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Pasture systems that include cool‐ and warm‐season species have the potential to enhance tall fescue (TF) [Schedonorus arundinaceus (Schreb.) Dumort.] forage systems beyond their typical season. The objectives of this study were to incorporate crabgrass (Digitaria ciliaris Retz.) into TF swards and compare the production of monoculture TF to a binary mixture of crabgrass and TF as well as its effect with different sources of nitrogen (such as red clover [Trifolium pratense L.] or sunn hemp [Crotalaria juncea L.]). The experiment was conducted in Crossville, TN, in 2020 and 2021. The treatments were as follows: (1) TF + 0 N (T), (2) TF + ammonium nitrate (TA), (3) TF + red clover (TR), (4) TF + sunn hemp (TS), (5) TF + crabgrass + 0 N (TFC), (6) TF + crabgrass + ammonium nitrate (TCA), (7) TF + crabgrass + red clover (TCR), and (8) TF + crabgrass + sunn hemp (TCS). The plots containing red clover indicated a greater herbage mass (HM) and crude protein (CP) along with lesser neutral detergent fiber compared to the other treatments. Sunn hemp performed best during the mid‐summer, contributing to the increase of HM. Tall fescue swards that were mixed with crabgrass and a source of N (legumes or N fertilizer) had greater HM during the warm season, having the potential to decrease the stationarity of production. Thus, including crabgrass, red clover, and sunn hemp (grass and legumes, respectively) in TF pasture can be a great strategy to increase HM and improve nutritive value. Core Ideas: Inclusion of cool‐ and warm‐season grasses increases the seasonality of production.Crabgrass is a warm‐season grass that improves nutritive value in mixed pasture.Nitrogen fertilizer increases forage mass and nutritive value.Increasing the use of legumes in pastures may decrease the use of synthetic N fertilizer. [ABSTRACT FROM AUTHOR]

Traditional Chinese medicinal herbs have strict environmental requirements and are highly susceptible to weed damage, while conventional herbicides can adversely affect their quality. Laser weeding has emerged as an effective method for managing weeds in precious medicinal herbs. This technique allows for precise weed removal without chemical residue and protects the surrounding ecosystem. To maximize the effectiveness of this technology, accurate detection and localization of weeds in the medicinal herb fields are crucial. This paper studied seven species of weeds in the field of Dictamnus dasycarpus, a traditional Chinese medicinal herb. We propose a lightweight YOLO-Riny weed-detection algorithm and develop a YOLO-Riny-ByteTrack Multiple Object Tracking method by combining it with the ByteTrack algorithm. This approach enables accurate detection and localization of weeds in medicinal fields. The YOLO-Riny weed-detection algorithm is based on the YOLOv7-tiny network, which utilizes the FasterNet lightweight structure as the backbone, incorporates a lightweight upsampling operator, and adds structure reparameterization to the detection network for precise and rapid weed detection. The YOLO-Riny-ByteTrack Multiple Object Tracking method provides quick and accurate feedback on weed identification and location, reducing redundant weeding and saving on laser weeding costs. The experimental results indicate that (1) YOLO-Riny improves detection accuracy for Digitaria sanguinalis and Acalypha australis, ultimately amounting to 5.4% and 10%, respectively, compared to the original network. It also diminishes the model size by 2 MB and inference time by 10 ms, making it more suitable for resource-constrained edge devices. (2) YOLO-Riny-ByteTrack enhances Multiple Object Tracking accuracy by 3%, reduces ID switching by 14 times, and improves overall tracking accuracy by 3.4%. The proposed weed-detection and localization method for Dictamnus dasycarpus offers fast detection speed, high localization accuracy, and stable tracking, supporting the implementation of laser weeding during the seedling stage of Dictamnus dasycarpus. [ABSTRACT FROM AUTHOR]

Smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.] is one of the most troublesome summer annual weeds in cool‐season turfgrass. Field experiments demonstrated a strong relationship between spring photosynthetic active radiation reaching the soil surface and the resulting smooth crabgrass cover in Kentucky bluegrass (Poa pratensis L.) 2/3 months later in summer. Both smooth crabgrass and canopy penetrating light were consistently reduced by higher mowing heights. Follow‐up experiments in controlled environments were initiated to improve our understanding of how light quality and quantity influence smooth crabgrass germination and growth. Smooth crabgrass germination was ≥99% following exposure to blue, red (R), far red (FR), both R and FR light pulses, or complete darkness treatments. A second germination experiment examined six levels of turfgrass canopy shade (0%, 24%, 44%, 77%, 90%, and 100% photosynthetic photon flux density [PPFD] reduction) and found that smooth crabgrass germination was ≥99% for all treatments. These experiments indicate that light quality and quantity do not affect smooth crabgrass germination. A greenhouse experiment examined five levels of turfgrass canopy shade (0%, 44%, 59%, 81%, and 91% PPFD reduction). Smooth crabgrass quantum and PSII (Photosystem II) operating efficiency increased in response to shade, while leaf number and thickness, specific leaf weight, tillering, mass, electron transport rate, and stomatal conductance decreased with increasing shade. Overall, the results demonstrate that smooth crabgrass is able to germinate regardless of canopy density, but seedling growth, development, and plant function are diminished in a dense turfgrass canopy shade. [ABSTRACT FROM AUTHOR]

This research addresses the conjunctions in the poetry of Jassim Muhammad Jassim Al-Ajja in light of transformational-generative grammar theory. The study includes several poetic examples from the poet's two collections, "A Sky That Does Not Title Its Clouds" and "Impositions for the Fingers of Grass ".Jassim Muhammad Jassim Al- Ajja's poetry was chosen for this study because, to my knowledge, it has not been the subject of recent linguistic analysis. Furthermore, the poet is considered one of the most prominent contemporary poets in the Mosul poetry scene, blending creative poetic work with academic critical work, which has resulted in a rich linguistic expression. His poetry is abundant with many elements of conjunctions, the focus of this research and study. This study aims to unveil the essence of this poet's work and to analyze his poetry according to modern linguistic methodologies, particularly the transformational-generative approach. The research examines conjunctions in the poet's work in light of the key hypotheses of transformational-generative grammar, specifically the deep structure and surface structure hypotheses, which posit that every surface structure has an underlying mental deep structure. The research is divided into an introduction and two sections. The introduction discusses the poet's life, his poetry collections, his critical writings, and the academic studies written about him. The first section addresses transformational-generative theory in terms of its philosophical roots and stages, while the second section explores conjunctions in light of our theory under investigation. The research concludes with a summary of the most significant findings derived from the study. [ABSTRACT FROM AUTHOR]

Two new integracides, dedimethyl integracide B (1) and integracide K (2), were isolated from rice cultures of Fusarium armeniacum M-3, an endophyte isolated from Digitaria ciliaris, together with the known terpenoids, integracide B (3) and 2-deoxy-integracide B (4). Assignment of the signals in the 1H and 13C NMR spectra of 1 and 2 was achieved using DEPT, HMQC, HMBC, and NOESY spectra. Compound 2 exhibited moderate cytotoxicity against HeLa cells. [ABSTRACT FROM AUTHOR]

The challenge of managing invasive weed species continues to affect the agricultural industry, presenting ecological, economic, and agronomic hurdles that lead to over 100 billion USD in annual crop losses globally. One such concern is the management of Agrostis stolonifera L., commonly known as creeping bentgrass, particularly due to its ability to form hybrids. This scenario underscores the urgent need for innovative, effective, and environmentally sustainable herbicides, steering the focus toward natural substances as potential candidates. We report here a promising natural lactone, commonly known as menthalactone, which is derived from Mentha piperita L. Its phytotoxic activity was assessed against the monocot, bentgrass, and a dicot, lettuce (Lactuca sativa L.). Menthalactone displayed outstanding activity against bentgrass and was further evaluated for phytotoxic characteristics. The germination of A. stolonifera seeds was significantly inhibited with an IC50 value of 4.9 ± 1.2 µM. In contrast to bentgrass seeds, Lemna pausicostata L. plants were less responsive to menthalactone treatment, shown by an IC50 of 293.4 ± 70.6 µM. Both species are monocots, and the results suggest that menthalactone might have effects on seed germination but not on the metabolism of green tissues. The susceptibility of three common, obnoxious weed species, i.e., ryegrass (Lilium perenne), barnyard grass (Echinochloa crus-galli (L.) P. Beauv.), and crabgrass (Digitaria sanguinalis (L.) Scop.), to menthalactone was assessed. Menthalactone at 1000 µM completely inhibited the germination of all three species of grasses, while 330 µM inhibited germination by less than 50%. The post-emergence application of menthalactone at 1% did not produce a significant inhibitory effect against ryegrass, barnyard grass, or crabgrass. [ABSTRACT FROM AUTHOR]

