Jute fibre is obtained from which part of the plant?

Economically important fibre-yielding plants are classified by which plant part supplies the textile fibre: bast fibres are extracted from the phloem/bark layer of the stem (e.g., jute, flax, hemp), seed fibres from the seed-coat hairs (e.g., cotton), and leaf fibres from the vascular strands within the leaf (e.g., sisal, banana, pineapple).

Jute (Corchorus capsularis and Corchorus olitorius) is a bast-fibre crop. After the plants are harvested, the stalks are bundled and submerged in water for retting — a controlled microbial process that breaks down the pectin binding the outer bark to the woody stem core. Once retting loosens the bark, workers strip the long fibrous strands from the stem by hand, then wash and dry them to obtain jute fibre, commonly called the "golden fibre" of India and Bangladesh.

• Leaf — leaves are the plant's photosynthetic organs; certain other crops (sisal, banana) do yield fibre from their leaves, but jute's fibre-bearing tissue is not located in the leaf.

• Flower — the flower is the plant's reproductive structure (sepals, petals, stamens, carpels) and plays no part in jute's fibre extraction process.

• Root — the root anchors the plant and absorbs water and minerals from the soil; it is not processed for jute fibre.

The stem — specifically the bast (phloem/bark) layer beneath its outer surface — is therefore the correct answer.