.............................................................................................................................. ii Co-Authorship.................................................................................................................... iv Acknowledgements............................................................................................................. v Table of

Multiple herbicide-resistant waterhemp ( Amaranthus tuberculatus (Moq.) J.D. Sauer) has limited herbicide options for Iowa row crop production. Soybean Glycine max (L.) Merr.) cultivars and corn Zea mays L.) hybrids resistant to 2,4-D, dicamba, glufosinate have provided more management. A probability-based survey of fields was conducted in fall 2019 wherein seeds were collected their susceptibi...