2 BULLETIN 644, IT. S. DEPARTMENT OF AGRICULTURE. 



That a clearer understanding may be had of the relations between 

 lint percentages and lint indexes in cotton varieties, as discussed in 

 this paper, a brief definition of each is included, together with a word 

 as to the adoption of these measures of cotton values. 



LINT PERCENTAGES. 



The percentage of lint, or lint per cent, as it is generally termed, 

 is the relation between the weight of the fiber and the weight of the 

 >eeds from which the fiber is obtained in the process of ginning and 

 is expressed as a percentage of the unginned seed cotton. A decrease 

 in the weight of the seeds without a corresponding decrease in the 

 weight of the fiber would alter this relation in the direction of in- 

 creasing the percentage of lint. Conversely, an increase in the 

 weight of the seeds without change in the weight of the fiber would 

 result in a reduction in the percentage of lint. 



The first commercial use of the percentage of lint was made by 

 early operators of gins, who purchased cotton in the seed, ginned it, 

 and resold the products. In those days, when the seed was consid- 

 ered a waste product, it was of especial importance to these gin oper- 

 ators to know the ultimate value of the seed cotton they purchased. 

 The amount of fiber they might secure from a given weight of seed 

 cotton, or the lint percentage, was the basis of such purchases. The 

 emphasis laid upon the percentage of lint by these buyers of seed 

 cotton naturally led to the belief among the growers that it was the 

 thief factor or measure of value of varieties. To-day this relic of 

 an admittedly bad method of selling cotton x is still accepted with- 

 out question or apparent examination by planters and also by many 

 of the breeders of cotton. The result is that inferior and unproduc- 

 tive varieties frequently have been planted merety because their lint 

 percentages are high, while varieties that are superior both in pro- 

 ductiveness and in quality of fiber have been rejected because their 

 percentages of lint are considered low. 



LINT INDEXES. 



The lint index is the weight in grams of the fiber produced by 100 

 seeds and may be said to be a measure of the abundance of the fiber 

 rather than a measure of the relation between the weight of the 

 fiber and the weight of the seed, as is the percentage of lint. 



Through years of association, the general cotton-growing public- 

 lias come to consider a lint percentage of 33£ a basis of credit for a 

 variety of cotton. So. in time, breeders ma} 7 determine a basic lint 



1 Creswel]. C. F. Disadvantages of selling cotton in the seed. T". S. Dept. Agr. Bui. 

 375, 18 p. 1916. 



— Losses from selling cotton in the seed. U. S. Dept. Agr., Farmers' Bui. 775. 



S p. 191G. 



