Vegetative propagation

 

Vegetative propagation

This is the natural regeneration of plants other than seeds to develop new plants.  The new plants are sometimes called Clones

 

Advantages of vegetative propagation

• It is possible to maintain desirable characteristics such as disease resistance and physical appearance
• It makes it possible to propagate crops that are seedless or have viable seeds
• The growth habit of a crop can be regulated to attain a desirable shape and size
• It is possible to produce more than one crop variety on the same plant
• Vegetative propagation imparts desirable characteristics to crops, such as seedless in citrus fruits
• It is completely independent of the processes of pollination and fertilization
• It enables cross-bred plants to be maintained in their new condition indefinitely
• The new plants are exactly  the same as the parent plant when vegetatively propagated
• The young plants are hardy and vigorous than seedlings.  This is due to a lot of food reserves available to the growing plant
• Vegetatively propagated plants grow and mature faster than seed propagated plants

 

Disadvantages of vegetative propagation

• Vegetatively propagated plants are difficult to breed and genetically improve since there is no possibility for cross breeding
• If the vegetative materials curry a disease there is the danger of transferring diseases to the new plants or locations
• Vegetative  materials are bulky , making them difficult to transport and plant out
• Due to high moisture content, most vegetative materials cannot be stored for a long time, they lose viability or sprout in store
• It is difficult to dress vegetative materials against diseases and pests
• Vegetative materials' planting cannot easily be mechanized
• Due to the amount of materials required and the transport costs involved.  It is expensive to plant a large field with vegetative materials

 

Methods of vegetative propagation

These involve use of specialized vegetative and perennating organs

Bulbs; a bulb is modified shoot with short stem and storage leaves.  Bulbs are used in propagation of onions, garlic, and tulips.

Corms; a corm is a short, swollen, vertical underground stem.  Corms are used in propagation of coco yams, taro

Stolons; this is a creeping horizontally growing stem that grows on top of the soil surface.  It is used in propagation of blackberry, gooseberry, blackcurrant, and redcurrant

Runners; runners bear axillary buds and the buds give rise to adventitious roots and new plants.  They are used in propagation of strawberry and creeping buttercup

Rhizomes; rhizomes bear leaves, buds and adventitious roots.  Rhizomes are used in propagation of ginger, cardamom, and turmeric.

Suckers; these shoots which radiate from buds below the ground level.  They are used in propagating crops such as banana, pineapples, and sisal

Tubers; tubers have axillary buds that have capacity to sprout in to new independent plant.  Tubers are used in propagation of crops like; potatoes and arrow root and yams

Bulbils; these are aerial bulbs or buds produced in leaf axils, which on separation, are capable of growing into a new plant.  They are used in propagating sisal.

Turf splits; turf is a clump or bunch of tillers originating from a common base.  Turf splits are used in propagation of most pasture grasses

Crowns; these develop from the top of fruits.  Mature crowns on fruits are dormant but become active after detachment from the fruit.  They are used in propagating pineapples

Slips; these are shoots borne on the peduncle just below or on the base of the fruit.  Slips are used in propagation of pineapples.

Vines; these are soft cuttings obtained from mother plants and planted directly into the main field to give rise to new plants.  They are used in propagation of sweet potatoes.

 

Cuttings

These are pieces of plants (stem, roots, or leaves) that are cut and then planted.  They have buds which develop into a shoot.  Cuttings are used to propagate plants like sugarcane, tea, and cassava.

The ability of the cuttings to root and shoot depends on the following factors;

• Plant species; some plant species have natural ability to establish from cuttings.  These cuttings easily sprout when provided with suitable growth medium
• Age of the plant; cuttings from young plant parts root better and easily than leaf or root cuttings.
• Type of rooting medium; the rooting medium  must be sterile , porous but capable  of providing sufficient oxygen and moisture
• Chemical and other treatments given to cuttings such treatment with growth hormones
• Weather conditions such as humidity , temperature and sunlight
• Watering frequency
• The amount of leaves on the cutting

 

Cuttings to use for plant propagation should have the following qualities

• Should have  reasonable number of buds and the buds should be viable
• Should be free from pest and diseases
• Buds should be free from mechanical or pest or diseases damage
• Should be of average maturity with enough food reserves
• Should be from desired variety
• Should be alive or fresh for optimum viability
• For some cuttings, should have optimum number of leaves

 

Layering

Layering is the practice of stimulating a part of a branch to produce roots while still attached to the mother plant.  The rooted part is then cut off and planted as a new plant

 

Procedure of layering

1. The process of layering starts with selection of a suitable branch on the growing plant, the branch should not be having  any form of deformities and should be free  from pests or diseases
2. The selected branch is then wounded mildly.  Wounding allows transportation and accumulation of healing and growth hormone around the wound.  Accumulation of especially Idole acetic acid (IAA) induces growth of roots around the wound.  The process of rooting is also encouraged by presence of suitable rooting medium around the wound
3. Prepare the rooting medium; the rooting medium can be sandy soil mixed with organic matter or peat soils.  The rooting medium should be well sterilized, provide optimum aeration and moisture.
4. The rooting medium is then placed around  the wound and then wrapped with a piece of perforated polythene sheet or cloth
5. The rooting medium should be watered periodically to prevent drying of the rooting medium
6. After about  2-4 months depending on the species, when the roots have fully developed, the branch is cut off and then planted out in pot nursery or directly planted in the field

 

Types of layering

Marcotting or aerial layering; it is used when the branch or the stem cannot bend to touch the ground; instead, the soil is curried up and tied to the branch.  This form of layering requires more skills and labour, and success is fairly low.

