A Laboratory Exercise for Teaching Depth of Weed Emergence Concepts

Abstract

The influence of weed seed burial depth on seedling emergence is a common and important topic in undergraduate weed science courses. A laboratory exercise was developed at Iowa State University to actively demonstrate changes in weed seedling emergence with increased seed-burial depth. Twenty-five ivyleaf morningglory and wild mustard seeds were sown in pots in monoculture, and the number of emerging seedlings was counted for 3 wk. The results from two semesters were analyzed to determine whether the experiment was successful in meeting its intended outcomes. Assessment of student perceptions and attitudes indicated that the activity increased students' understanding of weed biology; improved students' critical thinking, reading, and writing skills; and improved students' ability to make scientific observations, interpret graphical information, and analyze and summarize research data.

Using a Pervasive Invader for Weed Science Education

“…After exercise completion, student evaluations were obtained using the online software Survey Monkeye (Portland, OR; used in 2011) and in-class surveys (in 2012). Students were asked to rate nine statements reflecting their overall impressions about the exercise on a scale of 1 to 5, with 1 being strong agreement, 3 as neutral, and 5 as strong disagreement (Gibson and Liebman 2004).…”

“…Courses that offer diverse curricula focused on locally important weed issues may improve the students' ability to master complex subjects. In particular, weed science courses that include experimentation with living weeds have been reported to enhance critical thinking skills and increase student understanding of important weed science concepts (Gibson and Liebman 2004). Using weed species that pose the greatest threat to United States' resources would help prepare future weed science professionals to control invasive weeds.…”

Experiential Learning Activities in the Weed Science Classroom

“…These exercises help students understand weed-cropsoil interactions by decomposing a system into components. For example, in Gibson and Liebman (2004), burial depth is shown to influence both germination potential and recruitment of two weeds species. Similarly, a laboratory exercise has been developed at the University of Wisconsin-Madison, and used at the University of Maine, that demonstrates the incorporation of experiential learning principles to facilitate a systems-level understanding of weed community, recruitment, and their potential impact on crop productivity (Luschei 2002).…”