Q79: The following are the usual diameter classes used in India. - Silviculture, Agroforestry, Forest Management, Tree Improvement & Utilization - ICAR AIEEA PG Forestry / Agroforestry 09 July 2023 (Shift 1) Paper | Agrigyan

Detailed Analysis of Indian Diameter Class Intervals:

• Standard Diameter Class Intervals in India (Option 3): In Indian forest inventories and working plans, standard diameter class intervals (widths) adopted according to stand composition and accuracy requirements are $2\text{ cm}$, $5\text{ cm}$, and $10\text{ cm}$ (e.g., $2\text{ cm}$ classes for young crops/research plots, $5\text{ cm}$ classes for regular working plans and yield tables, and $10\text{ cm}$ classes for extensive regional forest surveys). Hence, Option 3 is correct.
• Options 1, 2, and 4: Do not represent the triad of recognized standard diameter class interval widths used across working plan codes in India.