Tip layering; in this method, the tip of the shoot bearing the terminal bud is wounded and then bent to the ground.  It is then held in position using pegs and covered with layer of moist soil.  The covered part is induced to produce roots by applying a moist rooting medium

Compound or serpentine layering; in this method, the branch is bent several times and held in the soil with pegs.  This produces several new rooted plants from the mother plant.  This form of layering is commonly used in runners and stolons

Trench or ground layering; in this method, the branch to be layered is first wounded, then bent to the ground and laid in a trench.  It is then held in position using pegs and covered with a layer of moist soil.  The covered part is induced to produce roots by applying a moist rooting medium.  The branch is then cut off from the mother plant and transplanted

 

Stool or mound layering; this method is used when the branch or stem cannot bend enough to reach the ground level.  In this form the soil the soil is heaped high to form a mound where the branch or stem can be able to reach or the rooting medium is placed in the container and then raised high supported on a stand or stool, and then the branch is slightly bent into the rooting medium in the container.

 

Benefits of layering

• The propagule has high chances of survival than cuttings
• A large planting material is obtained in a short period of time
• Plants propagated from layered propagules mature faster than plants from cuttings
• Seedlings from layering are more adapted to the environmental conditions
• Seedlings from layering are more resistant to pests and diseases

 

Disadvantages of layering

• The method requires more skills to curry out
• There are high chances of spreading pests and diseases from mother plant to the propagules
• Propagules are usually large requiring more labour to handle and plant

 

Grafting

This is an artificial plant propagation method involving uniting a shoot from one plant to the root stock or another plant so that they grow as one plant.  The shoot and the rootstock should be from plants of the same species.

The upper portion of the graft is called the scion whereas the lower portion of the graft is called the stock.  Grafting is only done in woody plants and in plants of the same species.

The union of the graft is due to regeneration of cambial tissues; callus cells are responsible for the healing of the union wound.

 

Advantages / benefits of grafting

• Grafting can be used to change the plant from being undesirable to desirable.  This is done by replacing the undesired shoot with desired shoot
• It enables propagation of crop that would be difficult to propagate by other means
• Grafted crops mature faster than seed propagated crops
• Grafting can be used to test for disease resistance in some crops.  This is done by grafting susceptible scion to a resistant stock and observing the response
• It makes the growing of more than one type of plant on one stock possible.  This economizes space required to grow the different types of crops in the garden
• Root stocks with desirable qualities such as disease and pest resistance, drought resistance and resistance to salinity can be harnessed for production of beneficial but susceptible crops
• Grafting may be used to repair damaged plant parts; when the stem or branch is damaged either by pests or browsing animal, it can be cut off and replaced with a better health stem or branch
• Provides an opportunity of utilizing good qualities of the rootstock and scion of different plants

 

Disadvantages of grafting as mean of propagation of crops

• The method requires a lot of skills to carry out
• It is not reliable as any slight mistake can lead to total failure.
• It can only be done in propagation of some few crops
• The method requires a lot of time and labour
• Grafted crops can easily be damaged by wind
• Spread of diseases from the mother plant to the grafted plants may occur
• Grafting can only take place in closely related families thus not giving a chance to have different families on the same root stock.

 

Procedures of grafting

1. Select a seed from a mother that is vigorous and well adapted to the soil condition to provide the rootstock
2. Raise the seed in a pot nursery
3. A seedling is ready for grafting when the stem is pencil thick
4. Select a dormant shoot from a mother plant with desired qualities and of the same species as the rootstock to provide the scion
5. Grafting should be done on a cool day or in a cool environment
6. Use a sterilized razor blade or grating blade to cut the scion and the stock.
7. Make matching cuts on both the scion and the stock.  The cuts can be V-shaped or straight slanting cut on both the scion and stock.
8. Remove all the leaves from the scion to reduce transpiration
9. Join the scion to the stock; make sure the cambia of the scion and the stock are in contact
10. Tie the joint with grafting tape and apply grafting wax to prevent bacterial and fungal infection
11. Keep the grafted plant in cool humid environment and away from wind until buds starts to grow
12. Remove the grafting tape after the joint has healed and then transplant to the main field

 

Conditions that should be fulfilled for grafting to be successful

• The scion and the stock must be from woody plants
• The scion and the rootstock must be from plants of the same species
• The scion and the rootstock must be of the same growth habit
• The scion and the rootstock should preferably be of the same diameter
• During grafting the cambia of the scion and the rootstock must be in contact
• The scion must be dormant at the time of grafting
• The scion and the rootstock must be at the proper physiological stage of growth
• Post graft care such as keeping the graft union moist and protected from infection until the wound has healed

 

Factors affecting the success of grafting

• Compatibility of the scion and the root; the scion and the rootstock should be from genetically related plants (plants of the same species)
• Type of the plant; grafting is only possible in some plants especially those with woody stems
• Grafting technique used; the cuts made in the scion and rootstock should be matching for the joint to be firm and to encourage maximum cambial contact
• Post grafting care; good care of newly grafted plants is vital to accelerate union and healing of the plants.  Plants should be provided with warm temperature and high humidity and the joint protected from infection.
• Pest and disease infestation; any pest or disease infestation to the newly grafted plants can lead to failure of the plants.  These can be controlled by ensuring high level of hygiene in the nursery.
• The quality of the rootstock or the scion; these should be healthy and vigorous.  The scion should be dormant and not actively growing at the time of grafting.

