Novel management strategies for controlling smutgrass have potential to influence sward dynamics in bahiagrass forage systems. This experiment evaluated population shifts in bahiagrass forage following implementation of integrated herbicide and fertilizer management plans for controlling smutgrass. Herbicide treatments included indaziflam applied PRE, hexazinone applied POST, a combination of PRE + POST herbicides, and a nonsprayed control. Fertilizer treatments included nitrogen, nitrogen + potassium, and an unfertilized control. The POST treatment reduced smutgrass coverage regardless of PRE or fertilizer application by the end of the first season and remained low for the 3-yr duration of the experiment (P < 0.01). All treatments, including nontreated controls, reduced smutgrass coverage during year 3 (P < 0.05), indicating that routine harvesting to remove the biomass reduced smutgrass coverage. Bahiagrass cover increased at the end of year 1 with POST treatment (P < 0.01), but only the POST + fertilizer treatment maintained greater bahiagrass coverage than the nontreated control by the end of year 3 (P < 0.05). Expenses associated with the POST + fertilizer treatment totaled US$348 ha−1 across the 3-yr experiment. Other smutgrass control options could include complete removal of biomass (hay production) and pasture renovation, which can cost 3-fold or greater more than POST + fertilizer treatment. Complete removal of biomass may reduce smutgrass coverage by removing mature seedheads, but at a much greater expense of US$2,835 to US$5,825 ha−1, depending on herbicide and fertilizer inputs. Bahiagrass renovation is US$826 ha−1 in establishment costs alone. When pasture production expenses are included for two seasons postrenovation, the total increases to US$1,120 ha−1 across three seasons. The importance of hexazinone and fertilizer as components of smutgrass control in bahiagrass forage was confirmed in this study. Future research should focus on the biology of smutgrass and the role of a PRE treatment in a long-term, larger-scale forage system.

The widespread adoption of multiple-herbicide-resistant corn and soybean often causes the problem of volunteers in corn–soybean rotation, which necessitates alternative herbicides for effective management. The objective of this research was to evaluate PRE and POST herbicides labeled in corn for control of dicamba/glufosinate/glyphosate-resistant volunteer soybean. Field experiments were conducted from 2021 to 2023 near Clay Center, NE. Two separate field experiments were conducted to evaluate 12 PRE and 14 POST herbicides to control volunteer soybean in Enlist® corn. Soybean resistant to dicamba/glufosinate/glyphosate was planted perpendicular to corn rows to mimic volunteer soybean. Among the PRE herbicides tested, acetochlor/clopyralid/flumetsulam (1,190; 1,050/106/34 g ai ha−1) and acetochlor/clopyralid/mesotrione (2,304; 1,961/133/210 g ai or ae ha−1) provided 97% and 99% control of volunteer soybean, respectively, in 2021 and 68% and 89% control, respectively, in 2023 at 42 d after PRE. Among POST herbicides tested, 2,4-D choline (1,064 g ae ha−1), acetochlor/clopyralid/mesotrione (2,304; 1,961/133/210 g ai or ae ha−1), atrazine/bicyclopyrone/mesotrione/S-metolachlor (2,409; 700/42/168/1,499 g ai ha−1), clopyralid/flumetsulam (192; 146/46 g ai ha−1), nicosulfuron + atrazine (34 + 1,120 g ai ha−1), and thiencarbazone-methyl/tembotrione + atrazine (76; 12/63 + 896 g ai ha−1) provided ≥97% volunteer soybean control, ≥94% density reduction, and ≥97% biomass reduction 28 d after POST herbicide application. Corn yield did not differ from the weed-free control in these treatments. The results of this study suggest that PRE and POST herbicides are available for control of dicamba/glufosinate/glyphosate-resistant volunteer soybean in Enlist® corn and that careful selection of an herbicide is required based on the herbicide-resistant soybean planted in the previous year.

