18 BULLETIN 1153, U. S. DEPAKTMENt I : ,: AGRICULTURE. 



by the higher yields of the open rows and exposed plants that con- 

 tinued to set bolls late in the season in the San Antonio experiments 

 of 1921. 



Where close spacing is used, 6 inches or less, the vegetative 

 branches, or secondary stalks, are likely to be suppressed without the 

 further precaution of deferred thinning that may be required with the 

 wider spacing of the plants, to 10 or 12 inches. The use of deferred 

 thinning is to suppress vegetative branches under conditions of very 

 luxuriant growth, but under ordinary conditions thinning should 

 be done when the plants are 5 or 6 inches high. Several experi- 

 ments have been reported where the largest yields were from rows 

 that were not thinned. If thinning is deferred longer than neces- 

 sary some of the lower fruiting branches as well as the vegetative 

 branches are likely to be suppressed. A special need of close spac- 

 ing is to be recognized with cotton that is planted late or where 

 thinning has been deferred till the plants are 10 inches or a foot 

 high. No thinning may be necessary with open or scattering stands 

 where plants do not average less than 2 or 3 inches apart in the row. 



