This presentation covers the concept of maturity and maturity indices in fruits and vegetables, essential for optimizing harvest timing and postharvest quality. It explains physiological and horticultural maturity, discusses the importance of proper harvest stage, and details various subjective and objective methods for assessing maturity. Understanding these indices ensures better storage, transport, and marketability of produce. Key academic terms include maturity, physiological maturity, maturity indices, harvest, and quality.
Introduction to Maturity and Maturity Indices
- Maturity is the stage when fruits or vegetables are fully developed and can ripen normally after harvest.
- Proper harvest timing is crucial for maintaining postharvest quality.
- Maturity indices are signs or measurements indicating readiness for harvest.
- Harvesting at correct maturity improves shelf life, flavor, and market value.
Concept of Maturity
- Maturation is the process leading to full tissue development in fruits and vegetables.
- Ripening occurs after maturity and involves flavor and color development.
- After maturity, the fruit relies on its own reserves as the supply from the plant stops.
- The stage of maturity at harvest affects storage life and quality.
Effects of Premature and Overmature Harvesting
- Premature harvesting leads to poor quality, low sugar, high acidity, and poor flavor.
- Immature fruits may not ripen properly and have short shelf life.
- Overmature fruits are prone to spoilage and have reduced storage life.
- Proper harvest stage is essential for optimal yield and marketability.
Principles of Harvest Maturity
- Produce should reach peak acceptable quality for consumers at the time of sale.
- Fruits and vegetables must have acceptable flavor, appearance, size, and shape.
- Harvested produce should be safe and non-toxic.
- Harvest maturity should ensure adequate shelf life and handling properties.
Types of Maturity
- Physiological maturity: Stage when fruit can ripen normally after harvest; applies mainly to fruits and fruit vegetables.
- Climacteric fruits: Harvest at mature but unripe stage for storage and transport.
- Non-climacteric fruits: Harvest at ripe stage for best quality.
- Horticultural (commercial) maturity: Stage when produce meets consumer and market preferences; varies by intended use and variety.
Classification of Horticultural Maturity
- Physiologically immature: Not ready for harvest, poor quality.
- Firm and mature: Optimal for harvest, good quality and handling.
- Harvest ripe: Fully ripe, best for immediate consumption but limited shelf life.
Advantages of Estimating Maturity
- Maintains product quality and freshness.
- Improves storage life and handling.
- Facilitates ripening and senescence management.
- Maximizes returns and enables long-distance transport.
- Helps manage pest and disease risks.
Maturity Indices: Definition and Importance
- Maturity indices are signs or measurements indicating readiness for harvest.
- Ensure sensory quality (flavor, color, aroma, texture, nutrition).
- Enable adequate postharvest life and market scheduling.
- Facilitate efficient harvest and packing operations.
Types of Maturity Indices
- Subjective indices: Qualitative; based on senses (color, size, shape, firmness, sound, juice content).
- Objective indices: Quantitative; measurable (TSS, acidity, starch, oil content, firmness, dry matter, days after bloom, heat units, respiration, ethylene).
Visual Indices/Methods
- Size, shape, and surface character indicate maturity (e.g., banana fingers become rounded, mango shoulders fill out).
- Surface gloss changes (melons, grapes) and drying of leaves or bracts (root crops) are indicators.
- Skin color changes from green to yellow/red/purple as fruits mature.
- Color charts and colorimeters provide objective color measurement.
Physical Methods
- Firmness/solidity assessed by hand pressure (lettuce, cabbage) or penetrometer (e.g., mango: 1.75–2 kg/cm²).
- Tenderometer measures pea maturity based on texture.
- Finger squeeze/touch used for peas, beans, okra (experience-based).
- Specific gravity increases with maturity; used for grading (e.g., Dasheri mango: 1.02).
- Juice content increases as fruit matures; measured by extracting and quantifying juice volume.
- Acoustic/sound tests (e.g., watermelon, jackfruit) detect maturity by tapping.
