Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2018 The influence of multiple herbicide resistance on growth and development of Amaranthus tuberculatus and the efficacy of the very long chain fatty acid-inhibiting herbicides on multiple herbicide-resistant Amaranthus tuberculatus; Investigating a putative 4-hydroxylphenylpyruvate dioxygenase-inhibiti Eric Alexander Lyle Jones Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Agricultural Science Commons, Agriculture Commons, and the Agronomy and Crop Sciences Commons Recommended Citation Jones, Eric Alexander Lyle, "The influence of multiple herbicide resistance on growth and development of Amaranthus tuberculatus and the efficacy of the very long chain fatty acid-inhibiting herbicides on multiple herbicide-resistant Amaranthus tuberculatus; Investigating a putative 4-hydroxylphenylpyruvate dioxygenase-inhibiti" (2018). Graduate Theses and Dissertations. 16386. https://lib.dr.iastate.edu/etd/16386 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. The influence of multiple herbicide resistance on growth and development of Amaranthus tuberculatus and the efficacy of the very long chain fatty acid-inhibiting herbicides on multiple herbicide-resistant Amaranthus tuberculatus; Investigating a putative 4-hydroxylphenylpyruvate dioxygenase-inhibiting herbicide–resistant Ambrosia trifida population by Eric Alexander Lyle Jones A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Agronomy (Weed Science) Program of Study Committee: Micheal D.K. Owen, Co-Major Professor Robert G Hartzler, Co-Major Professor Allen D. Knapp The student author, whose presentation of the scholarship herein was approved by the program of study committee, is solely responsible for the content of this thesis. The Graduate College will ensure this thesis is globally accessible and will not permit alterations after a degree is conferred. Iowa State University Ames, Iowa 2018 Copyright © Eric Alexander Lyle Jones, 2018. All rights reserved. ii DEDICATION I dedicate my thesis to Gary Park, Robert Park, and Turner Jones. I love and greatly miss you three. While I may not have adopted the “outlaw” lifestyle as most Park and Jones men are destined to, I hope you all are looking down upon me with smiling faces. You all shaped me into the person I am today. The many fond memories I have with you three will continue to bring me joy. You all left too early and I am eager until we meet again. iii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS iv ABSTRACT vi CHAPTER 1 GENERAL INTRODUCTION AND LITERAURE REVIEW 1 CHAPTER 2 INFLUENCE OF MULTIPLE HERBICIDE RESISTANCE ON GROWTH AND DEVELOPMENT IN AMARANTHUS TUBERCULATUS 12 CHAPTER 3 INVESTIGATING EFFICACY OF SELECTED VERY LONG CHAIN FATTY ACID-INHIBITING HERBICIDES ON AMARANTHUS TUBERCULATUS POPULATIONS WITH EVOLVED MULTIPLE HERBICIDE RESISTANCES 36 CHAPTER 4 INVESTIGATING A PUTATIVE HPPD-RESISTANT AMBROSIA TRIFIDA POPULATION 56 CHAPTER 5 GENERAL CONCLUSIONS 72 BIBLIOGRAPHY 75 iv ACKNOWLEDGEMENTS Foremost, I would like to address my Mother, Leah Jones, for providing me a life that only the finest people deserve. From cleaning my wrestling clothes in years past to helping me figuring out the “real world”, my Mother has been my number one consultant. Secondly, I would like to address my father, Terry Jones. My father taught me how to have a strong work ethic and to never half-heartedly finish a job and be satisfied with the outcome. I am forever grateful for my parent’s guidance and love during my presently short journey of life. Next, I would like to thank my committee consisting of Drs. Micheal Owen, Robert Hartzler, Allen Knapp, and John Hinz. I will be forever grateful to be the last “gradual” student of Dr. Owen’s prestigious lab group. I was granted the freedom to study my specific interests in weed science. I will always appreciate the guidance you offered and the challenge of your hands-off approach. It has also been a pleasure to share a similar lineage, interests, and hobbies with my major professor. I would like to thank Dr. Hartzler for challenging my understanding of weed science topics and allowing me to assist in teaching his famed weed identification class (Agronomy 217). While I may not have been the greatest teaching assistant, I would like to say it was a great opportunity to teach future agronomists a valuable skill. It should be mentioned our weekly chats (discussion, civil arguments, etc.) were never taken in vain; you are a great teacher, mentor, and “nozzle head” (despite your many notions that