Postattachment Control of Swamp Dodder (Cuscuta gronovii) in Cranberry (Vaccinium macrocarpon) and Carrot (Daucus carota)

Abstract

In a 3-y field study, the isopropylamine salt of glyphosate [N-(phosphonomethyl)glycine] at 1.7 kg ai/ha and sulphosate [trimethyl sulfonium salt of N-(phosphonomethyl)glycine] at three rates, a split application of 0.6 + 0.6 or single applications of 1.1 or 1.7 kg ai/ha satisfactorily controlled swamp dodder (Cuscuta gronoviiWilld. ex R. & S. # CVCGR) in cranberry (Vaccinium macrocarponAit.). While none of these treatments decreased cranberry yield, sulphosate at 1.1 or 1.7 kg/ha did increase yield. Glyphosate at 0.4 kg/ha applied late in the life cycle of carrot (Daucus carotaL.) when swamp dodder was in full flower satisfactorily controlled swamp dodder while increasing yield of carrot roots. Glyphosate applied early in the life cycle of carrot and dodder controlled swamp dodder but lowered yield of carrot roots.