Cutleaf Evening Primrose Control with Postemergence Herbicides

Abstract

Cutleaf evening primrose, a member of the Onagraceae family and native to the southeastern United States, is found in agricultural fields, nursery crops, roadsides, landscaped areas, and no-till production systems. Cutleaf evening primrose management has become increasingly difficult due to its ability to endure control measures beyond the rosette stage. Greenhouse trials were conducted during the 2025 growing season to assess the efficacy of labeled burndown herbicides for cutleaf evening primrose control. Field-collected cutleaf evening primrose seedlings were transplanted into pots and placed in a greenhouse for evaluation at two growth stages. The recommended herbicide rates (at 1×) tested were glyphosate at 1,260 g ae ha ⁻¹ , glufosinate at 672 g ai ha ⁻¹ , 2,4-D at 1,065 g ae ha ⁻¹ , paraquat at 840 g ai ha ⁻¹ , and glyphosate + 2,4-D, respectively. Herbicides were sprayed at late rosette and bolting growth stages. Control of cutleaf evening primrose was evaluated at 7, 14, 21, and 28 d after herbicide treatments (DAT). Shoot dry biomass data were collected at 28 DAT. Application of 2,4-D either alone or mixed with glyphosate resulted in 98% to 100% control at both growth stages. Depending on the growth stage at which herbicides were applied, cutleaf evening primrose was controlled 66% to 75% with glyphosate, 60% to 81% with glufosinate, and <25% with paraquat. The highest dry biomass reductions (≥80%) were observed with glyphosate, 2,4-D, and glyphosate + 2,4-D applications at the rosette stage. The study revealed that 2,4-D-alone or with glyphosate provided near-complete control of cutleaf evening primrose.