COTTON BREEDING 55 



reference to their structure, vigor, and rapidity of setting 

 and developing the squares and bolls. 



61. Qualities associated with high yield. While it 

 is true that the plants of each distinct variety conform 

 more or less to what is often termed "variety type," there 

 are a number of qualities that experience has shown to be 

 rather closely correlated with high yield. The most im- 

 portant of these are outlined below: 



(1) The primary branches and first fruiting limbs must 

 be borne rather low on the main-stem. A cotton plant that 

 bears its first limbs high up on the main-stem is usually 

 late and unproductive. 



(2) The internodes of the main-stem, the primary limbs, 

 and the fruiting limbs must be short. They should not 

 exceed from 2 to 3 inches, especially in the lower part of the 

 plant. This insures the production of a large number of 

 nodes from which either bolls or fruiting limbs are pro- 

 duced. 



(3) The bolls must be relatively large. Aside from 

 giving a larger yield, an increase in the size of bolls in- 

 creases the ease and rapidity of picking, and less trash" 

 will be gathered with the cotton. Large bolls are also more 

 storm-resistant than small bolls. 



(4) In weevil-infested districts it is essential that after 

 the crop has reached the fruiting stage, the squares be set 

 and the bolls developed in a short length of tune. Farmers 

 often use the wrong standards for measuring earliness, 

 such as dates of planting, the opening of the first bolls, or 

 the date of securing the first bale. A cotton variety that 

 opens its bolls first is not necessarily the most productive 

 under weevil conditions. 



(5) The plants must be resistant to such diseases as 

 wilt, root-knot, and anthracnose. . The United States 



