Field studies were conducted in 2020 and 2021 near Crowley, Louisiana, to evaluate florpyrauxifen-benzyl applied at 0, 7.3, 14.6, 21.9, and 29.2 g ai ha−1 coated onto the surface of urea fertilizer or as a postflood spray for residual control of ducksalad. All studies were conducted on a Crowley silt loam (fine smectic, thermic Typic Albaqualfs), pH 6.5, and with 2.3% organic matter. Square plots were 1.5 × 1.5 m−2. Each plot contained a plastic ring 53 cm in diameter and 30 cm deep. At 70 d after treatment (DAT), ducksalad emergence did not exceed 23% when florpyrauxifen-benzyl was applied via surface-coated urea, compared with 98% to 99% emergence following postflood spray applications. By 56 DAT, more than 93% of ducksalad treated with florpyrauxifen-benzyl as a postflood spray, regardless of rate, had reached the petiolate leaf stage. However, ducksalad treated with florpyrauxifen-benzyl as a surface-coated urea application resulted in 3% to 18% petiolate leaf development at 56 DAT. Similar to ducksalad emergence and petiolate leaf development, applying florpyrauxifen-benzyl coated onto the surface of a urea prill reduced ducksalad flowering compared with postflood spray applications. This reduction in flowering throughout the growing season could reduce seed production and potentially impact future ducksalad infestations. Findings suggest florpyrauxifen-benzyl applied via surface-coated urea is more effective at reducing ducksalad emergence, petiolate leaf development, flowering, and fresh weight biomass compared with being applied as a postflood spray. Overall, applications of florpyrauxifen-benzyl applied via surface-coated urea reach the soil surface rapidly, increasing growth inhibition of ducksalad and possibly other germinating weed species.

Nissan Chemical Corporation and Gowan USA are currently developing iptriazopyrid, a novel herbicide that inhibits 4-hydroxyphenylpyruvate dioxygenase (HPPD), for weed control in rice. Field experiments were conducted near Crowley, Louisiana, to evaluate iptriazopyrid mixed with common auxin herbicides used in Louisiana rice production. Iptriazopyrid was applied at a reduced rate of the proposed 1 × label rate to determine possible compatibility issues. The study was organized as a randomized complete block with a two-factor factorial arrangement of treatments, and treatments were applied at 94 L ha−1 post-flood. Factor A consisted of either no iptriazopyrid or iptriazopyrid applied at 50 g ai ha−1, whereas factor B included each auxin herbicide. Across all evaluation intervals, barnyardgrass was controlled by 68% to 80%, whereas broadleaf signalgrass was controlled by 27% to 31% when iptriazopyrid was applied alone. Iptriazopyrid alone controlled barnyardgrass by 80% 35 d after treatment, compared with 29% and 43% when iptriazopyrid was mixed with triclopyr or 2,4-D, respectively. Mixtures of iptriazopyrid with triclopyr and 2,4-D resulted in antagonism for barnyardgrass, while only the iptriazopyrid and 2,4-D mixture was antagonistic for broadleaf signalgrass control. The mixture of iptriazopyrid with quinclorac indicated a neutral interaction for both grasses while an antagonistic interaction was observed for alligatorweed control. Iptriazopyrid mixed with florpyrauxifen resulted in a neutral interaction across all weed species evaluated and proved to be the most compatible mixing partner among the auxin herbicides within these studies. The results of these studies indicate that iptriazopyrid should not be mixed with triclopyr or 2,4-D when targeting barnyardgrass. To prevent antagonistic interactions split applications or alternative mixture partners should be considered. Supplemental research is needed to determine whether antagonism is rate dependent and whether increasing the rate of iptriazopyrid to the 1 × labeled rate will overcome the antagonism.

Rice is often planted in the mid-southern United States around the same time that paraquat is applied either preplant or preemergence herbicide to other row crops in adjacent fields. Additionally, off-target movement of paraquat may occur onto rice late in the season due to paraquat’s use as an aid in soybean harvest. Although previous research has documented rice response to early season and late-season exposure to sublethal concentrations of paraquat, research quantifying rice injury after multiple exposures is not available. Therefore, research was conducted from 2019 to 2021 in Mississippi with the aim of evaluating rice growth and yield after exposure to sublethal concentrations of paraquat multiple times during the rice life cycle. Paraquat (84 g ai ha−1) was applied to rice at the spiking to 1-leaf (VEPOST) and 3- to 4-leaf (MPOST) growth stages to simulate early season exposure, while late-season exposure of paraquat was simulated with applications to rice at a rate of 28 g ai ha−1 when 50% of plants in a plot had visible panicles (HEAD) to the day of draining (DRAIN), and a sequential treatment with rice exposure at HEAD followed by DRAIN. Rice injury was greatest pooled across early season exposure, when paraquat exposure occurred at HEAD followed by DRAIN. Rough rice grain yield was reduced by 15% and 18% from HEAD and HEAD followed by DRAIN exposures, respectively, compared with the no-late-season exposure. Whole milled rice yields were not affected by multiple exposures to paraquat. Multiple exposures to paraquat had the greatest effect on rice performance when the exposure occurred both early and late in the season.