For sustainable weed management, herbicides produced from natural ingredients could be an excellent environmentally acceptable alterna-tive to synthetic chemical herbicides. This study looked at the alle-lopathic effects of methanol extract of Parthenium hysterophorus stem, leaf, and flower on seed germination and seedling growth of two weed species, crabgrass (Digitaria sanguinalis L.) and goosegrass (Eleusine indica L.). Five different concentrations of the extract (0, 25, 50, 75, 100, and 150 g L-1) were compared. Percent inhibition in seed germination, root and shoot growth were calculated and EC50 (concentration required to cause 50% growth inhibition) of test weeds were measured. The extracts affected the seed sprouting and seedling growth of test weed species significantly. Leaf and flower extracts were found more phytotoxic than the stem extract. An amount of 50 g L-1 of plant mass was enough to suppress effectively all parameters of the test weed species (designated as EC50). The leaf and flower of Parthenium hysterophorus might contain a number of plant inhibitors or phytotoxins, which could be exploited in future to create a natural herbicide. [Fundam Appl Agric 2024; 9(1.000): 39-43]

This study determined the growth kinetic (maximal specific growth rate (h-1), generation time (h), and viability (CFU/ml) of yogurt starter cultures; Streptococcus salivarious subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in acha (Digitaria exilis, Stapf) based milk was carried out. Acha-based milk was extracted, batch pasteurized in an Erlenmeyer flask, and inoculation with 3% yogurt cultures (Direct Vat type (DVS) Yo mix consisting of Streptococcus salivrarious subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in ratio 1:1 The result showed that Streptococcus thermophilus counts increased from 4.00 x 106 to 2.40 x 108 (CFU/ml) at an extended time of 6 h, while Lactobacillus bulgaricus counts increased from 5.00 x 106 (CFU/ml) to a maximum count of 1.42 x 108 (CFU/ml) at 5 h during acha milk fermentation. Comparatively, Streptococcus thermophilus count increased from 6.80 x 107 to 1.70 x 108 (CFU/ml), while that of Lactobacillus bulgaricus increased from 1.20 x 107 to 9.60 x 107 (CFU/ml) after 6 h of fermentation in the dairy milk. The maximum specific growth rate of 0.406 h1 and doubling time (td) of 102 min was registered for Lact obacillus bulgaricus, while Streptococcus thermophilus exhibited higher growth with a specific growth rate of 0.416 h-1 at a doubling time of 100 min. The acidifying activity of the lactic acid bacteria showed a lower rate of 0.619 h-1 in the acha milk compared with 1.136 h-1 observed in the dairy milk. The curdling time for the acha milk occurred 1.5 hours after that of the control. These findings confirmed the possibility of producing yogurt from 'acha' based milk as an alternative to conventional cow milk-based yogurt. [ABSTRACT FROM AUTHOR]

We examine the Digitaria filiformis complex to determine the proper taxonomic rank and conservation status of each member. The taxonomy of the D. filiformis complex is debated and includes two widespread taxa, D. filiformis var. filiformis and D. filiformis var. villosa; a rare taxon of southern Florida and the West Indies, D. filiformis var. dolichophylla; and a possibly extinct taxon that supposedly is a single-site endemic in New Hampshire, USA, D. filiformis var. laeviglumis. We conducted molecular analyses and morphologic comparisons of the four members of the D. filiformis complex, together with specimens from Venezuela (morphology only) and Mexico purportedly identified as D. filiformis var. laeviglumis. Based on results of phylogenetic analyses of plastid and nuclear ITS sequences and morphologic comparisons, we elevated taxonomic ranks, recognizing four species in the D. filiformis complex, and circumscribe the Mexican species D. glabrifloris (sp. nov.). Digitaria dolichophylla is much rarer than previously recognized, moving from Secure Globally to Imperiled with extinction (G2). After research and field investigations, we changed the global rank of D. laeviglumis from Globally Historical (GH) to Globally Extinct (GX), as there is virtually no likelihood of rediscovery. [ABSTRACT FROM AUTHOR]

An in-depth genotypic characterisation of a diverse collection of Digitaria insularis was undertaken to explore the neutral genetic variation across the natural expansion range of this weed species in Brazil. With the exception of Minas Gerais, populations from all other states showed high estimates of expected heterozygosity (HE > 0.60) and genetic diversity. There was a lack of population structure based on geographic origin and a low population differentiation between populations across the landscape as evidenced by average Fst value of 0.02. On combining haloxyfop [acetyl CoA carboxylase (ACCase)-inhibiting herbicide] efficacy data with neutral genetic variation, we found evidence of presence of two scenarios of resistance evolution in this weed species. Whilst populations originating from north-eastern region demonstrated an active role of gene flow, populations from the mid-western region displayed multiple, independent resistance evolution as the major evolutionary mechanism. Atarget-site mutation (Trp2027Cys) in the ACCase gene, observed in less than 1% of resistant populations, could not explain the reduced sensitivity of 15% of the populations to haloxyfop. The genetic architecture of resistance to ACCase-inhibiting herbicides was dissected using a genome wide association study (GWAS) approach. GWAS revealed association of three SNPs with reduced sensitivity to haloxyfop and clethodim. In silico analysis of these SNPs revealed important non-target site genes belonging to families involved in herbicide detoxification, including UDPGT91C1 and GT2, and genes involved in vacuolar sequestration-based degradation pathway. Exploration of five genomic prediction models revealed that the highest prediction power (≥0.80) was achieved with the models Bayes A and RKHS, incorporating SNPs with additive effects and epistatic interactions, respectively. [ABSTRACT FROM AUTHOR]

Digitaria insularis is a Poaceae disseminated mainly by seeds that can cause problems in agroecosystems. The objective of this work was to evaluate the influence of the age of D. insularis submitted to mowing on morphophysiological characteristics. Plants were grown in a greenhouse and cut close to the substrate at 21, 35, 49 and 77 days after emergence (DAE) or uncut, with evaluation of the variables up to 105 DAE. Except for chlorophyll b, the other variables were influenced by the age of the plants when cutting (p<0.05). Plant height and number of leaves decreased with increasing cutting age. The highest chlorophyll a content was observed in the cut at 51 DAE. Epicuticular wax mass was greater in the 49 DAE (0.4 mg cm-2) cut. The shoot dry mass decreased with increasing age at the cut, reaching zero (0 g) after 54 DAE. The root dry mass reached the minimum point when the aerial part was cut at 57 DAE. Shoot water content decreased with increasing cutting age. The root water content showed a biphasic behavior, with the lowest water content (18.8%) in the cut at 49 DAE. These results suggest that mowing close to 21 DAE favors the development of D. insularis. Therefore, D. insularis plants in optimal development conditions should be managed by mowing priority between 49 and 60 DAE. [ABSTRACT FROM AUTHOR]