 

Incompatibility in grafting

Graft incompatibility is a situation where the grafted plants fail grow as one plant exhibited by death of the scion

Signs of incompatibility in grafted plants

• Browning of the scion
• Premature death of the planting Abnormal growth of the scion or rootstock
•  Poor health of the plant

 

Causes of graft incompatibility

• Physiological and bio chemical differences between the scion and the rootstock
• Grafting of plants of different growth habits
• Diseases especially viral infections to scion
• Incompetent workmanship (lack of grafting skills)
• Unfavorable micro-climate provided to the grafted planting
• Grafting of actively growing scion

 

Methods of grafting

Splice grafting; a straight slanting cut is made on both the scion and the stock so that the joining surfaces come together obliquely

 

Cleft grafting; the top of the stock is cut off and a wedge cut is made in the rootstock where a wedge shaped scion into the stock

 

Saddle grafting; a V-shaped cut is made on the stock and the scion is cut in wedge shape that fits properly into the stock

 

Whip or tongue grafting; in this method , a straight slanting cut is made on both the scion and the stock and then after a second cut is made on both scion and stock to produce a notch -like arrangements that accommodates each other and fit slightly together

 

Side grafting; in this method V-cut is made on the side of the rootstock at an angle of about 30 where a wedge shaped scion is fitted

 

Budding or bud grafting

This form of grafting which involves uniting a bud from one plant to the rootstock of another plant where it regenerates as new plant.  The bud and the scion should be from plants of the same species.

The bud to graft should be in dormant state while the stock should be the one that is highly adapted to soil condition and vigorous.

 

Methods of budding

T-budding

It is used on young socks with a bark which is able to slip off.  In this method a vertical cut is made through the bark of the rootstock and after, a horizontal cut is made at the top of the vertical cut to make a T-shaped cut.  The bark is then loosened and the bark flaps lifted.  A shield shaped piece of bud is inserted under the bark and the union is wrapped with the grafting tape

 

Patch budding

This is used on old stocks with hard bark or with a thick bark that cannot peel off or cannot be lifted from the wood.  In this method a rectangular piece of bark is removed from the rootstock where a rectangular shaped bud is inserted and then wrapped with grafting tape

 

Procedure for bud grafting

1. Select a seed from a mother that is vigorous and well adapted to the soil condition to provide the rootstock
2. Raise the seed in a pot nursery
3. A seedling is ready for bud grafting when the stem is pencil thick
4. Bud grafting should be done on a cool day or in a cool environment
5. Select a dormant bud from a plant of the same species as the rootstock
6. Use a sterilized razor blade or grafting blade to cu the bud.  Peel off wood from the bark of the bud patch
7. Make a T-cut in the bark of the rootstock and gently lift up the bark
8. Gently push the bud under the bark
9. Wrap the bud with grafting tape and apply grafting  wax to prevent water and infection from bacteria and fungi
10. Cut off the part of the stock above the bud and remove any other bud from the rootstock
11. Inspect the bud after about 15- 20 days, green color of the bud indicates that the bud is still alive and that the graft is successful.  Browning of the bud indicates that the bud is dead
12. Buds are ready for transplanting after 40- 60 days

 

Care given to drafts and buds

• Wrapping the grafts and buds with grafting tape to make the union firm and to prevent the scion from falling off.
• Protection of the union against water that can lead to rotting
• Reducing the amount of leaves to reduce transpiration and dehydration of the scion
• After the union is firm, the grafting tape should be removed to prevent girdling due to buildup of translocate substance above the union
• Once the bud is established the part of the rootstock above the bud should be cut off to encourage the bud to sprout

 

Advantages of budding

• Budding is simple than grafting
• Shoots from buds are more strong and resistant to wind damage than shoots from grafts
• Budding is more economical since a single shoot can produce several buds
• Several buds from different varieties can be grafted on the same stock easily
• Unlike in shoot grafting buds do not easily spread pests

 

Tissue culture

Tissue culture is the growing of living cells from shoot tips in a controlled medium.  In tissue culture, living tissues from desired varieties are placed in the growth medium that leads to rapid cell division to take place.  The cells are then cloned (sub culture) each cell developing into independent plantlet.  The culture medium is made up of nutrients, indoleacetic acid, and cytokinins

 

Advantages of tissue culture as a method of propagating crops

• Tissue culture seedlings are free from diseases
• Many seedlings can be obtained in a short period of time
• The seedling are not as bulky as cuttings
• In crops which are difficult to produce using seeds or vegetative organs, this is the only quick means of multiplying such crops
• Crops are identical genetically and all crop are the same in behavior e.g uniform ripening of crops making harvesting easier

 

Limitations of tissue culture as means of propagating crops

• The method is expensive since it requires special lab equipment and chemicals
• The method requires special skills to carry outbreak
• Cell mutation may take place it the lab resulting into change in crop behaviour
• Tissue culture seedling take more time to mature
• In some crops such as root and tuber crops the first harvest is always low
• The seedlings are highly susceptible to pests and diseases

 

Farm Budgeting

Farm Budgeting

Farm budgeting is the process of estimating the future outcomes of a proposed farm plan.

