1934 - Isely, Dwight. Relationship between early varieties of cotton and boll weevil injury. 

 J. Econ. Ent. 27(4):762-766. 



Controlled experiments were conducted in Arkansas from 1926-1929, using a 

 strain of Trice (a very early cotton), Acala (an early strain) and Snowflake (a late 

 variety). In 1927 Rowden was substituted for Snowflake. Under average conditions 

 late varieties were shown to carry a much greater weevil hazard. There was less 

 to be gained by dusting early, rapidly maturing cotton. 



1934 - Sanborn, C. E., H. C. Young, E. Hixson, E. E. Scholl, and C. F. Stiles. History 

 and control of the boll weevil in Oklahoma. Okla. Agr. Expt. Sta. B. 222:32. 



An account of work carried out in Oklahoma during 1921-34 on the control of 

 the cotton boll weevil, the bionomics of which are outlined. Cultural measures are 

 recommended, supplemented where necessary by the application of a calcium 

 arsenate dust every 4 or 5 days after the infestation has reached 10%. 



1934 - Robinson, J. M., and F. S. Arant. Entomology. Ala. Agr. Expt. Sta. Rpt. 44:27-29. 

 Auburn. 



Studies on the control of the boll weevil with calcium arsenate dust were 

 continued in 1932. Of 10 applications made during the fruiting season, 4 were af- 

 fected by rain within 24 hours, the yields of cotton were slightly above the aver- 

 age for the past 6 years, and there was a definite increase on all fertilized plots 

 that had been dusted. The increased yields from dusted cotton were 213, 128, 426, 

 and 400 lbs. of seed cotton per acre on the plots receiving 500, 1,000, 1,500 and 

 2,000 lbs. of fertilizer per acre, respectively. 



1941 - Calhoun, P. W. Topping cotton in early fall as a possible means of reducing the 

 spring boll weevil population in the northwestern part of the Florida Sea Island 

 cotton belt. Fla. Ent. 24 (2): 35 -40, 5 ref. Gainesville. 



The investigations were carried out in view of the exceptionally large num- 

 bers of boll weevils that develop in autumn in cotton bolls in the upper parts of 

 the plants in the northwestern part of the Florida Sea Island cotton belt. These 

 populations commonly exceed 10,000 weevils per acre, and control was so diffi- 

 cult that the growing of Sea Island cotton on a large scale generally had to be 

 abandoned. 



An experment was made in the autumn of 1940 over some 200 acres of 

 heavily infested cotton; most of the fields had produced less than half their crop. 

 Almost all the bolls on the upper half of the plants contained 2 to 5 larvae or 

 pupae, while the tops were producing an abundance of squares. The plants were 

 topped on September 10, about 10 days before the final picking; the upper parts 

 (about one -third of each plant) that contained bolls severely infested with ad- 

 vanced stage larvae or pupae were cut off, in order to destroy as much of the 

 squaring portion as possible without discarding any sound bolls. As soon as the 

 discarded tops died, the adult weevils feeding on them moved back to the plants, 

 and fed on the few remaining squares and on bolls that were not ready to open. 

 As the population had already been high for several weeks, nearly all the sound 

 bolls were tough, fibrous and almost ready to open. About two weeks after topping, 

 the adult weevils began to decrease innumbers, until only a few remained. Whether 

 most of them died or migrated is not known. The immature stages died in great 

 numbers in the young bolls on the removed tops, and the percentage emergence 

 was much lower than it would have been had the tops remained on the plants. The 

 bolls on the living plants that had been attacked, but not completely ruined by the 

 weevils, apparently opened more quickly and fully as a result of topping, which 

 seemed to result in less waste cotton being left in the field at the final picking. 

 It is thought that the cost of the operation was more than covered by the increase 

 in the amount of the cotton harvested. 



If an abundance of squares in autumn helps the weevil to survive the winter, 

 the scarcity of squares in the fields that have been topped will decrease the per- 

 centage of survival of the relatively few weevils that remain, and so increase the 

 effect of the reduction in the population caused by the topping. If practiced co- 

 operatively on a sufficiently extensive scale, topping should thus prevent the 



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