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United States Department of Agriculture

Agricultural Research Service

Title: Grain sorghum as a trap crop for the corn earworm in cotton

Authors
item Tillman, Patricia
item Ruberson, John - UNIV. OF GEORGIA
item Mullinix, Ben - UNIV. OF GEORGIA

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: January 30, 2002
Publication Date: June 1, 2002
Citation: Tillman, P.G., Ruberson, J.R., Mullinix, B. 2002. Grain sorghum as a trap crop for the corn earworm in cotton. Proceedings of the Beltwide Cotton Conference.

Interpretive Summary: Since Bt cotton is less resistant to the corn earworm (CEW), and CEWs have developed resistance to pyrethroids in isolated locations in the southeast, the CEW can be a serious problem in cotton in Georgia. Grain sorghum is highly attractive to CEW moths, and so a strip of grain sorghum trap crop was planted in cotton to determine if the grain sorghum could provide a trap crop for the CEW. Corn earworms were heavily attracted to the grain sorghum trap, laying 17 times as many eggs in sorghum as in cotton. Also, the sorghum trap in the trap fields protected the cotton so economic thresholds of CEW did not occur eliminating the need for insecticide applications for this pest in these fields. These results demonstrate that grain sorghum is an excellent trap crop for the CEW in cotton.

Technical Abstract: The ability of grain sorghum to serve as a trap crop for the corn earworm (CEW) in cotton was investigated in Mystic, GA in 2001. Three 150 ft x 12 row strips of sorghum (sorghum trap) and 3 strips cotton (cotton trap) were planted along a single edge of 3 cotton fields adjacent to corn. Corn earworm populations were monitored in the sorghum trap, in the cotton trap, in field cotton associated with the sorghum trap, in field cotton associated with the cotton trap, and three control fields with no trap crop, but still adjacent to corn. CEW eggs were much higher in the sorghum trap than in the cotton trap. CEW eggs were not different between trap cotton and field cotton associated with the traps. Also, CEW eggs were not different for field cotton associated with the sorghum trap and field cotton associated with the cotton trap. Control fields had higher CEW eggs than trap fields. These results demonstrated that grain sorghum was an effective trap crop for the CEW in cotton.

Last Modified: 7/28/2014
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