- Other methods: exudation of latex (papaya), electrical properties, NMR, X-rays (lettuce).
Chemical Measurements
- Total soluble solids (TSS) measured with a refractometer; indicates sugar content.
- Titratable acidity (TA) determined by titration; acidity decreases with maturity.
- Brix:acid ratio is a key indicator of flavor and maturity.
- Oil content used for avocados; minimum 8% oil (excluding skin and seed) for harvest.
- Starch content measured for crops like apples and bananas; decreases as fruit ripens.
Calculated Indices
- Calendar date: Based on typical harvest periods for varieties and locations.
- Days from full bloom (DFFB): Reliable but varies with season and location (e.g., mango: 110–125 days).
- Growing degree days (GDD): Cumulative heat units predict maturity; base temperature varies by crop.
- GDD formula: (Daily mean temp – Base temp) × Number of days (flowering to harvest).
Physiological Methods
- Respiration rate: Climacteric fruits show a rise at maturity (e.g., apple, pear).
- Internal ethylene evolution: Peaks at maturity in climacteric fruits.
- Volatile production: Specific aroma compounds indicate maturity (e.g., apple: ethyl-2-methyl butyrate).
Summary: Integrated Use of Maturity Indices
- Combining subjective and objective indices ensures accurate harvest timing.
- Selection of indices depends on crop, intended use, and market requirements.
- Proper maturity assessment maximizes quality, shelf life, and market value.
Objective Questions
Q1. What happens to the inflow of food material from the plant once a fruit reaches maturity?
A. It increases
B. It stops due to abscission layer
C. It decreases gradually
D. It becomes irregular
Answer: B
Q2. Which of the following is a consequence of premature harvesting of fruits?
A. Increased sugar content
B. Poor quality and faster deterioration
C. Enhanced flavor development
D. Longer storage life
Answer: B
Q3. For distant market and storage, when should climacteric fruits be harvested?
A. At full ripe stage
B. At immature stage
C. At maturity before ripening
D. At senescence
Answer: C
Q4. Which instrument is specifically used to test the maturity of peas by measuring tenderness?
A. Penetrometer
B. Tenderometer
C. Hydrometer
D. Colorimeter
Answer: B
Q5. Which maturity index is considered objective and quantitative?
A. Color
B. Size
C. TSS (Total Soluble Solids)
D. Aroma
Answer: C
Q6. What is the base temperature for calculating growing degree days (GDD) for spinach?
A. 10°C
B. 13°C
C. 15°C
D. 2°C
Answer: D
Q7. Which method is used to determine the maturity of lettuce in the industry?
A. Penetrometer
B. X-rays
C. Color chart
D. Tenderometer
Answer: B
Q8. Which of the following is NOT a principle of harvest maturity?
A. Produce should be toxic
B. Produce should develop acceptable flavor
C. Produce should have optimum size and shape
D. Harvested commodity should have peak quality at consumption
Answer: A
Q9. Which fruit's maturity can be assessed by the rounding of individual fingers from an angular shape?
A. Mango
B. Banana
C. Melon
D. Papaya
Answer: B
Q10. What is the minimum oil content required in avocados at the time of picking?
A. 5%
B. 6%
C. 7%
D. 8%
Answer: D
This presentation covers the principles and practices of harvesting and post-harvest handling of vegetable crops, focusing on maturity indices, harvesting methods, post-harvest operations, and marketing. Emphasis is placed on maintaining crop quality, minimizing post-harvest losses, and optimizing economic returns. Key concepts include maturity indices, post-harvest handling, sorting and grading, storage, and marketing systems.
Introduction to Harvesting and Post-Harvest Handling
- Harvesting: Gathering mature crops from the field.
- Post-harvest handling: Operations after harvest to maintain quality and reduce losses.
- Proper techniques are essential for quality, shelf-life, and profitability.
Maturity and Maturity Indices
- Maturity: Stage when a crop is ready for harvest.
- Maturity indices: Observable signs indicating readiness for harvest.
