Concept:
Harvest maturity indices are objective and subjective criteria used to determine the optimal stage for picking fruits and vegetables.
Harvesting at the correct maturity stage ensures optimum eating quality, flavor, shelf life, and processing suitability.
These indices are categorized based on their underlying measurement principles into visual, physical/mechanical, chemical, and physiological methods. Step 1: Visual Means (A):
Visual methods rely on external optical observation without damaging the produce.
They include observing skin/peel color change (e.g., dark green to light green or yellow in mango), size and shape development, fullness of cheeks, or drying of aerial plant parts (e.g., top drying in onion/garlic).
Thus, A matches with IV. Peel colour, size, drying of plant parts. Step 2: Physical Means (B):
Physical methods measure mechanical properties, density, or detachment force.
They include firmness (penetrometer/pressure tester), specific gravity (flotation method), and the ease of separation of fruit from the stalk (abscission zone formation).
Thus, B matches with I. Ease of separation or abscission, firmness, specific gravity. Step 3: Chemical Means (C):
Chemical methods quantify internal biochemical constituents through laboratory or field instruments.
They include measuring Total Soluble Solids (TSS via refractometer), titratable acidity, TSS-to-acid ratio, starch-iodine index, and sugar content.
Thus, C matches with II. TSS, acidity, solid to acid ratio. Step 4: Physiological Method (D):
Physiological methods monitor vital metabolic activities of the fruit tissue.
They include measuring the rate of respiration ($\text{CO}_2$ output) and the rate of internal ethylene ($\text{C}_2\text{H}_4$) gas evolution during the climacteric peak.
Thus, D matches with III. Ethylene production. Step 5: Final Answer:
Matching these pairs gives A-IV, B-I, C-II, D-III, which corresponds to option (B).
