dormant plants growing in stooling blocks in March (or anytime January to early April) grown in the middle Rio Grande Valley, New Mexico. Cuttings are taken from the previous season’s growth and are at least 18 cm in length. Cuttings are sealed in polybags to prevent desiccation, and brought to the nursery on ice in coolers. Cuttings are then placed in a walk-in cooler (2 – 4^oC) for storage. Note: the earlier the cuttings are taken (late January through February) the longer the cuttings can be stored before bud burst occurs during storage. Once bud burst occurs, rooting success drops quickly. Once placed in a growing environment, these propagules grow to target height specifications quickly, so holding dormant cuttings as late as possible helps reduce the occurrence of “oversized” seedlings.

Propagule Processing: Cuttings are trimmed to 15 cm in length with a diagonal cut at the basal end and terminal buds are removed just prior to sticking.

Pre-Planting Treatments: Cuttings are stuck to a depth of 10 cm. Growing media is a 2:1:1 (v:v:v) peat:perlite:vermiculite mixture. Controlled release fertilizer 14-14-14 (N-P-K) 3 – 4 month is incorporated into the media at the rate of 4 kg/m³. Cuttings are watered in and kept moist throughout the rooting period using an intermittent misting schedule. Mist is provided via an irrigation system using mini-sprinklers. Cuttings are rooted on standard greenhouse benches.

Growing Area Preparation/
Annual Practices for Perennial Crops:
Propagation (Establishment phase) occurs in a greenhouse and the active growth phase occurs in both a greenhouse and a shade house. The hardening phase occurs in the shade house and the dormant seedlings are over-wintered in a cold frame (small poly-topped greenhouse). Cuttings are stuck in early May and after 8 to 10 weeks in the greenhouse and once they reach 25 – 30 cm in height are moved outside to the shade house facility. Seedlings are kept here until dormant and leaves have been shed which typically occurs in late October in northern New Mexico. At this point the seedlings are moved into the cold frame for over wintering. Irrigation heads are spaced to provide head to head coverage. Shade house and cold frame irrigation is provided via a sub-irrigation system. In the greenhouse seedlings are fertilized using a fertigation system, which utilizes the irrigation system. Seedlings are not fertilized in the shade house or cold frame.

Establishment Phase: (Greenhouse) Intermittent mist is maintained until vigorous shoot and root growth is apparent. Containers are irrigated periodically to keep the media evenly moist. Greenhouse night and day temperatures range from 18 to 26°C and no supplemental light is provided.

Length of Establishment Phase: 2 to 4 weeks

Active Growth Phase: (Greenhouse/Shade house) The first portion (4 to 10 weeks) of the active growth phase occurs in the greenhouse. Containers are irrigated as needed, which progressively increases as the seedlings grow. Typically, irrigation intervals involve irrigating once every 3 to 4 days for the first two weeks after rooting is complete, then once every 2 to 3 days through the next several weeks then once every one to two days for the remainder of the active growth period in the greenhouse. Containers are allowed to dry down to a moderate state between irrigations. This irrigation regime is used to help minimize root disease problems. All irrigations are performed early in the morning, which allows foliage to sufficiently dry before nightfall, minimizing foliar disease problems. During the first two weeks of the active growth phase in the greenhouse, plants are fertigated every other irrigation with a liquid-based, foliar feed fertilizer (27-15-12; N-P-K) at a rate of 25 ppm N. During the remaining 8 weeks of the active growth phase in the greenhouse seedlings are fertilized every other irrigation with a liquid-based fertilizer (20-10-10; N-P-K) at a rate of 50 ppm N until they attain the target shoot height (~25 cm). During the greenhouse portion of the active growth period greenhouse temperatures during the day are 21 to 26°C and during the night 18 to 22°C. Ambient photoperiod is supplemented with 5 min light interruptions every 2 hours throughout the night from 75 watt incandescent lights suspended 2 meters above greenhouse benches. Once transferred outside, ambient temperature and light regimes are utilized. The remaining 12 to 14 weeks is performed in the shade house. Seedlings are irrigated once every other day using a sub-irrigation system. No supplemental fertilizers are used during this portion of the active growth phase.

