PROPAGATION OF HOME GARDENS Flashcards
(34 cards)
Methods of propagation
- Sexual reproduction
2. Asexual reproduction: (vegetative propagation)
what is Sexual reproduction?
propagation through seeds resulted from pollination and fertilization.
Advantages of Sexual reproduction
- Long storage possibility
2. Plant seeds are mostly free of viruses.
Disadvantages of sexual reproduction
- Genetic segregation: produces plants with different genotypes, especially if seeds are resulted from cross pollination.
2 Trees resulted from seeds need long time to arrive to their fruiting stage.
about Sexual reproduction
- considered the prevailing method in nature
- Allows plants to survive and maintain its type as a result of hybridization between strains to keep up with changing environment.
- it’s a way to improve production, and to produce hybrids free of viruses and also disease resistant plants
Seeds quality tests
- Purity test
- Germination test
- Viability test
- Purity test
it is the percentage of the required seed weight from the total sample weight
What are strange substances?
The strange materials may consist of three main components:
- Remaining plant parts (in addition to dusts and rocks)
- Seeds other than the required type (barley seeds in wheat sample are considered strange materials).
- Seeds of grasses and herbs.
What are purity tests good for?
This test helps in determining seed amount required for planting and in determining seed prices.
Example of a purity test
Example: a 100 g sample of bean seeds contains 90g of beans, and the remaining are strange substances.
Purity= 90/100 x 100% = 90%
- Germination test
it is the percentage of seeds capable of germinating and producing plant.
Which two tests are considered important in calculation of the actual required seed quantity?
Purity and germination percentage tests
Example: If you buy 1 kg of tomato seeds, where purity is 90% and germination percentage is 80%, How much of seeds are not useful?
In each (kg) we use:
(1000 x 90) ÷ 100 = 900 gm pure seeds.
80% of them are capable of germination, and 20% are dead.
900 x 80/100= 720 gm only out of the 1000 gm are capable of germination
i.e.: 1000-720 = 280 gm of seeds we pay for but they are not useful
- Viability test
it is the ability of seeds to germinate quickly and produce strong seedling.
Plant seeds are divided into two main groups in terms of their requirements to break dormancy stage:
- Seeds need treatment before planting
2. Seeds do not need treatment before planting
What is scarification?
It is the removal of the solid coating of seeds.
(Scratch seeds with sand or rough materials)
- The use of hot water or acids
- This process is conducted on seeds with hard coats to facilitate water absorption and speed germination (such as olive seeds)
What is Cold stratification?
- Keeping seeds in moist condition and low temperature
- Seeds are placed in sand layers and then placed in a refrigerator while maintaining good moisture
Soaking with chemicals. What are the two types?
- Plant hormones
2. Encouraging chemicals
What are some plant hormones?
- gibberellins
- cytokinins
- ethylene
What are some Encouraging chemicals?
- Thiourea
- Sodium Hydrochloride
What are some seed treatments before planting?
- Scarification
- Cold stratification
- Soaking with chemicals.
- Embryo planting
What is embryo planting?
Is removing most of the seed components and the embryo is planted in a special environment.
This method is used if seeds contain germination inhibitors.
What are the environmental factors that affect germination?
- Water
- Oxygen
- Temperature
- Light
- Resistance to pathogens
How does water affect germination?
- All plant seeds need varying amounts of water for germination.
- Certain plant seeds need small amounts of soil moisture (tomato) while other plant seeds need large amounts of soil moisture (Primula – an ornamental plant).