This study assessed the potential of using dichlobenil to manage hair fescue in lowbush blueberry crops when targeted or broadcast-applied (7,000 g ai ha−1) as justification for developing a precision-targeted applicator. A randomized complete block design was used to assess both application methods, and results were compared with industry-standard propanamide (2,240 g ai ha−1). Targeted and broadcast-applied dichlobenil in fall 2020 significantly reduced average total tuft density in the nonbearing year (2021) by 75% and 67%, respectively, and in the bearing year (2022) by 61% and 59%, respectively. Broadcast pronamide applications in fall 2020 significantly reduced total tuft density by 84% in the nonbearing year (2021) and 81% in the bearing year (2022). These reductions in total tuft density resulted in average lowbush blueberry yields of 416, 557, 573, and 617 g m−2 for the control, pronamide applications, and targeted and broadcast-applied dichlobenil, respectively. Increases in yield were not significant, though the large variation within the sample is the probable cause. The similarities between targeted and broadcast-applied treatments demonstrate the potential of using targeted dichlobenil. Given the high product cost of dichlobenil at Can$1,873 ha−1, hair fescue’s non-uniform distribution in lowbush blueberry fields and the lowbush blueberry industry’s overreliance on pronamide, targeted application of dichlobenil has significant potential. This work justifies the development of a mechanized precision-targeted applicator for use in lowbush blueberry cropping systems.

In 2022, trials were carried out in New Jersey and New York to assess the efficacy of weed management and the response of two cole crops to various herbicide combinations and rates. The experiments involved the application of S-metolachlor and microencapsulated (ME) acetochlor either alone or combined with oxyfluorfen. Different application timings of oxyfluorfen were tested in greenhouse and field studies. Results from the greenhouse trials show that substituting S–metolachlor with ME acetochlor in over-the-top applied mixes with oxyfluorfen caused 15% to 22% less crop injury and increased seedling biomass by 33%. In field studies, nontreated plots exhibited significant weed growth, reaching up to 71% coverage 28 d after transplanting (DATr), whereas herbicide-treated plots exhibited weed cover at or below 10% by 28 DATr. Mixtures or sequential applications of oxyfluorfen and chloroacetamides achieved excellent control (≥99%) of the weed species complex compared to single applications of oxyfluorfen or chloroacetamides. However, applying both oxyfluorfen and a chloroacetamide posttransplanting, either as a tank mixture or in sequence, resulted in ≥19% injury. Despite the effective weed control achieved with herbicide treatments, mixing herbicides posttransplanting reduced relative commercial yield by 46% to 94% compared to oxyfluorfen applied alone or followed by chloroacetamides. The findings from these experiments will inform regional crop safety guidelines and support potential modifications to oxyfluorfen labels regarding sequential applications with chloroacetamides.

With Palmer amaranth and waterhemp evolving resistance to nine and six different sites of action (SOAs) globally, soybean producers continue to search for new options to control these problematic weeds. Bayer CropScience has announced its intentions to launch a Convintro™ brand of herbicides, one being a three-way premixture for preemergence use in soybean. The premixture will contain diflufenican (WSSA Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15), adding a new SOA for soybean producers throughout the United States. With the anticipated launch of the premixture, research is needed to evaluate the length of residual control provided by the new herbicide. Research trials were conducted in Fayetteville and Keiser, AR, and Morrice, MI, in 2022 and 2023. A 0.17:0.35:0.48 ratio of a diflufenican:metribuzin:flufenacet (DFF)-containing premixture was applied alone and in combination with additional metribuzin and dicamba. Also, metribuzin, acetochlor, a S-metolachlor:metribuzin premixture, and a flumioxazin:pyroxasulfone:metribuzin premixture were applied preemergence. The DFF-containing premixture was more effective in reducing Palmer amaranth/waterhemp emergence than acetochlor in four of six trials at 28 d after treatment (DAT). Palmer amaranth and waterhemp densities in plots treated with the DFF-containing premixture exhibited similar results to plots treated with the S-metolachlor:metribuzin premixture and the flumioxazin:pyroxasulfone:metribuzin premixture at 28 DAT. By 56 DAT, Palmer amaranth and waterhemp densities were comparable or superior in plots with the DFF-containing premixture than in those treated with acetochlor and metribuzin, and the S-metolachlor:metribuzin premixture at five of six sites. The addition of dicamba or metribuzin to the DFF-containing premixture did not reduce Palmer amaranth or waterhemp density compared to the DFF-containing premixture at 28 or 56 DAT. Overall, the DFF-containing premixture generally provided greater or comparable control over several standard herbicides, providing growers a new product for preemergence control of Amaranthus species in soybean fields.

