Plant Propogation and Nursery Management

Asexual Propagation

• It is independent of sexual propagation process as there is no involvement of sex organs.
• It takes place due to mitotic division. Mitotic division continues in shoot tip, root tip and cambium (Fig.1.2).

Fig.1.2: Stages of asexual reproduction

• When some portion of plant is wounded, mitotic division takes place.
• Under mitotic division, chromosomes divide longitudinally to form two daughter cells. This forms the basis of asexual propagation.
• The plants raised through asexual process are identical to mother plants. Cutting, division, layering, budding and grafting are main techniques of asexual propagation.

Advantages

• Asexually propagated plants are true to type to their mother plants.
• Asexually propagated plants have short juvenile phase and bear flowers and fruits in the early age (3-4 years) than seedling plants.
• The vegetatively propagated plants are smaller in stature and hence management operations like spraying, pruning and harvesting etc. become easy.
• Plants in which seed setting does not take place (e.g. pineapple and banana), asexual propagation serves as a substitute for sexual propagation.
• Using asexual methods, desirable characters of a mother plant can be perpetuated/ multiplied easily.
• The benefits of rootstocks and scion are usually exploited through asexual propagation.
• Repairing of damaged portion of plant is possible through asexual propagation as in case of bridge grafting.
• It is possible to convert a non-productive local variety into productive improved variety by using asexual methods.
• It is possible to grow several varieties on one plant or change variety of existing plant by top working.

Disadvantages

• Asexual propagated plants have shorter life-span.
• Asexual propagation restricts diversity.
• Sometimes asexual propagation disseminates diseases e.g. Tristeza virus in citrus.
• Technical expertise/skill is required.