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Crabgrass (Digitaria sanguinalis) is a common malignant weed in corn fields in China. Recently, the acetolactate synthase (ALS) inhibitor, nicosulfuron, has shown decreasing efficacy against crabgrass. In order to elucidate the molecular basis of resistance to nicosulfuron in crabgrass, we conducted bioassays, combined with gene sequence analysis, relative expression and relative copy number analysis, to characterize resistance in crabgrass populations collected from Beijing, Heilongjiang, Jilin and Anhui provinces. Whole-plant dose-response results indicated that only population collected in Heilongjiang province (HLJ) had developed low level of resistance to nicosulfuron compared with the sensitive population (SD22). No known resistant mutation of ALS gene was found in HLJ population. The real-time fluorescence quantitative PCR results showed that the ALS gene copy number did not differ significantly between the HLJ and SD22 populations. However, the ALS gene expression in the HLJ was 2.07-fold higher than that of the SD22 population at 24 h after treatment with nicosulfuron. Pretreatment with the cytochrome P450 (CYP450) inhibitor malathion, piperonyl butoxide (PBO), and the glutathione S-transferase (GST) inhibitor 4-Chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl) all partially reversed HLJ resistance. Among them, the synergistic effect of PBO and nicosulfuron is the most significant. This is the first report of resistance to nicosulfuron in crabgrass through ALS gene overexpression and possible metabolic resistance. [ABSTRACT FROM AUTHOR]

The genus Pyricularia includes species that are phytopathogenic fungi, which infect different species of Poaceae, such as rice and sorghum. However, few isolates have been genetically characterized in North America. The current study addresses this lack of information by characterizing an additional 57 strains of three grasses (Stenotaphrum secundatum, Cenchrus ciliaris and Digitaria ciliaris) from two distant regions of Mexico. A Pyricularia dataset with ITS sequences retrieved from GenBank and the studied sequences were used to build a haplotype network that allowed us to identify a few redundant haplotypes highly related to P. oryzae species. An analysis considering only the Mexican sequences allowed us to identify non-redundant haplotypes in the isolates of C. ciliaris and D. ciliaris, with a high identity with P. pennisetigena. The Pot2-TIR genomic fingerprinting technique resulted in high variability and allowed for the isolates to be grouped according to their host grass, whilst the ERIC-PCR technique was able to separate the isolates according to their host grass and their region of collection. Representative isolates from different host grasses were chosen to explore the pathogenic potential of these isolates. The selected isolates showed a differential pathogenic profile. Cross-infection with representative isolates from S. secundatum and C. ciliaris showed that these were unable to infect D. ciliaris grass and that the DY1 isolate from D. ciliaris was only able to infect its host grass. The results support the identification of pathogenic strains of Pyricularia isolates and their cross-infection potential in different grasses surrounding important crops in Mexico. [ABSTRACT FROM AUTHOR]

The root traits of many warm-season pasture species have not been characterised thoroughly. Depending on the nature of legume root architecture, alternative phosphorus (P) application strategies may improve the success of legume establishment and persistence, particularly if legumes exhibit a spatially responsive root system. The purpose of the present experiment was to investigate the root morphology of several warm-season pasture species and to determine the response of these species to a subsurface application of P fertiliser. Monocultures of two grasses (Panicum coloratum and Digitaria eriantha) and two legumes (Medicago sativa and Desmanthus spp.) were established in pots to investigate root morphology and P acquisition in response to three soil-P distribution treatments. The P fertiliser that was applied to the subsurface 'band' layer was labelled with 32P-radioisotope to determine P recovery. There were significant differences in shoot yield and root morphology among the species. The largest shoot yields were usually produced by plants grown in the uniform high-P treatment, while the grasses generally produced longer roots more efficiently than the legumes across the three soil-P distribution treatments. Nevertheless, each species responded to the banded high-P treatment by acquiring more P from the zone of P enrichment (banded high-P = 31% cf., uniform low-P = 3%, and uniform high-P = 9%). This result suggests that a subsurface application of P fertiliser at the planting stage will benefit warm-season pasture species, particularly grasses that are highly responsive to fertiliser placement. Nevertheless, preferential placement of fertiliser below legumes may improve the productivity of this component if their root systems have more time to respond spatially. [ABSTRACT FROM AUTHOR]

Background: Haloxyfop‐P‐methyl, an acetyl‐CoA carboxylase (ACCase)‐inhibiting herbicide, has been extensively used to control grass weeds. Widespread use of haloxyfop‐P‐methyl in cotton fields in China has led to the development of glutathione transferase (GST)‐mediated resistance in Digitaria sanguinalis. An RNA‐seq analysis identified DsGSTU1, a tau class glutathione transferase from the D. sanguinalis transcriptome as a potential candidate. Here, we cloned DsGSTU1 from D. sanguinalis young leaf tissues and subsequently characterized DsGSTU1 by a combination of sequence analysis, as well as functional heterologous expression in rice. RESULTS: The full‐length coding DNA sequence (CDS) of DsGSTU1 is 717 bp in length. Higher DsGSTU1 expression was observed in haloxyfop‐P‐methyl‐resistant (HR) D. sanguinalis than in haloxyfop‐P‐methyl‐susceptible (HS) plants. Overexpression of the DsGSTU1 gene was confirmed by transformation into the wild‐type (WT) Nipponbare rice with pBWA(V)HS, a recombinant expression vector. GST activity in transgenic rice seedlings was 1.18–1.40‐fold higher than the WT rice seedlings before and after haloxyfop‐P‐methyl treatment, respectively. Additionally, transgenic rice seedlings overexpressing DsGSTU1 were less sensitive to haloxyfop‐P‐methyl. CONCLUSION: Our combined findings suggest that DsGSTU1 is involved in metabolic resistance to haloxyfop‐P‐methyl in D. sanguinalis. A better understanding of the major genes contributing to herbicide‐resistant D. sanguinalis facilitates the development of resistance management strategies for this global invasive grass weed. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Simple Summary: Digitaria sanguinalis is considered one of the most malignant grass weeds worldwide and is widely distributed in Chinese maize fields. In this study, we explored the mechanism of metabolic resistance via cytochrome P450s of the LJ-01 population of Digitaria sanguinalis, which evolved high-level resistance to the ALS inhibitor nicosulfuron and evolved cross- and multiple resistance to thifensulfuron-methyl and pyrazosulfuron-ethyl, as well as the PS II inhibitors bromoxynil octanoate and atrazine. This study provides scientific and theoretical guidance for the control of resistant populations in D. sanguinalis. Large crabgrass (Digitaria sanguinalis (L.) Scop.) is one of the major malignant grass weeds in Chinese maize (Zea mays L.) fields, and it has recently developed resistance to the acetolactate synthase (ALS)-inhibiting herbicide nicosulfuron. This study focused on a suspected nicosulfuron-resistant (R) population (LJ-01) of D. sanguinalis, collected from Lujiang County in Anhui Province, China, to explore the resistance level and potential resistance mechanism. Whole-plant dose–response testing confirmed that the LJ-01 population evolved a high level of resistance to nicosulfuron (11.5-fold) compared to the susceptible (S) population, DY-02. The ALS gene sequencing and relative expression assay of the R plants indicated that target gene mutation and overexpression were not responsible for the resistance phenotype. However, pretreatment with malathion, a known cytochrome P450 monooxygenase (P450) inhibitor, alleviated the resistance of the R population to nicosulfuron by approximately 36%. High-performance liquid chromatography (HPLC) analysis revealed that the R plants metabolized nicosulfuron faster than the S plants. Moreover, cross-resistance testing suggested that the R population exhibited low levels of resistance to thifensulfuron-methyl and pyrazosulfuron-ethyl, but it remained susceptible to rimsulfuron. Multiple resistance patterns showed that the R population evolved low resistance to the photosystem inhibitors bromoxynil octanoate and atrazine and sensitivity to the acetyl-CoA carboxylase (ACCase) inhibitor cyhalofop-butyl and the 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors tembotrione, mesotrione, and topramezone. This study reports, for the first time, the simultaneous resistance to ALS and different photosystem inhibitors in D. sanguinalis. The nicosulfuron resistance observed in the R population could primarily be attributed to an enhanced metabolism involving P450 enzymes. [ABSTRACT FROM AUTHOR]