As herbicide resistance continues to render commonly used rice herbicides ineffective, alternative sites of action are paramount to maintaining yield and producer profitability. Combining a slow-release formulation and a fenclorim seed treatment might allow the safe use of S-metolachlor in rice. Experiments were initiated in 2022 and 2023 near Colt, AR, on a silt loam soil to evaluate crop safety using a capsule suspension (CS) formulation of S-metolachlor and a fenclorim seed treatment in rice. The first experiment assessed the tolerance of two cultivars (‘Diamond’ and ‘DG263L’) to three rates (0.42, 0.84, and 1.68 kg ai ha−1) of a CS S-metolachlor at a delayed preemergence (DPRE) application timing in conjunction with a fenclorim seed treatment. The second experiment evaluated a 1- to 2-leaf (EPOST) application of a CS S-metolachlor at 0.56 and 1.12 kg ai ha−1 to fenclorim-treated rice. Fenclorim reduced injury and partially protected rice yield when S-metolachlor was applied DPRE at 1.68 kg ai ha−1 in both years. However, in one year, under adverse conditions, rice yields were only 65% and 66% of the nontreated control for fenclorim-treated ‘Diamond’ and ‘DG263L’, respectively. An EPOST application of S-metolachlor at 1.12 kg ai ha−1 resulted in 44% to 51% visible injury 35 d after treatment. Relative rice yields were 88% and 89% of the nontreated weed-free treatment in 2022 and 2023, respectively. Fenclorim provided enhanced crop safety at both the 0.84 and 1.68 kg ai ha−1 rates of S-metolachlor. However, the potential for reduced yield can arise when unfavorable conditions occur soon after application. An EPOST application timing of CS S-metolachlor at 0.56 kg ai ha−1 may be a viable option in rice, but 1.12 kg ai ha−1 is too high on a silt loam soil, resulting in significant rice injury.

Alternative strategies to fumigation are needed to manage weeds and improve strawberry fruit yield in annual hill plasticulture production systems. Field experiments were conducted in Blackstone, VA, for two consecutive growing seasons, 2013/14 and 2014/15, to assess the efficacy of 4 wk and 8 wk soil solarization (SS) and application of mustard seed meal (MSM) at 1,121 kg ha−1, alone and in combination, for weed control efficacy and crop yield estimation in this production system. These treatments were compared to the use of 1,3-dichloropropene (1,3-D) + chloropicrin (Pic) as a fumigation standard at 188 kg ha−1 and an untreated control (UTC). Over both growing seasons, compared to 1,3-D+ Pic, the SS-MSM-8wk and SS-8wk treatments provided equivalent or reduced cumulative weed count, including weed count of several dominant weed species such as annual ryegrass, speedwell, common chickweed, and cudweed. The SS-4wk and MSM-4wk treatments did not affect weed density compared with the UTC. The MSM-8 wk and 4-wk treatments reduced cumulative weed counts over that of the UTC. In the second growing season, the total yield was significantly higher after the 1,3-D + Pic fumigation treatment compared with yield after other treatments. The SS-4wk, MSM-4wk, and MSM-8wk treatments did not improve the total or marketable yield compared with the UTC. The marketable yield after the SS-MSM-8wk treatment was similar to that of the 1,3-D + Pic treatment. In conclusion, the SS-8wk and SS-MSM-8wk treatments may be effective weed management strategies for organic growers, small farms, or growers who cannot use chemical fumigants due to new regulations and potential risks to human health.

Herbicide-resistant Palmer amaranth is creating additional challenges for producers who choose to adopt a furrow-irrigated rice production system due to the absence of a sustained flood, enabling extended weed emergence. Fluridone has been shown to effectively control Palmer amaranth in cotton production systems and was recently registered for use in rice. Experiments were initiated in 2022 and 2023 1) to evaluate Palmer amaranth control and rice tolerance to preemergence- and postemergence-applied fluridone at 0.5× (84 g ai ha−1) and 1× (168 g ai ha−1) rates on a silt loam soil; and 2) assess the effect of various herbicide programs that contain fluridone on Palmer amaranth biomass, seed production, and rough rice grain yield. Preemergence applications of fluridone at a 1× rate in combination with clomazone resulted in 84% control of Palmer amaranth 21 d after treatment (DAT). Fluridone, in combination with clomazone preemergence, caused up to 36% rice injury 21 DAT; however, early season injury did not negatively affect rice yields. Palmer amaranth biomass and fecundity were reduced with herbicide programs that included fluridone plus florpyrauxifen-benzyl, and, in some instances, there was no Palmer amaranth biomass or seed production following multiple applications of both herbicides. Fluridone- and florpyrauxifen-benzyl–based herbicide programs achieved effective control of Palmer amaranth when applied timely, but injury to hybrid rice is enhanced with preemergence applications of fluridone that are not permitted with the current label.

