Value Addition to Vegetables

Principles of Vegetable Drying

Vegetable drying is a process that involves removing moisture from the produce, thereby extending its shelf life. The primary principle behind drying is to reduce the water content, making it difficult for microorganisms to grow. This process preserves the nutrients and flavor of the vegetables.

Principles of Drying Vegetables

• Moisture Removal: The primary goal of drying is to remove moisture from vegetables to prevent spoilage. By reducing water content, microbial growth and enzymatic reactions are minimized, extending the shelf life of the produce.
• Preservation of Nutrients and Flavor: Proper drying techniques ensure that the essential nutrients, color, and flavor of the vegetables are retained as much as possible.
• Pre-treatment: Vegetables often require pre-treatment, such as blanching or treating with acidic solutions, to preserve color, texture, and nutritional content during the drying process.
• Temperature and Humidity Control: The drying process requires careful control of temperature and humidity. Too high a temperature can destroy nutrients and cause scorching, while too low a temperature may lead to incomplete drying and potential spoilage.
• Air Circulation: Efficient drying depends on proper air circulation to carry away the moisture being evaporated from the vegetables.

Methods of Drying Vegetables

1. Sun Drying

   Sun drying involves using natural sunlight to evaporate the moisture from vegetables. This method is energy-efficient and cost-effective, relying solely on the sun and air.

   • Slice the vegetables uniformly to ensure even drying.
   • Spread the sliced vegetables in a single layer on clean surfaces or drying racks.
   • Cover the vegetables with a thin mesh or cloth to protect them from insects.
   • Turn the vegetables periodically to ensure they dry evenly on all sides.
   • Monitor the weather and avoid sun drying during high humidity or rainy days.
2. Air Drying

   Air drying involves drying vegetables in a well-ventilated area at room temperature. It’s a simple method that doesn’t require any special equipment, just a dry, airy space.

   • Hang or spread the vegetables in a dry, airy place.
   • Ensure there is good airflow around the vegetables to facilitate drying.
   • Turn or rotate the vegetables periodically to ensure even drying.
   • Use fans if necessary to enhance air circulation and speed up the drying process.
3. Oven Drying

   Oven drying uses a conventional oven set at a low temperature to gradually remove moisture from vegetables. This method is more controlled than sun or air drying and is suitable for smaller batches.

   • Set the oven to the lowest possible temperature, usually around 140°F (60°C).
   • Spread the vegetables in a single layer on a baking sheet.
   • Prop the oven door open slightly to allow moisture to escape during drying.
   • Rotate the trays and stir the vegetables occasionally to ensure they dry evenly.
   • Monitor the vegetables closely to prevent over-drying or burning.
4. Dehydrator Drying

   Dehydrator drying uses a specialized appliance that provides controlled heat and air circulation, making it one of the most efficient methods for drying vegetables. It’s ideal for consistent results.

   • Pre-treat the vegetables if necessary, such as by blanching.
   • Arrange the vegetables in a single layer on the dehydrator trays.
   • Set the dehydrator to the appropriate temperature, usually between 125°F to 135°F (50°C to 60°C).
   • Rotate the trays periodically if the dehydrator does not have an automatic rotation feature.
   • Check the vegetables regularly to ensure they are drying evenly and remove them when fully dried.
5. Microwave Drying

   Microwave drying uses microwave energy to quickly evaporate moisture from vegetables. This method is best for small quantities and quick drying, though it requires careful monitoring to avoid overcooking.

   • Spread a small amount of vegetables on a microwave-safe plate in a single layer.
   • Use a low power setting on the microwave and dry the vegetables in short intervals.
   • Turn the vegetables frequently during drying to ensure even moisture removal.
   • Monitor the process closely to prevent overcooking or burning, adjusting the time and power as needed.

Practical Skills

• Selection of Vegetables: Choose fresh, high-quality vegetables for drying.
• Preparation: Wash, peel, and slice vegetables uniformly.
• Monitoring: Keep a close eye on the drying process, adjusting temperature, airflow, and drying time as needed.
• Storage: Once dried, store vegetables in airtight containers in a cool, dark place to preserve quality.