Digitaria is a large pantropical genus, which includes a number of economically problematic agricultural weeds. Difficulties in species identification and the circumscription of the genus have previously hindered progress in understanding its evolution and developing a stable classification. We investigate the evolutionary history of Digitaria by combining two approaches: (i) phylogenetic analyses of the currently available Sanger sequence data with previously unpublished sequences mainly from South East Asia, and (ii) newly generated genomic data from low-copy nuclear genes obtained using the Angiosperms353 probe kit, with new data mainly from Madagascar. Both methods gave congruent results. The combination of these results allowed us to confirm a new clade structure within Digitaria lineages, in partial agreement with the previous morphology-based classifications. We confirm that Digitaria as traditionally circumscribed is not monophyletic, comprising Anthephora , Baptorhachis , Chaetopoa , and Chlorocalymma. We present an inference of key character evolution with morphological support for clades with spikelets arranged in binate and ternate groups, with variable trichome morphology, spikelet length, and culm length. Geographical clade structure is also observed. No phylogenetic signal of weedy function was observed. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to detect the protective effect of abscisic acid on chilling injury of Digitaria sanguinalis ( L ) Scop, and whether this effect is related to antioxidant enzymes and osmotic adjustment. [ Metbods] D. sanguinalis plants were sprayed with abscisic acid solution, and exposed to cold stress at 15oC for 3 d after one day and then at 5oC for 25 to 30 d in a growth chamber. The changes of plant osmotic potential under this treatment were detected. [Results] Under low temperature stress, the osmotic potential of plants in the abscisic acid treatment and the control increased, but the osmotic potential level of the abscisic acid treatment plants was lower. The SOD activity of plants in the ABA treatment and the control decreased under low temperature stress. Under low temperature stress, the activity of catalase and peroxidase in ABA-treated plants was higher than that in control plants. [ Conclusions] This study provides a theoretical basis for the impact of abscisic acid on the physiological response of D. sanguinalis to cold injury. [ABSTRACT FROM AUTHOR]

The low nutritive value of pastures in tropical regions represents a limitation in the productivity of grazing ruminants. The objective was to determine the in vitro chemical and fermentative characteristics of nine tropical grasses (Aruana [Panicum maximun Jacq. cv. Aruana], Bermuda [Cynodon dactylon L.], Estrella de África [Cynodon Cynodon nlemfuensis Vanderyst], Insurgente [Brachiaria brizantha Hochst. Stapf.], Llanero [Andropogon gayanus Kunth], Mombaza [Panicum maximun Jacq. cv. Mombaza], Pará [Brachiaria mutica Stapf], Pangola [Digitaria eriantha Steud.], and Tanzania [Panicum maximun Jacq. cv. Tanzania]) at three regrowth ages (30, 45, and 60 days). The chemical analysis was used to determine the concentrations of dry matter (DM), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and ash (Ce). The in vitro trial measured partial (24, 48, and 72 h) and cumulative biogas and methane production, fermentation kinetics estimators (A, b, and k), dry matter degradation (DMD) and detergent neutral fiber degradation (NDFD), pH, and ammonia nitrogen (N-NH3). The experimental design was completely randomized at each regrowth age. In conclusion, based on chemical analysis and fermentative characteristics, Pangola and Estrella pastures performed better at each regrowth age. [ABSTRACT FROM AUTHOR]

Simple Summary: A major challenge for livestock producers in a cool-season grass system is the seasonality of forage production, and in particular, the quantity and quality gap that usually occurs during the summer. Crabgrass is a warm-season annual crop with better forage quality than most other common summer annual grasses and can potentially be mixed with summer annual legumes. In this study, we evaluated on field plots the effect of intercropping two summer legumes (cowpea and lablab) with crabgrass on forage yield, nutritional composition, and fiber digestibility. We determined the degradability of the neutral detergent fiber under in vitro conditions using rumen fluid from lactating dairy cows. The results of this study showed that mixing crabgrass with cowpea and lablab partially mitigated the biomass yield drag from the legume monocultures while increasing crude protein concentration and fiber digestibility compared to the monoculture of crabgrass. Under the conditions of this study, the biggest impact of intercropping legumes was observed on the first of three harvests, which suggests that the evaluated legumes might not be an ideal complement for a multi-cut grass like crabgrass. The objective of this study was to evaluate the effects of interseeding crabgrass (CG) with two annual summer legumes on forage nutritional composition, dry matter (DM) yield, and in vitro fiber digestibility. The study was conducted as a randomized complete block design with four replicates per treatment. Plots were randomly assigned to one of six forage mix treatments. Crabgrass, cowpea (CWP), and lablab (LL) were planted in monoculture or in mixtures, resulting in six treatments. Throughout the growing season (three cuts), CG had the highest biomass yield, followed by the CG grown in mixtures with CWP and LL, whereas the two annual legume monocultures had the lowest yield. Cowpea and LL planted in monocultures had the highest concentration of CP and fiber digestibility, while the CG monoculture had the lowest. Furthermore, growing CG in a mixture with CWP and LL boosted the CP concentration and fiber digestibility to intermediate levels to those observed between both legume monocultures and CG. Regardless of treatment, the highest forage quality and yield was observed in the first harvest, with a drastic decline in the following harvests. In conclusion, the benefits of mixing crabgrass with legumes might be less than expected and should be carefully evaluated by livestock producers, especially when considering the effects of DM yield, forage quality, and pasture seeding costs. [ABSTRACT FROM AUTHOR]

4,8-dihydroxy-l-tetralone (4,8-DHT) is an allelochemical isolated from the outer bark of Carya cathayensis that acts as a plant growth inhibitor. In order to explore the mechanism of 4,8-DHT inhibiting weed activity, we treated three species of Digitaria sanguinalis, Arabidopsis thaliana, and Poa annua with different concentrations of 4,8-DHT and performed phenotype observation and transcriptome sequencing. The results showed that with an increase in 4,8-DHT concentration, the degree of plant damage gradually deepened. Under the same concentration of 4,8-DHT, the damage degree of leaves and roots of Digitaria sanguinalis was the greatest, followed by Arabidopsis thaliana, while Poa annua had the least damage, and the leaves turned slightly yellow. Transcriptome data showed that 24536, 9913, and 1662 differentially expressed genes (DEGs) were identified in Digitaria sanguinalis, Arabidopsis thaliana, and Poa annua, respectively. These DEGs were significantly enriched in photosynthesis, carbon fixation, glutathione metabolism, phenylpropanoid biosynthesis, and oxidative phosphorylation pathways. In addition, DEGs were also enriched in plant hormone signal transduction and the MAPK signal pathway in Arabidopsis thaliana. Further analysis showed that after 4,8-DHT treatment, the transcript levels of photosynthesis PSI- and PSII-related genes, LHCA/B-related genes, Rubisco, and PEPC were significantly decreased in Digitaria sanguinalis and Arabidopsis thaliana. At the same time, the transcription levels of genes related to glutathione metabolism and the phenylpropanoid biosynthesis pathway in Digitaria sanguinalis were also significantly decreased. However, the expression of these genes was upregulated in Arabidopsis thaliana and Poa annua. These indicated that 4,8-DHT affected the growth of the three plants through different physiological pathways, and then played a role in inhibiting plant growth. Simultaneously, the extent to which plants were affected depended on the tested plants and the content of 4,8-DHT. The identification of weed genes that respond to 4,8-DHT has helped us to further understand the inhibition of plant growth by allelochemicals and has provided a scientific basis for the development of allelochemicals as herbicides. [ABSTRACT FROM AUTHOR]

The search for sustainable agriculture has increased interest in using endophytic bacteria to reduce fertilizer use and increase stress resilience. Stress-adapted plants are a potential source of these bacteria. Some species of these plants have not yet been evaluated for this, such as pangolão grass, from which we considered endophytic bacteria as potential plant growth promoters. Bacteria from the root, colm, leaves, and rhizospheric soil were isolated, and 132 strains were evaluated for their in vitro biological nitrogen fixation, IAA and siderophores production, and phosphate solubilization. Each mechanism was also assessed under low N availability, water stress, and low-solubility Fe and P sources in maize greenhouse experiments. All strains synthesized IAA; 63 grew on N-free media, 114 synthesized siderophores, and 46 solubilized P, while 19 presented all four mechanisms. Overall, these strains had better performance than commercial inoculant in all experiments. Still, in vitro responses were not good predictors of in vivo effects, which indicates that the former should not be used for strain selection, since this could lead to not testing strains with good plant growth promotion potential. Their heterologous growth promotion in maize reinforces the potential of stress-adapted plant species as potential sources of strains for inoculants. [ABSTRACT FROM AUTHOR]