This trial assessed the effect of preemergence herbicides on newly transplanted blackberries. A 2-yr field trial was initiated in 2021 and conducted at two locations in Fayetteville and Clarksville, AR. Seven treatments consisted of six preemergence herbicides (flumioxazin, mesotrione, napropamide, oryzalin, pendimethalin, and S-metolachlor) and one nontreated check. Preemergence herbicide treatments were applied to field plots of newly transplanted blackberry plugs (‘Ouachita’), using a CO2 backpack sprayer at 187 L ha−1 covering a 1-m swath, ensuring spray pattern overlap over newly planted blackberries in 2021 and reapplied in the same manner to established blackberries of the same plots in 2022. Data were collected on crop injury and plant height of blackberry plants in each plot. Yield data were collected in the second year, and fruit were analyzed for soluble solids content, pH, and average berry weight. In the first year, mesotrione and flumioxazin treatments caused injury to newly transplanted blackberries, and mesotrione-treated blackberries (58% in Fayetteville, 29% in Clarksville) did not fully recover by 84 d after treatment (DAT). Napropamide, S-metolachlor, oryzalin, and pendimethalin did not cause crop injury greater than 6% throughout the 2021 season. In the second year (2022), no crop injury was caused by any herbicide treatments. Results from these trials verify that flumioxazin, napropamide, oryzalin, and pendimethalin at the tested rates would be appropriate options for weed control in newly planted blackberries. These results corroborate regional recommendations against the use of mesotrione in first-year blackberry plantings. The findings from this trial indicate that S-metolachlor would be safe for registration for use on blackberries because of its limited effect on crop injury and blackberry yield.

Numerous annual and perennial weeds infest sugarcane. End-season weed infestations are managed before sugarcane is replanted by fallowing (cultivation and sequential glyphosate applications) or by rotating to glyphosate-tolerant soybean in Louisiana. With the occurrence of perennial grasses and glyphosate-resistant weeds, growers need to utilize alternative late POST (LPOST) herbicide programs in soybean to reduce weed infestations in newly planted sugarcane (soybean-sugarcane rotation). Current rotational restrictions limit the use of acifluorfen, clethodim, fomesafen, and quizalofop to control troublesome weeds before soybean harvest and the subsequent planting of sugarcane. However, there is a lack of information on the carryover effects of these soybean herbicides on newly planted sugarcane. Field experiments were conducted at Schriever, LA, and St. Gabriel, LA, in 2017 to 2018 and in 2020 to 2021 to determine sugarcane injury and yield component response to herbicides labeled for LPOST applications in soybean, including acifluorfen, clethodim, fomesafen, lactofen, and quizalofop, applied at the field-use rates (1X) 45 d prior to or immediately after sugarcane planting. Separate field experiments were conducted at those two locations in Louisiana in 2018 to 2019 and in 2020 to 2021 to determine sugarcane injury and yield component response to five rates of fomesafen applied immediately after sugarcane planting. Results of the herbicide screening experiment showed no reductions in sugarcane shoot and stalk population, stalk height, sugarcane yield, sucrose content, or sucrose yield from the selected herbicides at either application timing. Fomesafen applied at 790 (2X) and 1,580 (4X) g ha−1 resulted in 7% and 13% average visible injury to sugarcane at 27 d after treatment (DAT), respectively; injury symptoms persisted until 62 DAT. Transient injury observed at 62 DAT did not correspond to reduced sugarcane stalk population, height, sucrose content, sugarcane yield, or sucrose yield. This research indicates a potentially low risk of carryover and yield loss in newly planted sugarcane from late-season applications of selected soybean herbicides.

