CROPS 337 



individuals of the second year; and 500 or more plants of each of the in- 

 dividual selections. 



The method here outlined is to be continued indefinitely, as it is only by 

 the careful and continuous selection that high bred strains can be kept up to 

 a state of efficiency, and if for any reason is interrupted there is a general 

 and rapid decline. 



428. Score Card. For careful comparisons in making selec- 

 tions a score card arranged to compare and emphasize the 

 points especially sought is desirable. The United States Bureau 

 of Plant Industry uses the score on p. 338 in judging hybrids of 

 sea island and upland cotton for the purpose of securing cotton 

 for cultivation in upland regions which will have long staple, big 

 bolls, opening well and easy to pick, and black seed. In this case 

 all plants not having black seeds were rejected. 1 



429. Scale of Qualities. In place of a score card, such as sug- 

 gested above, the Texas Station proposes a set of maximum 

 and minimum qualities, as follows: 



For Early Fruiting. The first fruit limb must not be higher than the fifth 

 joint above the seed leaf joint. The first primary or wood limb must not be 

 above the fifth joint, and the number of primary limbs should not exceed four. 



For Rapid Fruiting. The joints on the main stem, fruit limbs, and primary 

 limbs must not exceed three inches. Fruit limbs should grow in succession at 

 each joint of the main stem and primary limbs, and should be continuous in 

 growth for continuous fruiting. 



For Productiveness. The bolls should not be less than 1.5 inches in di- 

 ameter. The per cent, of limb to seed cotton should not be less than 33.3. 

 The rate of growth is very important, and, therefore, the larger the plant of 

 the type, the greater is its inherent rate of growth, its earliness, rapidity of 

 fruiting, and yield. 2 



430. INFLUENCE OF ENVIRONMENT. "All evidence indicates that the seed 

 produced by plants grown on good soil under the best conditions produces in 

 its turn the best and most vigorous seed. It is thus desirable to plant the 

 selection field on good rich soil of the same kind on which the crop is to 

 be generally cultivated. If the general crop is to be grown on a light, sandy 

 soil, it would of course be wrong policy to place the selec^on field on a rich, 

 heavy loam. The soil should be of the kind used for the general fields, but 

 unexhausted by previous cultivation. It is also desirable that the selectioa 



1 U. S. Dept. Agr. Yearbook 1902, p. 376. 

 -Texas Sta. Bui. No. 79 (1905), p. 8. 



