THE CONTROL OF COTTON WTLT AND EOOT-KNOT. 



13 



BREEDING METHODS. 



The progenv-row method consists in the selection of the best plants 

 to be found, in plantino; the seed from each in a separate row, and in 

 tlie final choice that autumn of the best row or rows, the seed from 

 wJiicli is increased as rai)idly as possible the following years. The 

 details of tliis method as now practiced and recommended for the 

 breeder are as follows: 



Preparation of land. — Assuming that, to start liis breeding work, 

 the prospective breeder has obtained from the Department of Agri- 

 culture or elsewhere a few individual plant selections made the 

 previous year, he should first select a piece of land badly infected 

 with ^\alt, separated as far as possible from any other cotton field to 

 avoid cross-pollination ; often a plat may conveniently be located in a 

 cornfield or in a field of the same variety being grown for seed. Care 

 should be taken that the land is not infected with root-knot. The 

 plat should be prepared and fertilized as for other cotton and the 

 rows laid off in a block, side by side (see figs. 10, 11, and 12), 4 to 4^ 

 feet apart and 200 to 2.50 feet long, thus providing for 100 hills 2 to 

 2h feet apart in each progeny row. Plenty of space is necessary to 

 permit the normal development of the individual plants. 



Diagrams illustrating metjiods of seed selection. 



A/o./ 



2-0- 

 3-7 



—^ — :? 



'^i:j~^i:^s~^-—^ 



Fig. 10.— ( Virst Year?) Five selections, made from individual plants of the Dixie variety, are planted in 

 100 hill rows. This plat is isolat<><i or placed in a c-ornfiold or in a field of Dixie cotton to prevent crossing 

 with other cotton. All wilted and inferior phints are pulled out during the season. At the end of the 

 season the rows are carefully inspected, Nos. 2 and 4 selected as the most wilt resistant and productive, 

 and Nos. 1, 3, and 5 discarded. From these selected progen.v rows, indicated by "x," io individual selec- 

 tions arc made, indicated by circles and numbers. These are ginned and 8 discarded because of too low 

 lint percentage or other undesirable characters, leaving the 7 best plants for use next season. All the re- 

 maining plants in the 2 selected progeny rows are picked into 2 lots for planting increase plats the follow- 

 ing year. 



[Cir. 9:.'] 