Importance of Farm Budgeting

1. It helps the farm in decision making.
2. It helps the farmer to predict future
3. It helps the farmer to avoid incurring losses by investing in less profitable enterprises.
4. It helps the farmer to secure loans from financial institutions such as Agricultural
5. Finance Corporation and commercial banks.
6. It ensures a periodic analysis of the farm business.
7. It acts as a record which can be used for future reference.
8. It pinpoints strengths or weaknesses in farm operations.

 

Types of Budgets

Partial Budget

This type of budget is used when making minor changes on the farm.  It involves estimating the extra costs to be incurred and returns expected from the changes made.

 

Complete Budget

This type of budget is made when a complete reorganization of the farm business is to be done.  It is also needed to guide the farmer when setting up an entirely new farm or when changing from one enterprise to another.

 

Source of information for farm budgeting.

1. Farmer's own data: This is obtained from the farmer's record books.  This is possible only if the farmer has been keen to keep accurate and complete records.
2. Data from farmer group and organizations such as cooperatives.
3. Experimental data: In Uganda, such data can be obtained from research stations such as Namulonge, Kawanda, and Serere and from district farm institutes.
4. Data on prices of inputs and output, the information may be obtained from many manufacturer of agricultural products.
5. Data prepared by farm management experts.

Procedure for making a budget.

• State the objectives of the business.  This involve stating the reasons for setting up the farming business.
• Take a farm inventory.  The farmer makes a list of the available resource inputs, and if possible their monetary values.  Such inputs include machinery, farm buildings, breeding stock, size of land, inputs etc.
• Plan for the resources.  This involves indicating how the resources are to be utilized.
• Estimate the production.  The farmer calculate the expected output from the enterprise.
• Estimate the income and expenditure.  The farmer calculate what he expects to spend in the production process and the expected income when the products are sold.
• Analyze the input and output relationship.  This enables the farmer to find out if there are possibilities of exploiting supplementary in the enterprises to be undertaken.
• Analyze the existing production weakness.  The weakness may be either structural or operational.

 Structural weakness are those associated with poor utilization of resources such as land, machinery, labour, and buildings.

Operational weakness are those related to managerial efficiency of the farmer such as supervision of daily activities, purchasing inputs in time etc.

VEGETABLE PRODUCTION

 

VEGETABLE PRODUCTION

Vegetables are crops grown for their edible leaves, roots, stems, bulbs, and fruits.  They are rich in source of vitamins and minerals.  Some are also used to feed livestock.  Others are sold fresh in the market to provide income.  Vegetables are also a source of raw materials for industries.

 

Benefits of growing vegetables on the farm

•      They are rich sources of minerals and vitamins to human diet.

•      They can be sold for cash to generate income for the farmers.

•      They provide roughages in the diet important in the proper functioning of the stomach.

•      Their residues can also be used as fodder for livestock and poultry.

•      Their residues can also be used as mulches to provide organic matter in the soil.

•      Growing vegetables requires relatively less labour as compared to other crops.

•      They take less time to mature and this gives returns faster

•      They can easily be grown on small scale in home gardens

•      Vegetables can be eaten raw as salads or cooked as vegetables

•      Legume vegetables fix nitrogen in the soil

•      They can easily be inter planted with other crop to allow efficient utilization.

 

Disadvantages of growing vegetables

•      Their production requires a lot of labour and time, they need to be raised in the nursery first, then transplanting them to the main garden, irrigating them and spraying them against pest and diseases

•      They are highly perishable thus need to be sold immediately after harvesting.  This makes marketing of vegetables difficult.

•      Their production requires relatively more capital

•      They have limited market; their demand is restricted to urban and Peri-urban centers.

•      They are highly affected by pests and diseases requiring constant spraying with pesticides which pollute the environment and make vegetable production expensive.

 

Classification of vegetables

1.   Classification of vegetables on the basis of the part used as food.  Such parts include; leaves, stems, roots, fruits, flowers, pods, and bulbs.

Vegetables are grouped into the following categories:

1.   Leaf vegetables for example kales and cabbages.

2.   Root vegetables for example carrots, beets, radishes and turnip

3.   Fruit vegetables for example French beans and okra.

4.   Stem vegetables for example asparagus, leeks and spring onions.

5.   Bulb vegetables for example bulbed onions and garlic.

Classification of vegetables of vegetable according to their botanical family

1.   Solanaceae family for example tomatoes, pepper, egg plants, Irish potatoes etc

2.   Brassicaceae family for example cabbage, cauliflower, kale etc

3.   Cretaceously family for example pumpkin, cucumber, and water melon.

4.   Alliaceae family for example onions, leek and garlic

5.   Leguminosae for example beans, peas etc.

Principles of vegetable growing

•      Always plant at the right time

•      Plant at the current spacing

•      Plant seeds at recommended depth

•      Maintain a soil cover throughout the growing period e.g always mulch the soil.

•      Control weeds in the field

•      Always rotate the vegetables with legumes

•      Harvest them at the right stage of growth

•      Always grade the harvested crops according to size and quality, shape and colour.

