Abstract Two studies were conducted in 2022 and 2023 near Rocky Mount Clayton, NC, to determine the optimal granular ammonium sulfate (AMS) rate application timing for pyroxasulfone-coated AMS. In study, AMS rates included 161, 214, 267, 321, 374, 428, 481 kg ha -1 , equivalent 34, 45, 56, 67, 79, 90, 101 N respectively. All coated with pyroxasulfone at 118 g ai top-dressed onto 5- 7-leaf cotton. (118 ) was on 321 (67 7-leaf, 9- 11-leaf, first bloom both studies, weed control cotton...

Cotton growers rely heavily upon glufosinate and various residual herbicides applied preplant, PRE, POST to control Palmer amaranth resistant glyphosate acetolactate synthase-inhibiting herbicides. Recently deregulated in the United States, cotton dicamba, glufosinate, (B2XF cotton) offers a new platform for controlling herbicide-resistant amaranth. A field experiment was conducted North Carolina Georgia determine B2XF tolerance compare by dicamba currently used, nondicamba program both...

Abstract North Carolina growers have long struggled to control Italian ryegrass, and recent research has confirmed ryegrass biotypes resistant nicosulfuron, glyphosate, clethodim, paraquat. Integrating alternative management strategies is crucial effectively such biotypes. The objectives of this study were evaluate with cover crops fall-applied residual herbicides investigate crop injury from herbicides. This was conducted during the fall/winter 2021-22 in Salisbury 2022-23 at Clayton, NC....

Abstract Typically, weed density is used to predict weed-induced yield loss, as it easy and quick quantify, even though does not account for size time of emergence relative the crop. Weed-crop leaf area relations, while more difficult measure, inherently differences in plant size, representing weed-crop interference accurately than alone. Unmanned aerial systems (UAS) may allow efficient quantification crop cover over a large scale. It was hypothesized that UAS imagery could be maize loss...

Residual herbicides are routinely recommended to aid in control of glyphosate-resistant (GR) Palmer amaranth cotton. Acetochlor, a chloroacetamide herbicide, applied PRE, controls amaranth. A microencapsulated (ME) formulation acetochlor is now registered for PRE application Field research was conducted North Carolina evaluate cotton tolerance and by ME alone various combinations. Treatments, consisted ME, pendimethalin, or no herbicide arranged factorially with diuron, fluometuron,...

Palmer amaranth (Amaranthus palmeri S. Wats.) is a highly competitive weed that can be difficult to manage in many cropping systems. Research date has not quantified the growth and development of A. manner allows direct comparisons across was conducted compare growth, development, seed production when competing with corn (Zea mays L.), cotton (Gossypium hirsutum peanut (Arachis hypogaea soybean [Glycine max (L.) Merr.] emerging crops or three weeks after emerge. Regardless emerged, greatest...

Abstract Residual herbicides applied to summer cash crops have the potential injure subsequent winter annual cover crops, yet little information is available guide growers’ choices. Field studies were conducted in 2016 and 2017 Blacksburg Suffolk, Virginia, determine carryover of 30 commonly used corn, soybean, or cotton on wheat, barley, cereal rye, oats, ryegrass, forage radish, Austrian pea, crimson clover, hairy vetch, rapeseed crops. Herbicides bare ground either 14 wk before crop...

Abstract Field experiments were conducted at Clayton and Rocky Mount, North Carolina, during the summer of 2020 to determine growth fecundity Palmer amaranth plants that survived glufosinate with without grass competition in soybean crops. Glufosinate (590 g ai ha −1 ) was applied early postemergence (when 5 cm tall), mid-postemergence (7–10 cm), late (>10 cm) orthogonal combinations those timings. Nontreated grown weedy (i.e., intraspecific competition), weed-free in-crop (WFIC), fallow...

Glyphosate-resistant (GR) Palmer amaranth is a widespread problem in southeastern cotton production areas. Herbicide programs to control this weed no-till commonly include flumioxazin applied with preplant burndown herbicides approximately 3 wk before planting followed by fomesafen PRE and then glufosinate or glyphosate POST. Flumioxazin are both protoporphyrinogen oxidase (PPO) inhibitors. Multiple yearly applications of PPO inhibitors cotton, along use rotational crops, raise concerns over...

Cotton growers commonly use glufosinate-based programs to control glyphosate-resistant Palmer amaranth. amaranth must be small (≤7.5 cm) for consistent by glufosinate, and often miss the optimum application timing. XtendFlex ™ cotton may provide a tool larger Glufosinate, dicamba, glufosinate plus dicamba were compared in rescue situation. Herbicides applied 16- 23-cm weeds (POST-1) followed second (POST-2) 12 d later. Glufosinate-ammonium at 590 g ai ha −1 diglycolamine salt 560 ae POST-1...

Abstract Palmer amaranth ( Amaranthus palmeri S. Watson) populations resistant to acetolactate synthase (ALS)-inhibiting herbicides and glyphosate are fairly common throughout the state of North Carolina (NC). This has led farm managers rely more heavily on with other sites action (SOA) for A. control, especially protoporphyrinogen oxidase glutamine synthetase inhibitors. In fall 2016, seeds from were collected NC Coastal Plain, state’s most prominent agricultural region. separate...

