Natural vegetative propagation

Vegetative Propagation is a method of plant production which relies on the use of vegetative structures such as stems, leaves or roots to perpetuate the parent plants. Plant propagation involves the formation and development of new individuals which are utilised in the establishment of new plantings. The importance of plant propagation in crop production is that it perpetuates plants as independent units.

There are two main ways or methods of plant propagation. First, propagation by seed (sometimes called the sexual method). The second is vegetative propagation or asexual method.

1.      Propagation by Seed

This method of propagation is employed in the propagation of most self-pollinated crops and other plants and many cross-pollinated ones. Plants or progenies (off springs) resulting from propagation by seed are expected to show some degree of variability with regard to various characteristics, e.g. plant height, vigour or yield, etc., except in the case of the highly homozygous self-pollinated ones which will be uniform with respect to many of their characteristics. Many cereal and legumes crops are propagated by means of seed. Others are such as tobacco, sunflower, cotton, etc.

2. Vegetative Propagation

This method includes all methods of propagation other than seed-propagation which do not depend on the formation of seed. It relies on the use of vegetative structures such as stems, leaves or roots to perpetuate the parent plants. The vegetative parts contain or develop buds which give rise to new individuals. Many flowering and ornamental crops and certain vegetables are propagated vegetative. Sweet potatoes, Irish potatoes and cassava are propagated vegetative. 

One main advantage of vegetative propagation is that plants produced result in plants which are an identical copy of the ‘parent’ plant. Thus, from one of the few plants possessing some desirable characteristics, many plants can be produced. Plants which originate from one plant through vegetative propagation are called clones. Provided the environment in which the plants are growing does not change, vegetative propagation plants will breed true to type and variety with regard to such agronomically important characteristics as size (fruit), shape (fruit or seed), quality, time from planting to maturity, keeping or storing qualities and chemical composition (e. g oil content)

Vegetative propagation is used when the plants either does not produce seed or when although the seeds are produced, they are not viable or they do not breed true to type as is the case in out-crossed crop varieties. The use of vegetative propagation may be easier and faster where the seed shows prolonged dormancy. Vegetative propagation is also useful where certain individual plants are more disease resistant than others. Some crops start bearing earlier when they are propagated vegetatively than when they are raised directly from the seed. For example, vegetative propagated citrus comes to fruiting within three to four years compared to eight years in seedling plants.

Plantlets are vegetative structures that develop on some plant leaves. These miniature, young plants arise from meristem tissue located along leaf margins. Upon maturity, plantlets develop roots and drop from leaves. They take root in the soil forming new plants. An example of a plant that propagates in this manner is Kalanhoe or mother of thousand plant. Plantlets may also develop from the runners of certain plants such as spider plants.