Propagation of Difficult to Root Semi-Hardwood Shrubs and Hardwood Trees in Oasis® Rootcubes® Wedge® Medium

screen-shot-2016-09-21-at-11-15-32-am

Chamaecyparis propagation

Vijay Rapaka, Ph.D.
Manager, Corporate Grower
Research & Technical Support
Smithers-Oasis Company, Kent, OH USA

screen-shot-2016-09-21-at-11-15-49-am

Rooted Daphne tangutica cuttings

 

screen-shot-2016-09-21-at-11-16-10-am

Chamaecyparis obtusa ‘Templehof’ cuttings

Introduction

Propagation medium plays a vital role in the rooting of cuttings, and has three basic functions: (i) to support or hold the cutting in place, (ii) to supply water and nutrients during rooting and subsequent growth, and (iii) to supply oxygen in the root zone. Several different types of media can be used for the propagation of cuttings (e.g., organic or inorganic). However, an ideal medium is one which maintains a proper balance of air / water ratio during the entire course of propagation. In other words, the media should drain well without any compromise, to provide good aeration and yet retain enough moisture to keep the cuttings turgid. This is of the utmost importance, especially when dealing with several of the semi-hardwood and hardwood cuttings because of two reasons: (i) the rooting usually takes more than several months, and (ii) they do not like the rooting zone to stay too wet. An ideal medium should be sterile, inert, and homogenous to ensure a clean start and uniform rooting. This fact sheet demonstrates how rooting success and uniformity in rooting can be improved using the Rootcubes® Wedge® Medium in three different hard-to-root species: Daphne tangutica, Chamaecyparis obtusa ‘Templehof’, and Chamaecyparis pisifera ‘Mops’.

Daphne tangutica is a semi-hardwood evergreen shrub with fragrant spring flowers and attractive glossy foliage. The blooms last from early spring to mid-summer with an occasional rebloom thereafter. Daphne prefers a temperate climate with a well-drained soil. Chamaecyparis obtusa ‘Templehof’ and Chamaecyparis pisifera ‘Mops’ are hardwood evergreen trees.

Propagation trials were conducted with Daphne tangutica, Chamaecyparis obtusa ‘Templehof’, and Chamaecyparis pisifera ‘Mops’ in a peat / perlite based conventional medium and Oasis® Rootcubes® Wedge® Medium.

Materials and Methods

Plant Material and Propagation of Cuttings: Daphne tangutica cuttings were harvested and stuck on the next day. Chamaecyparis obtusa ‘Templehof’ and Chamaecyparis pisifera ‘Mops’ cuttings were harvested and stuck on the same day. All the cuttings were treated with Hormodin 2 (0.3% IBA) rooting hormone before inserting into the rooting media.

Rooting media:
The cuttings were propagated in a conventional mix (control medium) and an OASIS® Rootcubes® Wedge® Medium.

Control Medium:

  • In the case of Daphne tangutica, cuttings were rooted in 40% perlite + 30% aged bark + 30% peat moss.
  • In the case of Chamaecyparis obtusa ‘Templehof’ and Chamaecyparis pisifera ‘Mops,’ cuttings were propagated in 50% perlite + 50% sand.

OASIS® Rootcubes® Wedge® Medium:

  • The Rootcubes® Medium is an engineered propagation, medium formulated with an optimal air / water ratio and is consistent from cell to cell, which promotes faster and uniform rooting.
  • The unique cell structure allows the cuttings to uptake water easily and establish quickly in the propagation area. This will help to reduce the requirement for frequent misting. As a result, the media doesn’t stay too wet and the cuttings root faster.
  • The foam media is a thermoset material and is considered to be sterile because of the high temperature involved during the manufacturing process.

Irrigation and Propagation Conditions:

Initially, the propagation media was thoroughly watered with a hose and a breaker to completely saturate the media. During the course of propagation, the cuttings were misted using a boom irrigation system. Two weeks before the end of the rooting period, the cuttings were watered with a complete nutrient with 0.5 mS/cm.

