UNITED STATES DEPARTMENT OF AGRICULTURE 



DEPARTMENT BULLETIN No. 1153 



Washington, D. C. ▼ Kay 12, 1923 



BOLL-WEEVIL COTTON IN TEXAS. 



By 0. F. Cook. Bionomist in Charge. Office of Crop Acclimatization and Adapta- 

 tion Investigations, Bureau of Plant Industry. 



CONTENTS. 



Page. Page. 



Nature of boll-weevil cotton 1 Feasibility of wider lanes 9 



Distinctive characters of boll-weevil Factors of the spacing problem 9 



cotton - Early crops from small plants 11 



Sterile involucres of boll-weevil cot- Late thinning to suppress vegetative 



ton 3 branches 14 



Weevils sheltered by large plants 4 Close spacing necessary with late 



Weevil damage on exposed plants 5 t' inning 15 



Open lanes between cotton rows 6 Conclusions 16 



Wider lanes and closer spacing in List of publications on weevil resist- 



the rows__ 7 ance and close spacing of cotton 19 



NATURE OF BOLL-WEEVIL COTTON. 



The expression " boll-weevil cotton " is used by farmers in Texas, 

 who recognize the effects of weevil injury in altering the behavior 

 of the plants by forcing them into rank growth, so that the damaged 

 fields are different from normally productive cotton. In addition to 

 the direct injuries inflicted by destroying flower buds and bolls, the 

 insects are responsible indirectly for an abnormal luxuriance that 

 changes the form and appearance of the plants. Texas has had more 

 experience with weevil injury than other States, with varied con- 

 ditions and seasons that bring out the contrasts between the normal 

 behavior of the cotton crop and the abnormal behavior of " bad 

 weevil years.'' The weevils entered southern Texas from Mexico in 

 1892. but did not reach Louisiana till 1903. Arkansas and Oklahoma 

 were invaded in 1905, Alabama in 1909, Georgia in 1914, and North 

 Carolina in 1919. 



Cotton tends, of course, to grow rank in the rich Texas soils if 

 moisture is abundant and the spring weather is warm, but such 

 natural tendencies to luxuriance are greatly increased when the 

 weevils are abundant and the floral buds are destroyed so that no 

 fruit can be set. The spring generations of weevils are bred in the 

 flower buds, and breeding begins as soon as the buds are large 

 enough to furnish the partly developed pollen that is the principal 

 food of the weevils. Most of the infested buds are blasted and drop 

 to the ground in a few days. 



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