Target-site mutation and enhanced metabolism endow resistance to nicosulfuron in a Digitaria sanguinalis population.

Digitaria sanguinalis is a competitive and annual grass weed that commonly infests crops across the world. In recent years, the control of D. sanguinalis by nicosulfuron has declined in Hebei Province, China. To determine the resistance mechanisms of D. sanguinalis to nicosulfuron, a population of D. sanguinalis where nicosulfuron had failed was collected from a maize field of Hebei Province, China. Whole-plant dose-response experiments demonstrated that the resistant population (HBMT-15) displayed 6.9-fold resistance to nicosulfuron compared with the susceptible population (HBMT-5). Addition of the glutathione S-transferase (GSTs) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) significantly reduced the resistance level of the HBMT-15 population to nicosulfuron, and the GSTs activity of the HBMT-15 population was higher than the HBMT-5 population after nicosulfuron treatment. In vitro acetolactate synthase (ALS) enzyme experiments revealed that the nicosulfuron I50 value for the HBMT-15 population was 41 times higher than that of the HBMT-5 population. An Asp376 to Glu substitution in the ALS gene was identified in the HBMT-15 population. The HBMT-15 population had a moderate (2- to 4-fold) level of cross-resistance to three other ALS inhibitors (imazethapyr, pyroxsulam, and flucarbazone­sodium), but was susceptible to pyrithiobac­sodium. This study demonstrated that both an Asp376 to Glu substitution in the ALS gene and GSTs-involved metabolic resistance to ALS inhibitors coexisted in a D. sanguinalis population.

Ile-1781-Leu Target Mutation and Non-Target-Site Mechanism Confer Resistance to Acetyl-CoA Carboxylase-Inhibiting Herbicides in Digitaria ciliaris var. chrysoblephara.

Digitaria ciliaris var. chrysoblephara is a xerophytic weed severely invading rice fields along with the application of rice mechanical direct seeding technology in China. This study identified one resistant population (M5) with an Ile-1781-Leu substitution in ACCase1 showing broad-spectrum resistance to three chemical classes of ACCase-inhibiting herbicides, including metamifop, cyhalofop-butyl, fenoxaprop-p-ethyl, haloxyfop-p-methyl, clethodim, sethoxydim, and pinoxaden. The other two populations, M2 and M4, without any resistance-responsible mutations, only exhibited resistance to aryloxyphenoxypropionate (APP) herbicides cyhalofop-butyl and fenoxaprop-p-ethyl. Pre-treatment with the cytochrome P450 monooxygenase (P450) inhibitor PBO significantly reduced the cyhalofop-butyl resistance by 43% in the M2 population. Pre-emergence weed control with soil-applied herbicides, such as pretilachlor, pendimethalin, and oxadiazon, can effectively inhibit the germination and growth of D. ciliaris var. chrysoblephara. The present study reported a xerophytic weed species invading rice fields featuring broad-spectrum resistance to ACCase-inhibiting herbicides as a result of Ile-1781-Leu mutation of ACCase. Both target- and P450-involved non-target-site mechanisms may be contributing to resistance in D. ciliaris var. chrysoblephara species.

Cloning and functional characterization of a tau class glutathione transferase associated with haloxyfop-P-methyl resistance in Digitaria sanguinalis.

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.

Management of Digitaria insularis in soybean pre-sowing desiccation by ACCase alternative herbicides and its impact on soybean carryover.

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.

Synthesis of Novel Pyrazole Derivatives Containing Phenylpyridine Moieties with Herbicidal Activity.

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.

Efficient Total Synthesis and Herbicidal Activity of 3-Acyltetramic Acids: Endogenous Abscisic Acid Synthesis Regulators.

An efficient synthesis method will allow a large number of tetramic acid analogues to be synthesized for property and potency optimization. In this study, a facile and efficient method was described for the synthesis of 3-acyltetramic acids. The synthesis was accomplished mainly via (1) mild intramolecular cyclization and (2) the formation of ß-ketoamides between nucleophiles and acyl Meldrum's acids. 3-Acyltetramic acid exhibited phytotoxicity against Echinochloa crusgalli and Portulaca oleracea. At a dosage of 750 g ha-1, 6k and 6a showed high herbicidal activity against E. crusgalli, Digitaria sanguinalis and P. oleracea, Amaranthus retroflexus, respectively. 6k inhibited the synthesis of endogenous abscisic acid, thus seedling germination and plant growth. The incorporation of various acyl Meldrum's acids and amino acid esters was applicable to the parallel synthesis of 3-acyltetramic acids. The mode of action and herbicidal activity indicate that 3-tetramic acid had good herbicidal performance and was a promising herbicide candidate. This study will provide a reference for novel herbicide development.

Design, Synthesis, and Herbicidal Activity of Naphthalimide-Aroyl Hybrids as Potent Transketolase Inhibitors.

