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Crop Response, Weed Management Systems, and Tank Mix Partners with Isoxaflutole in HPPD Tolerant Cotton

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Crop Response, Weed Management Systems, and Tank Mix Partners with Isoxaflutole in HPPD Tolerant Cotton Crop Response, Weed Management Systems, and Tank Mix Partners with Isoxaflutole in HPPD Tolerant Cotton by Delaney Caitlin Foster, B.S. A Thesis In Plant and Soil Science Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE Approved Dr. Peter A. Dotray Chair of Committee Dr. Frederick T. Moore Dr. J. Wayne Keeling Dr. Cade Coldren Mark Sheridan Dean of the Graduate School May, 2021 Copyright 2021, Delaney Caitlin Foster Texas Tech University, Delaney Caitlin Foster, May 2021 ACKNOWLEDGMENTS First, I’d like to thank my committee chair and mentor Dr. Peter Dotray for taking a chance on this South Georgia girl from ABAC. Dr. Dotray truly provided me with every resource I could ever need to succeed and for that I am forever thankful. His goal was for me to leave west Texas and share with others about my time here in the same manner I talked about my experiences in Georgia (excitedly)… I’d say he accomplished just that. Thank you for being a great mentor and providing me endless learning experiences. Thanks are also in order to my committee members. Dr. Wayne Keeling always helped me see the big picture, I hope one day growers trust my professional opinion as much as they do his. Dr. Keeling challenged my weed ID skills more than a few times each summer with samples brought to him by growers and consultants; this seemingly small real-world experience was invaluable. Thank you to Dr. Frederick Moore with BASF Corporation for bringing an industry perspective to the table and for advocating the importance of the IFT work, as well as helping me share my results at conferences and meetings. Dr. Cade Coldren taught the first graduate class I attended and gave me a great outside look on statistics while always being excited to learn about weed science. A special thank you to Dr. Corey Thompson with BASF for the great advice, technical support, and answering my unending questions about this project… he could’ve easily defended my thesis better than I. Bobby, Grace, Kyle, Jon, Ubaldo, and Andrew, thank you for your companionship and support. Without all of you, I’d still be measuring plant heights in the field. To my best friend Taylor Randell, thank ii Texas Tech University, Delaney Caitlin Foster, May 2021 you for the advice and weekly phone calls from Georgia. Even moving halfway across the country, we pick up where we left off every time. I appreciate the BASF Corporation employees who attended my field tours and conference presentations. Each of you met my project with excitement for this future technology and I’m thankful I was able to share this work with the folks who will be promoting it soon. I have no doubt these opportunities helped prepare me for professional life in the future. I would also like to thank Texas Tech University for the opportunity to research and learn in and outside of the classroom as well as Texas A&M AgriLife Research and Extension for the use of resources and personnel. Without either institution, my research would not have been possible. Finally, thank you to my family – Mom, Dad, Brody, and Kelsi, for all of their love and support while I “make a career out of school”. Your encouragement means the world. iii Texas Tech University, Delaney Caitlin Foster, May 2021 TABLE OF CONTENTS ACKNOWLEDGMENTS .................................................................................... ii LIST OF TABLES ................................................................................................ v CHAPTER I: LITERATURE REVIEW ............................................................ 1 Literature Cited ............................................................................................... 12 CHAPTER II: COTTON RESPONSE TO HERBICIDE SYSTEMS USING ISOXAFLUTOLE ................................................................................. 18 Abstract ........................................................................................................... 18 Introduction ..................................................................................................... 20 Materials and Methods .................................................................................... 22 Results and Discussion .................................................................................... 25 Literature Cited ............................................................................................... 30 CHAPTER III: WEED MANAGEMENT IN HERBICIDE SYSTEMS USING ISOXAFLUTOLE ................................................................................. 47 Abstract ........................................................................................................... 47 Introduction ..................................................................................................... 49 Materials and Methods .................................................................................... 51 Results and Discussion .................................................................................... 52 Literature Cited ............................................................................................... 55 CHAPTER IV: TANK MIX PARTNERS WITH ISOXAFLUTOLE ACROSS THE COTTON BELT ....................................................................... 63 Abstract ........................................................................................................... 63 Introduction ..................................................................................................... 65 Materials and Methods .................................................................................... 67 Results and Discussion .................................................................................... 68 Literature Cited ............................................................................................... 80 iv Texas Tech University, Delaney Caitlin Foster, May 2021 LIST OF TABLES Table 2.1. Treatments, application timing, herbicide, and rates used in crop tolerance experiments at New Deal and Lubbock in 2019 and 2020................................................................................................................ 33 Table 2.2. Cotton response 14 days after planting at New Deal and Lubbock, TX in 2019 and 2020 systems trials. .............................................................. 34 Table 2.3. Cotton response 14 days after the early postemergence application at New Deal and Lubbock, TX in 2019 and 2020 systems trials. .................. 35 Table 2.4. Cotton response 7 days after the mid-postemergence application at New Deal and Lubbock, TX in 2019 and 2020 systems trials....................... 36 Table 2.5. Cotton response 10 days after the postemergence-directed application at New Deal and Lubbock, TX in 2019 and 2020 systems trials. ................................................................................................. 37 Table 2.6. Cotton density 21 days after planting at New Deal and Lubbock, TX in 2019 and 2020 systems trials. ............................................................. 38 Table 2.7. Cotton heights 14 days after the early postemergence application at New Deal and Lubbock, TX in 2019 and 2020 systems trials....................... 39 Table 2.8. Cotton lint yield at New Deal and Lubbock, TX in 2019 and 2020 systems trials. ................................................................................................. 40 Table 2.9. Cotton heights at harvest at New Deal and Lubbock, TX in 2019 and 2020 systems trials. ................................................................................. 41 Table 2.10. Cotton micronaire measurements at New Deal and Lubbock, TX in 2019 and 2020 systems trials. .................................................................... 42 Table 2.11. Cotton length measurements at New Deal and Lubbock, TX in 2019 and 2020 systems trials. ........................................................................ 43 Table 2.12. Cotton uniformity measurements at New Deal and Lubbock, TX in 2019 and 2020 systems trials. .................................................................... 44 Table 2.13. Cotton strength measurements at New Deal and Lubbock, TX in 2019 and 2020 systems trials. ........................................................................ 45 Table 2.14. Cotton elongation measurements at New Deal and Lubbock, TX in 2019 and 2020 systems trials. .................................................................... 46 Table 3.1. Herbicide treatments, rates, and application timings used in non- crop weed control experiments at Halfway, TX in 2019 and 2020. .............. 57 Table 3.2 Palmer amaranth control 14 days after the preemergence application at Halfway, TX in 2019 and 2020 systems trials. ....................... 58 Table 3.3. Palmer amaranth control 21 days after the preemergence application at Halfway, TX in 2019 and 2020 systems trials. ....................... 59 v Texas Tech University, Delaney Caitlin Foster, May 2021 Table 3.4. Palmer amaranth control and counts 21 days after the early postemergence application at Halfway, TX in 2019 and 2020 systems trials. ................................................................................................. 60 Table 3.5. Palmer amaranth control 21 days after the mid-postemergence application at Halfway, TX in 2019 and 2020 systems trials. ....................... 61 Table 3.6. Palmer amaranth control 10 days after the postemergence-directed
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