•      Always destroy crop residues after harvesting to destroy pests and diseases

•      Also apply fertilizers if the soil fertility is low

•      Always prepare land in time

•      Control pests by sanitary measures and chemicals

•      Carry out irrigation in the dry season

•      Grow key varieties that are suitable for climate and farming system

 

Nursery Practices

A nursery bed is a piece of land of any convenient length prepared for raising seedlings for the later transplanting.  A seedbed is a piece of land of any size that has been prepared for sowing seeds or receiving planting materials.  A seedling bed is a special type of nursery bed used for raising seedlings that have been removed from nursery bed due to overcrowding before they are ready for transplanting.

 

Reasons for raising vegetable seedlings in a nursery bed

•      It economizes on the amount of water  and chemicals used since seedlings are in small area

•      Many seedlings are raised in a small unit area

•      It reduces crop failure since it is possible adequate care to crops in a nursery bed.

•      It reduces the time taken by the crop in the field

•      It enables a farmer to select only healthy and vigorously- growing seedlings that establish faster

•      It reduces the amount of labour spent caring for the seedlings

•      It makes it easier to manage the seedlings in terms of watering, weeding, and controlling pests and diseases.

•      Some vegetable seeds are very small to successfully plant at the correct spacing and depth.

 

Factors to consider when selecting a site for a nursery bed

1.   Nearness to the water source; the site should be established near a water source for easy watering

2.   Type of soil; the site should have well-drained, deep, and fertile soil, preferably sandy loam.

3.   It should be easily accessible by the farmer and machines.

4.   Topography; it should be on a gentle sloping land to avoid flooding of the beds when it rains.

5.   Security; it should be well secured from thieves and damage by livestock.

6.   Well-sheltered; the place should be free from strong winds

7.   Previous cropping; areas where the same crop species had been planted should be avoided.

8.   Freedom from pests and diseases; the site should be free from pests and diseases.

 

Establishing a vegetable nursery

Preparation of the nursery bed

•      Select a suitable site and mark it out.

•      Clear vegetation and remove the trash

•      Dig or plough the site deeply to remove all perennial weeds

•      Harrow the bed to a fine tilth and then level it

•      Measure and divide the nursery bed into sections of about 1m wide and any convenient length , with 60cm paths between individual beds

•      Sterilize the soil by burning trash on top of the bed or using soil sterilizers.

•      Spread phosphatic fertilizers or well rotten manure

•      Mix the fertilizer or manure well with the soil using a rake

•      Make shallow drills, 1cm deep, and 10 to 20 cm apart.

•      Drop the seeds uniformly in the drills.  Cover the seeds lightly with soil.

•      Spread a thin layer of mulch on top of the bed

•      Water the nursery bed and erect a shade to minimize water loss through evaporation.

 

Nursery management practices

The routine nursery management practices include the following

•      Mulching; it involves spreading of mulch material such as plants leaves over the soil surface immediately after sowing seeds.  It is done to insulate the soil against moisture.  After emergence of seedlings, all the mulch is removed to avoid smothering the young seedlings

•      Shading; this involves the erection of a shade over the nursery bed.  It is done to prevent scorching of seedlings by direct sunshine.  Shading also prevent damage of seedlings by raindrops.

•      Watering; this involves the application of water to the nursery bed.  It is done to maintain the right moisture levels in the nursery.  Watering is most important when the conditions are dry.

•      Thinning or pricking out; this refers to the removal of excess seedlings from the nursery bed.  The removed seedlings are taken to another space within the same nursery bed or to a seedling bed.  Thinning reduces overcrowding in the nursery and enables seedlings to grow vigorously and healthily

•      Pest and disease control; this involves using appropriate methods such as spraying, to control diseases and pests.  Most caterpillars are destructive to seedlings

•      Weed control; it involves controlling weeds to reduce their competition for growth factors with the seedlings.  It is done by uprooting the weeds to minimize root disturbance

•      Hardening off; this refers to the gradual exposure of seedlings to conditions close to those found in the field after transplanting.  It is done by reducing the amount of shade, and the frequency of watering the seedlings.  Hardening off enables the seedling to withstand harsh conditions in the field.

•      Transplanting; is done during the evening or during cloudy day or cool day.  Transplant only healthy and vigorous seedlings.  During transplanting, seedling should be lifted with the soil lump around the roots to minimize disturbance to the roots.  Before transplanting, the nursery should first be watered to soften the soils so as to reduce damage to the seedlings during lifting of seedlings.

 

Steps in transplanting vegetable seedlings

•      The stage of transplanting vegetable seedlings from the nursery bed is 10 to 15 cm height, or 4^th   to 6^th true leaf stage or 4 to 6 week of age.

•      Transplant the seedlings when it is cool

•      Water the nursery bed before lifting the seedlings to minimize root damage.

•      Select healthy and strong seedlings

•      Lift the seedlings with a lump of soil on their roots

•      Use appropriate tool for lifting, such as a garden trowel

•      Avoid damaging the roots when lifting seedlings.  Dig holes in the seedbed that are big enough.

•      Put insecticides in the planting holes to control soil-borne pests

•      Plant the seedlings at the same depth as they were in the nursery

•      Mix phosphatic fertilizer or well-rotten manure with top soil and fill in the planting holes

•      Firm the soil around the base of the seedlings.

