American burnweed is an early successional summer annual species in the Asteraceae. This weed is a poor competitor; however, it rapidly colonizes disturbed and low-maintenance areas, especially following an environmental disturbance. Recently, turfgrass managers have made adjustments to maintenance practices to satisfy budget requirements and address environmental concerns. This has resulted in reduced mowing frequency in some golf course rough and out-of-play turf areas, and has allowed establishment of broadleaf weed species such as American burnweed which would otherwise be controlled by frequent mowing. The purpose of this study was to evaluate PRE and POST herbicide treatments for American burnweed control in an unmown bermudagrass golf course rough. Single PRE applications of simazine at 2.24 kg ai ha⁻¹ and indaziflam at 0.06 kg ai ha⁻¹ provided > 80% American burnweed control 24 wk after treatment (WAT) in 2012 and 2013. Sequential combination applications of liquid formulations of dimethenamid-p pendimethalin (2.24 1.68 kg ai ha⁻¹) provided 95% American burnweed control 24 wk after initial treatment in 2012 and 2013. Other PRE treatments did not provide consistent control of American burnweed across rating dates and years. Regardless of year, four POST treatments provided ≥ 87% control at 8 and 16 WAT. These included thiencarbazone foramsulfuron halosulfuron (0.02 0.044 0.07 kg ai ha⁻¹), thiencarbazone iodosulfuron dicamba (0.02 0.15 0.005 kg ai ha⁻¹), triclopyr clopyralid (0.88 0.32 kg ai ha⁻¹), and sulfentrazone metsulfuron (0.4 0.04 kg ai ha⁻¹). Several PRE and POST American burnweed control solutions exist for low maintenance bermudagrass areas. Future research should continue to screen other herbicides for control efficacy and focus on application timing to balance season-long control with minimal chemical inputs.

Nomenclature: Clopyralid; dicamba; dimethenamid-p; foramsulfuron; halosulfuron; indaziflam; iodosulfuron; metsulfuron; pendimethalin; simazine; sulfentrazone; thiencarbazone; triclopyr; American burnweed, Erechtites hieraciifolia (L.) Raf. ex DC.; bermudagrass, Cynodon dactylon (L.) Pers.

Erechtites hieraciifolia es una especie anual de verano de sucesión temprana de la familia Asteraceae. Esta maleza es un competidor pobre. Sin embargo, coloniza rápidamente áreas perturbadas y con poco mantenimiento, especialmente después de una perturbación ambiental. Recientemente, especialistas en el manejo de céspedes han hecho ajustes a las prácticas de manejo para satisfacer requisitos de presupuesto y para responder a preocupaciones ambientales. Esto ha resultado en una reducción en la frecuencia de chapia en áreas fuera-de-juego en campos de golf (‘rough’), lo que ha permitido el establecimiento de especies de malezas de hoja ancha tales como E. hieraciifolia, las cuales serían controladas con una chapia frecuente. El propósito de este estudio fue evaluar tratamientos de herbicidas PRE y POST para el control de E. hieraciifolia en un rough de un campo de golf con césped bermuda sin chapia. Aplicaciones PRE simples de simazine a 2.24 kg ai ha⁻¹ e indaziflam a 0.06 kg ai ha⁻¹ brindaron >80% de control de E. hieraciifolia a 24 semanas después del tratamiento (WAT) en 2012 y 2013. Aplicaciones secuenciales de combinaciones de formulaciones líquidas de dimethenamid-p pendimethalin (2.24 1.68 kg ai ha⁻¹) brindaron 95% de control de E. hieraciifolia a 24 semanas después del tratamiento inicial en 2012 y 201