Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/5/2004
Publication Date: 6/14/2004
Citation: Showler, A. 2004. Assessment of pre-emptive insecticide applications at pinhead square size for boll weevil control. In: Proceedings of the Beltwide Cotton Conferences, January 5-9, 2004, San Antonio, Texas. p. 1689-1692. 2004 CDROM.
Interpretive Summary: The value of preventative insecticide sprays for boll weevil management is not well understood, though it is commonly practiced in the Lower Rio Grande Valley of Texas. In this study, preventative sprays at pinhead-size fruiting stage of cotton growth failed to reduce boll weevil reproduction or increase cotton lint yields. These findings suggest that preventative, or automatic, sprays might be more effective if they are applied when squares are larger and more utilized by boll weevils.
Technical Abstract: Automatic 'pre-emptive' insecticide applications for boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), control initiated at pinhead square formation and followed by one or two more application 3-7 d apart is widely practiced in the Lower Rio Grande Valley of Texas, but the tactic has been controversial for more than 20 years. Using 0.11-ha experimental field plots, this study demonstrated that three pre-emptive applications of cyfluthrin failed to significantly affect square production, boll weevil reproduction, and cotton lint yield. The reasons for the failure of pre-emptive spraying at pinhead square formation are discussed.