Acha is rich in pentosan; a carbohydrate compound with good water absorption capacity properties that could be utilized in production of pasta products like noodles. This study investigated the effect of chemical modification (oxidation, acetylation, pre-gelatinization and dual) on proximate composition, functional, pasting, mineral, color and antioxidant properties of acha (Digitaria exilis) starch and its resultant noodles making potential. Starch was extracted from acha grains and then dried, milled and sieved through a 75-micron screen and the native and modified acha starch were substituted into wheat flour at 15% to produce noodles. Results showed that modified acha starches have significant influenced (p<0.05) in all the quality attributes evaluated. The modified acha starches showed least moisture content with an increase in protein and ash contents, while carbohydrates decreases when compared to the native starch. Modification increases and improved the functional characteristics of the acha starches. Pasting properties of native starch was significantly higher than modified starches. Some minerals element of native starch was most predominant than the modified starches. There was a slight reduction in phenolic and flavonoid compounds while colour of the acha sample was relatively higher due to modification. Conclusively, this study showed that starch modification improved the quality of acha and sensory scores revealed that the most preferred acha noodles are from pregelatinized acha starch. Thus, chemical modification could serve as alternative food grade starch additive for the possibility of new food applications. [ABSTRACT FROM AUTHOR]

During a survey of the mycobiota of sourgrass (Digitaria insularis), a graminaceous weed from Brazil, severe foliage blight symptoms were observed on plants at different places of the state of Minas Gerais. A fungus identified as Bipolaris yamadae, after a polyphasic study, including analysis of ITS, GPDH and TEF-1α genes, was isolated from diseased tissues. Pathogenicity to sourgrass was confirmed through inoculations of healthy plants. This is the first report of B. yamadae causing foliage blight on D. insularis in Brazil and worldwide. [ABSTRACT FROM AUTHOR]

This study evaluated the bromatological and histological features of native African grasses under grazing in Brazilian semi-arid rangelands. An experimental grid design was used in a randomised sampling method for four replicate samples of three African grasses. The grasses evaluated were: Cenchrus ciliaris L., Digitaria pentzii Stent. and Megathyrsus maximus (Jacq.). The bromatological and histological traits analysed included dry matter (DM), crude protein (CP), neutral detergent fibre corrected to ashes and protein (NDFap), lignin, mesophyll, vascular bundle, phloem, xylem, vascular sheath, sclerenchyma, bulliform cells, and the adaxial and abaxial epidermis. The type of grass and grazing cycle correlated with DM, NDF and lignin (p < 0.05), whereas CP was not affected by these factors (p > 0.05). Dry matter ranged between 128 and 304 g kg−1; CP ranged between 90 and 167 g kg−1; NDFap between 542 and 707 g kg−1, and lignin between 10 and 40 g kg−1. The proportion of xylem (8.4%), vascular sheath (30.5%) and total vascular bundles (38.1%) were greater in M. maximus (p < 0.05). The percentage of sclerenchyma did not differ between species (p > 0.05). Digitaria pentzii and C. ciliaris had a greater proportion of mesophyll than M. maximus (p < 0.05). Of the three grasses analysed. Digitaria pentzii exhibited the highest forage quality, because it had the lowest concentration of fibre and lignin, with lower proportions of lignified tissues. [ABSTRACT FROM AUTHOR]

Increased planting density can provide crops a competitive advantage over weeds. This study appraised the growth and seed production of two noxious grassy weeds, i.e. feather fingergrass (Chloris virgata SW.) and junglerice [Echinochloa colona (L.) Link] in response to different mungbean [Vigna radiata (L.) R. Wilczek] densities (0, 82, 164, 242, and 328 plants m−2). A target-neighbourhood study was conducted using a completely randomized design with five replications, and there were two experimental runs in 2016–2017. The leaf, stem, and total aboveground biomass of C. virgata was 86, 59, and 76% greater than E. colona. For seed production, E. colona outnumbered C. virgata by producing 74% more seeds. Mungbean density-mediated suppression of height was more pronounced for E. colona compared with C. virgata during the first 42 days. The presence of 164–328 mungbean plants m−2 reduced the number of leaves of E. colona and C. virgata by 53–72% and 52–57%, respectively. The reduction in the inflorescence number caused by the highest mungbean density was higher for C. virgata than E. colona. C. virgata and E. colona growing with mungbean produced 81 and 79% fewer seeds per plant. An increase in mungbean density from 82 to 328 plants m−2 reduced the total aboveground biomass of C. virgata and E. colona by 45–63% and 44–67%, respectively. Increased mungbean plant density can suppress weed growth and seed production. Although increased crop density contributes to better weed management, supplemental weed control will be needed. [ABSTRACT FROM AUTHOR]

This work was carried out with the objective of check the resistance of populations of Digitaria insularis to the herbicide glyphosate in the municipalities of Jaboticabal and Itápolis (SP). The experiment was carried out in a greenhouse, in a 2 x 7 factorial scheme, in a randomized block design was used, with four replications. Were evalueted two populations of Digitaria insularis and seven doses of glyphosate (0D, 1/4D, 1/2D, D, 2D, 4D and 8D, where D is the recommended dose of 450 g ha-1 of acid equivalent). Visual evaluations of control were evaluated at 5, 10, 15 and 20 days after herbicide application (DAA), and, at the end, the dry mass of the plants. The control and fresh weight reduction estimates were fitted to a non-linear log-logistic regression model and the I50, I80 and RF of the populations were calculated. The highest control scores were achieved 20 days after application and the highest amounts of dry mass were from treatments with lower doses. The two populations of Digitaria insularis, from Jaboticabal and Itápolis, were considered to have low resistance to the herbicide glyphosate, indicating the existence of selection pressure for the herbicide glyphosate. [ABSTRACT FROM AUTHOR]

Large crabgrass (Digitaria sanguinalis) is one of the most problematic weeds in summer crops in Argentina. Emergence throughout the season of several cohorts allows the weed to escape postemergence control. Demographic models are useful tools to understand and compare the effect of different agronomic management decisions on weed population growth, as well as to identify critical functional stages that affect population growth rates. The objectives of this work were (i) to study population dynamics of D. sanguinalis in soybean, (ii) to determine the effect of glyphosate application timing on weed demographic parameters and soybean yield losses, and (iii) to evaluate the effect of weed density on soybean yield loss. A field experiment was conducted in two locations, in a completely randomized design with three replicates. Treatments included a control without glyphosate and glyphosate applied at soybean stages V4 or R1. The demographic stages (initial seedbank, seedlings, and adult plants) and parameters (establishment, survival, and fecundity) were estimated. Reproductive organs were evaluated in each cohort, including raceme per plant, spikelets per raceme, and seeds per spikelet. Weed and crop biomass and yield crop were assessed at harvest. Three cohorts were identified, the first of which emerged in November and contributed 93% of the total seedlings and 71% of the total adults. Glyphosate applied at V4 reduced the survival rate of the first cohort, as well as the total shoot biomass and the fecundity rate, increasing the biomass and crop grain yield. Both application timings affected tillers per plant, racemes per tiller, and fertile spikelets per raceme. Glyphosate at R1 did not effectively reduce weed competition, but reduced seed production as application at V4. Yield losses estimated with the model of the rectangular hyperbola according to weed density showed a yield loss at low densities (I) of 18%, and a maximum yield loss (A) of 82%. To avoid yield losses, herbicide applications targeting the first cohort are more effective than later applications targeting subsequent cohorts. However, at both times glyphosate applications reduced the number of seeds entering the seedbank, and therefore the population growth rate. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the use of alternative herbicides to ACCase inhibitors to control Digitaria insularis (sourgrass) during pre-sowing soybean desiccation. Two field experiments were conducted with two temporal replicates under different climatic conditions, with the following treatments: imazethapyr + glyphosate, clethodim + fluroxypyr, chlorimuron + glyphosate, imazapic + imazapyr, mesotrione + atrazine + glyphosate, tembotrione + atrazine + glyphosate, nicosulfuron + atrazine and imazamox + glyphosate, all of which were composed of a sequential application of glufosinate ammonium. The water stress conditions in experiment 1 compromised the efficacy of acetolactate synthase enzyme (ALS) inhibitor herbicides in the control of sourgrass. Even under water restriction conditions, the treatments containing mesotrione + atrazine + glyphosate and tembotrione + atrazine + glyphosate provided control greater than 80%. In experiment 2, the combination of ALS inhibitors with glyphosate proved to be a great alternative for the management of sourgrass control. All treatments showed no significant phytotoxicity in soybean for either experiment. [ABSTRACT FROM AUTHOR]

