Field studies were conducted in 2013 at Houlka, MS and in 2014 at Houston, MS to evaluate herbicide programs for yellow nutsedge control and sweetpotato crop response. Treatments consisted of halosulfuron-methyl at 13, 26, and 34 g ai ha⁻¹ 2 wk after transplanting (WAP) followed by (fb) S-metolachlor at 856 g ai ha⁻¹ 4 WAP; a sequential application of 13 g ha⁻¹ halosulfuron-methyl at 2 and 4 WAP; and halosulfuron-methyl at 13 g ha⁻¹ plus either S-metolachlor or 1,123 g ai ha⁻¹ alachlor 2 WAP. Crop injury in treated plots ranged from 29 to 44% at 3 WAP. Injury from the sequential application increased slightly between 3 and 5 WAP (29 to 38%), but decreased between 5 WAP and harvest (19%). Injury with all other treatments was unchanged from 5 WAP through harvest. The sequential application of halosulfuron-methyl provided the greatest control of yellow nutsedge throughout the duration of the study with ≥ 83% control from 5 WAP through harvest. Control from all other treatments ranged from 38 to 78% from 5 WAP through harvest. No. 1, canner, and marketable sweetpotato yields of the hand-weeded check were 19,900; 7,140; and 27,590 kg ha⁻¹, respectively. No. 1, canner, and marketable yields of the weedy check were only 15, 51, and 25% of the hand-weeded check, respectively. With the exception of halosulfuron-methyl at 13 g ha⁻¹ fb S-metolachlor, which was similar to the weedy check, no. 1 and marketable yields with all treatments were greater than the weedy check, but less than the weed-free check. A sequential application of halosulfuron-methyl and a tank mix of halosulfuron-methyl plus S-metolachlor would fit well into an overall yellow nutsedge management program in sweetpotato. However, as halosulfuron-methyl is not registered for use in sweetpotato, growers must continue to manage yellow nutsedge primarily with crop rotation and sanitation.

Nomenclature: Alachlor; halosulfuron-methyl; S-metolachlor; yellow nutsedge, Cyperus esculentus L.; sweetpotato, Ipomoea batatas L. Lam. ‘Beauregard'.

Se realizaron experimentos de campo en 2013 en Houlka, Mississippi, y en 2014 en Houston, Mississippi, para evaluar programas de herbicidas para el control de Cyperus esculentus y la respuesta del cultivo batata. Los tratamientos consistieron en halosulfuron-methyl a 13, 26, y 34 g ai ha⁻¹ 2 semanas después del trasplante (WAP) seguido de (fb) S-metolachlor a 856 g ai ha⁻¹ 4 WAP; una aplicación secuencial de 13 g ha⁻¹ de halosulfuron-methyl a 2 y 4 WAP; y halosulfuron-methyl a 13 g ha⁻¹ más S-metolachlor o 1,123 g ai ha⁻¹ de alachlor 2 WAP. El daño en el cultivo en las parcelas tratadas varió de 29 a 44% a 3 WAP. El daño de la aplicación secuencial aumentó ligeramente entre 3 y 5 WAP (29 a 38%), pero decreció entre 5 WAP y la cosecha (19%). El daño causado por todos los demás tratamientos se mantuvo sin cambios en el período entre 5 WAP y la cosecha. La aplicación secuencial de halosulfuron-methyl brindó el mayor control de C. esculentus durante la duración del estudio con ≥83% de control entre 5 WAP y la cosecha. El control con los otros tratamientos varió de 38 a 78% entre 5 WAP y la cosecha. Los rendimientos No. 1, para enlatado, y comercializable de la batata en el testigo con deshierba manual fueron 19,900; 7,140; y 27,590 kg ha⁻¹, respectivamente. Los rendimientos No. 1, para enlatado, y comercializable del testigo sin deshierba fueron solamente el 15, 51, y 25% en comparación con el testigo con deshierba manual. Con la excepción de halosulfuron-methyl a 13 g ha⁻¹ fb S-metolachlor, el cual fue similar al testigo sin deshierba, los rendimientos No. 1 y comercializab