There is limited information on the crop safety and weed control potential of commercially available PRE herbicides when applied under plastic mulch on various cucumber and summer squash cultivars grown in Florida. Two cucumber field trials were conducted at the Gulf Coast Research and Education Center in Wimauma, FL, in fall 2021 and spring 2022 to determine the effects of halosulfuron, pendimethalin, S-metolachlor, sulfentrazone, fomesafen, napropamide, oxyfluorfen, and flumioxazin on crop growth and development, yield, and the control of various weed species in the fields. We conducted this trial using three cucumber cultivars: ‘Speedway’, ‘Dominator’, and ‘Mongoose’. Two summer squash field trials were conducted simultaneously, evaluating all the mentioned herbicides, except flumioxazin, in addition to rimsulfuron on three summer squash cultivars: ‘Spineless Beauty’, ‘Payload’, and ‘Everglade’. In the cucumber trials, crop damage varied with cultivar and ranged from 3% to 16% in fall 2021. All herbicides caused ≥10% crop injury, except oxyfluorfen and flumioxazin, at 28 d after transplanting (DATr) in spring 2022. In the summer squash trial, halosulfuron, S-metolachor, and flumioxazin were the three most injurious PRE herbicides, causing more than 10% crop injury in seed-grown summer squash, with no effect of PRE herbicides on crop injury in transplant-grown summer squash in fall 2021. In spring 2022, crop injury with PRE herbicides varied with cultivar, where pendimethalin and S-metolachlor were consistently the most injurious PRE herbicides, causing 14% to 25% injury at 28 DATr. All PRE herbicides caused some damage to cucumber and summer squash, with limited differences between cultivars and no effect on overall crop yield.

Italian ryegrass control is one of the most significant limitations in wheat production in the United States today. Resistance to Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Groups 1, 2, and 9 in Arkansas have further complicated postemergence control, whereas residual herbicides still show effective weed control. One problem is the potential of HRAC/WSSA Group 15 herbicides to injure wheat when applied preemergence, indicating the need for a herbicide safener. A series of experiments were conducted in Fayetteville, AR, to evaluate crop tolerance and Italian ryegrass control using a capsule suspension (CS) formulation of S-metolachlor in conjunction with fenclorim-treated wheat. Experiments were conducted as a two-factor factorial with S-metolachlor applied at three rates (0.37, 0.74, and 1.12 kg ai ha–1) and a microencapsulated formulation of acetochlor at 1.05 kg ai ha–1, and three rates of a fenclorim seed treatment at 0, 0.5, and 2.0 g ai kg–1 of seed. Separate experiments utilized either a preemergence (PRE) or a delayed-preemergence (DPRE) application timing. In both experiments, S-metolachlor at 0.74 and 1.12 kg ai ha–1 provided 77% to 96% control of Italian ryegrass by preharvest, whereas acetochlor only provided 49% to 72% control. Visible wheat injury from PRE applications ranged from 7% to 49% for all treatments 21 d after treatment (DAT), with a reduction in injury when fenclorim-treated wheat was used for both the 0.74 and 1.12 kg ai ha–1 rate of S-metolachlor. In the DPRE experiments, wheat injury ranged from 5% to 16% 21 DAT with no noticeable safening from the presence of fenclorim at any herbicide rate. The results of these experiments indicate that a DPRE application using a CS formulation of S-metolachlor would be more favorable for producers to mitigate the potential for injury to wheat while providing Italian ryegrass control. Additionally, at the DPRE application timing, fenclorim is unnecessary for S-metolachlor to be safely applied at the rates evaluated.

Two studies were conducted in 2022 and 2023 near Rocky Mount and Clayton, NC, to determine the optimal granular ammonium sulfate (AMS) rate and application timing for pyroxasulfone-coated AMS. In the rate study, AMS rates included 161, 214, 267, 321, 374, 428, and 481 kg ha−1, equivalent to 34, 45, 56, 67, 79, 90, and 101 kg N ha−1, respectively. All rates were coated with pyroxasulfone at 118 g ai ha−1 and topdressed onto 5- to 7-leaf cotton. In the timing study, pyroxasulfone (118 g ai ha−1) was coated on AMS and topdressed at 321 kg ha−1 (67 kg N ha−1) onto 5- to 7-leaf, 9- to 11-leaf, and first bloom cotton. In both studies, weed control and cotton tolerance to pyroxasulfone-coated AMS were compared to pyroxasulfone applied POST and POST-directed. The check in both studies received non-herbicide-treated AMS (321 kg ha−1). Before treatment applications, all plots (including the check) were maintained weed-free with glyphosate and glufosinate. In both studies, pyroxasulfone applied POST was most injurious (8% to 16%), while pyroxasulfone-coated AMS resulted in ≤4% injury. Additionally, no differences in cotton lint yield were observed in either study. With the exception of the lowest rate of AMS (161 kg ha−1; 79%), all AMS rates coated with pyroxasulfone controlled Palmer amaranth ≥83%, comparably to pyroxasulfone applied POST (92%) and POST-directed (89%). In the timing study, the application method did not affect Palmer amaranth control; however, applications made at the mid- and late timings outperformed early applications. These results indicate that pyroxasulfone-coated AMS can control Palmer amaranth comparably to pyroxasulfone applied POST and POST-directed, with minimal risk of cotton injury. However, the application timing could warrant additional treatment to achieve adequate late-season weed control.

