Plant Propagation of Seeds Flashcards
What factors are important for triggering seed germination?(there are 7)
Temperature: Extremely low or cold temperature is not favorable for seed germination. They prefer higher temperatures. The germination rate of seed is directly proportional to the rise in temperature.
Moisture or water: Dry seeds do not germinate. Water is an essential factor to trigger off the process of seed germination.
Soil: During growth, seeds require mineral elements for further growth which is obtained from the soil.
Light: For seed germination light is not essential in the early stages of germination but plays a main role in the later stages of the life cycle of plants.
Viability of the seeds: After the seeds are formed, they remain viable up to certain period which may vary from plant to plant or seed to seed. Many sees die or incapable of supporting growth after a certain period of time.
Dormancy period: Many seeds do not germinate abruptly after they are produced . Certain seeds undergoe a resting time through which they stay dormant and germinate when conditions are favourable. Preence of growth inhibitors like abscisic acid induce dormancy in seeds.
Thinness or thickness of seed coat: Different seeds have varying degrees of thickness to enable the seeds to remain feasible. Seeds with a thin seed coat tend to germinate faster than those with thicker seed coats.
What plant hormone can be used to help trigger germination in difficult seeds?
Gibberillins- Gibberlic Acid
In general, what techniques should you use to choose seeds to plant and get them off to a good start?(there are five)
1) Look for plump, heavy, healthy looking seeds (small, flattened discolored seeds or those that float in water may be unhealthy or dead).
2) Store seeds in a cool, dry place. The refrigerator will keep seeds viable for long periods of time, and may help temperate species break dormancy. Store seeds in paper packets (plastic may encourage molding).
3) Percent germination drops as seeds get older, so plant more seeds than you need plants if the seeds are more than a year old.
4) Bury large seeds at a depth of about 2 times their diameter. Tiny seeds may be simply sprinkled over the soil surface, or mixed in with a little soil and sprinkled over the potting medium. Generally, don’t plant seeds more than 1” deep, and much less with small seeds.
5) Give seedlings as much light as possible (up to 16 hours daily) and keep them uniformly moist (but not wet). Warm temperatures will encourage growth (70s), especially in semi-tropical plants like peppers and tomatoes. Avoid letting seedlings dry out.
6) Uniformly moist. Little plants do not have much of a root system
7) Small seeds spread over the surface.
What is an application of GAA (gibberellic acid) ?
used to help break dormancy in difficult seeds.
What factors affect dormancy?there are four)
Several factors may be required to break seed dormancy. Water and a relatively warm temperature (75 F) will do it for most seeds. Some (often small seeds) also require light (or darkness) for germination. Many temperate plants have seeds that won’t break dormancy until they’ve experienced cold temperatures simulating winter. Some seeds (esp. of wild plants with hard seeds) may need a year in the soil for proper germination.
What is stratification?
stratification is the process of treating stored or collected seed prior to sowing to simulate natural winter conditions that a seed must endure before germination.
Why remove the leaves from herbaceous cuttings?
This allows the lower portion of cutting to be inserted into the propagating medium, and also reduces the amount of leaves from which moisture can be lost. If too much moisture is lost, the cutting will dry out. Remember, the cutting doesn’t have any roots yet to pull up more water to replace any it loses!
What does Rootone do for cuttings?
Rootone® is the long-trusted rooting hormone of choice for many gardeners. Rootone® contains fungicide to control damping off and other soil borne diseases that plague cuttings. Rootone® also contains growth regulators to promote fast, healthy rooting of cuttings.
How should the treatment of succulent cuttings and herbaceous cuttings differ?
Rooting herbaceous plants: The most important consideration here is to prevent the cutting from wilting.
Stems: Choose a stem segment with 3 or more nodes, no longer than 4-6”. Remove all but the upper 3-4 mature leaves. If planting the cutting upright, about 1/3 of the stem should be under the soil (1-3” depending on size). It is important to cover at least one leaf node, as this will be where roots are made. Don’t bury any leaves – cut them off if they’re in the way. Herbaceous cuttings must be kept very moist until they’ve rooted, as this will prevent damage from wilting. If the leaves are particularly large, cut most of them off or cut half of each leaf off. A plastic bag placed over the pot can help.
Leaves: Choose a healthy leaf with at least 1” of petiole. Cut off any excess petiole. If the leaf is larger than about 2” wide and 3” long, you may want to cut off half of it to slow transpiration. Dip petiole in rooting hormone, knock off excess, lay leaf on soil and tuck petiole under soil surface at a slight angle. A new plant will usually begin to form at the junction of the petiole and blade.
Rooting succulents: The most important consideration here is to prevent the cutting from rotting.
Succulent cuttings generally contain enough stored water to establish themselves. The major challenge is preventing them from getting too wet and rotting. Moisten soil to encourage root production, but don’t water again until the soil dries. Planting cuttings in a clay pot will help the soil to drain.
How is water use different in herbaceous plants compared to succulent plants?
succulent cutting does not need rootone like herbaceous because they have stored food and water.Rootone on both to reduce fungus. Succulent cutting will root with a lot of water. Let the soil dry out for a day-relatively dry and then add water. Herbaceous plants does not store water. Keep wet until they make roots or they will dry out. Planting cuttings in a clay pot will help the soil to drain.
In general, what techniques should you use to choose healthy cuttings to plant and get them off to a good start?
Not a gigantic cuttling because it needs more water and deals with more stress. Small cuttling are not as demanding and they do not need as much water. Pick a cuttling with 3 or 4 nodes- new growth or new roots and several places to add new parts.
How are vegetative propagation and propagation via seeds different?
seedlings are genetically different from their parents, cuttings are clones of their parents)- genetic differences. Cutting will get identical copies- exact genetic copy of parent’s.Starting from cutting will grow faster than a seed.
