Mississippi State University Scholars Junction Theses and Dissertations Theses and Dissertations 1-1-2016 Application Timing of Herbicides for Miscanthus (Miscanthus X Giganteus) Control and Effects of Mowing on Rhizome Initiation and Production Dosha Nicole Barksdale Follow this and additional works at: https://scholarsjunction.msstate.edu/td Recommended Citation Barksdale, Dosha Nicole, "Application Timing of Herbicides for Miscanthus (Miscanthus X Giganteus) Control and Effects of Mowing on Rhizome Initiation and Production" (2016). Theses and Dissertations. 719. https://scholarsjunction.msstate.edu/td/719 This Graduate Thesis - Open Access is brought to you for free and open access by the Theses and Dissertations at Scholars Junction. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholars Junction. For more information, please contact [email protected]. Template B v3.0 (beta): Created by J. Nail 06/2015 Application timing of herbicides for Miscanthus (Miscanthus x giganteus) control and effects of mowing on rhizome initiation and production By TITLE PAGE Dosha Nicole Barksdale A Thesis Submitted to the Faculty of Mississippi State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Plant and Soil Sciences in the Department of Plant and Soil Sciences Mississippi State, Mississippi December 2016 Copyright by COPYRIGHT PAGE Dosha Nicole Barksdale 2016 Application timing of herbicides for Miscanthus (Miscanthus x giganteus) control and effects of mowing on rhizome initiation and production By Dosha Nicole Barksdale Approved: ____________________________________ John D. Byrd, Jr. (Major Professor) ____________________________________ Daniel B. Reynolds (Committee Member) ____________________________________ Rocky W. Lemus (Committee Member) ____________________________________ David J. Lang (Committee Member) ____________________________________ Michael S. Cox (Graduate Coordinator) ___________________________________ J. Mike Phillips Department Head ____________________________________ George M. Hopper Dean College of Agriculture and Life Sciences Name: Dosha Nicole Barksdale ABSTRACT Date of Degree: December 9, 2016 Institution: Mississippi State University Major Field: Plant and Soil Sciences Major Professor: Dr. John D. Byrd, Jr. Title of Study: Application timing of herbicides for Miscanthus (Miscanthus x giganteus) control and effects of mowing on rhizome initiation and production Pages in Study: 84 Candidate for Degree of Master of Science Herbicide treatments were tested on mature stands of Miscanthus in 2013 and 2014 in Winston and Oktibbeha counties Mississippi. Twenty-one different herbicide treatments and two application timings, summer and fall, were evaluated. Glyphosate at 4,500 g ae ha-1 applied in the summer provided the best Miscanthus control at each location. Control with fall applications of glyphosate varied between locations. Two greenhouse studies were conducted in 2014 and 2015 at Mississippi State, MS to evaluate the effects of mowing on seedling Miscanthus, as well as the time period between seed germination and rhizome initiation. Rhizomes were visible on seedling plants 15 or 13 weeks after germination in 2014 and 2015, respectively. Removal of the Miscanthus terminal reduced the number of rhizomes produced compared to plants with intact terminals. However, terminal removal increased the number of shoots produced compared to plants with intact terminal. DEDICATION I would like to dedicate this work to my husband, Blake, and my children, Cade and Issac. They were my inspiration to continue forward even when I doubted myself. Becoming a mother in graduate school meant more exhaustion, longer nights, and earlier mornings, but then again it gave me a heightened level of determination. With the enduring love and support of my husband, I was able to overcome any obstacle that graduate school offered. I can only hope that I am able to set forth the same example for my children as my parents, Earl and Lisa Clardy, have done for me. Whether it is financial or emotional support, my parents have always stood by my side and helped ensure my success along the way. Therefore, I also dedicate this work to my parents because without their love, guidance, and support this journey would not have been possible. God has truly blessed me. ii ACKNOWLEDGEMENTS I would like to take this opportunity to thank those who had a positive impact on my educational experience, as well as my life during my time spent as a graduate student. I am truly grateful to Dr. Byrd for giving me the opportunity to further my education under his guidance. It has been a blessing having Dr. Byrd as my major professor. Jim Taylor, Maria Zaccaro, David Russell, and Chris Maddox were instrumental in helping with my research. They braved thick Miscanthus fields, blistering heat, and gigantic ticks to help me conduct my research and for that I am truly grateful. Last but not least, my father, Earl Clardy, for helping me design and build the rhizotrons that were vital to my greenhouse research. iii TABLE OF CONTENTS DEDICATION .................................................................................................................... ii ACKNOWLEDGEMENTS ............................................................................................... iii LIST OF TABLES ............................................................................................................. vi LIST OF FIGURES .......................................................................................................... vii CHAPTER I. INTRODUCTION ................................................................................................1 Implications of Sterility .........................................................................................4 Comparison of Similar Grasses and Control Methods ..........................................8 Literature Cited ....................................................................................................17 II. RHIZOME INITIATION IN SEEDLING MISCANTHUS AND EFFECTS OF MOWING ON RHIZOME PRODUCTION ...................25 Abstract ................................................................................................................25 Introduction .........................................................................................................26 Learning from History ...................................................................................27 Clonal Plants ..................................................................................................28 Implications of Dispersal and Effects of Mowing Similar Plants .................32 Material and Methods ..........................................................................................36 Plant Material ................................................................................................36 Greenhouse Experiment ................................................................................36 Results and Discussion ........................................................................................38 Experiment one ..............................................................................................38 Experiment Two ............................................................................................39 Conclusions .........................................................................................................40 Literature Cited ....................................................................................................45 III. EVALUATION OF HERBICIDE EFFICACY AND APPLICATION TIMING FOR MISCANTHUS CONTROL ............................................49 Abstract ................................................................................................................49 Introduction .........................................................................................................51 Control Methods for Miscanthus ...................................................................53 iv Control Methods of Similar Perennial Plants ................................................57 Materials and Methods ........................................................................................61 Results and Discussion ........................................................................................63 Louisville Studies ..........................................................................................63 Dairy Unit Studies .........................................................................................65 Conclusions .........................................................................................................66 Literature cited .....................................................................................................72 APPENDIX A. SUPPLEMENTAL TABLES AND FIGUERS ..................................................77 v LIST OF TABLES 2.1 Means of cut and uncut Miscanthus seedlings, Plant Science Research Center greenhouse, Mississippi State University for 2014. .................42 2.2 Means for cut and uncut Miscanthus seedlings, Plant Science Research Center greenhouse, Mississippi State University for 2015. .................42 3.1 Miscanthus visual control as affected by chemical treatments 12 months after treatment (MAT) in a field study at Louisville, MS for 2013. ........................................................................................68