The light levels during the course of propagation were between 200-250 μmol•m-2•s-1 and the daily light integral (DLI) was 4 to 5 μmol•m-2•s-1. The root zone temperatures were maintained between 76° and 82° F (24° to 28° C) using bottom heating.

Rooting Evaluation and Observations:

Rooting evaluation on Daphne tangutica cuttings was done 50 days after insertion and in the case of Chamaecyparis obtusa ‘Templehof’ and Chamaecyparis pisifera ‘Mops,’ rooting evaluation was 110 days after insertion. The percentage of rooted cuttings was recorded and photographs were taken. The trials were conducted at large-scale commercial nurseries.

Results & Discussion

The rooting response of all the three crops species are presented in Figure 1. The results demonstrated that all three crops performed significantly better in the Rootcubes® Medium compared to the conventional peat/perlite based growing medium. In the case of Daphne tangutica, 81% of the cuttings rooted in the Rootcubes® Medium® and only 33% of the cuttings rooted in the control medium. In the case of Chamaecyparis obtusa ‘Templehof,’ 80% of the cuttings rooted in the Rootcubes® Medium and only 20% of the cuttings rooted in the control medium. Lastly, in the case of Chamaecyparis pisifera ‘Mops,’ 85% of the cuttings rooted in the Rootcubes® Medium and 50% of the cuttings rooted in the control medium. The improved performance in the Rootcubes® Wedge® Medium can be attributed to its consistent air/water ratio during the whole course of propagation.

Conclusions

The current study opens up a new avenue for the successful propagation of semi-hardwood and hardwood cuttings, which don’t like wet feet.

Figure 1: Effect of two different types of rooting media: (A) control medium and (B) Rootcubes® Wedge® Medium, on the rooting of semi-hardwood, Daphne tangutica, and hardwood, Chamaecyparis obtusa ‘Templehof’ and Chamaecyparis pisifera ‘Mops’ evergreen cuttings. In the case of Daphne tangutica, the control medium was (40% perlite + 30% aged bark + 30% peat moss) and in the case of Chamaecyparis obtusa ‘Templehof’ and Chamaecyparis pisifera ‘Mops,’ the control was (50% perlite + 50% sand). All the cuttings were treated with Hormodin 2 (IBA 0.3%) rooting hormone before inserting into the rooting media.

screen-shot-2016-09-21-at-11-26-32-am

Figure 2.1: Effect of two different types of rooting media, (A) control medium (40% perlite + 30% aged bark + 30% peat moss) and (B) Rootcubes® Wedge® Medium, on the rooting performance of Daphne tangutica cuttings. Cuttings were treated with Hormodin 2 (IBA 0.3%) rooting hormone and immediately inserted into the rooting medium. The rooting evaluation was done 50 days after inserting the cuttings. Photos were taken at the time of the rooting evaluation.

screen-shot-2016-09-21-at-11-57-17-am

Figure 2.2: Daphne cuttings rooted uniformly in the OASIS® Rootcubes® Wedge® Medium.

screen-shot-2016-09-21-at-11-58-31-am

Figure 3.1: Effect of two different types of rooting media, (A) control medium (50% perlite + 50% sand) and (B & C) Rootcubes® Wedge® Medium on the rooting of Chamaecyparis obtusa ‘Templehof’ cuttings. Cuttings were treated with Hormodin 2 (IBA 0.3%) before inserting into the rooting medium. Rooting evaluation was done 110 days after inserting the cuttings. Photos were taken at the time of evaluation.

screen-shot-2016-09-21-at-12-00-14-pm

Figure 3.2: Chamaecyparis obtusa ‘Templehof’ cuttings rooted in (A) control medium and (B) Rootcubes® Wedge® Medium. In foam, approximately 80% of the cuttings rooted, whereas in the control medium only 20% of the cuttings were rooted and the majority remained at the callus stage.

