Question

The fibre of sunn hemp is obtained from:
A. Leaf
B. Mesocarp
C. Phloem
D. Testa

Answer 1

Fibres can be obtained from various parts of the plant as per the need of the product. Skin fibre is obtained from the phloem of the plant. Sunn hemp is also known as Indian hemp. Fibres obtained from phloem have great strength. They are used in making fishing nets, rug yarns etc. Most of the herbs are cultivated to obtain instance flax, bast fibres etc.

Complete answer:
Bast fiber or skin fibers are obtained from plants. Crotalaria junica, also known as sunn hemp, originated in India. It is obtained from the legume family (fabaceae). It is now widely grown in the tropics and subtropics region. It is used as the source of green manure, fodder. It can also be used as biofuel. It has yellow flowers and elongated leaves.
Sunn hemp is a shrubby herbaceous legume growing at the height of 1-4m. It is strongly tap rooted and has several lateral roots also. Stems of the plant grow up to 2 cm in diameter. Their inflorescence is terminal open racemose.
Phloem (the inner bark or the skin) and bast surrounding the stem of certain plants mainly dicotyledonous plants provides bast fibres and skin fibres. They provide strength to the stem. Various herbs are cultivated to obtain technically important bast fibers such as instance flax, hemp etc. Due to the strength of the phloem sunn hemp are obtained from phloem and not from leaf, mesocarp and testa.

Thus, the correct answer is option C.

Note: Sunn hemp is mainly grown as fibre crop. It is used traditionally to manufacture ropes, strings, floor mats and fishing nets. After 2000 its use increased. It is environment friendly as it is obtained from nature. Its foliage is also used as a protein diet supplement. Raw seeds of sunn hemp are toxic. They should be boiled before feeding cattle. They can also suppress weeds. Harvesting of the fibres should be done at the flowering stage.