This article examines the chronicles composed by Meccan authors ʿIzz al-Dīn ibn Fahd and his son Jār Allāh ibn Fahd in order to trace continuities and transformations across the turn of the sixteenth century. Mecca’s reliance on donations of voluntary alms, especially the donations that were sent on a regular basis from the Mamluk and Ottoman sultans to sustain the population of the city, is well known. The Meccan chroniclers provide sufficient detail about these donations to show the growing impact of alms sent from Indian rulers—rice in particular is noted—starting at the end of the fifteenth century, which may also signal the more widespread consumption of rice in local cuisine. This development indicates a broadening of the scope of the Indian commerce in non-luxury goods and the reorientation of Mecca and the Hijaz within global commercial connections.

Iptriazopyrid is a novel herbicide that inhibits 4-hydroxyphenylpyruvate dioxygenase. When it receives authorization for use in rice production, iptriazopyrid will be the first azole carboxamide herbicide to receive registration for use in the United States. Because herbicides are commonly mixed to broaden the weed control spectrum and efficacy, herbicide interactions with iptriazopyrid must be evaluated. Field experiments were conducted near Colt, Arkansas, in 2024 and 2025, to evaluate interactions between iptriazopyrid and either synthetic auxins or residual herbicides labeled for use in rice fields. The experiments were designed as a two-factor, randomized complete block design, with the presence of iptriazopyrid at 50 g ai ha−1 as the first factor and the presence of labeled synthetic auxins or residual herbicides as the second factor. Applications targeted barnyardgrass at the 3- to 4-leaf stage, and Colby’s method was utilized to determine herbicide interactions. Only 2,4-D demonstrated antagonism to iptriazopyrid throughout the experiments. When applied alone, iptriazopyrid provided 75%, 83%, and 79% barnyardgrass control at 1, 2, and 4 wk after treatment (WAT), respectively, compared with 12%, 18%, and 8% control when it was mixed with 2,4-D. The iptriazopyrid + triclopyr combination was antagonistic for barnyardgrass control at 1 and 2 WAT, with 61% and 73% control, respectively; however, the relationship was no longer significant at 4 WAT. Barnyardgrass density supported an antagonistic interaction between 2,4-D and iptriazopyrid because combinations of the two led to higher densities than iptriazopyrid applied alone. No residual herbicide antagonized iptriazopyrid for barnyardgrass control; nor did barnyardgrass densities differ when iptriazopyrid was applied alone. Overall, these findings show that iptriazopyrid offers reasonable flexibility when mixed with some, but not all, synthetic auxins labeled for rice, and that there is no reduction in barnyardgrass efficacy when mixed with residual herbicides.

Wingleaf primrose-willow (Ludwigia decurrens Walter) is a pervasive rice (Oryza sativa L.) weed native or naturalized to South America, the Caribbean, and the southeastern United States. While it was first noted in California in 2011 and provided with the highest pest rating “A” by the California Department of Food and Agriculture, enforcing eradication or quarantine was relatively disregarded, and it did not appear to spread significantly past its initial infestation area. Here, we report the spread within four counties (Butte, Placer, Shasta, and Tehama) of California, for which it has been found up to 184 km away from the initial infestation, and the expansion of the initial infestation within Butte County. As L. decurrens is already a problematic rice weed in parts of Asia, Africa, India, and the United States, monitoring new infestations is pivotal to prevent negative economic and environmental consequences to California and the United States.

Fall panicum is a major annual grass weed in drill-seeded rice production systems on organic soils in Florida. Field studies conducted in 2021 and 2022 aimed to determine the effects of season-long fall panicum interference on rough rice yield on organic soils. The relationship between fall panicum density and percent rough rice yield loss relative to the weed-free control was described using the rectangular hyperbola model. Yield loss increased with increasing fall panicum density. The initial slope parameter (I), representing percent yield loss as density approaches zero, was estimated at 9.7%, indicating that even very low fall panicum densities caused measurable yield reductions. The asymptote parameter (A), representing percent yield loss as density approaches infinity, was estimated at 118%, suggesting that yield loss approaches 100% at very high fall panicum densities within the biological limits of the crop-weed interference. Within the observed density range (1 to 49 plants m−2), yield loss was predicted to increase from approximately 9% to 95%, and 50% yield loss was estimated to occur at 9 plants m−2. Thousand-grain weight declined linearly with increasing fall panicum density, with each additional fall panicum plant per square meter reducing thousand-grain weight by 0.18 g, indicating that fall panicum interference affected grain filling. These results demonstrate that fall panicum is highly competitive with rice and that even low infestations can result in substantial yield loss, showing the importance of timely and effective management in Florida rice organic soil production systems.