screen-shot-2016-09-21-at-12-01-13-pm

Figure 4.1: Effect of two different types of rooting media: (A) control medium (50% perlite + 50% sand) and (B) Rootcubes® Wedge® Medium, on the rooting of Chamaecyparis pisifera ‘Mops’ cuttings. Cuttings were treated with Hormodin 2 (IBA 0.3%) before inserting into the rooting medium and propagated under a boom irrigation system. Rooting evaluation was done 110 days after inserting the cuttings. The photos were taken at the time of evaluation.

screen-shot-2016-09-21-at-12-02-15-pm

Figure 4.2: Chamaecyparis pisifera ‘Mops’ cuttings rooted in (A) control medium and (B) Rootcubes® Wedge® Medium. Approximately 85% of the cuttings rooted in foam, whereas in the control medium only 50% of the cuttings were rooted.

screen-shot-2016-09-21-at-12-03-46-pm

The following is the general procedure for the propagation of semi-hardwood or hardwood cuttings in a Rootcubes® Wedge® Medium:

  • Start with clean cuttings harvested from healthy-stock plants. Disinfect the cuttings if required using proper protocols.
  • Insert the cuttings on the same day. If the cuttings have to be stored before they are inserted, follow proper storage procedures.
  • Prepare the propagation area by placing the foam medium on the bench.
  • Thoroughly water the medium using complete nutrient solution. Complete saturation of the foam can be achieved by sub irrigation or overheard water. Note: With overhead watering, consider using a hose and a nozzle. It takes several passes to completely saturate the foam medium. If you are using a foam medium for the first time, break open and inspect the center of the foam plugs to ensure whether the foam is completely saturated. Note: Overhead misting is not sufficient enough to saturate the foam medium.
  • Insert the cuttings ~25% of the height of the foam.
  • Use the right rooting hormone (IBA and/or NAA) and concentration to improve the uniformity and speed of rooting. Conduct trials with various concentrations to identify the optimal concentration for your particular crop and growing conditions.
  • Misting / watering: The frequency of watering depends on the crop and also the greenhouse conditions such as light intensity temperature, humidity, and also the air movement. Generally, it is not required to mist often in the case of semi-hardwood and hardwood cuttings. It is important that the cuttings should never wilt or dry during course of propagation. Also, the foam media should never dry out excessively during the course of propagation.
  • Fertilizer and watering: Once the cuttings start to callus, apply fertilizer as required, with complete nutrient solution at an EC or 0.5 mS/cm.
  • Light levels: The recommended light levels for propagation are 200 – 250 μmol•m-2•s-1 or a daily light integral (DLI) of 4 to 5 μmol•m-2•s-1.
  • Temperature: Optimal rooting occurs when root zone temperatures are maintained (if required use bottom heating) between 76° and 82° F (24° to 28° C).

Transplanting  the Rootcubes® Wedge® Medium

The Rootcubes® Wedge® Medium can be transplanted into a pot or a container to be grown inside a greenhouse or in an outdoor location, as long as the growing media can be maintained moist with a drip or some other sort of irrigation system, until the plants are established. Once rooted, it is recommended to transplant the foam medium rather quickly. It is not recommended to overwinter or delay the transplant process once the cuttings are rooted. Also, it is not recommended to transplant the foam directly into the soil, where the soil moisture cannot be controlled.

The following is the general procedure:

  • Fully saturate the Rootcubes® Medium before transplant.
  • Always transplant into a moist media and bury the surface of the foam.

    o Note: Do not let the foam dry out excessively before or during the transplant process.
    o Note: Transplanting into dry media can jeopardize the survival of the plant because foam can dry out excessively.

  • Thoroughly water the medium immediately after transplant. After that, water just as required.

    o Note: Once transplanted, water quickly moves out of the foam into the surrounding matrix. As a result, roots grow rapidly into the surrounding media. Even if you happen to see the foam surface dry after transplant, it is totally fine, as long as the media surrounding the foam plug is wet.

    o Note: Overwatering can delay the transplant performance because the root will not quickly grow out of foam.

Stay up to date with all of the latest products, upcoming events & much more.
SUBSCRIBE
Copyright © 2016 OASIS® Grower Solutions. Privacy. Web design by Mobkii