Effective Fruit Propagation Methods & Nursery Success

Topic 2: Fruit Propagation Techniques

Importance of a Quality Plant Nursery

A good plant nursery is key to the success of an orchard, ensuring plants possess the desired characteristics of size, age, conformation, and health.

Nursery Establishment Criteria

A fruit nursery must be located in areas with good accessibility and suitable weather conditions. The soil must have abundant organic matter.

Fundamental Propagation Types

Sexual Reproduction (Seed Propagation)

This method uses seeds, which are zygotic embryos.

Advantages:

• Produces vigorous plants.
• Plants produced are generally free from viral diseases.

Disadvantages:

• Lack of uniformity in the produced plants.

Apomictic Reproduction

This involves asexual propagation using an asexual seed embryo (e.g., polyembryonic seeds).

Vegetative (Asexual) Propagation

This method uses vegetative parts of the plant (propagules) for reproduction.

Advantages:

• Maintains the characteristics of the mother plant.
• Increases precocity (earlier fruiting or flowering).

Disadvantages:

• Can spread viral diseases.
• Carries a risk of genetic erosion.

Plant Propagation Methods (Hartman and Kester, 1994)

Sexual Propagation Methods

• A) Propagation by seeds (standard sowing).
• B) In Vitro Cultivation of:
  • Ova (e.g., carnations, tobacco, petunia)
  • Embryos (e.g., Iris, olive)
  • Seeds (e.g., orchids)
  • Spores (e.g., ferns)

Apomictic Propagation Methods (Asexual Embryos)

• A) Standard Sowing: Nucellar embryos (e.g., citrus, mango).
• B) In Vitro Culture: Nucellar embryos (e.g., citrus).

Vegetative Propagation Methods

Propagation by Cuttings

• Leaf stem cuttings
• Leaf with bud cuttings
• Root cuttings
• Fruit cuttings

Grafting Techniques

• Bud grafting (Yolk grafting)
• Canopy grafting
• Chip budding or Veneer grafting
• Patch grafting
• Ring grafting
• Slit grafting (Cleft grafting)
• Crown grafting
• Side grafting
• Side-tongue grafting (Whip and tongue grafting)
• Bridge grafting
• Approach grafting
• Support grafting (Inarching or Bracing)

Layering Techniques

• Tip layering
• Simple layering
• Trench layering
• Air layering

Other Vegetative Methods

• Propagation by Runners
• Propagation by Offsets (Suckers/Plantlets, referred to as "little ones")
• Propagation by Division

Seed Storage Practices

Seeds should be thoroughly cleaned of any attached pulp or debris. Disinfection is recommended (e.g., using Busan 10%, Copper 5%, Benomyl 5%). Seeds must be air-dried before storage. Store them in permeable bags in a cool, dry, and well-ventilated place. Protect seeds from insect infestation.

Seed Scarification

Scarification involves mechanically abrading, chemically weakening, or otherwise breaking the hard seed coat (endocarp and other protective layers) to enhance water absorption and allow germination.

Seed Stratification

Stratification involves exposing seeds to a period of moist-cold or moist-warm conditions to break dormancy. This can be done by placing seeds in a container with layers of moist sand or other suitable media, or by planting them in specific outdoor locations (e.g., on land facing south, depending on species requirements).

Detailed Vegetative Propagation Techniques

The most common methods include:

Staking (Propagation by Cuttings)

This consists of separating a plant fragment or organ (a cutting), keeping it alive, and inducing it to regenerate missing organs (roots and/or shoots) to form a new, complete plant.

Layering

Layering is a method where adventitious roots are induced to form on a stem while it is still attached to the parent plant. Once sufficient roots have developed, the rooted stem (layer) is detached to become a new, independent plant.

Offsets (Hijuelos/Suckers)

Offsets, also known as hijuelos or suckers, are daughter plants that form at the base of the parent plant's trunk, below the crown (soil line), or on the roots at varying distances from the main trunk. This is a common method for commercial propagation, often performed during the winter.

Grafting

Grafting is a horticultural technique where tissues from one plant (the scion) are joined to another plant (the rootstock) so they unite and continue to grow as a single plant. The rootstock provides the root system and support, while the scion develops into the desired top portion of the plant, providing the fruit or flowers. Both parts eventually fuse, forming one integrated plant.

In Vitro Propagation (Micropropagation)

In vitro propagation, or micropropagation, is a modern laboratory method for rapidly obtaining multiple plants from a very small plant fragment, cells, or tissues, which are used as the plant material. This technique is performed under sterile conditions in a nutrient medium.