- Indices include color, size, shape, texture, weight, and composition.
Maturity Indices of Selected Vegetables
| Vegetable |
Maturity Index |
| Potato |
Culm yellow and dry; skin does not slip easily. |
| Cabbage |
Compact head; firm when pressed. |
| Cauliflower |
Compact, creamy-white curd; no discoloration. |
| Sweet corn |
Kernels exude milky sap when pierced. |
| Lettuce, Mustard, Pechay |
Well-developed, green leaves; not yellowing. |
| Sweet pepper |
Full size, firm, deep color. |
| Radish |
Large, firm, crispy roots; not pithy. |
| Tomato |
Green for distant markets; breaker to ripe for local. |
Types of Maturity
- Physiological maturity: Crop has completed development; ripening begins.
- Commercial maturity: Harvest stage based on market or processing needs.
- Harvest timing may differ based on intended use.
Methods of Determining Maturity
- Visual method: Color, size, shape, abscission zones.
- Feel method: Firmness, crispness, texture by touch.
- Chemical analysis: Sugar, acid, starch content.
- Physical means: Pressure tester, specific gravity.
- Computation method: Days from planting or flowering to harvest.
Preparations Prior to Harvesting
- Inspect fields for crop readiness and remove obstructions.
- Prepare harvesting tools and materials.
- Construct temporary sheds for harvested produce.
- Avoid exposing harvested crops to sunlight.
Harvesting Tools and Materials
- Use appropriate tools: scissors, pruning shears, knives.
- Proper tools reduce damage and maintain quality.
Considerations During Harvesting
- Harvest at optimal time of day (e.g., morning or late afternoon).
- Harvest at proper maturity for intended use.
- Avoid sun exposure to prevent wilting and sunscald.
- Handle produce gently to prevent mechanical injury.
- Avoid deep piling to prevent crushing and heat buildup.
Post-Harvest Handling: Key Operations
- Trimming and cleaning: Remove damaged or diseased parts.
- Sorting and grading: Classify by size, shape, color, and quality.
- Drying and curing: For tubers and bulbs to heal wounds.
- Proper storage: Maintain suitable temperature and humidity.
Mechanical and Physiological Damages
- Mechanical injuries: Cuts, abrasions, bruises during harvest/handling.
- Physiological losses: Yellowing, wilting, sprouting, toughening.
- Both types reduce quality and market value.
Cleaning and Trimming the Harvest
- Cleaning removes soil, dirt, and residues.
- Wiping with a soft cloth is preferred for some vegetables.
- Trimming removes undesirable, damaged, or diseased parts.
- Improves appearance and reduces transport costs.
Sorting and Grading
- Sorting: Grouping by industry or consumer standards.
- Grading: Classifying by color, size, shape, maturity, defects.
- Grades: Fancy, No. 1, 2, 3, 4, or off-grade.
- Honest grading enhances market value and reputation.
Packing and Packaging
- Packing: Placing produce in suitable containers for transport/storage.
- Use crates (wooden/plastic) with liners to prevent injury.
- Do not mix different grades in one container.
- Proper packing reduces losses and maintains quality.
Curing and Storage
- Curing: Exposing tubers/roots to warm, humid conditions to heal wounds.
- Recommended for potatoes, sweet potatoes, onions (15–19°C, high RH).
- Storage: Delays sale/distribution; controls supply and stabilizes price.
- Not all vegetables are suitable for long-term storage.
Transporting Harvested Produce
- Transport from farm to market must minimize damage.
- Avoid throwing, trampling, or overloading containers.
- Proper loading preserves quality and reduces losses.
Causes of Post-Harvest Losses
- Technological: Decay, yellowing, wilting, rotting, sprouting.
- Mechanical: Cuts, punctures, cracks, abrasions from poor handling.
- Non-technological: Lack of storage, transport, adverse weather, market demand.
- Microbial decay often follows mechanical or physiological damage.
