326 



in the presence and absence of weevils. Under each condition, Deltapine 15 pro- 

 duced a significantly lower yield than Coker 100 W. The decreased yield of 

 Deltapine 15 were due to greater square and boll abscission and the production 

 of smaller bolls, rather than to greater susceptibility of this variety to 

 weevils. Deltapine 15 fruited as early as Coker 100 W, and its nondeterminate 

 growth was not expressed. Hence, the boll weevil did not limit the produc- 

 tivity of Deltapine 15 any more than it limited the productivity of Coker 

 100 W. 



631. . 1968. Effects of nitrogen fertilization on cotton under boll weevil 



attack in North Carolina. J. Econ. Entomol. 61: 282-283. 

 Square, bloom, and boll production of cotton increased as nitrogen fertilization 

 was increased from 35 to 105 lb per acre. More boll weevils, Anthonomus grandis 

 Boheman, were attracted to the more heavily fertilized cotton, and greater num- 

 bers of squares and bolls were damaeed by weevils. However, the percentage of 

 damaged fruits did not vary significantly. Consequently, both yield and weevil 

 damage increased as nitrogen fertilization was increased. 



. >. 



632.. -. , and Covington, B. M. 1968. Effects of square removal on cotton pro- 

 duction with reference to boll weevil damage. J. Econ. Entomol. 61: 

 1060-1067. 

 Effects of increasing, constant, and fluctuating patterns of square removal (aver- 

 aging 45% for 8 weeks) on fruiting characteristics, early date, and yield of Coker 

 100 W cotton in North Carolina were investigated during 1957-59 in an area pro- 

 tected from boll weevils, Anthonomus grandis Boheman. Plants compensated for each 

 pattern of square removal by increasing square production, the percentage of bolls, 

 set, and the average weight of bolls. However, the extent to which each of these 

 plant responses contributed to the total compensation varied with the patterns of 

 square removal. The increasing pattern of square removal increased square produc- 



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' -y 



