Controlling volunteer glyphosate-resistant (GR) crops has become an economic issue for producers in the Lower Rio Grande Valley (LRGV) and provides breeding sites that support the boll weevil (Anthonomus grandis Boheman). The LRGV is the last zone in the U.S. that has significant populations of the boll weevil. This research was initiated to identify herbicide chemistries or mixtures of these chemistries that are both effective at controlling GR cotton and non-phytotoxic to the commercial crop. To evaluate herbicide efficacy, GR cotton varieties were planted and herbicides were applied at 4-6 leaf stage. Bromoxynil + Atrazine, Paraquat, Paraquat + Sulflufenacil, and Topramezone + Atrazine, consistently had 100% mortality while several other herbicides had > 85% mortality, but still reduced hostability to < 8.5%. All herbicides tested for phytotoxicity had significant differences from the control except Diflufenzopyr + Dicamba and Diflufenzopyr + Dicamba + Prosulfuron. Further research should continue to evaluate herbicide products and multiple applications in order to eliminate fruit production on volunteer cotton and aid the boll weevil eradication program in their efforts.
January 30, 2015
The right to download or print any of the pages of this thesis (Material) is granted by the copyright owner only for personal or classroom use. The author retains all proprietary rights, including copyright ownership. Any reproduction or editing or other use of this Material by any means requires the express written permission of the copyright owner. Except as provided above, or any use beyond what is allowed by fair use (Title 17 Section 107 U.S.C.), you may not reproduce, republish, post, transmit or distribute any Material from this web site in any physical or digital form without the permission of the copyright owner of the Material. Inquiries regarding any further use of these materials should be addressed to Administration, Jernigan Library, Texas A&M University-Kingsville, 700 University Blvd. Kingsville, Texas 78363-8202, (361)593-3416.