This study evaluated some physical, physicochemical, and functional properties of three fonio types (early maturing, intermediate maturing, and late maturing) cultivated in the Northern part of Ghana. Black fonio types were purchased from a local farmer at Chereponi, sorted, milled, and stored for further analysis. Nutritional composition, physicochemical and functional properties were determined using appropriate methods. Proximate and nutritional compositions of the black fonio types varied. Thousand-grain weights and bulk density of the fonio types ranged from 0.407-0.513 g and 0.655-0.688 g/mL, respectively. Water absorption capacity, solubility, and swelling power of the samples ranged from 1.63-1.97 mL/g, 5.43-6.27%, and 5.88-6.33 g/g, respectively. Viscosities of the intermediate fonio types were lower than those of the other two fonio types. The fonio samples showed a typical A-type crystal starch structure. The three fonio types studied have potential applications in infant weaning food formulations and even in bakery and related products to address food security, particularly in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

Few studies have evaluated seed quality in native to semi-arid zones' grasses. The objective was to validate published methodologies to carry out viability tests using Tetrazolium (TZ) test for caryopses (Cs) of Bouteloua curtipendula, Leptochloa dubia, Digitaria californica, Setaria macrostachya and Pennisetum ciliare, considering the imbibition time, TZ concentration and cut in the Cs. In addition, showing staining patterns according to evaluated treatments. Viability and vigor data was expressed as percent and hence transformed to arcsine. A completely randomized experimental design was carried out using a factorial arrangement: A) imbibition time before cutting; B), type of cut; C), TZ concentration, and Tukey's test (p<0.05) for mean comparisons. The Cs longitudinal cut was the most adequate (P<0.05), it allows observing Cs' embryonic structures and determining damaged sites; however, the Cs of D. californica and S. machrostachya are permeable to TZ and it was not necessary to section the Cs, which facilitates its evaluation. The ISTA protocols for viability in Poaceae are not directly applicable for the species evaluated, because the imbibition time for these species is not considered, which was 3 to 4 hours. It is recommended to use a 0.5% TZ concentration and evaluate 12 hours after the imbibition time between Cs and the TZ solution. [ABSTRACT FROM AUTHOR]

Background: Crabgrass (Digitaria ciliaris, Poaceae) is a globally distributed weed, including in Afro-Eurasia, America, and Australia. As a highly gregarious plant, crabgrass is an important habitat for a diverse array of insects, and a potential habitat for agricultural pests. To compare the insect communities associated with the crabgrass community, insects were sampled using sweep sampling (100 sweeps per sample) at five sites, including Daejeon (Daejeon and Gap rivers), Anseong, Namhae, and Inje, with a focus on the Daejeon River. Results: A total of 5,888 individual insects belonging to eight orders, 42 families, and 115 species were collected from the five sites. Both the number of species and individuals of Hemiptera were the highest at all of the sites. In the present study, 73% of the insect population fed on D. ciliaris as a host plant. The dominant species in the D. ciliaris community was Laodelphax striatellus (Delphacidae), being ubiquitous at all the sites which showed a high abundance of rice pests in the communities and the suitability of D. ciliaris as an alternative host plant for them. The Shannon-Wiener diversity index was highest in Inje on 17 September (2.88), and the Chao1-bc diversity index was highest in the Gap River on 5 September (80). The sampling efficiency of 100 sweep samples (sample coverage) was calculated to be as high as 90%. The results of the samples taken from September to November in the Daejeon River showed that the number of species and individuals decreased gradually over time, and the number of dominant species decreased sharply between September and October. Similarity analysis indicated that sampling dates that were closer together yielded sampled assemblages with higher faunal similarity. In addition, in each sampling, the difference in the minimum temperature during the two-week period prior to sampling and faunal similarities were negatively correlated. Conclusions: This study provides foundational data that could enhance our understanding of insect diversity in D. ciliaris. The data can facilitate ecological conservation and management of Korean grasslands generally, as well as identification of potential pests that may disperse from D. ciliaris communities to nearby farmland. [ABSTRACT FROM AUTHOR]

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Glyphosate alone or a tank mixture of glyphosate and 2,4-D is commonly used for broad-spectrum weed control under fallow conditions in Australia. Air temperature or mixing glyphosate with 2,4-D, may influence the efficacy of glyphosate on feather fingergrass (Chloris virgata Sw.), a problematic summer-season weed of Australia. Dose–response studies were conducted with four populations of feather fingergrass under temperature-controlled glasshouse conditions (35/25 °C and 25/15 °C at 12 h/12 h) to assess the level of glyphosate resistance in relation to temperature regimes. Four parameter log-logistic models were used to develop dose–response curves. Based on plant mortality percentage, LD50 (lethal dose for 50% mortality) values of glyphosate at 25/15 °C for populations Ch, SGM2, SGW2, and CP2 were 137, 60, 650, and 1067 g ae ha−1, respectively. However, at 35/25 °C, the corresponding LD50 values were 209, 557, 2108, and 2554 g ae ha−1, respectively. A similar response was observed for the parameter GR50 (dose for 50% growth reduction) values of glyphosate. These results indicate that populations SGW2 and CP2 are highly glyphosate-resistant and in the summer season, it may be very difficult to control these populations due to poor glyphosate efficacy. These results further suggest that the efficacy of glyphosate for feather fingergrass control can be improved if applied during cooler temperatures (25/15 °C) or the spring season compared with warmer temperatures (35/25 °C) or the summer season. In another study, 2,4-D antagonized glyphosate remarkably in the CP2 (glyphosate-resistant) population but only marginally in the Ch (glyphosate-susceptible) population. Thus, it is not advisable to mix 2,4-D with glyphosate for the control of glyphosate-resistant feather fingergrass populations. The results further suggest that the use of this mixture is useful if the feather fingergrass is not glyphosate-resistant; however, the use of the mixture is to be avoided if the population is glyphosate-resistant in order to not exacerbate the potential resistance problem. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chlorsulfuron, metsulfuron‐methyl and ethametsulfuron can damage sensitive crops in rotation pattern as a result of their long persistence in soil. To explore novel sulfonylurea (SU) herbicides with favorable soil degradation rates, four series of SUs were synthesized through a structure‐based drug design (SBDD) strategy. RESULTS: The target compounds, especially Ia, Id and Ie, exhibited prospective herbicidal activity against dicotyledon oil seed rape (Brassica campestris), amaranth (Amaranthus retroflexus), monocotyledon barnyard grass (Echinochloa crusgalli) and crab grass (Digitaria sanguinalis) at a concentration of 15 a.i. g ha−1. Additionally, Ia, Id and Ig displayed excellent inhibitory effects against AtAHAS, with Kapp i values of 59.1, 34.5 and 71.8 μm, respectively, which were much lower than that of chlorsulfuron at 149.4 μm. The π‐π stack and H‐bonds between the Ia conformation and AtAHAS in the molecular docking results confirmed the series of compounds to be conventional AHAS inhibitors. In alkaline soil (pH = 8.46), compounds Ia–Ig revealed various degrees of acceleration in the degradation rate compared with chlorsulfuron. Besides, compound Ia showed considerable wheat and corn safety under postemergence at the concentration of 30, 60 and even 120 a.i. g ha−1. CONCLUSION: Overall, based on the synthetic procedure, herbicidal activity, soil degradation and crop safety, the Ia sulfonylureas series were chosen to be investigated as prospective AHAS inhibitors. The 5‐dimethylamino group on SUs accelerated the degradation rate at different levels in alkaline soils which seems to be controllable in conventional cropping systems in their further application. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To optimize integrated weed management, it is essential to understand the competitive ability of maize hybrids with new traits when coexisting with the weed community. Thus, the aim of this study was to evaluate the competitive ability of the maize against E. indica and D. insularis weeds under greenhouse (controlled conditions) and in the field by additive and replacement series designs, with different densities for each condition. In greenhouse experiments, maize coexisting with E. indica resulted in negative relative growth for leaf area and shoot dry mass, indicating damage to both species. However, maize with D. insularis did not exhibit negative relative growth, suggesting a different interaction. The analysis of relative competitiveness and aggressiveness revealed significant values for maize with D. insularis , indicating a competitive relationship. In contrast, maize with E. indica showed non-significant values, suggesting a less competitive interaction. In field experiments, the full model and reduced models showed good fit to the data, with non-significant differences between them, indicating that the interference of these weed species on maize yield were similar. The Principal Component Analysis identified four principal components. For PCs 1 and 2, chlorophyll-related variables exhibited a high relative contribution, showing a positive correlation with cases involving high density of D. insularis. Variables related to ear insertion height, plant height, stem diameter, and stand of plants had greater relative importance for PC 1, especially for cases with higher density of E. indica. This highlights the resilience of maize to competitive conditions and suggests that its capacity for rapid growth in height makes this crop effective in competition for light, even against other C4 species. • The weed competition pattern is influenced by the environment in which the experiment is carried out. • E. indica has greater competitive ability than the D. insularis in low density. • Principal component analysis indicates that morphophysiological variables were affected differently depending on the weed. [ABSTRACT FROM AUTHOR]

