CROP PROPAGATION

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1.          What is crop:

A crop is any cultivated plant, fungus, or alga that is harvested for food, clothing, livestock fodder (food, especially dried hay or straw, for cattle and other livestock) , biofuel, medicine, or other uses. In contrast, animals that are raised by humans are called livestock,

except those that are kept as pets. Microbes, such as bacteria or viruses, are referred to as cultures. Microbes are not typically grown for food, but are rather used to alter food. For example, bacteria are used to ferment milk to produce yogurt.

 Example of some major crops includes sugarcane, pumpkin, maize (corn), wheat, rice, cassava, soybeans, hay, potatoes and cotton.

2.          What is propagation:

Plant propagation is the process of creating new plants from a variety of sources: seeds, cuttings, bulbs and other plant parts. 

Plant propagation can also refer to the artificial or natural dispersal of plants. Plant propagation is the branch of horticulture which deals with the deliberate (or intentional) production of new plants using various starter materials (e.g. organs, tissues), including their intensive but temporary care. 

It is primarily practiced to produce seedlings or clones of nursery crops for out planting, or for planting in containers for display or decoration or other uses. In general, there are two methods of propagating plants which is the sexual and asexual.

Sexual propagation:

Sexual propagation is with the use of seed or spore that is separated from the parent plant. This method is so termed "sexual" because there is the involvement of the sexes, referring to the contribution of both the male and female gametes in the production of new plants. 

The propagated plant therefore has a genotype which results from combining those which originate from the parental sources of male and female gametes. Consequently, the resulting plant may exhibit either, or somewhat different, or a combination of parental characteristics.

The young plant that is produced from seed is called seedling while clonal seedling or simply clone is used for that which is vegetatively produced. However, seedling is now used as a general term to refer to any young plant without regard to the method of propagation. 

It does not mean, however, that all plants which are propagated by seed are sexually reproduced. There are some exceptions, notably the hawkweed (Hieracium sp.) and farm crops like mangosteen (Garcinia mangostana) which produce apomictic seeds. Apomixis is the production of seeds without sexual union. It also occurs in citrus, lanzones, and polyembryonic mango.

        Asexual propagation:

        Asexual propagation, also called vegetative propagation, is with the use of planting materials which are vegetative parts of any plant rather than seeds or spores which are reproductive parts. In most techniques, the propagule is separated first from the parent plant and treated to induce regeneration or otherwise directly planted.

Asexual or vegetative propagation does not involve the union of the male and female gametes. Both meiosis and fertilization are not required in the production of propagules and new plants. Plant propagation involves the use of propagating materials consisting of plant parts which develop through mitotic cell division. As a result, the new plants, called clones, are genotypic duplicates of the mother plants.

With the inclusion of apomictic seeds, the following vegetative plant organs are used in natural asexual propagation: bulb and bulblet, clove, corm and cormel, tuber and tubercle, rhizome, stolon, slip, sucker, crown and plantlet.

Having summarized that plant propagation is the process of generating new plants from a variety of sources like seeds, cuttings, bulbs, corms, leaves, roots, etc. Plant propagation also refers to the artificial and natural transportation and dispersal of seeds and plant parts and offspring. Plant propagation is essential for production and development of new plants in any horticulture nursery.

Methods of Plant Propagation

3.          Uses of crop propagation:

i.                Plant propagation helps to produce large number of offspring's in short time and with minimum mortality.

ii.                Plant propagation is necessary for production of new breeds or varieties of plants which have better genetic constitution and improved quality and quantity of the produce.

iii.                Exact genetic replica of the mother plants can be produced in vegetative plant propagation.

iv.                Fertilization does not occur in vegetative production and therefore the new offspring's are genetic replicas of the mother plants, used to retain quantitative and qualitative traits of the mother plants.

v.                Vegetative propagation is used in case of seedless plants and plants which are difficult to propagate by seed.

4.          Disadvantages of crop propagation:

i.            Since many plants are produced, it results in overcrowding and lack of nutrients.

ii.          Qualitative and quantitative improvement in next generation is not possible by vegetative propagation method. Propagation of plants by these methods is expensive and requires technical skill and expertise.

iii.        Plants propagated by vegetative means gradually lose their vigor as there is no genetic variation. They become more prone to pest and diseases attack than plants grown by sexual methods.

iv.         Hybrids propagated by this method cannot produce true to type offspring's and they may lose their traits and characteristics.

v.           Some plants like Seedless Grapes, Papaya, Peppermint are difficult to propagate by this method as they do not produce seeds or the seeds are not viable.

vi.         Orchids and bamboo plants produce seeds which are viable for very short time or are difficult to germinate and produce.

5.          Advantages of crop propagation:

i.            Propagation method is very useful for bringing about genetic improvement in plants with respect to quality and quantity of yield.

ii.           Propagation is necessary for crop improvement and development of new varieties and hybrids. It is economical, as large number of offspring's are produced in a very short time.

iii.        The offspring are genetically identical and therefore advantageous traits can be preserved.

iv.         Only one parent is required which eliminates the need for special mechanisms such as pollination, etc.

v.           It is faster. For example, bacteria can multiply every 20 minutes. This helps the organisms to increase in number at a rapid rate that balances the loss in number due to various causes.

vi.         Many plants are able to tide over unfavorable conditions. This is because of the presence of organs of asexual reproduction like the tubers, corm, bulbs, etc.

vii.       Vegetative propagation is especially beneficial to the agriculturists and horticulturists.

viii.     They can raise crops like bananas, sugarcane, potato, etc that do not produce viable seeds.

ix.         The seedless varieties of fruits are also a result of vegetative propagation.

x.           The modern technique of tissue culture can be used to grow virus-free plants.