Principle of Preserving Vegetables

Vegetable preservation is essential for extending the shelf life of vegetables and ensuring they remain safe and nutritious for consumption. The principles of vegetable preservation are based on controlling the factors that cause spoilage, such as microbial growth, enzymatic activity, and oxidation. Here are the key principles:

• Controlling Moisture Content
  • Drying/Dehydration: Removing water from vegetables to inhibit the growth of bacteria, yeast, and molds. Dehydrated vegetables have a much longer shelf life because moisture, which is necessary for microbial growth, is significantly reduced.
  • Salting: Salt draws moisture out of vegetables through osmosis, reducing water activity and creating an environment that is inhospitable to most spoilage organisms.
• Temperature Control
  • Refrigeration: This slows down the metabolic and enzymatic processes in vegetables, which helps to extend their freshness by delaying spoilage.
  • Freezing: Halts microbial activity by lowering the temperature below the point at which most microorganisms can grow, thereby preserving the vegetables for extended periods.
• Acidity (pH Control)
  • Pickling: Involves immersing vegetables in an acidic solution, usually vinegar or lemon juice, which lowers the pH and creates an environment where most spoilage organisms cannot thrive.
  • Fermentation: Vegetables are submerged in a brine solution where lactic acid bacteria convert sugars into lactic acid, lowering the pH and naturally preserving the vegetables.
• Sugar Preservation
  • Jam and Jelly Making: High sugar concentration in jams and jellies binds the water in vegetables, making it unavailable for microbial growth. The low water activity and acidic environment (from added lemon juice or vinegar) help to preserve the product.
• Exclusion of Air (Anaerobic Conditions)
  • Canning: Involves placing vegetables in airtight containers and heating them to destroy any microorganisms and enzymes. The vacuum seal prevents new contaminants from entering, thereby preserving the vegetables.
  • Vacuum Sealing: Removes air from the packaging, reducing the oxygen available to aerobic spoilage organisms and slowing down the oxidation of nutrients.
• Use of Chemical Preservatives
  • Sulfur Dioxide, Sodium Benzoate, and Potassium Sorbate: These chemicals are sometimes added to preserved vegetables to inhibit the growth of bacteria, yeast, and molds. However, their use is often regulated and should be done according to food safety guidelines.
• Blanching
  • Pre-treatment: Blanching involves briefly boiling vegetables before freezing or drying. This process inactivates enzymes that cause spoilage and helps retain colour, flavor, and nutritional value during storage.

Common Methods of Vegetable Preservation

1. Canning

   Principle: Canning involves processing vegetables at high temperatures to kill microorganisms and sealing them in airtight containers to prevent recontamination.

   • Water Bath Canning: Used for high-acid vegetables (e.g., tomatoes) where the natural acidity helps prevent bacterial growth.
   • Pressure Canning: Required for low-acid vegetables (e.g., green beans) to achieve higher temperatures necessary to kill harmful bacteria like Clostridium botulinum.
2. Freezing

   Principle: Freezing slows down the enzymatic activity and microbial growth that cause spoilage. It preserves the texture, flavor, and nutritional value of vegetables.

   • Blanching: Vegetables are briefly boiled and then cooled quickly to deactivate enzymes before freezing.
   • Freezing: Vegetables are frozen at low temperatures (-18°C or lower).
3. Drying/Dehydration

   Principle: Drying removes moisture from vegetables, which inhibits the growth of bacteria, yeast, and molds.

   • Sun Drying: Uses natural sunlight to dry vegetables, but it's slower and less controlled.
   • Oven Drying: Uses low heat in an oven to dry vegetables evenly.
   • Dehydrator Drying: Specialized equipment that provides a controlled environment for efficient drying.
4. Pickling

   Principle: Pickling preserves vegetables by immersing them in a solution of vinegar (acetic acid), salt, or brine, which creates an acidic environment that inhibits bacterial growth.

   • Vinegar Pickling: Vegetables are soaked in vinegar and spices.
   • Fermentation: Vegetables are salted and allowed to ferment naturally, producing lactic acid that preserves the vegetables (e.g., sauerkraut, kimchi).
5. Fermentation

   Principle: Fermentation involves the conversion of sugars in vegetables into lactic acid by beneficial bacteria, which acts as a preservative.

   • Process: Vegetables are submerged in a saltwater brine, and the natural bacteria ferment the sugars over time, creating an acidic environment that prevents spoilage.
6. Salting (Salting or Brining)

   Principle: Salt draws out moisture from vegetables, creating an environment where spoilage organisms cannot survive.

   • Method: Vegetables are either dry salted or placed in a saltwater brine, depending on the desired preservation method.
7. Sugar Preservation (Candying)

   Principle: High concentrations of sugar draw moisture out of vegetables through osmosis, creating an environment that is inhospitable to bacteria and fungi.

   • Method: Vegetables are soaked in a sugar syrup and then dried.
8. Smoking

   Principle: Smoking involves exposing vegetables to smoke from burning wood, which contains antimicrobial compounds that help preserve the vegetables.

   • Method: Typically used in combination with drying or salting to enhance flavor and preservation.
9. Vacuum Packing

   Principle: Vacuum packing removes air from the package, reducing the oxygen available for microbial growth and oxidation.

   • Method: Vegetables are placed in vacuum-sealed bags or containers and stored in a cool, dark place.
10. Chemical Preservation

    Principle: Chemical preservatives such as sodium benzoate or sulfur dioxide are added to vegetables to inhibit microbial growth.