 

Cultivation some common vegetable crops

Cabbage (Brassica oleracea)

Ecological requirements

 

Altitude; cabbage with large-round head prefers high altitude of 1800 to 2900m while cabbage with small- conical head prefers low altitude of 900 to 1500m above the sea level.

 

Rainfall; the crop requires well distributed rainfall throughout the growing period.  Where the rain is not sufficient.  Irrigation of the crop should be done

 

Soil; the crop requires deep, well drained and fertile soil of moderate pH

 

Varieties; cabbage has many types and varieties.  Some are quick maturing while others are slow maturing.  Early maturing varieties include; Copenhagen market, sugar loaf, Brunswick, Chinese cabbage, celery, early jersey, and cafe spits Kool and early offenham.  Mid-season or late maturing varieties include; drumhead, gold acre savoy, perfection, succession and winning stadt

Nursery practices

•      Choose a site where there has never been Solanaceae crop in the last three years

•      Make seedbeds depending on the soil moisture, the bed may be raised or sunken

•      Apply fertilizers such as phosphatic and nitrogenous fertilizers.

•      Select good seeds from a reliable supplier

•      Sow the seeds in shallow drills in rows and then cover the seeds with a thin layer of soil.  Drills should be 1cm deep and 15-20 cm apart

•      Provide shade or mulch.  Mulch should be removed as soon as the seeds start to germinate this prevents etiolation of the seedlings due to too much shading.

•      Water the bed twice a day.  The frequency of watering however depends on the weather

•      Control weeds by hand pulling of any weed

•      Control pests and diseases through spraying with appropriate insecticides and sanitation

•      Acclimatize the seedling before they are transferred to the field.

 

 

Land Preparation

The land should be deeply cultivated, the vegetation should be destroyed, and trees and tree stumps should be removed.  Dig holes at the spacing of 60cm X 60cm. incorporate farm yard manure in the soil.

 

Transplanting

•      Seedlings are ready for transplant after one month, when they are 6-10cm in height

•      Water the seedlings before transplanting to soften the soil so to allow easy lifting of seedlings

•      Select and transplant healthy and vigorous seedlings and discard the weak and stunted ones

•      Transplanting should be done on cool or cloudy day or in the evening.

•      During transplanting seedlings should be lifted with a lump of soil to prevent root damage

•      Plant the seedling to the same depth as they were in the nursery.

 

Spacing; Spacing varies with the climate or variety.  The spacing is 60cm X 60cm for most varieties

 

Fertilizer application; manure should be spread in the seed bed.  Also super phosphate should be applied per planting holes and later top dressed with CAN or nitrogen sulphate.

 

Mulching; mulches should be applied in between the rows or around the crop.  Mulches can be obtained from dry plant tissues.  Mulches help to conserve moisture in the soil, prevent weed growth, and also prevent the soil from slashing to the leaves which could spread soil pathogen to the crop.

 

Weed control; this is very important in cabbages which are not mulched.  Cabbage field should be kept free from weeds to reduce competition for growth factors and pests in the field.  Weeding can be done by hand pulling, or using herbicides.

 

Pests and diseases control; cabbages should be sprayed with fungicides and other pesticides to reduce attack by pests and diseases.  Common pests include; diamond back moth and cut worms.  These can be controlled by applying pesticides.  Some diseases include black rot and blackleg.  These can be controlled by sanitary measures and fungicides.

 

Harvesting; the best time to harvest cabbages is when the heads are heavy and hard.  Harvest the head with at least 4 wrapping leaves.  Harvesting is done using knives.

 

 

 

Green Pepper (Capsicum annum)

Growth requirements

Green pepper prefers sandy loam soil that drains freely and contains plenty of organic matter.  Warm climate is ideal with well distributed rainfall.

 

Husbandry practices

Land preparation

The land should be deeply ploughed and tree canopies reduced to allow full sunlight to reach the plants.  Also work some organic matter into the soil to enhance nutrient and moisture supply to crops.

 

Planting; seedlings from the nursery bed are usually used for planting.  They are transplanted when they are 8-10 weeks old.  Planting in the field is done at the beginning of the rainy season to ensure ample moisture supply to the crops.  Dig holes large enough to accommodate the roots.  Transplant the seedlings during cool hours.  Plant the seedlings in the holes and refill them loosely with top soil.

 

Spacing; green peppers should be planted approximately 12-18 inches apart to have room to grow without competing with one another, and allow ample working space for the gardener.

 

Irrigation; peppers are thirsty plants.  They need a moderate supply of water from the moment they sprout until the end of the season.  Irrigation during dry weather helps to maintain moisture supply to keep the plants in production.  Drip or overhead irrigation can be used for this purpose.

 

Weed control; pepper plant is less tolerant to weed infestation.  Weeds provide a refuge for most pests and can also spread fungi and viruses to nearby healthy pepper plants.  Weed control can be achieved by mulching, hand hoeing and pulling of growing weeds

 

Fertilizer application; peppers are light feeders.  Too much application of fertilizer tends to make the pepper plants develop lush foliage at the expense of fruit production.  Apply NPK 5-10-10 fertilizer into the soil prior to transplanting, also side- dress the plants with a light sprinkling of NPK 5-10-10 when blossoming starts, just to give the plants a boost if needed

 

Mulching; cover the prepared bed with organic mulch or use a dark coloured polythene mulch at least a week before transplanting.  This will heat the soil beneath and provide a better growing condition for young pepper plants.  The generated heat also helps to kill harmful bacteria and root nematodes.  Mulch will also help the soil retain moisture throughout the season as the plants grow.

