THE CONTROL OF COTTON WILT AND EOOT-KNOT. 17 



than earlier. After the necessary notes have been taken on the note 

 bhmks pro\dded, the individual selections should be picked separately 

 into cloth bags or strong paper bags and i)lainly marked with the 

 nuin])or of the plant. The rows should tlien be })icked, a record 

 being made of the exact number of ])lants ])icked in each row. Tlie 

 second i)icking should be made when most of tlie cotton has opened, 

 but before frost has caused the premature opening of late bolls. 

 For comparing the yields the cotton from all the progeny rows, in- 

 cluding the first and second picldngs, should l)e weighed separately 

 and the jaeld per hundred plants calculated. 



Ginning. — The ginning of the individual selections and progeny 

 rows should be left until winter, when the rush of fall work is over. 

 For ginning individual plants a small hand gin is essential. Three 

 types of hand gins are on the market: (1) A small saw gin, very 

 similar in appearance to the ordinary commercial saw gin, but 

 having only 10 saws and furnished with a handle by means of which 

 it is operated; (2) a small-sized roller gin of the type generally used 

 to gin Sea Island cotton and also operated by a handle; and (3) a 

 gin somewhat similar to the roller gin but having a series of fingers 

 instead of beaters to break the lint from the seed. The price of 

 these gins is from $50 to $75. It is often possible for several farmers 

 to club together to bear the expense of such an outfit. Progeny 

 rows, as w^ell as individual plants, can best be ginned on a hand 

 gin. Ill ginning different individual plants or progeny rows, great 

 care should be exercised that the gin be thoroughly cleaned out 

 after each operation, so that not a single seed will be left to mix 

 with the succeeding lots or to render the results of both lots less 

 accurate. 



Lint percentage. — Before being ginned the seed cotton of each 

 plant should be carefully weighed on a pair of scales that will weigh 

 in irrams. Before wei";lung the cotton all burrs or trash should be 

 picked out and any sand present knocked out by beating the cotton, 

 over a wire screen. After ginning, the seed should be weighed and 

 the weight of lint determined by the difference between the weight 

 of the seed and the seed cotton. The weight of the lint divided 

 b}^ the weight of the seed cotton equals the percentage of lint. In 

 the final selection of the best individuals for future breeding, prefer- 

 ence should be given to those having a high lint percentage, other 

 tilings being equal, and selections having less than .35 per cent of 

 lint should be discarded. 



Length of lint. — The length of the lint of individual selections should 

 be roughly noted in the field when selections are made and no plants 

 with a distinctly short lint should be saved. If more accurate data 

 are desired the}^ can be obtained by a more careful study of the cotton. 



[Cir. 92] 



