Nurseries: We have different types of nurseries and they are vegetable nurseries, tree nurseries, grafting nurseries and layering nurseries. The types of nurseries are well explained below.
Categories of nurseries:
Vegetable Nursery:
- They are used for raising the seedlings of vegetable crops.
- Tomatoes, cabbages, kale, onions, brinials and peppers.
Vegetable Propagation Nurseries:
- They are used for inducing root production in cuttings before they are transplanted,
- The cuttings can be planted directly in the soil and hence called bare root nurseries.
- Or planted into containers such as pots, polythene bags and others, hence called containerized nurseries.
Tree Nurseries:
- These are used for raising tree seedlings.
- The seedlings can be raised in bare root nurseries or in containerized nurseries.
Nursery Management Practices:
These are the practices carried out in the nursery while the planting materials are growing.
They include:
- Mulching; —light mulch should be applied on the nursery bed. lt be should be removed on the 4 day
- Weed control.
- Pricking out.
- Pests and disease control.
- Hardening off
Preparation of vegetative materials for planting:
Cuttings -These are plant parts such as stems, leaves and roots induced to produce roots and used as planting materials.
Grafting –
- It is the practice of uniting two separate woody stems.
- The part bearing the roots are referred to as root stock while the part which is grafted onto the root stock is known as scion.
- The scion has buds which develop into the future plant.
- The ability of the root stock and the scion to form a successful union is termed as compatibility.
Methods of Grafting
Whip or tongue grafting:
- In this case the diameter of the rootstock and the scion are the same.
- It is carried out when the diameter of the scion and the rootstock is ‘pencil’ thick.
Side grafting:
In this case the diameter of the rootstock is bigger than that of the scion.
Other types of grafting include:
- Approach rafting,
- Notch grafiing
- Bark grafting.
Budding:
- It is the practice of uniting a vegetative bud to a seedling of another plant.
- The scion has only one bud and some bark with or without wood.
- The bud is inserted in a slit made on the bark of the stock.
- It is held tightly on the stock by tying with a budding tape until it produces a shoot.
Methods of Budding:
- T-budding Top
- budding Patch
Importance of Budding and Grafting:
- Plants with desirable root characteristics but with undesirable products may be used to produce desirable products for example lemon-orange graft.
- They facilitate the changing of the top of the tree from being undesirable to desirable
- They make it possible to grow more than one type of fruit or flower on the same plant.
- They help to propagate clones that cannot be propagated in any other way.
- They help to shorten the maturity period.
Layering
- It is the process by which a part of a plant is induced to produce roots while still attached to the mother plant.
- Once the roots have been produced, the stem is then cut off and planted.
Types of layering;
- Marcotting or aerial layering.
- Tip layering.
- Trench layering.
- Compound or serpentine.
Tissue Culture for Crop Propagation
- Tissue culture is a biotechnology used in cloning vegetative propagated plants.
- It is based on the ability of plant tissue (or cells) to regenerate other parts of the plant.
- The tissues are derived from shoot tips where cells are undergoing rapid cell division and are not differentiated.
- The cells are then provided with the right conditions which enable them to multiply and develop roots.
The Right Conditions for tissue culture:
- Culture medium.
- Correct temperature.
- Correct light intensity and
- Correct relative humidity.
Importance of Tissue Culture in Crop Propagation
- It is used to recover and establish pathogen-free plants especially in the control of viral diseases.
- It is used in mass production of plantlets or propagules.
- It is fast and requires less space than the cultural methods of using cutting which requires a bigger space.
Transplanting Seedlings
- Transplanting of vegetable and tree seedlings are generally the same.
- Generally, vegetable seedlings are ready for transplanting when they are one month old or have 4 -6 leaves or are about 10-15cm in height.
- Before transplanting, the nursery bed is adequately watered 3 – 4 hours before lifting the seedlings.
- This ensures the seedlings are lifted easily with a ball of earth around the roots to minimize root damage.
- Tree seedlings take a little longer to reach transplanting age compared to vegetable crop seedlings.
- The roots are trimmed before lifting the seedlings.
- Transplanting should be done at the onset of the long rains to give the young trees a good start.
After transplanting the young trees should be protected from damage by animals for a period of about one year.