Length of Active Growth Phase: 8 to 10 weeks

Hardening Phase: (Shade house) This phase begins in late summer (end of August typically) to early fall as soon as seedlings attain their target shoot height. A series of incrementally increasing water stresses is applied to restrict any further height growth. In Mora, NM, ambient day temperatures are still quite warm but nights begin cooling markedly. The interval between irrigations becomes progressively longer due to seedlings becoming acclimated to water deficits and the gradual cooling associated with the onset of fall. Seedlings are fertilized every third irrigation (fertigated) with a liquid based fertilizer (10-30-20; N-P-K) at a rate of 25 ppm N. Seedlings are considered “hardened” once buds have formed and leaves have been shed.

Length of Hardening Phase: 8 to 10 weeks

Harvesting, Storage and Shipping: (Cold Frame) Seedlings are moved from the shade house into a cold frame (low-tech, twin-walled poly-topped greenhouse) in late October to early November. This step is necessary as the diurnal fluctuations in temperatures throughout the winter can result in daily freeze/thaw episodes which can damage the seedlings. The temperature in the cold frame ranges from 2 to 4^oC day and night. Seedlings are irrigated on an as needed basis based on moisture levels in the root plug. No supplemental light is provided. Seedlings are kept in the cold frame until shipped which is typically in late February or early March.

Length of Storage: 5 months

References: Carter, J.L. 1997. Trees and Shrubs of New Mexico. Johnson Books, Boulder, CO 534 pp.

[ITIS] Integrated Taxonomic Information System. 2001. (On-line database). URL: http://www.itis.gov (accessed 3 December 2008.).

Citation:

Harrington, John T.; Loveall, Mark W. 2008. Propagation protocol for production of container Salix amygdaloides Anderss. cuttings (164 ml conetainer); New Mexico State University-Mora Research Center, Mora, New Mexico. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 16 January 2009). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.

