The acreage of soybeans treated with postemergence herbicides for broadleaf weed control has increased over the past few years. This trend has occurred because of inconsistent control of cocklebur (Xanthium pensylvanicum Wallr), giant ragweed (Ambrosia trifida L.), jimsonweed (Datura stramonium L.), and morningglory (Ipomoea hederacea (L.) Jacq. and Ipomoea purpurea (L.) Roth) with soil applied herbicides.
Martin, James R. and Witt, W. W., "Response of Soybean Cultivars to Postemergence Herbicides" (1982). Agronomy Notes. 105.