Common cattail is a perennial weed that naturally occurs in wet or saturated soils, such as in marshes, lakes, ponds, irrigation and drainage canals, and streams, throughout North America. Recently, common cattail has become an important problem for the drill-seeded rice systems in the Sacramento–San Joaquin River Delta of northern California. This research was conducted in 2022 and 2023 at three sites near Stockton, CA, to evaluate the efficacy of florpyrauxifen-benzyl, a newly registered auxin-mimic herbicide, to control common cattail in drill-seeded rice. Florpyrauxifen-benzyl was applied alone at 40 g ai ha–1 and 80 g ha–1 on 0- to 1-m-tall and 1- to 2-m-tall common cattail and in a sequential application of florpyrauxifen-benzyl at 40 g ha–1 followed by 40 g ha–1 between 14-d intervals on 0- to 1-m-tall and 1- to 2-m-tall common cattail. Triclopyr, another auxin-mimic rice herbicide widely used in California, was applied alone at 420 g ae ha–1 on 0- to 1-m-tall common cattail for comparison. Triclopyr was also applied in combination with florpyrauxifen-benzyl at 40 g ha–1 at the 0- to 1-m growth stage. The injury symptoms on common cattail started within 3 d after treatment (DAT) for the florpyrauxifen-benzyl + triclopyr mixture treatment and within 7 DAT for all other florpyrauxifen-benzyl applied treatments. All florpyrauxifen-benzyl treatments controlled 100% of common cattail at 28 DAT regardless of application rate and timing. Common cattail height and dry biomass at 28 DAT were lower for all treatments compared to the nontreated control. While the common cattail control was excellent for all florpyrauxifen-benzyl applications, rice injury was minimal. This research indicates that common cattail up to 2 m tall can be effectively and rapidly controlled in rice fields with florpyrauxifen-benzyl at 40 g ha–1.

An experiment was conducted in 2022 and 2023 near Rocky Mount and Clayton, NC, to evaluate residual herbicide-coated fertilizer for cotton tolerance and Palmer amaranth control. Treatments included acetochlor, atrazine, dimethenamid-P, diuron, flumioxazin, fluometuron, fluridone, fomesafen, linuron, metribuzin, pendimethalin, pyroxasulfone, pyroxasulfone + carfentrazone, S-metolachlor, and sulfentrazone. Each herbicide was individually coated on granular ammonium sulfate (AMS) and top-dressed at 321 kg ha−1 (67 kg N ha−1) onto 5- to 7-leaf cotton. The check plots received the equivalent rate of nonherbicide-treated AMS. Before top-dress, all plots (including the check) were treated with glyphosate and glufosinate to control previously emerged weeds. All herbicides except metribuzin resulted in transient cotton injury. Cotton response to metribuzin varied by year and location. In 2022, metribuzin caused 11% to 39% and 8% to 17% injury at the Clayton and Rocky Mount locations, respectively. In 2023, metribuzin caused 13% to 32% injury at Clayton and 73% to 84% injury at Rocky Mount. Pyroxasulfone (91%), pyroxasulfone + carfentrazone (89%), fomesafen (87%), fluridone (86%), flumioxazin (86%), and atrazine (85%) controlled Palmer amaranth ≥85%. Pendimethalin and fluometuron were the least effective treatments, resulting in 58% and 62% control, respectively. As anticipated, early season metribuzin injury translated into yield loss; plots treated with metribuzin yielded 640 kg ha−1 and were comparable to yields after linuron (790 kg ha−1) was used. These findings suggest that with the exception of metribuzin, residual herbicides coated onto AMS may be suitable and effective in cotton production, providing growers with additional modes of action for late-season control of multiple herbicide–resistant Palmer amaranth.