Propagation by plant cuttings:

Vegetative propagation using plant cuttings applies to many crops. This method allows the production of clones or plants which are considered “duplicates” of the parent plants geno-typically, and usually also phenotypically. Just like other vegetative propagation

methods, it is advantageous where a plant does not produce seeds, the seeds are sterile, or whenever seeds are not available. With crops that can be easily propagated using plant cuttings, this method has numerous advantages. Many new plants can be produced in a limited space from a few stock plants. It is simple and can be easily applied without having to learn the special techniques in grafting or budding. It is rapid because there is no need to produce rootstocks. Plant cuttings may consist of segments of the root or whole leaves or portions of leaves, or segments of stems which are used as planting materials. Depending on the plant part used, these propagules are called by special terms such as root cuttings, leaf cuttings, leaf bud cuttings or stem cuttings. In sugarcane, the stem cutting is called cane cutting while in bamboo, it is culm cutting. Culm is the technical term for the main stem of plants belonging to the grass family Gramineae (alternatively named

Poaceae). Root cuttings are segments of the root while leaf cuttings are either entire leaves, with or without the petiole, or portions of leaf blades. Leaf bud cuttings consist of a leaf with petiole, and a short piece of the stem with axillary bud. Stem cutting sare segmented parts of the stem, or entire stems detached from the main branch. Where the stem cutting includes the tip or apex, it is called tip cutting. Special terms are also used to classify stem cuttings such as hardwood or woody cuttings, semi hardwood or semi woody cuttings, softwood cuttings and herbaceous cuttings. These are classifications of stem cuttings based on the nature of wood and stage of growth. Hard wood, semi hardwood and softwood cuttings are taken from woody trees and shrubs while herbaceous cuttings are made from succulent, herbaceous plants like chrysanthemum, coleus, tomato, eggplant and squash. Propagation with the use of plant cuttings is common for dicots but there are some monocots that can be rooted by this method like bamboo and sugarcane. Compared to the other methods, propagation by stem cuttings has the widest application. Plants that can be propagated by root cuttings are Breadfruit (Artocarrpus altilis), blackberry (Rubus sp.), fig (Ficus carica), garden phlox (Phlox paniculata), Japanese pagoda tree (Sophora japonica), lilac (Syringa vulgaris), Malus sp., oriental pear (Pyrus calleryana), Rosaspp.  Plants that can be propagated by leaf Cuttings African violet (Saintpaulia ionantha), Begoniaspp., Bryophyllumspp.), Crassulaspp., Kalanchoespp., lily (Lilium longiflorumand L. candidum), Oxalis spp., Peperomiaspp., Sedumspp., snake plant (Sansevieria trifasciata), sweet potato, wax plant (Hoya carnosa). Generally, these plants have thick leaves. Jasmine (Jasminum sambac) and dracaena (Dracaena godseffiana) have also been propagated experimentally by leaf cuttings. Plants That Can be Propagated by Stem Cuttings Acerola (Malpighia glabra), bamboo, black pepper (Piper nigrum), cacao (Theobroma cacao), cassava (Manihot esculenta), citrus (Citrusspp.), coffee (Coffea spp.), eggplant (Solanum melongena), grape (Vitis vinifera), guava (Psidium guajava), lagundi (Vitex negundo), lanzones (Lansium domesticum), makabuhay (Tinospora orispa), malunggay (Moringa oleifera), molave (Vitex parviflora), Norfolk Island Pine (Araucaria heterophylla), passion fruit (Passiflora edulis), physic nut (Jatropha curcas), pili nut (Canarium ovatum), pineapple(Ananas comosus), rubber (Hevea brasiliensis), red mombin (Spondias purpurea), sambong (Blumea balsamifera), santol (Sandoricum koetjapi), sapodilla (Manilkara zapote), starapple (Chrysophullum cainito), sugarcane (Saccharum officinale), tsaang gubat (Ehretia microphylla), tomato (Lycopersicon esculentum), tubli (Derris sp.).

Note: Plant cuttings may not always produce the desired plant characteristic. The use of root cuttings in propagating variegated plants may result to reversion to the normal, evergreen type. This also occurs when variegated snake plant (Sansevieria laurenti) is propagated by leaf cutting. This is because these plants are periclinal chimeras in which the inner cross sectional areas of the plant body are normal while the thin outer layers are mutated cells which are responsible for the variegation. With root and leaf cuttings, the new plants regenerate from the inner cells, resulting to normal growth and loss of variegation. In snake plant, the variegated character can be perpetuated by division of rootstock instead of leaf cutting propagation.

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Bank Details
Admin: Acct. Name. Umar Isunoya Ibrahim
Acct. No.: 6019090219 - Fidelity Bank
Acct. No.: 0161209600 - GT-Bank
Acct. No.: 0737214916 Access Bank

For Complaint, Confirmation etc.

Contact: nurt9ja/ Ibrahim on 08100770125