Methyl bromide (MeBr), a widely used soil fumigant in tomato production, has been banned for ordinary agricultural uses. In the absence of MeBr, a viable alternative is imperative for weed control and prevention of economic loss in tomato production. A field study was conducted in the summers of 2010 and 2011 at Fayetteville, AR, to compare the efficacy and economics of herbicide programs consisting of pre-transplant followed by (fb) post-transplant herbicides in low-density polyethylene (LDPE) mulched tomato. Pre-transplant imazosulfuron at 0.112, 0.224, and 0.336 kg ai ha⁻¹ and S-metolachlor at 1.6 kg ai ha⁻¹ were fb a post-transplant mixture of trifloxysulfuron plus halosulfuron at 0.008 and 0.027 kg ai ha⁻¹ at 4 wk after transplant (WATP). The standard MeBr treatment (2:1 mixture of MeBr plus chloropicrin at 390 kg ai ha⁻¹), weed-free (hand weeding) control, and nontreated weedy check were used for comparison. Pre-transplant S-metolachlor fb post-transplant herbicides controlled Palmer amaranth ≥ 89%, large crabgrass ≥ 88%, and yellow nutsedge ≥ 90%, which was comparable to the control with MeBr. Tomato recovered the injury (≤ 19% at 6 WATP) from post-transplant herbicides in the later weeks. S-metolachlor–containing herbicide programs yielded marketable tomato fruit comparable to the yield with MeBr. Economic evaluation of the herbicide programs demonstrated a net return of $3,758.50 ha⁻¹ from the S-metolachlor–containing herbicide program in LDPE-mulched tomato. Likewise, this herbicide program showed minimum loss of ≤ $671.61 ha⁻¹ in net return relative to MeBr. In conclusion, a herbicide program consisting of pre-transplant S-metolachlor fb post-transplant trifloxysulfuron plus halosulfuron is a viable alternative to MeBr for weed control and marketable yield in LDPE-mulched tomato production.

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; tomato, Solanum lycopersicum L. ‘Amelia'.

Methyl bromide (MeBr), un fumigante ampliamente usado en la producción de tomate, ha sido prohibido para usos agrícolas ordinarios. En ausencia de MeBr, una alternativa viable es imperativa para el control de malezas y la prevención de pérdidas económicas en la producción de tomate. En Fayetteville, AR, durante los veranos de 2010 y 2011, se realizó un estudio de campo para comparar la eficacia y la economía de programas de herbicidas para tomate que consistieron de herbicidas pre-trasplante seguidos de (fb) herbicidas pos-trasplante en coberturas plásticas de polyethylene de baja densidad (LDPE). Imazosulfuron en pre-trasplante a 0.112, 0.224, y 0.336 kg ai ha⁻¹ y S-metolachlor a 1.6 kg ai ha⁻¹ fueron fb una mezcla pos-trasplante de trifloxysulfuron más halosulfuron a 0.008 y 0.027 kg ai ha⁻¹ a 4 semanas después del trasplante (WATP). Para fines de comparación, se usaron el tratamiento estándar de MeBr (mezcla 2:1 de MeBr más chloropicrin a 390 kg ai ha⁻¹), un testigo limpio de malezas (deshierba manual), y un testigo enmalezado sin tratamiento. S-metolachlor en pre-trasplante fb herbicidas pos-trasplante controlaron Amaranthus palmeri ≥89%, Digitaria sanguinalis ≥88%, y Cyperus esculentus ≥90%, lo que fue comparable al control con MeBr. El tomate se recuperó del daño (≤19% a 6 WATP) causado por los herbicidas pos-tr