 

Staking; peppers are easily damaged when laden with fruit.  For support, tie the plants to stakes using nylon strings, which have some 'give' as the stems enlarge.  The support prevents logging of plans; keeping the plant and fruit away from the ground to prevent infection with soil bacterial

 

Pests and diseases control; regular pest control is important.  Destructive pests like cut worms, horn worms, aphids and borers are controlled by using pesticides and keeping the plats weed free.

Diseases such as anthracnose mosaic, and bacterial spot can be controlled by planting disease-resistant varieties, spraying with fungicides and bactericides and ensuring proper sanitation.

 

Harvesting; peppers are usually harvested at an immature stage and also can be harvested at any stage of growth, but their flavour doesn't fully develop until maturity.  Frequent harvesting increases yields.  If you continually pick the peppers before they mature, the plants will continue to produce fruits in their quest to develop viable seed.  Use a sharp knife or garden shears to cut the tough stem.

 

 

Tomatoes (Solanum lycopersicum)

 

Ecological requirements

Altitude; 0 to 2100 m above sea level

Temperature; optimum temperature of 21 to 27degrees, with a diurnal range of 5 to 6

Rainfall; 760mm to 1300mm per annum that is well distributed.  Irrigation is carried out in dry areas or during the dry season

Soils; deep fertile and well drained loamy soils

Soil pH; 6 to 6.5

 

Nursery establishment and management

Nursery establishment

•      Select a suitable site where members of solanaceae family have not been grown for the last three years.  In high rainfall areas, the nursery bed should be raised to facilitate drainage whereas in dry areas the nursery beds should be sunken to conserve the available moisture.

•      Dig the site deeply to remove perennial weeds and stones

•      Harrow the site to a fine tilth.  The nursery should be 1m wide and of any length

•      Level the nursery using the rake

•      Make shallow drills, 1cm deep and 10cm to 20cm apart across the bed using sticks or a finger

•      Drop seeds singly and uniformly and cover lightly with soil

•      Spread a thin layer of mulch on top of the bed

•      Water the bed

 

Nursery management

•      Remove the mulch as soon as the seedlings start to emerge

•      Erect a shade above the nursery

•      Water the nursery twice a day ; in the morning and late in the evening

•      Control weeds regularly

•      Control pests and diseases once symptoms of attack are noticed

•      Prick out or thin the seedlings to 7cm or 8cm apart to avoid overcrowding

•      Harden off the seedling before transplanting to increase their chances of survival in the field

 

Land preparation

This should be done early before the onset of rains

•      Clear all vegetation and remove any tree stumps

•      Plough the seedbed deeply and remove all perennial weeds

•      Harrow the land to a medium tilth

•      Prepare planting holes, 15cm deep, and 15cm wide.  The spacing should be 0.9m X0.6m X0.5m depending on varieties

 

Transplanting

•      Apply organic manure or one teaspoonful of DSP in the planting holes

•      Apply an appropriate insecticide to control soil-borne pests

•      Transplant the seedlings when they attain a height of 10cm to 15cm 0r at 4^th to 6^th true leaf base stage or 4 to 6 weeks of age

•      Transplant on a cool cloudy day or late in the afternoon

•      Water the nursery bed well before transplanting.  Use a garden trowel to lift the seedlings with ball of soil around the roots.

•      Select only the healthy and vigorously growing seedlings

•      Water the seedbed before it receives the seedlings

•      Place each seedling in the planting hole.  Plant at the same depth as they were in the nursery.

•      Firm or compact the soil around the seedlings.  Mulch and then water the seedlings.

 

Field management practices

•      Conduct timely gapping of seedlings that might have died after transplanting.

•      Water regularly, especially during the dry spell

•      Top dress by two split applications of nitrogenous fertilizers

•      Weed early and regularly, Stake all tall varieties

•      Prune to remove excess suckers and prevent leaves from touching the ground

•      Stake all plants; this is not important in dwarf varieties

•      Control pests such as the American boll worms by spraying with appropriate pesticides

•      Control diseases such as tomato blight through spraying with appropriate chemicals.

 

Harvesting

Timely harvesting helps to reduce damage of the fruits by pests and to enable transportation of the fruits to the market.  Tomatoes are usually harvested using hands

Fresh market fruits should be picked as soon as they start to ripen

Fruits for canning need to ripen properly for processing

 

Onion (Allium cepa)

Varieties: early cape yellow flat, Excel, Granex, Red Bermuda, Red creole, Texas grano, White creole, and yellow Bermuda

 

Growth requirements: onion can be grown under a wide range of climatic conditions, but they succeed best in mild climate without excessive rainfall or great extremes of heat and cold.  Cool conditions, with an adequate moisture supply are most suitable for early growth, followed by warm, drier conditions for maturation, harvesting and curing.  They can be grown on variety of soils but grow best on light fertile soil.  Optimum pH is about 6.0 – 7.0

 

Husbandry practices

Seedbed preparation

Land should be thoroughly prepared, remove all trees and tree stumps, cultivate the soil deeply, and then carry out secondary tillage to pulverize the soil

 

Planting; planting is carried out at the beginning of the rain season.  For direct planting, seed are sown directly in shallow drills of 1cm, in rows about 30cm apart at the rate of 4-5 kg/ha and later thinned to about 7.5cm apart within the row.

