Joseph Mettler Successfully Defends M.S. Thesis

Joseph Mettler successfully defended his M.S. thesis in Plant Sciences at North Dakota State University (NDSU) and presented a research seminar on November 15, 2021. His thesis title is “Herbicide Screening in Industrial Hemp (Cannabis sativa L.) Production,” and his advisor is Dr. Kirk Howatt, associate professor and annual weeds scientist in the Department of Plant Sciences.

There are currently no herbicides registered for use in industrial hemp, so Mettler researched industrial hemp response to pre- and post-emergence herbicides. A broad preliminary greenhouse screening was conducted on many pre- and post-emergence herbicides, and then seven of each of the herbicide types were selected to be further evaluated in the field. Several pre-emergence herbicides showed promise, as some resulted in less than 20% visible injury with no negative, and even some positive, impacts on seed yield. These could be pursued for registration. Post-emergence herbicides were too injurious to hemp and showed little promise in being utilized in the hemp industry.

Mettler is originally from Swanville, Minnesota, and completed his B.S. at NDSU with a double major in Crop and Weed Sciences (advised by Dr. Edward Deckard) and Natural Resources Management (advised by Dr. Carolyn Grygiel) and a minor in Soil Science. He was hired as a research specialist in the NDSU weed science program and was inspired to pursue his Master’s degree alongside his work.

His advice for current and future graduate students is to “get involved and become good friends with your statistician.” 

He is continuing to work in the weed science program and plans to “live life to the fullest.”

Mettler’s graduate committee members were Howatt, Dr. Burton Johnson, Dr. Marisol Berti, and Bryan Hanson from the Langdon Research Extension Center.

Author: Kamie Beeson
Editor: Karen Hertsgaard