Crabgrass (Digitaria spp.) is deemed as a productive and nutritious warm‐season annual forage for livestock in the U.S. transition zone. However, there is limited information about nitrogen (N) source and rate effects on productivity and nutritive value of crabgrass in North Carolina. Herbage accumulation (HA), N removal, crude protein (CP), total digestible nutrients (TDN), and tissue nitrate (NO3−) concentrations were evaluated for 2 yr (2020 and 2021) in two physiographic regions (Piedmont and Coastal Plain). Treatments were five rates of chemical N fertilizer (up to 480 kg N ha−1), five rates of plant‐available N from broiler poultry litter (up to 472 and 399 kg N ha−1 in 2020 and 2021, respectively), and one control (zero N). Overall crabgrass responses were not different between N sources. At Coastal Plain, HA increased from 4,990 kg dry matter (DM) ha−1 and plateaued at 7,136 kg DM ha−1 at an agronomic optimum N rate (AONR) of 198 (SE = 49) kg N ha−1. At Piedmont, HA responses were erratic, estimation of an AONR was not possible, and HA values were approximately half or less to those at Coastal Plain. Removal of N was linearly associated with HA. Increasing N rate had a marginal positive effect on CP (ranged from 126 to 154 g kg−1) and no effect on TDN (averaged 626 g kg−1). Tissue NO3− values were below the toxic threshold for feeding livestock. Poultry litter is an effective N source for crabgrass. Nitrogen rate effects were more apparent on crabgrass' productivity; nutritive value was generally high regardless of N rate and source. Core Ideas: Poultry litter is an effective N source for crabgrass production.At Coastal Plain herbage accumulation plateaued at 7,136 kg DM ha−1 at an agronomic optimum N rate of 198 (SE = 49) kg N ha−1.Herbage accumulation at Piedmont was erratic and approximately half or less than Coastal Plain.Concentrations of crude protein ranged from 126 to 154 g kg−1 and calculated total digestible nutrients averaged 626 g kg−1.Tissue NO3− values were mostly below the toxic threshold for feeding livestock. [ABSTRACT FROM AUTHOR]

A series of new acylthiourea derivatives were synthesized and characterized. The results of preliminary herbicidal activity tests showed that most compounds had good herbicidal activity against Digitaria adscendens and Amaranthus retroflexus, especially for compounds 4b (N-(2-chloro-4-methylsulfonylbenzoyl)-N'-(2-chlorophenyl) thiourea) and 4f (N-(2-chloro-4-methylsulfonylbenzoyl)-N'-(2,3-dichlorophenyl) thiourea). In vivo acetylhydroxylate synthase (AHAS) enzyme activity inhibition tests showed that all compounds had inhibitory activities against the enzyme at a concentration of 100 mg·L−1, with the highest inhibition rate up to 37.05% (compound 4f). In addition, molecular docking analysis was conducted by using the yeast AHAS as the target enzyme. The results of molecular docking were similar to the bioassay experiments, showing compounds 4b and 4f were potent inhibitors of AHAS. [ABSTRACT FROM AUTHOR]

Context: Different environmental factors occurring during seed development could be responsible for maternal effects on seed dormancy. Understanding these effects on Digitaria sanguinalis (L.) Scop seeds would help to predict it's seedling emergence. Aims: To study D. sanguinalis maternal effects on seed dormancy level under environmental variations imposed by soybean (Glycine max L.) crop, changing (1) nutrient availability, (2) radiation and (3) soybean canopy presence during different phenological stages of the weed. Methods: Field plots experiments under semi-controlled conditions were established to reach these objectives. Key results: Among different factors evaluated, radiation was the most important factor, mainly during the reproductive stages of the weed. The reduction in solar radiation received by the mother plant diminished seed dormancy level even in those panicles receiving full sunlight in shaded plants. Conclusions: Results suggest that solar radiation and temperature operate together in the mother plants to modify seed dormancy level. Implications: Crop management decisions such as long crop cycles, late sowing date and narrow inter-row distances would reduce seed dormancy level and would anticipate a concentrated seedling emergence of the weed. Understanding weed seedling emergence process is very important for researchers and producers to design successful weed management strategies reducing weeds population. In some weeds, seed dormancy is defined during seed development in mother plant, and allows weeds to increase the emerge windows and avoid controls. In our work, we found that the reduction in solar radiation received by the mother plant diminished seed dormancy level which should be considered by producers to establish weed management strategies in the next season. [ABSTRACT FROM AUTHOR]

Across much of the eastern United States, tall fescue [TF; Schedonorus arundinaceus (Schreb.) Dumort.], a cool‐season (i.e., C3) perennial grass, is the primary forage for pasture systems, thereby leaving producers vulnerable to reduced summer forage production and drought. Warm‐season (i.e., C4) forages can complement existing production systems by supplementing summer forage production and drought resiliency. Therefore, our objective was to compare five, C4 forage options in a grazing trial: switchgrass (SW; Panicum virgatum L.), eastern gamagrass (EG; Tripsacum dactyloides L.), a big bluestem (Andropogon gerardii Vitman) and indiangrass (Sorghastrum nutans L. Nash) blend (BBI), bermudagrass (BG; Cynodon dactylon L. Pers), and crabgrass (CG; Digitaria sanguinalis L. Scop.). Research was conducted 2014–2016 at two locations in Tennessee. Weaned beef heifers (237–242 kg initial weight) grazed 1.2‐ha pastures with three replications per species and location. Average daily gains (kg d−1) (0.62 [BBI], 0.41 [BG], 0.44 [CG], 0.42 [EG], 0.51 [SW]), grazing days (d ha−1) (412 [BBI], 459 [BG], 455 [CG], 664 [EG], 617 [SW]), and total gain (kg ha−1) (259 [BBI], 186 [BG], 200 [CG], 276 [EG], 315 [SW]) all varied among forages (P <.001). Similarly, forage nutritive values differed (P <.001) among forages: season‐long crude protein ranged from 94 (BG) to 115 (CG and EG) g kg−1, neutral detergent fiber (NDF), 601 (CG)–680 (SW) g kg−1, and acid detergent fiber (ADF) 379 (BG)–417 (EG) g kg−1. These forage options should be evaluated in the context of TF pastures to establish a broader understanding of their contribution within an overall forage system. Core Ideas: The C4 grasses provide a beneficial complement to C3‐dominated pasture systems.Native grasses tended to have greater rates of gain and grazing days than bermudagrass or crabgrass.Overall, rates of gain for the forages in this study were lower than in comparable studies.Native grasses had greater total gain per hectare than bermudagrass or crabgrass.Bermudagrass and crabgrass provided more grazing days during late summer than native grasses. [ABSTRACT FROM AUTHOR]

