doi: 10.5660/WTS.2025.14.4.4 Citation BibTeX RIS Mendeley

Comparison of species and distribution of weeds in upland and paddy soybean fields in Korea

Comparison of species and distribution of weeds in upland and paddy soybean fields in Korea

• Yeon-Ho Park (National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• Jeongran Lee (National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• Kyu-Hui Lee (National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• Eun-Hye Lee (National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)
• Jin-Won Kim (National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea)

This study was conducted to investigate the differences in weed emergence between upland and paddy field soybean fields, to provide the knowledge essential for effective weed control in paddy soybean cultivation. Weed emergence in upland and paddy soybean fields in Korea was surveyed from 2020 to 2023. The frequency and coverage were analyzed, and importance values were calculated based on relative frequency and relative coverage. In total, 210 species were observed across 339 upland soybean sites, whereas 88 species were observed in 74 paddy soybean sites. In both upland and paddy soybean fields, members belonging to Asteraceae, Poaceae, Cyperaceae, and Polygonaceae families accounted for the highest proportion of observed weeds. Based on importance values, 20 weeds were identified as major weeds in upland and paddy soybean fields, 11 of which were common to both cropping systems. Differences in importance value was calculated for each weed, and cropping system-specific weeds were designated when the difference was greater than fivefold. Elusine indica was identified as an upland soybean-specific weed, whereas Eleocharis kuroguwai, Persicaria hydropiper, Fimbristylis miliacea, and Aeschynomene indica were identified as paddy soybean-specific weeds. According to the list of registered soybean herbicides provided by the Pesticide Safety Information System (RDA), only four active ingredients are available for P. hydropiper and A. indica, two species considered problematic in paddy soybean cultivation. Furthermore, the use of these ingredients in soybean fields is strictly limited. A review of the legal aspects of herbicide use and registration of new herbicides is essential for improving soybean production, as paddy soybeans are gaining increasing importance within total soybean production in Korea.