Excavations at the Jizhong site in eastern China reveal the agricultural and horticultural range of the ancient Yue state, uncovering rice, gourds and fruit seeds, and the integration of proto-urban foodways with state development. This suggests that increasing dietary complexity and urban-rural integration were inherited by the subsequent Qin-Han dynasties.

Drill-seeded rice (DSR) offers several agronomic and environmental advantages over conventional puddled-transplanted rice (PTR), including labor and water savings, reduced cultivation costs, and lower greenhouse gas emissions. Despite these benefits, weed control remains a major bottleneck in the widespread adoption of DSR. Imidazolinone (IMI)-resistant rice, which allows the use of imidazolinone herbicides, has the potential to overcome weed control challenges in DSR and can therefore facilitate the transition from PTR to DSR. However, limited information exists on the effectiveness of IMI herbicide–based weed control programs in drill-seeded IMI-resistant rice in northwestern India. Field experiments were conducted in Karnal, India, from the 2020 through 2023 growing seasons to 1) evaluate the timing and rates of imidazolinone herbicides for effective weed control in IMI-resistant rice under DSR conditions, and 2) assess the potential carryover effects of IMI herbicides on succeeding crops. Results showed that sequential early postemergence applications of imazethapyr followed by (fb) late postemergence applications of either 100 fb 150 g ai ha−1 or 125 fb 125 g ai ha−1) effectively reduced the biomass of key weed species by 83% to 100%, including barnyardgrass, crowfootgrass, and Chinese sprangletop, and provided yields that were similar to weed-free treatments. These sequential postemergence treatments were consistently more effective than conventional preemergence herbicide applications of oxadiargyl fb a postemergence application of bispyribac-sodium. Sequential preemergence fb postemergence applications of imazethapyr were relatively less effective in controlling weeds and minimizing yield losses compared to sequential postemergence applications. However, in the second and third years, oxadiargyl (90 g ai ha−1) applied preemergence fb imazethapyr (100 g ai ha−1) applied postemergence achieved comparable weed control efficiency to those of sequential postemergence applications of imazethapyr (125 fb 125 g ai ha−1). No phytotoxicity was observed in the succeeding crops of wheat, mustard, chickpea, lentil, and corn from any of the herbicide treatments applied to IMI-resistant rice.

Rice (Oryza sativa L.) agriculture of the southern United States is plagued by strong biotic competition with several species in the Echinochloa genus. Despite clear genomic differences between barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] and junglerice [Echinochloa colona (L.) Link], the two major Echinochloa agricultural weeds are nearly indistinguishable phenotypically. This inability to reliably differentiate the species has led farmers to treat the group as a single species, often resulting in ineffective weed control efforts. In this study, we first develop a simple chloroplast-anchored PCR-based restriction enzyme assay to differentiate between E. colona and the other Echinochloa species of agricultural concern. Applying this assay, we identify a strong bias toward E. colona in 2024 rice field collections from eastern Arkansas. Finally, we evaluate anecdotal reports of interspecific hybridization between the species and find no evidence. Despite the drawbacks of the maternally inherited nature of the chloroplast genome, the availability of this species determinant assay will help USDA and academia extension agents and stakeholders to make educated, species-specific decisions about precision chemical weed control and field management.

Species in the genus Echinochloa present a major management challenge in rice production worldwide. Understanding the herbicide resistance status of Echinochloa is crucially necessary for raising awareness and developing effective management programs. This study investigated the status of herbicide resistance by junglerice, the predominant Echinochloa species in Texas rice fields. A total of 58 junglerice populations collected during a field survey (2015–2016) of Texas rice fields were screened with two preemergence herbicides; quinclorac (Group 4) and clomazone (Group 13); and four postemergence herbicides: fenoxaprop (Group 1), imazethapyr (Group 2), quinclorac (Group 4), and propanil (Group 5). At 21 d after application (DAA) of herbicide treatments, percent survival, and percent visible injury data were recorded. Based on the injury levels observed, the populations were categorized into being either putative resistant (≤50% injury), less sensitive (51% to 90% injury), or susceptible (≥91% injury). Results showed that herbicide resistance is widespread among the junglerice populations surveyed in Texas. About 5% of the populations showed multiple resistance to all four postemergence herbicides that were evaluated. Dose-response assays were conducted on the populations with the lowest injury ratings to determine the extent of resistance and revealed a >70-fold resistance to imazethapyr, a >15-fold resistance to propanil, and a 3-fold resistance to fenoxaprop, compared with a susceptible check. The results suggested that integrated management practices are needed to manage junglerice in Texas rice production.