you are indeed not!). v Dr. Knapp provided me with my basic understanding of plant physiology (Agronomy 316), which did not seem basic at the time. Prior knowledge of the two photosystems, carotenoids, and plastoquinones has made learning herbicide physiology easier than expected. Your helpful comments and insights were invaluable to writing this thesis and journal manuscripts. I would like to thank Dr. John Hinz for exposing me to the addictive subject of “weed science”. What may have been an internship to another Iowa State University student became my lifelong passion. I am glad you decided to give this “city slicker” a chance to prove himself! I would like to extend my thanks to Angela Rieck-Hinz as well for contributing to improve my interest in agronomy and weed science. Finally, I would like to acknowledge Damian (Damos) Franzenburg, James (Jimmi) Lee, Iththiphonh (Alex) Macvilay, James (Lux-um-burger) Lux, and Daniel (Dandy Danielson) Kohlhase. I am certain without the help and guidance from all of you I would not have made it to this point. It is doubtful I will ever be able to work with another group that will be able to rival the fun and memories I established with you all. vi ABSTRACT Iowa farmers rely mainly on herbicides for weed management. Inconsistent and unsatisfactory weed control is being realized as the spread of herbicide-resistant weed populations has increased. Populations of waterhemp (Amaranthus tuberculatus (Moq.) J.D. Sauer) and giant ragweed (Ambrosia trifida L.) have evolved resistance to glyphosate and other herbicides commonly used in crop fields. This research focuses on the growth and development of multiple herbicide-resistant waterhemp and assessing the evolution of new herbicide-resistant waterhemp and giant ragweed populations. Significant differences in growth, flowering, accumulated biomass, and seed production were detected when the multiple herbicide-resistant waterhemp populations were compared to a herbicide-susceptible waterhemp population. While statistically significant differences were detected, the small differences are not likely to select herbicide-susceptible waterhemp populations over MHR waterhemp populations. Thus, it can be concluded that plants with multiple herbicide resistances are not likely incurring a fitness penalty and may remain in the agroecosystem. Currently, very long chain fatty acid- and 4-hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27)-inhibiting herbicides are still efficacious on many waterhemp and giant ragweed populations, respectively. Since herbicides impart such a large selection pressure on weed populations, the recurrent use of specific herbicides may decrease efficacy longevity as only herbicide-resistant individuals will remain. 1 CHAPTER 1. GENERAL INTRODUCTION Introduction Weeds are plants with the ability to colonize areas disturbed by man, a consequence of plant domestication (Harlan 1992, Dekker 2011). Every control tactic that has been employed to eradicate weeds has failed (Gressel et al. 2016). Herbicides, once considered the end-all-be- all weed control tools, are becoming less efficacious as the evolution of herbicide-resistant weeds increases. In addition to selecting for herbicide-resistant weeds, herbicides have caused shifts in weed population demographics to more resilient weed species (Keeley 1987). If farmers want to continue to manage weeds successfully, basic weed biology must be learned (Swanton and Weise 1991). An integrated weed management (IWM) approach will consist of “many little hammers” rather than “one big hammer”, meaning many less efficacious tactics used together will provide high efficacy with relatively low selection pressure (Liebman and Gallandt 1997). Little hammer tactics, including tillage, row spacing, cover crops, and utilization of grainivores, all rely on knowledge of weed biology in order to kill weeds efficiently (Liebman and Gallandt 1997, Harrison et al. 2003). Herbicide Resistance Besides tillage, herbicides provide the highest selection pressure for evolution in agricultural weeds (Gressel 2009, Zelaya and Owen 2005). Select individuals within the population possess natural mutations that allow the plant to survive a lethal herbicide dose. When the herbicide is applied, herbicide-susceptible individuals will die and herbicide-resistant individuals will produce seeds and add to the soil seed bank. Recurrent application of the same herbicide(s) will likely lead to the evolution of a herbicide-resistant weed population. 2 Weeds with multiple herbicide