The crop naturally depends upon the quality of the soil, and upon the attention which the fibre has received in its various stages ; the yield per acre varies in different districts. Three bales per acre, or 1,200 lb. is termed a 00% crop; but improved methods of manuring and of agricultural working are resulting in a yield above ioo, indeed as high as io4; it is stated in per centages although the value exceeds 'co. Sometimes the crop is stated in lakhs of r oo,000 bales each. The crop varies from year to year, but it seldom reaches io,000,000 bales; it is usually colour, but it is with great difficulty brought to a pure white by bleaching. A very striking and remarkable fact, which has much practical interest, is its highly hygroscopic nature. While in a dry position and atmosphere it may not possess more than 6% of moisture, under damp conditions it will absorb as much as 23%; the normal percentage is 12 to 13%.
Sir G. Watt, in his Dictionary of the Economic Products of India, mentions the following i r varieties of jute fibre : Serajganji, Narainganji, Desi, Deora, Uttariya, Deswal, Inkrabadi, Bhatial, Karimginji, Mirganji and Jungipuri. There are several other varieties of minor importance. The first four form the four classes into which the commercial fibre is divided, and they are commonly known as Serajgunge, Naraingunge, Daisee and Dow rah. Serajgunge is a soft fibre but it is superior in colour, which ranges from white to grey. Naraingunge is a strong fibre, pos sesses good spinning qualities, and is very suitable for good warp yarns. Its colour, which is not so high as Serajgunge, begins with a cream shade and approaches red at the roots. All the better class yarns are spun from these two kinds. Daisee is similar to Serajgunge in softness, is of good quality and of great length; its drawback is the low colour, and hence it is not so suitable for using in natural colour. It is, however, a valuable fibre for carpet yarns, especially for dark yarns. Dowrah is a strong, harsh and low quality fibre, and is used principally for heavy wefts. Each class is subdivided according to the quality and colour of the material, and each class receives a distinctive mark called a baler's mark. Thus the finest fibres may be divided as follows :— *1927 values are the Final Estimate ; the others are actual values.
between 8 and 9 million bales. For detailed particulars concern ing both fibre and cloth see The Report of the Committee of the Indian Jute Mills Association.
of a clear whitish-yellow colour, with a fine silky lustre, soft and smooth to the touch, and fine, long and uniform in fibre. When the fibre is intended for goods in the natural colour it is essential that it should be of a light shade and uniform ; but if intended for yarns that are to be dyed a dark shade the colour is not so important. The cultivated plant yields a fibre with a length of from 6 to 'oft., but in exceptional cases it has been known to reach 14 to 15ft. in length. The fibre is decidedly inferior to flax and hemp in strength and tenacity; and, owing to a peculiarity in its microscopic structure, by which the walls of the separate cells composing the fibre vary much in thickness at different points, the single strands of fibre are of unequal strength. Recently pre pared fibre is always stronger, more lustrous, softer and whiter than such as has been stored for some time—age and exposure rendering it brown in colour and harsh and brittle in quality. Jute, indeed, is much more woody in texture than either flax or hemp, a circumstance which may be easily demonstrated by its behaviour under appropriate reagents; and to that fact is due the change in colour and character it undergoes on exposure to the air. The fibre bleaches with facility, up to a certain point, suf ficient to enable it to take brilliant and delicate shades of dye The lower qualities are, naturally, divided into fewer varieties.
Each baler has his own marks, the fibres of which are guaran teed equal in quality to some standard mark. It would be im possible to give a list of the different marks, for there are hun dreds, and new marks are constantly being added. A list of all the principal marks is issued in book form by the Calcutta Jute Balers' association.
The relative prices of the different classes depend upon the crop, upon the demand, and upon the quality of the fibre. The prices of first marks averaged about £19 per ton between the years 1903-6; in the former year the price was £12.15s., whereas in the latter year the price had risen to £27.15s. The price in Dec. 1927 was between £36 and £37.