SEED PROPAGATION
Seed propagation is the method of plant propagation (multiplying,
reproducing, or breeding new plants) that is done through the use of seeds.
Seeds are made up of three separate parts, and when a seed matures in an
optimal environment, it will germinate and actively grow. Seed propagation
occurs naturally, but can be done intentionally by growers and farmers.Seed
propagation is how many plants naturally reproduce. Additionally, growers
can take advantage of seed propagation by obtaining seeds from plants they
wish to propagate or grow. Many gardeners will often save and grow
ornamental plants and crops from seeds, especially if the plant has many
desirable characteristics. This is because seeds carry the genetic information
of the parent plant, and will therefore retain many of the same
characteristics of the parent plant.In seed propagation, seeds can be
germinated and planted in individual containers or starter plugs until they
form seedlings. Once germinated, these seedlings can then be transferred to
larger containers, or planted in beds or fields. In addition, seeds can be sown
directly into the ground and allowed to grow. Additionally, seeds can be
gathered from parent plants, or they can be purchased at many different
retailers.As an alternative to seed propagation, gardeners can also propagate
plants via plant cuttings (clones), grafting, or plant tissues, depending in
their skillset, range of equipment they have available, and the plants they
are wishing to propagate.
Principles of Seed Propagation
1. Seed Dormancy: Seeds may exhibit dormancy, requiring specific
conditions to break dormancy and initiate germination. Dormancy can be
broken by various methods, including scarification, stratification, and seed
priming.
2. Seed Viability: Seed viability affects germination rates and is influenced by
factors such as storage conditions, seed age, and genetic makeup. Seed
viability can be tested using various methods, including the tetrazolium test
and the germination test.
3. Seed Dispersal: Seeds are dispersed through various means, including
wind, water, animals, and humans. Seed dispersal plays a crucial role in the
spread of plant species and the colonization of new habitats.
Methods of Seed Propagation*
1. *Direct Sowing*: Seeds are sown directly into the field or container. This
method is commonly used for large-seeded crops, such as corn and beans.
2. *Seed Starting*: Seeds are started in a controlled environment, such as a
greenhouse or indoor growing space, before being transplanted. This method
is commonly used for small-seeded crops, such as tomatoes and peppers.
3. *Seedlings*: Seeds are germinated and grown into seedlings, which are
then transplanted. This method is commonly used for crops that require a
head start, such as broccoli and cauliflower.
4. *Hydroponics*: Seeds are germinated and grown in a nutrient-rich solution
rather than soil. This method is commonly used for crops that require precise
control over nutrient levels, such as lettuce and herbs.
Factors Affecting Seed Propagation*
1. *Temperature*: Optimal temperature ranges vary among species, affecting
germination and growth. Temperatures that are too high or too low can
inhibit germination or damage seedlings.
2. *Light*: Light intensity and quality impact seed germination and seedling
growth. Some species require light to germinate, while others require
darkness.
3. *Water*: Adequate moisture is essential for seed germination and seedling
establishment. Overwatering can lead to seed rot and poor germination.
4. *Soil*: Soil quality, pH, and nutrient availability affect seed germination
and seedling growth. Soil-borne pathogens can also impact seed
propagation.
5. *Pests and Diseases*: Pests and diseases can significantly impact seed
propagation success. Common pests and diseases include fungi, bacteria,
viruses, and insects.
*Seed Propagation Techniques*
1. *Scarification*: Seeds are scratched or nicked to improve water uptake
and germination. This method is commonly used for seeds with hard seed
coats, such as beans and peas.
2. *Stratification*: Seeds are exposed to a period of cold or moist conditions
to break dormancy. This method is commonly used for seeds that require a
period of cold stratification, such as trees and shrubs.
3. *Seed Priming*: Seeds are treated with chemicals or hormones to enhance
germination and growth. This method is commonly used for seeds that
require a boost to germinate, such as lettuce and herbs.
4. *Seed Coating*: Seeds are coated with materials to improve germination,
growth, or pest resistance. This method is commonly used for seeds that
require protection from pests or diseases, such as corn and soybeans.
Advantages of Propagating from Seed:
• Seeds are the source used most widely
• New cultivars and varieties can be created through sexual propagation
• It tends to be cheaper to propagate from seed
• The majority of seeds are readily available
• Sexual propagation seldom requires expensive propagation structures
• Large numbers of plants can be produced in minimal space
• Sexual propagation can be used to create rootstocks for budding and
grafting
Sexual propagation promotes genetic variability which helps plants
evolve
against pathogens and fluctuating environmental conditions
• Manny seeds allow for the possibility to be stored.
• Trees grown from seed tend to live longer, bear more fruit and are
hardier.
• Propagating from seed generally carries a lower risk of transferring
diseases
from the parent plant. (Provided adequate sanitation practices are
followed)
• Certain plants can only be raised from seed.
Disadvantages of Propagating from Seed:
• Plants propagated from seed risk not being true to type (flowers,
growth habit etc. won't be the same as the mother plant) due to cross
pollination.
• In some cases, Sexual propagation can be slower than asexual.
• Some plants produce non-viable seeds.
• Some seeds are very difficult to germinate.
• The seed of certain plants need require to be treated chemically or
mechanically to stimulate germination.
• Certain plants don’t produce seed at all.
• In most cases seedlings have to go through an immature phase before
maturing and fruiting.
• Seed collection can be difficult, in some cases hazardous and timing
must be right to ensure the seed will be viable.
• Pollination is required to ensure seed is viable.
Conclusion
Seed propagation is a complex process influenced by various factors.
Understanding the principles, methods, and factors affecting seed
propagation is crucial for successful plant production. By applying
appropriate techniques and considering the specific needs of each species,
seed propagators can optimize germination rates, growth, and overall plant
quality.
References
1. Hartmann, H. T., & Kester, D. E. (1983). Plant propagation:
Principles and practices.
2. Seed Propagation" by the United States Department of
Agriculture (USDA)
3. "Plant Propagation" by the Royal Horticultural Society (RHS)
