COTTON BREEDING 55 



reference to their structure, vigor, and rapidity of setting 

 and developing the squares and bolls. -. 



61. Qualities associatecT 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 ihe 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-sterti, 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 nvunber of 

 nodes from which either bolls or fruiting Umbs 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 

 wiU be gathered with the cottOn. Large bolls are also more 

 storm-resistant than small boUs. 



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

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

 and the boUs developed in a short length of time. Farmers 

 often use- the wrong standards for measuring earliness, 

 such as dates of planting, the opening of the first boUs, 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 