Family Scientific Name:	Salicaceae
Family Common Name:	Willow or Poplar Family
Scientific Name:	Salix amygdaloides Anderss.
Common Name:	Peachleaf willow
Species Code:	SAAM
Ecotype:	Valencia County, New Mexico
General Distribution:	Widespread throughout North America. In New Mexico, this species is found statewide within riparian areas. (Carter 1997).
Propagation Goal:	Cuttings
Propagation Method:	Seed
Product Type:	Container (plug)
Stock Type:	164 ml conetainer
Target Specifications:	Height: 30 to 45 cm Caliper: 3 to 5 mm Root System: Firm root plug.
Propagule Collection:	Stem cuttings are taken from dormant plants growing in stooling blocks in March (or anytime January to early April) grown in the middle Rio Grande Valley, New Mexico. Cuttings are taken from the previous season’s growth and are at least 18 cm in length. Cuttings are sealed in polybags to prevent desiccation, and brought to the nursery on ice in coolers. Cuttings are then placed in a walk-in cooler (2 – 4^oC) for storage. Note: the earlier the cuttings are taken (late January through February) the longer the cuttings can be stored before bud burst occurs during storage. Once bud burst occurs, rooting success drops quickly. Once placed in a growing environment, these propagules grow to target height specifications quickly, so holding dormant cuttings as late as possible helps reduce the occurrence of “oversized” seedlings.
Propagule Processing:	Cuttings are trimmed to 15 cm in length with a diagonal cut at the basal end and terminal buds are removed just prior to sticking.
Pre-Planting Treatments:	Cuttings are stuck to a depth of 10 cm. Growing media is a 2:1:1 (v:v:v) peat:perlite:vermiculite mixture. Controlled release fertilizer 14-14-14 (N-P-K) 3 – 4 month is incorporated into the media at the rate of 4 kg/m³. Cuttings are watered in and kept moist throughout the rooting period using an intermittent misting schedule. Mist is provided via an irrigation system using mini-sprinklers. Cuttings are rooted on standard greenhouse benches.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Propagation (Establishment phase) occurs in a greenhouse and the active growth phase occurs in both a greenhouse and a shade house. The hardening phase occurs in the shade house and the dormant seedlings are over-wintered in a cold frame (small poly-topped greenhouse). Cuttings are stuck in early May and after 8 to 10 weeks in the greenhouse and once they reach 25 – 30 cm in height are moved outside to the shade house facility. Seedlings are kept here until dormant and leaves have been shed which typically occurs in late October in northern New Mexico. At this point the seedlings are moved into the cold frame for over wintering. Irrigation heads are spaced to provide head to head coverage. Shade house and cold frame irrigation is provided via a sub-irrigation system. In the greenhouse seedlings are fertilized using a fertigation system, which utilizes the irrigation system. Seedlings are not fertilized in the shade house or cold frame.
Establishment Phase:	(Greenhouse) Intermittent mist is maintained until vigorous shoot and root growth is apparent. Containers are irrigated periodically to keep the media evenly moist. Greenhouse night and day temperatures range from 18 to 26°C and no supplemental light is provided.
Length of Establishment Phase:	2 to 4 weeks
Active Growth Phase:	(Greenhouse/Shade house) The first portion (4 to 10 weeks) of the active growth phase occurs in the greenhouse. Containers are irrigated as needed, which progressively increases as the seedlings grow. Typically, irrigation intervals involve irrigating once every 3 to 4 days for the first two weeks after rooting is complete, then once every 2 to 3 days through the next several weeks then once every one to two days for the remainder of the active growth period in the greenhouse. Containers are allowed to dry down to a moderate state between irrigations. This irrigation regime is used to help minimize root disease problems. All irrigations are performed early in the morning, which allows foliage to sufficiently dry before nightfall, minimizing foliar disease problems. During the first two weeks of the active growth phase in the greenhouse, plants are fertigated every other irrigation with a liquid-based, foliar feed fertilizer (27-15-12; N-P-K) at a rate of 25 ppm N. During the remaining 8 weeks of the active growth phase in the greenhouse seedlings are fertilized every other irrigation with a liquid-based fertilizer (20-10-10; N-P-K) at a rate of 50 ppm N until they attain the target shoot height (~25 cm). During the greenhouse portion of the active growth period greenhouse temperatures during the day are 21 to 26°C and during the night 18 to 22°C. Ambient photoperiod is supplemented with 5 min light interruptions every 2 hours throughout the night from 75 watt incandescent lights suspended 2 meters above greenhouse benches. Once transferred outside, ambient temperature and light regimes are utilized. The remaining 12 to 14 weeks is performed in the shade house. Seedlings are irrigated once every other day using a sub-irrigation system. No supplemental fertilizers are used during this portion of the active growth phase.
Length of Active Growth Phase:	8 to 10 weeks
Hardening Phase:	(Shade house) This phase begins in late summer (end of August typically) to early fall as soon as seedlings attain their target shoot height. A series of incrementally increasing water stresses is applied to restrict any further height growth. In Mora, NM, ambient day temperatures are still quite warm but nights begin cooling markedly. The interval between irrigations becomes progressively longer due to seedlings becoming acclimated to water deficits and the gradual cooling associated with the onset of fall. Seedlings are fertilized every third irrigation (fertigated) with a liquid based fertilizer (10-30-20; N-P-K) at a rate of 25 ppm N. Seedlings are considered “hardened” once buds have formed and leaves have been shed.
Length of Hardening Phase:	8 to 10 weeks
Harvesting, Storage and Shipping:	(Cold Frame) Seedlings are moved from the shade house into a cold frame (low-tech, twin-walled poly-topped greenhouse) in late October to early November. This step is necessary as the diurnal fluctuations in temperatures throughout the winter can result in daily freeze/thaw episodes which can damage the seedlings. The temperature in the cold frame ranges from 2 to 4^oC day and night. Seedlings are irrigated on an as needed basis based on moisture levels in the root plug. No supplemental light is provided. Seedlings are kept in the cold frame until shipped which is typically in late February or early March.
Length of Storage:	5 months
References:	Carter, J.L. 1997. Trees and Shrubs of New Mexico. Johnson Books, Boulder, CO 534 pp. [ITIS] Integrated Taxonomic Information System. 2001. (On-line database). URL: http://www.itis.gov (accessed 3 December 2008.).