Pink purslane (Portulaca pilosa) control with postemergence herbicides

Abstract

Pink purslane is often ranked as one of the most troublesome weeds in vegetable production systems in Georgia. Pink purslane encroachment along the field edges and in-field of agronomic crops has recently increased. Postemergence (POST) herbicides are an effective component of agronomic crop weed management. However, little research has addressed pink purslane control in agronomic crops. Therefore, greenhouse and field studies were conducted from 2022 to 2023 in Tifton, Georgia, to evaluate the response of pink purslane to POST herbicides commonly used in agronomic crops. Greenhouse screening provided preliminary evidence whereby 13 of the 21 POST herbicides evaluated provided ≥ 80% above-ground biomass reductions. These 13 herbicides were then used for field studies. Results from the field studies, pooled across two locations, indicated only 3 of the 13 herbicides provided above-ground biomass reductions ≥ 70% compared to the non-treated control. These herbicides included atrazine at 1682 g ai ha-1, glufosinate at 656 g ai ha-1, and lactofen at 219 g ai ha-1 with 79%, 70%, and 83% biomass reduction, respectively (P < 0.05). This research suggests that many of the POST herbicides used in agronomic crops will not effectively control pink purslane. Thus, when trying to manage pink purslane with POST herbicides in agronomic crops, growers should plant crops/cultivars tolerant of either atrazine, glufosinate, and/or lactofen.