COTTON VARIETIES 



41 



importance of soil and climate as factors influencing the 

 variability of cotton. 



47. Classification of varieties. It is very difficult to 

 classify cotton varieties owing to the readiness with which 

 they are cross-fertilized and the great range of variation 

 of the individual plants within a variety. The most 

 satisfactory classification of Ameri- 

 can upland varieties known to the 



author is that proposed by Duggar 

 of the Alabama Experiment Sta- 

 tion which is given below: 



Group 1. Cluster type. 



Group 2. Semi-cluster type. 



Group 3. Rio Grande type, of 

 which the Peterkin is an example. 

 . Group 4. The early varieties 

 of the King type. 



Group 5. The Big-boll type. 



Group 6. The Long-limbed 

 type. 



Group 7. Intermediate varie- 

 ties. 



, Group 8. Long-staple Upland 

 varieties. 



48. Cluster type (Fig. 8). The 

 plants of this type possess the char- 

 acteristic property of producing one 

 or more long basal limbs with ex- 

 tremely short spur-like fruiting 

 limbs on the middle and upper 



parts of the main-stems. There is a tendency for the 

 bolls and leaves to be borne in clusters as a result of 

 the shortening of the internodes of the primary and fruit- 



FIG. 8. Plant of the 

 Jackson Limbless va- 

 riety of cotton repre- 

 senting the Cluster 

 group. 