    • Usage: Often used in commercial preservation, but requires careful measurement to ensure safety.

Marketing Processed Vegetables

Conducting a Market Survey for Processed Vegetables

1. Define Your Objectives
   • Purpose: Determine what you want to learn from the survey. For example, are you interested in consumer preferences, price sensitivity, or market potential?
   • Goals: Set clear goals such as understanding market demand, identifying target demographics, or assessing competitive landscape.
2. Design the Survey
   • Question Types: Include a mix of question types like multiple-choice, Likert scales (for levels of agreement or satisfaction), and open-ended questions.
   • Content: Questions should cover:
     • Consumer Preferences: What types of processed vegetables are preferred (e.g., frozen, canned, dried)?
     • Buying Habits: Where and how often do consumers purchase processed vegetables?
     • Price Sensitivity: What price range are consumers willing to pay?
     • Brand Awareness: Which brands are known and preferred by consumers?
     • Product Features: What attributes are important (e.g., organic, non-GMO, convenience)?
     • Sustainability: Are eco-friendly practices important to consumers?
3. Select Your Survey Method
   • Online Surveys: Use platforms like SurveyMonkey, Google Forms, or Typeform to reach a broad audience quickly.
   • In-Person Surveys: Conduct surveys at grocery stores, farmers' markets, or other relevant locations.
   • Phone Surveys: Reach out to potential customers via phone calls for more detailed feedback.
   • Focus Groups: Organize group discussions to get in-depth insights and feedback.
4. Identify Your Sample Size and Target Audience
   • Sample Size: Determine how many responses you need to get statistically significant results. This depends on the total market size and desired confidence level.
   • Target Audience: Choose your sample based on demographics such as age, gender, income, and location to ensure it represents your potential customers.
5. Distribute the Survey
   • Channels: Use appropriate channels to reach your target audience (e.g., social media, email newsletters, community boards).
   • Incentives: Consider offering incentives like discounts, free samples, or entry into a prize draw to encourage participation.
6. Analyze the Data
   • Data Cleaning: Remove incomplete or irrelevant responses.
   • Data Analysis: Use statistical tools and software to analyze the data. Look for trends, patterns, and significant insights.
   • Segmentation: Break down the data by different demographics or segments to understand specific preferences.
7. Report Findings
   • Summary: Provide an overview of key findings and insights.
   • Visuals: Use charts, graphs, and tables to present data clearly.
   • Recommendations: Based on the data, make recommendations for product development, marketing strategies, and business decisions.
8. Act on Insights
   • Strategy Development: Use the survey results to inform your product offerings, pricing, marketing, and distribution strategies.
   • Continuous Improvement: Regularly update your survey and market research to stay in tune with changing consumer preferences and market conditions.

How to Market Processed Vegetables

• Identify Your Target Market: Determine who your ideal customers are. This could include health-conscious consumers, busy families, or food service businesses.
• Highlight Health Benefits: Emphasize the nutritional value of processed vegetables. Many people are looking for convenient ways to eat healthier.
• Focus on Quality and Freshness: Ensure your processed vegetables maintain high quality and freshness. This can be a significant selling point.
• Packaging: Invest in attractive and functional packaging. Good packaging not only preserves the vegetables but also catches the eye of consumers.
• Brand Story: Share the story behind your brand. Consumers often connect with brands that have a compelling narrative, especially if it highlights sustainability or local sourcing.
• Distribution Channels: Decide where and how you will sell your products. Options include online platforms, local grocery stores, farmers' markets, or partnerships with food service providers.
• Marketing and Promotion: Use social media, influencer partnerships, and local events to promote your products. Offering samples or discounts can also attract new customers.
• Customer Feedback: Regularly gather and act on customer feedback to improve your product and customer experience.
• Regulatory Compliance: Ensure you meet all food safety and labeling regulations to build trust with consumers and avoid legal issues.
• Sustainability: Highlight any sustainable practices you follow in your processing and packaging. Many consumers are willing to pay a premium for eco-friendly products.

Value addition to Agro wastes and By-products

 Value addition to Agro wastes and By-products

Biogas

Biogas is a renewable energy source produced through the anaerobic digestion of organic materials. 

Identifying the materials used for making biogas

Biogas is typically produced through the anaerobic digestion of organic materials. The primary materials used to make biogas include:

Animal Manure: Commonly used from livestock such as cows, pigs, and poultry.

Agricultural Waste: Crop residues, such as straw, corn stalks, and rice husks.

Food Waste: Organic waste from households, restaurants, and food processing industries.

Sewage Sludge: Wastewater treatment plants often use sludge as a feedstock for biogas production.

Green Waste: Grass clippings, leaves, and other garden waste.

