Environmental Triggers of Winter Annual Weed Emergence in the Midwestern United States
This research study examined how soil temperature and moisture affects the emergence of nine species of weed in the Midwest, including Virginia Pepperweed. In July of 2010 and 2011, 1000 seeds were planted in different sites in the state of Nebraska. Soil moisture and temperature was measured at the constant depth of 2 centimeters. Emerging seedlings were subsequently counted and removed weekly until no emergence was observed in the Fall. The same protocol was done by planting in the Winter and removed weekly until no emergence in the Spring. The researchers found that 70% of the Virginia Pepperweed seedlings successfully emerged in late summer/fall while the remaining 30% emerged in the Spring. This ability to emerge in Fall and Spring allows the species to be classified as "facultative winter annual weeds." The overall results of the research provides knowledge on emergence of weeds in the winter. The models that the researchers successfully created will allow better weed management strategies in the future. For example, in the case of facultative winter annuals like Virginia Pepperweed, the optimal time for management strategies is early Spring.
Citation:
Werle, R; Bernards, ML; Arkebauer, TJ; Lindquist, JL. 2014. Environmental Triggers of Winter Annual Weed Emergence in the Midwestern United States. Weed Science. 62(1):83-96. DOI: 10.1614/WS-D-13-00091.1
