Timber technology — seasoning is primarily carried out to remove which component from wood? Select the most accurate purpose.

Introduction / Context:
Seasoning of timber is the controlled reduction of moisture content to levels suitable for service. Proper seasoning minimizes shrinkage, warping, fungal attack, and adhesive failures. This question focuses on the core purpose of seasoning and clarifies what it does not address directly (e.g., defects such as knots or twisted grain).

Given Data / Assumptions:

• Seasoning can be air, kiln, or chemical-assisted.
• Goal moisture for interior use commonly near 10%–12% depending on climate.
• The term “sap” here refers broadly to free and bound water within the wood.

Concept / Approach:
Moisture in wood exists as free water in cell lumens and bound water within cell walls. Seasoning removes free water first, then reduces bound water toward equilibrium moisture content. Removing moisture stabilizes dimensions and increases strength and durability. It does not eliminate inherent features like knots or correct grain distortions that originate during tree growth.

Step-by-Step Solution:

Verification / Alternative check:
Timber engineering guides consistently list moisture reduction as the primary goal of seasoning, with quantified targets for indoor and outdoor use.

Why Other Options Are Wrong:

• Knots: Natural growth features; cannot be removed by seasoning.
• Twisted fibre: Grain deformation is inherent; seasoning does not untwist fibres.
• Surface roughness: A machining/finishing issue, not addressed by moisture removal.

Common Pitfalls:
Assuming seasoning corrects structural defects; it only reduces moisture to improve performance and stability.

Final Answer:
Sap (moisture) from timber