For transplanted seedlings, transplanting is done on a cloudy day or in the evening.  Prior watering of the nursery bed is important to soften the soil and to allow easy lifting

 

Weed control; onions are less competitive and growth is very much affected by weed infestation.  Weed control is achieved by using herbicides and cultivation with a hoe however care must be taken not to damage roots and developing bulbs

 

Fertilizer Application; onions give good response to organic manures.  Phosphates and potash may be applied at or before planting, with later application of nitrogen as a top dress

 

Irrigation; onions require a good supply of soil moisture.  Most of the required water is normally provided by rainfall as long as planting is done at the beginning of the season.  However, if planting was done off season, or if the rainfall is scanty, irrigation of the plants is necessary

Pests and disease control; the most serious pests of onions are thrips, the stem and bulb nematodes

These are controlled by timely planting, crop rotation with non- host plant and spraying with appropriate pesticides.  The most important diseases of onions are downy mildew, purple blotch, and pink rot.  These can be controlled by field sanitation, crop rotation and spraying with appropriate fungicides

 

Harvesting; this must be done when onion is mature 90- 150 days after planting depending on the variety.  At maturity the tops droop, fall over, and begin to die back.  As all plants do not mature at the same time, harvesting is done when about 25% of the tops have fallen.  Bulbs are dug out using a hoe.

 

 

Carrots (Daucus carota)

 

Ecological requirements

Altitude; 0 to 2900m above sea level.  Temperature; optimum 24 degrees

Rainfall; optimum 750mm to 1000mm that is well distributed

Soil; deep, loose and well drained soils with a reasonable amount of sand

Soil pH; 6 to 6.5

 

Seedbed preparation

•      Dig the land early before the onset of rains

•      Clear vegetation and remove all stumps

•      Dig the seedbed to about 20cm deep and remove all perennial weeds

•      Harrow the land to a fine tilth.  Do not apply manure as it induces forking

 

Planting

·         Carrot seeds are sown directly into the main seedbeds

·         Make continuous drills 30cm to 40cm apart.  Apply DSP in the drills at the rate of 90kg/ha.

·         Apply potassium oxide for good root development and mix the fertilizer well with the soil before planting

·         Place the seeds in the drills at the rate  of 5 to 6 kg/ha

·         Cover the seeds lightly and then carry out rolling

 

Field management practices

·         Thin two weeks after germination to attain a distance of between 5cm and 8cm between individual plants.

·         Keep the field weed free

·         Earth around the plants during weeding to encourage tuber expansion and to prevent the tubers from getting a greenish colour due to exposure to the sun

·         Top dress with CAN at the rate of 60kg/ha.  Do not exceed this rate to avoid vegetative growth

·         Carry out irrigation during dry conditions

·         Control pests such as aphids and moles using appropriate pesticides

 

Harvesting

Carrots are ready for harvesting 3 to 5 months after sowing.  Avoid over maturing as it may cause root splitting.  Harvest manually by uprooting or lifting using a forked hoe.  Remove the leaves and wash the carrots.  Store at low temperature (0c) and high relative humidity

 

 

Bulb onions (Allium cepa)

Ecological requirements

Altitude; 300m above sea level, optimum 2100m.  Temperature of 13 to 29 degrees

Rainfall; over 1000mm, supplied throughout the growing period.  Otherwise irrigate

Soil; fertile and well drained

Soil pH; 5.6 to 6.8

 

Planting; onions can be sown directly into the main field or started off in a nursery bed

 

Direct seeding

•      Make seed drills spaced at 30cm to 38cm between rows and 10cm to 15 cm within the rows

•      Place the seeds in the drills at the rate of 7 to 11 kg/ha

 

Nursery establishment

•      Select a suitable site which is well-drained

•      Dig the site deeply to remove all perennial weeds

•      Harrow the site to a fine tilth

•      Mix the soil with well rotten manure

•      Add lime if the soil is acidic

•      Level the nursery bed using a rake

•      Sow the onion seeds very thinly into drills, 13mm deep

•      Cover the seeds with light soil

•      Water the nursery bed gently

•      Harden off the seedlings by reducing shading and watering intervals

 

Transplanting

•      Transplant the seedlings at the age of 8 weeks or when they attain the thickness of a pencil.

•      Spacing should be 30cm to 38cm X10cm to 15cm.

•      Apply DSP fertilizer in the drills at the rate of 250kg/ ha.

•      Trim roots and some leaves to regulate growth.

 

Field management Practices

•      Thin directly -sown onions to a spacing of 8cm between two plants within rows

•      Control weeds manually, taking care not to damage the shallow roots or compact soil around the crop.

•      Top dress using CAN at the rate of 250kg/ha.

•      Control pests such as onion thrips and nematodes using appropriate methods and insecticides.

•      Control diseases such as purple blotch and downy mildew using appropriate methods.

 

Harvesting and Marketing

Onions can be harvested at green stage or as dry bulbs.  Harvesting of dry bulbs is done when 25% of the crop has fallen over.  When leaves start drying, the crops should be broken or bent at the neck to hasten withering of the stem.  Harvesting can be done manually or mechanically.  The onions should be dried in the sun and the outer skin peeled off before storage.