Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2006
Publication Date: 4/1/2007
Citation: Greenberg, S.M., Norman, J.W., Sparks, A.N., Bradford, J.M., Yang, C., Sappington, T.W., Coleman, R.J., Showler, A. 2007. Chemical cotton stalk destruction for maintenance of host-free periods for the control of overwintering boll weevil in tropical and subtropical climates. Pest Management Science. 63(4):372-380.
Interpretive Summary: Cotton stalk destruction is a prime tool for managing overwintering boll weevils by reducing or eliminating the habitat and food available to the insects in regions where rainfall and warm temperatures prolong fall cotton growth. Mechanical operations for stalk destruction can be easily disrupted by adverse soil or weather conditions and are contrary to conservation tillage which Lower Rio Grande Valley cotton producers increasingly have adopted. Many producers using conservation tillage choose to leave the stalks standing through the winter for wind erosion control and need an efficacious way to control standing cotton. All of these problems contribute to the need for evaluation of alternative stalk control methods for both shredded and standing stalks. Several herbicides were tested in the reported trial and 2,4-D Amine applied twice was found to be 100% effective in killing stalks. These findings will aid in the identification of opportunities for improved effectiveness and economics of control of overwintering boll weevils, and the successful expansion of boll weevil eradication program into subtropical and tropical environments.
Technical Abstract: Cotton stalk destruction is a prime tool in management of several species of cotton pests in the Lower Rio Grande Valley of Texas, particularly the boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae). Mechanical methods of stalk destruction are generally successful, but some stalks may survive these operations. Moreover, adverse weather conditions and conservation tillage often impede immediate and complete stalk destruction using typical tool implements. These studies provide an examination of efficacy of different herbicides (thidiazuron [Harmony Extra]; dicamba diglycolamine salt [Clarity]’ 2,4-D Amine [Savage]; flumioxazin [Valor]; and Aim), rates, spray volumes, and application timings on shredded or standing cotton stalks after stripper or picker harvest. The herbicide 2,4-D Amine applied twice (immediately and 14 [or 21] days after cotton was harvested_ at one pound of formulated product in 10.0 gallons of water per acre provided 100% control on shredded or standing cotton stalks.