Signs of Deterioration in Vegetables
| Vegetable |
Sign of Deterioration |
| Leafy vegetables |
Yellowing |
| Cauliflower, Broccoli |
Opening florets, softening |
| Sweet corn |
Loss of sweetness |
| Okra |
Softening |
| Cucumber |
Yellowing |
| Beans |
Toughening, yellowing |
| Chayote, Tomato, Pepper |
Seed germination |
| Asparagus |
Elongation, feathering |
| Onion, Garlic, Sweet potato, Ginger |
Sprouting, rooting |
| Carrot |
Softening |
Marketing of Vegetable Products
- Marketing: Transfer of goods from producer to consumer.
- Types: Local market, nearby town market, wider regional/national markets.
- Freshness is crucial for leafy and perishable vegetables.
Methods of Marketing
- Retailing directly to consumers: Farmer sells in local markets.
- Selling to middlemen/wholesalers: Middlemen harvest and market crops.
- Selling at the farm: Direct negotiation with buyers.
- Selling through contracting companies: Pre-agreed contracts specify terms.
- Selling through cooperatives: Collective marketing for better returns.
Farm Records and Accounts
- Farm records: Written statements of facts and figures for management.
- Farm accounts: Financial statements tracking income and expenses.
- Essential for monitoring financial status and decision-making.
Classification of Costs in Vegetable Production
- Fixed costs: Incurred regardless of production (e.g., land tax, equipment depreciation).
- Variable costs: Change with production (e.g., seeds, fertilizers, labor).
- Cash costs: Actual money spent (e.g., hired labor, inputs).
- Non-cash costs: Family labor, own capital interest.
Computation of Net Income
- Gross income = Quantity produced × Price per unit.
- Total cost = Fixed costs + Variable costs.
- Net income = Gross income – Total cost.
Summary: Best Practices in Harvesting and Post-Harvest Handling
- Harvest at correct maturity using appropriate indices.
- Handle produce gently to avoid mechanical damage.
- Sort, grade, and pack properly for market requirements.
- Use suitable storage and transport methods to minimize losses.
- Maintain accurate records for better farm management.
Objective Questions
Q1. Which of the following is NOT a maturity index for vegetable crops?
A. Aroma
B. Color
C. Weight
D. Texture
Answer: A
Q2. What is the recommended method for checking if a green tomato is mature?
A. Smell the fruit
B. Slice and check if seeds slip away from the knife
C. Weigh the fruit
D. Check for yellowing of the skin
Answer: B
Q3. Which method is used to measure the softness of a fruit during maturity determination?
A. Visual method
B. Chemical analysis
C. Pressure tester
D. Computation method
Answer: C
Q4. What is the main purpose of curing newly dug tubers or roots?
A. Increase sweetness
B. Heal bruised or wounded produce
C. Reduce weight
D. Enhance color
Answer: B
Q5. Which of the following is considered a physiological loss in vegetables?
A. Cuts and abrasions
B. Yellowing and toughening of beans
C. Cracks and splits
D. Abrasion of outer covering
Answer: B
Q6. Which packing material is now commonly used for trading vegetable products?
A. Metal boxes
B. Polyethylene bags
C. Glass jars
D. Paper sacks
Answer: B
Q7. What is the main cause of sunscald in harvested tomatoes and peppers?
A. Exposure to rain
B. Exposure to sunlight
C. Exposure to cold
D. Exposure to wind
Answer: B
Q8. Which marketing method assures the farmer of a ready market and relieves him of many risks?
A. Retailing directly to consumers
B. Selling to middlemen or wholesalers
C. Selling in the farm
D. Selling through cooperatives
Answer: B
Q9. Which of the following is a fixed, non-cash cost in vegetable production?
A. Hired labor
B. Land tax
C. Care of implements
D. Seeds
Answer: C
Q10. To compute net income from vegetable production, which of the following is subtracted from gross income?
A. Only fixed costs
B. Only variable costs
C. Total cost of production
D. Total cost of marketing
Answer: C