Herbaceous Cuttings

Plant Science

Which of the following plants do you think would be easier to propagate using the leaves?

Plant Propagation by Cuttings

Asexual propagation - the controlled reproduction of plants by taking a piece of vegetative plant tissue and encouraging it to regenerate a complete plant.

Sexual propagation - development of a new plant by meiosis & fertilization in the flower to producea viable embryo in a seed.

Totipotency – ability of a single cell to regenerate all characteristics of the plant.

Advantages of asexual propagation

Plants are uniform Quick establishment Only means of propagation in certain

species Seed-borne diseases avoided Less expensive Heterozygous material may be

propagated without genetic alteration

Disadvantages of asexual propagation

Systemic viral infection can spread to all plants

Planting materials are bulky Storage of asexual material is cumbersome

and short term All plants are genetically identical and

subject to the same hazards to the same degree

Mechanical propagation in some cases is not practical

4 Categories of Cuttings

Softwood cuttings – from soft, succulent, new spring growth of deciduous or evergreen species

Semi-hardwood cuttings – from woody, broad leaved evergreens, and leafy summer cuttings of deciduous plants with partially matured wood

Hardwood cuttings – from dormant woody material – taken in late winter or early spring before leaves appear – from previous year’s growth

Herbaceous cuttings – from succulent, non-woody plants, with leaves at upper end

Types of Herbaceous Cuttings

Definition of a cutting -Detached vegetative material from a plant used to produce a new plant.4 types:

Stem Leaf Leaf-bud Root

Stem Cuttings

2 types Stem-tip cuttings – tip (terminal end)

is cut and used to produce a seedling Stem-section cuttings – pieces of

stems containing at least one bud (not a terminal bud) and used to produce a seedling

Leaf cuttings

A whole leaf or part of one that is detached and used to raise a new plant.

Examples: begonia, peperomia, African violet

Cutting consists of leaf plus part of the leaf stalk (petiole)

Leaf-vein cuttings – cutting the veins at several points and

securing the leaf on the media

Leaf-bud cuttings

Consists of a short piece of a leaf, petiole, and short piece of stem with an attached bud in the leaf axil.

Great when source material is scarce.

Root cuttings

Small sections of the roots are divided and planted vertically or horizontally.

Proximal – nearest the crown of the plant – always should be up

Distal – farthest from the crown

Cuttings and Water uptake

Removed from functioning root system

There is little to no water uptake and can lose water to the air

Placing cuttings under a intermittent mist system provides water and high humidity

Adventitious roots New roots form in places that normally

do not grow roots (Ex: Stems, leaves)

Cultural requirements The tissue of the cuttings should contain

enough of the organic and inorganic nutrients to support new growth to the point of becoming self-supporting.

- Electric heating cables are commonly used to hold the medium at about 75F. Air temperature of 70-80F day and 60-70F night are generally satisfactory.

Light Requirements

The presence or absence of light is generally not decisive in rooting, although light tends to inhibit root initiation.

The general practice is to use shading to decrease light intensity but not to exclude light.

Media

The rooting medium should be well aerated, hold sufficient moisture, and be easily sanitized.

Soil is generally a poor choice. Commonly used media include perlite, and various mixtures of sand, peat, and vermiculite.

In this lab we will use a 1:3, Bark Mix :Perlite mix

Auxins

Auxins - a group of natural plant growth hormones, which can be applied directly to the cuttings.

Most commonly used compounds: synthetic auxins, indolebutyric acid (IBA), and napthaleneacetic acid (NAA).

Available in powder and liquid forms Rootone, Hormodin, Rhizapon & Dip ‘N

Grow.

Common Auxins

Indole 3- butyric acid (IBA) - Best for general use, non-toxic to plants over a wide concentration range

Napthaleneacetic acid (NAA)

Powder Formulations Vs Liquid Formulations of Rooting Hormones

Is Dip’ N Gro the Way to Go?

Liquid rooting hormone vs. powder formulations

Contains both IBA and NAA Dilution rates – versatility of product Absorbance into cutting vascular

system Alcohol incorporated into product –

sanitation Superior Performance

Auxin Forms Powder – Rhizapon, Hormodin, etc.

› Easy to use, but not as uniform› Not as effective as liquid auxins Pre-

drilling holes for sticking

Liquid - Dip ‘n Grow› Usually 3 to 5 second dip in solution› Dip as a bundle, not one by one› Majority of auxin is absorbed at the cut

surface of cutting base› Versatile

Depending of plant material, concentration levels are suggested:› Herbaceous & Softwood 1:20› Semi-hardwood 1:10› Hardwood 1:5

Dip time: 3-5 seconds› 5-second dip is equally effective as a 160-

second dip in promoting root growth. Longer dips, may cause phytotoxicity

Problem with auxins – they degrade in light

Powder formulations – once opened, subject to clumping

Liquid – 3 year shelf life if kept in a sealed container

Once diluted, 10 hour effectiveness

Another Issue: Auxins in Excess

Inhibit bud development

Cause yellowing and dropping of leaves

Blackening of the stem

Eventual death of cutting

Which should a grower use?

Other Methods of Application

Spray auxins to runoff over base of cutting

Cuttings stuck in media and auxin sprayed on leaves and stem until auxin drips in to media

Total immersion of cuttings - ivy, clematis, Ficus

Pre-Chemical Treatment of Cuttings

Treated with broad spectrum fungicidal dips prior to sticking

Sources for plant materials:

Outdoor landscape Greenhouse Annuals Houseplants Friends and Neighbors

Lab: Herbaceous Cuttings

- In addition to the different concentration levels, the length of time that the growth regulator remains in contact with the base of the cutting can also have an effect on rooting, which will be demonstrated in this laboratory project.

Materials Needed

Plant cuttings (to be designated) Propagation knife or razor blade Labels Pencil 1000 ppm IBA (Indole-3-butyric acid) and 500 ppm NAA (1-Naphthaleneacetic acid) Dip’ N Grow Dilution cup Propagation medium in flats-

1:3 Bark Mix : Perlite

Herbaceous Cuttings: Methods

Each group should prepare 12 uniform stem cuttings from the same genus, species and if applicable the same cultivar or variety and divide them into 4 equal groups.Re-cut the base of each group of cuttings and dip the base of each group into 1000 ppm IBA 500 ppm NAA (1:19 Dip N’ Grow : water) for the following time periods:

0 second- control 2 seconds 15 seconds 30 seconds

Any Questions??