Industrial Organic Waste: Waste from industries like food processing, breweries, 

How is biogas produced

Biogas is produced through a process called anaerobic digestion, which involves the breakdown of organic materials by microorganisms in an oxygen-free environment. 

Step in making biogas

1. Collection of Organic Materials

Organic materials such as animal manure, agricultural waste, food waste, and sewage sludge are collected and prepared for digestion.

2. Pre-treatment

The collected materials may undergo pre-treatment, which could include shredding, mixing, or heating, to make them more suitable for digestion and to increase the efficiency of gas production.

3. Anaerobic Digestion

The organic materials are placed into a sealed container called a digester or bioreactor.

In the absence of oxygen, anaerobic bacteria break down the organic matter in a series of stages:

Hydrolysis: Complex organic molecules like carbohydrates, proteins, and fats are broken down into simpler molecules such as sugars, amino acids, and fatty acids.

Acidogenesis: The simpler molecules are further broken down into volatile fatty acids, alcohols, carbon dioxide, hydrogen, ammonia, and other by-products.

Acetogenesis: The volatile fatty acids and alcohols are converted into acetic acid, along with more carbon dioxide and hydrogen.

Methanogenesis: Methanogenic bacteria convert the acetic acid, hydrogen, and carbon dioxide into methane (CH₄) and more carbon dioxide.

4. Biogas Collection

The biogas, which is mainly composed of methane (CH₄) and carbon dioxide (CO₂), is collected from the top of the digester.

The gas may also contain small amounts of other gases, such as hydrogen sulfide (H₂S) and moisture, which may need to be removed or purified depending on the intended use.

5. Utilization

The biogas can be used directly for cooking, heating, or electricity generation.

It can also be upgraded to biomethane by removing impurities and used as a natural gas substitute or vehicle fuel.

6. Digestate Management

The remaining material, called digestate, is rich in nutrients and can be used as a natural fertilizer or soil conditioner in agriculture.

and dairy processing.

Identifying the materials used for paper-making

The materials used for paper making can be broadly categorized into three types:

1. Wood-Based Materials:

Wood Pulp: The most common raw material, derived from trees such as pine, spruce, fir, and eucalyptus. Wood pulp is created by breaking down the wood fibers through mechanical or chemical processes.

Hardwood vs. Softwood: Hardwood trees (e.g., oak, birch) provide shorter fibers, resulting in smoother paper, while softwood trees (e.g., pine) provide longer fibers, adding strength.

2. Non-Wood Plant Fibers:

Bamboo: Fast-growing and sustainable, bamboo is used in some specialty papers.

Cotton: Used for high-quality paper like stationery, currency, and archival documents, cotton provides durability and a smooth texture.

Hemp: Known for its strength and durability, hemp is used for specialty papers.

Bagasse: A byproduct of sugarcane processing, bagasse is used to make paper in regions where sugarcane is abundant.

Rice Straw: Common in areas with high rice production, this is an alternative to wood pulp.

3. Recycled Materials:

Recycled Paper: Post-consumer and post-industrial paper waste is collected, processed, and repurposed into new paper products.

Waste Paper: Includes materials like old newspapers, magazines, office paper, and cardboard, which are de-inked and reprocessed.

Making hand paper

How to Make Hand Paper

Materials:

Paper Pulp: This can be made from various natural materials like recycled paper, cotton rags, or plant fibers.

Paper Mold: A wooden frame with a fine mesh screen.

Deckle: A frame that fits around the paper mold to contain the pulp.

Blotter: A soft, absorbent material like felt.

Press: A heavy object to press the water out of the paper.

Drying Rack: A place to dry the paper.

Instructions:

Prepare the Pulp:

Recycle paper: Shred or tear the paper into small pieces and soak it in water until it's soft and pulpy.

Natural fibers: Boil or soak natural fibers like cotton rags or plant fibers until they're softened.

Blend: Use a blender or a hand-held immersion blender to break down the fibers into a fine pulp.

Create the Paper:

Fill the mold: Place the paper mold on a flat surface and fill it with the prepared pulp.

Deckling: Place the deckle around the mold to contain the pulp.

Shake: Gently shake the mold to distribute the pulp evenly.

Drain: Slowly pour off the excess water.

Press and Dry:

Blot: Place a blotter on top of the paper and press it gently to remove more water.

Press: Place a heavy object on top of the blotter to press the paper further.

Dry: Remove the paper from the mold and place it on a drying rack. Allow it to dry completely.

Tips:

Experiment: Try using different materials and techniques to create unique papers.

Incorporate elements: Add flowers, leaves, or other natural materials to your paper for decorative purposes.

Color: Use natural dyes or food coloring to color your paper.

Size: To strengthen the paper and prevent it from fraying, size it with a solution of alum or gelatin.

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.