Wild oat (Avena fatua L.) and feather fingergrass (Chloris virgata Sw.) are among the most problematic weed species in Australian winter and summer cropping systems, respectively. Pot trials were conducted in respective seasons to evaluate the integrated effect of simulated grazing and foliar-applied herbicides on the control of these weed species. Different herbicides were applied 1, 5, and 12 d after grazing on A. fatua plants and 1, 3, 7, 10, and 14 d after grazing on C. virgata. In general, the efficacy of herbicides was better on A. fatua when applied 5 or 12 d after grazing (i.e., 7–20 cm tall plants) and 7 to 14 d (i.e., 10–22 cm tall plants) after grazing on C. virgata. Clethodim 90 g a.i.·ha−1, and haloxyfop 52 and 78 g a.i.·ha−1 resulted in 100% mortality of A. fatua seedlings, irrespective of their application timings. Delayed application (5 or 12 d after grazing) of clethodim 60 g a.i.·ha−1 and pinoxaden 20 and 30 g a.i.·ha−1 resulted in 100% mortality of A. fatua. Glyphosate at the field rate (370 g a.e. ha−1) was the least effective herbicide to control A. fatua plants after grazing. Glufosinate application after grazing resulted in the greatest mortality (69 to 81%) of C. virgata. Depending on application timing, only glufosinate was able to provide complete control of C. virgata seed production. Butroxydim, clethodim, and haloxyfop were found to be promising herbicides to manage C. virgata after grazing but their applications had to be delayed by 7 to 14 d after grazing. This study identified several successful herbicide treatments that could be applied after grazing or mowing for integrated control of A. fatua and C. virgata. However, to achieve complete control of C. virgata, the application of these herbicides needs to be followed by other tools, including additional herbicide applications. [ABSTRACT FROM AUTHOR]

To discover new compounds with favorable herbicidal activity, a range of phenylpyridine moiety-containing pyrazole derivatives were designed, synthesized, and identified via NMR and HRMS. Their herbicidal activities against six species of weeds were evaluated in a greenhouse via both pre- and post-emergence treatments at 150 g a.i./hm2. The bioassay revealed that a few compounds exhibited moderate herbicidal activities against Digitaria sanguinalis, Abutilon theophrasti, and Setaria viridis in post-emergence treatment. For instance, compounds 6a and 6c demonstrated 50% inhibition activity against Setaria viridis, which was slightly superior to pyroxasulfone. Thus, compounds 6a and 6c may serve as the new possible leading compounds for the discovery of post-emergence herbicides. [ABSTRACT FROM AUTHOR]

Nanoparticles have been used to overcome the limitations of oral drug delivery. This study was performed to examine the effects of modifying Digitaria exilis starch by cross-linking with multifunctional excipients: citric acid (CA) and sodium tripolyphosphate (STPP) to produce starch citrate and phosphate respectively at 20 % concentration. Thereafter, nanoparticles were synthesized via the nanoprecipitation method in the presence of Tween® 80, using ibuprofen as the model drug. The physicochemical properties of the modified starch were evaluated and the nanoparticles characterized by the encapsulation efficiciency, loading capacity, particle size, polydispersity index, scanning electron microscope (SEM), fourier transform infrared spectroscopy(FTIR), in vitro drug release and release kinetics. Results show that both cross-linkers improved the physicochemical properties of the starch, and produced particles in the nanometer range (616 nm and 933 nm) for citric acid and sodium tripolyphosphate nanoparticles respectively. Spherical and pitted particles corresponding to citric acid and sodium tripolyphosphate nanoparticles respectively were produced and they both showed a controlled release of ibuprofen from the formulation and both followed the Higuchi kinetic model with R2 values that exhibited a non-fickian diffusion pattern. This study revealed that the two excipients had different effects on the size and morphology of the nanoparticles and controlled the release of drug from the nanoparticles. [ABSTRACT FROM AUTHOR]

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Timorese crabgrass (Digitaria radicosa) is a grass species commonly found in Southeast Asia and Oceania. Digitaria species have high intraspecific and interspecific genetic and phenotypic diversity, suggesting their potential usefulness as a genetic resource. However, as the only high-quality reference genome available is for a tetraploid Digitaria species, a reference genome of the diploid species D. radicosa would be a useful resource for genomic studies of Digitaria and Poaceae plants. Here, we present a chromosome-level genome assembly of D. radicosa and describe its genetic characteristics; we also illustrate its usefulness as a genomic resource for Poaceae. We constructed a 441.6 Mb draft assembly consisting of 61 contigs with an N50 contig length of 41.5 Mb, using PacBio HiFi long reads. We predicted 26,577 protein-coding genes, reaching a BUSCO score of 96.5%. To demonstrate the usefulness of the D. radicosa reference genome, we investigated the evolution of Digitaria species and the genetic diversity of Japanese Digitaria plants based on our new reference genome. We also defined the syntenic blocks between D. radicosa and 2 Poaceae crops, fonio and rice, and the diverse distribution of representative resistance genes in D. radicosa. The D. radicosa reference genome presented here should help elucidate the genetic relatedness of Digitaria species and the genetic diversity of Digitaria plants. In addition, the D. radicosa genome will be an important genomic resource for Poaceae genomics and crop breeding., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Genetics Society of America.)

The utilization of the invasive weed, Parthenium hysterophorus L. for producing value-added products is novel research for sustaining our environment. Therefore, the current study aims to document the phytotoxic compounds contained in the leaf of parthenium and to examine the phytotoxic effects of all those phytochemicals on the seed sprouting and growth of Crabgrass Digitaria sanguinalis (L.) Scop. and Goosegrass Eleusine indica (L.) Gaertn. The phytotoxic substances of the methanol extract of the P. hysterophorus leaf were analyzed by LC-ESI-QTOF-MS=MS. From the LC-MS study, many compounds, such as terpenoids, flavonoids, amino acids, pseudo guaianolides, and carbohydrate and phenolic acids, were identified. Among them, seven potential phytotoxic compounds (i.e., caffeic acid, vanillic acid, ferulic acid, chlorogenic acid, quinic acid, anisic acid, and parthenin) were documented, those are responsible for plant growth inhibition. The concentration needed to reach 50% growth inhibition in respect to germination (ECg50), root length (ECr50), and shoot length (ECs50) was estimated and the severity of phytotoxicity of the biochemicals was determined by the pooled values (rank value) of three inhibition parameters. The highest growth inhibition was demarcated by caffeic acid, which was confirmed and indicated by cluster analysis and principal component analysis (PCA). In the case of D. sanguinalis, the germination was reduced by 60.02%, root length was reduced by 76.49%, and shoot length was reduced by 71.14% when the chemical was applied at 800 μM concentration, but in the case of E. indica, 100% reduction of seed germination, root length, and shoot length reduction occurred at the same concentration. The lowest rank value was observed from caffeic acids in both E. indica (rank value 684.7) and D. sanguinalis (909.5) caused by parthenin. It means that caffeic acid showed the highest phytotoxicity. As a result, there is a significant chance that the parthenium weed will be used to create bioherbicides in the future. [ABSTRACT FROM AUTHOR]