Purple Moonflower Control with Postemergence Herbicides Eric P. Prostko and Daniel S. Price

1. Aim Callisto Atrazine Direx + MSMA Purple Moonflower Control with Postemergence Herbicides Eric P. Prostko and Daniel S. Price Associate Professor/Extension Weed Specialist and Crisp County Extension Agent The University of Georgia INTRODUCTION Purple moonflower (Ipomoea turbinata) is becoming common in many agricultural fields in Georgia. Because this weed has typically not been a major problem, growers are unfamiliar with its identification and control. Unfortunately, limited information on the control of this weed is available. Therefore, the objective of this research was to evaluate numerous postemergence herbicides for the control of purple moonflower in the greenhouse. RESULTS AND DISCUSSION Results are presented in Figures 1 and 2. The following treatments provided ≥ 90% visual control and biomass reduction: Reflex (3); Cobra (4); Ultra Blazer (5); Callisto (6); Atrazine (8); Aim (12); 2,4-D amine (13); Evik (19); Roundup P-Max + Aim (21); Roundup P-Max + Valor (22); Direx + MSMA (23); Direx + MSMA + Aim (24); Direx + MSMA + Valor (25). The following treatments provided 80-89% visual weed control and biomass reduction: Ignite (10); 2,4-DB (14); Roundup P-Max + Staple (20); and Gramoxone Inteon (26). Treatments that provided 70-79% visual control and biomass reduction included Laudis (7) and Cadre (9). All other treatments provided less than 70% visual control and biomass reduction. MATERIALS AND METHODS Purple moonflower seed were collected in the fall of 2008 from a commercial corn field in Crisp County. The seed were air dried at room temperature for 40 days. Prior to planting in the greenhouse, the seed were mechanically scarified with sandpaper to improve germination. Five seeds were planted into Styrofoam cups or plastic pots filled with Miracle-Gro potting mix. After emergence, the pots were thinned to contain 1 moonflower plant. Once the plants reached the 2 leaf stage (3-6” tall), 26 herbicide treatments were applied using a spray chamber calibrated to deliver 15 GPA using 8002XR nozzle tips. Each treatment was replicated 3 times and the experiment was repeated. Visual weed control ratings (0-100%) and above-ground fresh weight biomass data were collected 10 days after treatment. The data for each experiment were combined and means were separated using Fischer’s Protected LSD Test (P = 0.10). • NTC • Strongarm @ 0.45 oz/A + NIS • Reflex @ 16 oz/A + NIS • Cobra @ 12.5 oz/A + COC • Ultra Blazer @ 16 oz/A + NIS • Callisto @ 3 oz/A + COC + 28% UAN • Laudis @ 3 oz/A + COC + 28% UAN • Atrazine @ 48 oz/A + COC • Cadre @ 4 oz/A + COC • Ignite @ 22 oz/A • Linex @ 24 oz/A + NIS • Aim @ 1.5 oz/A + COC • 2,4-D amine @ 16 oz/A • 2,4-DB @ 18 oz/A + COC • Status @ 5 oz/A + NIS • Roundup PowerMax @ 22 oz/A • Staple LX @ 2.7 oz/A + NIS • Envoke @ 0.1 oz/A + NIS • Evik @ 2 lb/A + NIS • Roundup P-Max @ 22 oz/A + Staple LX @ 2.7 oz/A • Roundup P-Max @ 22 oz/A + Aim @ 1.5 oz/A • Roundup P-Max @ 22 oz/A + Valor @ 2 oz/A • Direx @ 32 oz/A + MSMA @ 40 oz/A + NIS • Direx @ 32 oz/A + MSMA @ 40 oz/A + Aim @ 1 oz/A + NIS • Direx @ 32 oz/A + MSMA @ 40 oz/A + Valor @ 1 oz/A + NIS • Gramoxone Inteon @ 32 oz/A + NIS NIS @ 0.25% v/v (Induce) COC @ 1% v/v (Agridex)