Speaker
Description
Exotic weeds have invaded into agroecosystem including crop fields and field margin area, causing various damages including losses in crop yield and vegetation diversity. We conducted a three-years field study to evaluate the impacts of exotic weeds on vegetation in field margin area and soybean yield. Exotic weed species invaded into soybean field such as velvetleaf, speen amarath, and common ragweed competed for light, resulting in reduced light transmittance into soybean canopy, led to stem elongation and reduced branching, and thus resulted in a significant soybean yield loss. Rectangular hyperbolic model enabled to predict soybean yield losses caused by both single and multiple weed interference. Exotic weeds invaded into field margin areas such as bur cucumber, giant ragweed, and Japanese hop grew faster and more vigorously than background vegetation and caused a significant reduction in perennial plant species, ultimately resulting in a significant loss of vegetation diversity. Our findings clearly demonstrate that invasive exotic weeds can compete against not only crops but also native plant species. A long-term strategy is required to manage invasive exotic weeds in agroecosystem based on understanding of physiologic and ecologic aspects of exotic weeds.
| Keywords | Exotic weed; Crop-weed competition; Vegetation diversity; Weed management; Soybean |
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