In the absence of an effective alternative to methyl bromide (MeBr), weeds cause a significant economic loss in bell pepper production. A study was conducted to evaluate the efficacy and economics of PRE followed by (fb) POST-directed (POST-DIR) herbicide programs compared with MeBr for weed control in low-density polyethylene (LDPE) mulched bell pepper production. Imazosulfuron at 0.112, 0.224, and 0.336 kg ai ha⁻¹ and S-metolachlor at 1.6 kg ai ha⁻¹ were PRE-applied fb POST-DIR applied mixture of trifloxysulfuron halosulfuron at 0.008 and 0.027 kg ai ha⁻¹, respectively, at 4 wk after transplanting (WATP). The standard MeBr treatment (67 and 33% mixture of MeBr chloropicrin) was applied at 390 kg ai ha⁻¹. In addition, a weed-free (hand weeding) and a non-treated control were used for comparison. S-metolachlor-containing herbicide program controlled Palmer amaranth ≥ 90%, large crabgrass ≥ 78%, and yellow nutsedge ≥ 90%, which were comparable to MeBr. After POST-DIR herbicide application, bell pepper was injured ≥ 17% with the S-metolachlor-containing herbicide program at 6 WATP; however, the crop later recovered. Marketable bell pepper yield in plots treated with S-metolachlor (≥ 29.9 ton ha⁻¹) was comparable to those treated with MeBr. Economic evaluation of the imazosulfuron herbicide programs demonstrated the loss of ≥ $7,300 ha⁻¹. Conversely, the S-metolachlor-containing herbicide program was profitable with a net return of $9,912 ha⁻¹. In addition, the S-metolachlor herbicide program generated a net profit of $173 ha⁻¹ compared to the MeBr application. Therefore, PRE-applied S-metolachlor fb POST-DIR applied trifloxysulfuron halosulfuron is a potential alternative to MeBr for weed management in LDPE-mulched bell pepper production given the weed spectrum evaluated in this study.

Nomenclature: Halosulfuron; imazosulfuron; methyl bromide (MeBr); S-metolachlor; trifloxysulfuron; large crabgrass, Digitaria sanguinalis (L.) Scop. DIGSA; Palmer amaranth, Amaranthus palmeri S. Wats. AMAPA; yellow nutsedge, Cyperus esculentus L. CYPES; bell pepper, Capsicum annum L. ‘Heritage'.

En ausencia de una alternativa efectiva a methyl bromide (MeBr), las malezas causan pérdidas económicas significativas en la producción de pimentón. Se realizó un estudio para evaluar la eficacia y los parámetros económicos de programas de herbicidas PRE seguidos de (fb) POST-dirigido (POST-DIR) y compararlos con MeBr para el control de malezas en coberturas de polyethylene de baja densidad (LDPE) en la producción de pimentón. Imazosulfuron a 0.112, 0.224, y 0.336 kg ai ha⁻¹ and S-metolachlor a 1.6 kg ai ha⁻¹ fueron aplicados PRE fb una mezcla de trifloxysulfuron halosulfuron a 0.008 y 0.027 kg ai ha⁻¹ aplicados POST-DIR, respectivamente, a 4 semanas después del trasplante (WATP). El tratamiento estándar con MeBr (mezcla de MeBr chloropicrin a 67 y 33%) fue aplicado a 390 kg ai ha⁻¹. Adicionalmente, un testigo libre de malezas (deshierba manual) y un testigo sin tratamiento fueron usados para fines de comparación. El programa de herbicidas que contenía S-metolachlor controló Amaranthus palmeri ≥ 90%, Digitaria sanguinalis ≥ 78%, y Cyperus esculentus ≥ 90%, lo que fue comparable a MeBr. Después de la aplicación POST-DIR de herbicidas, el pimentón sufrió daño ≥ 17% con el programa de herbicidas que contenía S-metolachlor, a 6 WATP, aunque el cultivo se recuperó posteriormente. En par