A putative glufosinate-resistant

Palmer amaranth is the most economically damaging glyphosate-resistant (GR) weed in southern United States. An understanding of basic biology, including relative growth and competitiveness GR glyphosate-susceptible (GS) phenotypes from a segregating population collected same geographical location, may yield information helpful management resistant populations. A North Carolina during 2010 was used as plant source for both GS traits. Research conducted greenhouse to compare following: level...

Glufosinate controls glyphosate-resistant Palmer amaranth, but growers struggle to make timely applications. XtendFlex TM cotton, resistant dicamba, glufosinate, and glyphosate, may provide an option control larger weeds. amaranth cotton growth, yield, fiber quality were evaluated in a rescue situation created by delaying the first POST herbicide application. Treatments consisted of two applications dicamba plus separated 14 d, with application (0-d delay) or delayed 7, 14, 21, 28 d. All...

Abstract Cover crops provide a number of agronomic benefits, including weed suppression, which is important as cases herbicide resistance continue to rise. To effectively suppress weeds, high cover crop biomass needed, necessitates later termination timing. mitigate potential planting issues and prevent surviving competition with cash crops. Field studies were conducted in Virginia determine the most effective options alone or combined glyphosate paraquat terminate range species. Results...

Flumioxazin and fomesafen are commonly used to control glyphosate-resistant Palmer amaranth in cotton other crops, thus increasing risk select for biotypes resistant protoporphyrinogen oxidase (PPO) inhibitors. A field experiment was conducted determine the potential fluridone acetochlor substitute soil-applied PPO inhibitors a management system with glufosinate applied twice POST diuron plus MSMA POST-directed conservation tillage cotton. Fluridone flumioxazin preplant 23 34 d prior...

Abstract Glufosinate is an effective postemergence herbicide, and overreliance on this herbicide for weed control likely to increase select glufosinate-resistant weeds. Common assays confirm resistance are dose–response molecular sequencing techniques; both can require significant time, labor, unique technical equipment, a specialized skillset perform. As alternative, we propose image-based approach that uses relatively inexpensive multispectral sensor designed unmanned aerial vehicles...

As resistance to herbicides limits growers' weed management options, integrated (IWM) systems that combine non-chemical tactics with are becoming critical. A 2 year study was conducted at three locations in VA, USA. The factorial evaluated: (1) soybean planting date (early or late planted) (2) without winter cover (cereal rye/wheat no cover), and (3) harvest seed control (HWSC). Prior the first year, resulted a 22% reduction common ragweed density compared cover. At lowest densities were...

Glufosinate controls GR Palmer amaranth (Amaranthus palmeri S. Wats.), but might be less effective than glyphosate on certain weeds. Glyphosate and glufosinate applications in tolerant cotton (Gossypium hirsutum L.) cultivars can broaden the spectrum of control aid resistance management. Research investigating sequential application potential interactions with co-applications is limited. Field research at six locations evaluated annual grass co-applied or sequentially applied. Herbicides...

Abstract Glufosinate is among the few remaining effective herbicides for postemergence weed control in North Carolina crops. The evolution of glufosinate resistance key weeds currently not widespread Carolina, but to better assess current status effectiveness, surveys were distributed at Extension meetings 2019 and 2020. designed provide information about farmers’ perception its use. Survey results indicate that many farmers (≥26%) apply correct timing (5- 10-cm weeds). In addition, (≥22%)...

Abstract Comparing fitness of herbicide-resistant and herbicide-susceptible weed biotypes is important for managing herbicide resistance. Previous research suggests there little to no penalty from amplification the 5-enolpyruvylshikimate-3-phosphate synthase ( EPSPS ) gene (a mechanism glyphosate resistance) in Palmer amaranth Amaranthus palmeri S. Watson) controlled studies greenhouse or growth chamber. A field study was conducted North Carolina at three locations naturally infested with A....

The high concentration of swine production in southeastern North Carolina generates public health concerns regarding the potential transport pathogens from these systems to nearby surface waters. microbial source tracking (MST) tool, antibiotic resistance analysis (ARA), was used identify sources E. coli a segment Six Runs Creek Sampson County, Carolina. Among 52 water samples, fecal coliform (FC) counts averaged 272.1 ± 181.6 CFU/100 mL. Comparisons isolates samples an ARA library with...

Abstract Residual herbicides are routinely applied to control troublesome weeds in pumpkin production. Fluridone and acetochlor, Groups 12 15 herbicides, respectively, provide broad-spectrum PRE weed control. Field research was conducted Virginia New Jersey evaluate tolerance herbicides. Treatments consisted of fomesafen at two rates, ethalfluralin, clomazone, halosulfuron, fluridone, S -metolachlor, acetochlor emulsifiable concentrate (EC), microencapsulated (ME), no herbicide. At one site,...

Abstract Rapeseed is a popular cover crop choice due to its deep-growing taproot, which creates soil macropores and increases water infiltration. Brassicaceae spp. that are mature or at later growth stages can be troublesome control. Experiments were conducted in Delaware Virginia evaluate herbicides for terminating rapeseed crops. Two separate experiments, adjacent each other, established termination by 14 herbicide treatments two timings. Termination timings included an early late simulate...