Transketolase (TK) was identified as a new target for the development of novel herbicides. In this study, a series of naphthalimide-aroyl hybrids were designed and prepared based on TK as a new target and tested for their herbicidal activities. In vitro bioassay showed that compounds 4c and 4w exhibited stronger inhibitory effects against Digitaria sanguinalis (DS) and Amaranthus retroflexus (AR) with the inhibition over 90% at 200 mg/L and around 80% at 100 mg/L. Also, compounds 4c and 4w exhibited excellent postemergence herbicidal activity against DS and AR with the inhibition around 90% at 90 g [active ingredient (ai)]/ha and 80% at 50 g (ai)/ha in the greenhouse, which was comparable with the activity of mesotrione. The fluorescent quenching experiments of At TK revealed the occurrence of electron transfer from compound 4w to At TK and the formation of a strong exciplex between them. Molecular docking analyses further showed that compounds 4w exhibited profound affinity with At TK through the interaction with the amino acids in the active site, which results in its strong inhibitory activities against TK. These findings demonstrated that compound 4w is potentially a lead candidate for novel herbicides targeting TK.

Synthesis, herbicidal activity and soil degradation of novel 5-substituted sulfonylureas as AHAS inhibitors.

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.

Documentation of Phytotoxic Compounds Existing in Parthenium hysterophorus L. Leaf and Their Phytotoxicity on Eleusine indica (L.) Gaertn. and Digitaria sanguinalis (L.) Scop.

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.

Light availability in the cultivation environment and the action of glyphosate on Digitaria insularis: physiological aspects and herbicide root exudation.

The root exudation decreases the susceptibility of some species to herbicides, which is still little studied in Digitaria insularis, popularly known as sourgrass, one of the main weeds of annual crops in the world. Thus, we sought to identify whether there is an occurrence of root exudation of glyphosate in D. insularis and the influence of this herbicide on physiological and control parameters of this species when cultivated under different light conditions. The experimental design was 2 x 5, with the first factor represented by environments: full sun and artificial shading. The second factor was represented by doses 0, 370, 740, 1110, and 1480 g ha-1 of glyphosate. The plants grown in shading showed more significant injury in the initial phase. The increase in the glyphosate doses reduced the photochemical efficiency of the photosystem II (ФPSII), electron transport rate (ETR), photosynthetic rate, stomatal conductance, transpiration rate, and water use efficiency of D. insularis regardless of the cultivation environment. The light restriction increased the ФPSII in D. insularis at three days after applying the herbicide (DAH); at 6 DAH, the shaded plants showed a more pronounced reduction in ФPSII. D. insularis did not show root exudation of glyphosate, and shading did not influence this process.

The life cycle of Puccinia digitariae on Digitaria eriantha and Solanum species in South Africa.

Rust fungi are important plant pathogens and have been extensively studied on crops and other host plants worldwide. This study describes the heterecious life cycle of a rust fungus on Digitaria eriantha (finger grass) and the Solanum species S. lichtensteinii (large yellow bitter apple), S. campylacanthum (bitter apple), and S. melongena (eggplant) in South Africa. Following field observations, inoculation studies involving telial isolates collected from Digitaria plants produced spermogonia and aecia on S. lichtensteinii, S. campylacanthum, and S. melongena. Likewise, inoculation of finger grass with aeciospores collected from the aforementioned Solanum species produced uredinia on D. eriantha. Pennisetum glaucum (pearl millet varieties Milkstar and Okashana, as well as 17 experimental lines) and S. elaeagnifolium (silverleaf nightshade or bitter apple) were resistant to the rust isolates. Morphological descriptions and molecular phylogenetic data confirmed the identity of the rust on Digitaria as P. digitariae, herein reinstated as a species and closely related to P. penicillariae the pearl millet rust, also reinstated. Puccinia digitariae has a macrocyclic, heterecious life cycle in which teliospores overwinter on dormant D. eriantha plants. Aecia sporulate on species of Solanum during spring and early summer to provide inocula that infect new growth of Digitaria.

A novel EPSPS Pro-106-His mutation confers the first case of glyphosate resistance in Digitaria sanguinalis.

BACKGROUND: Digitaria sanguinalis has been identified as a species at high risk of evolving herbicide resistance, but thus far, there are no records of resistance to glyphosate. This weed is one of the most common weeds of summer crops in extensive cropping areas in Argentina. It shows an extended period of seedling emergence with several overlapping cohorts during spring and summer, and is commonly controlled with glyphosate. However, a D. sanguinalis population was implicated as a putative glyphosate-resistant biotype based on poor control at recommended glyphosate doses. RESULTS: The field-collected D. sanguinalis population (Dgs R) from the Rolling Pampas has evolved glyphosate resistance. Differences in plant survival and shikimate levels after field-recommended and higher glyphosate doses were evident between Dgs R and the known susceptible (Dgs S) population; the resistance index was 5.1. No evidence of differential glyphosate absorption, translocation, metabolism or basal EPSPS activity was found between Dgs S and Dgs R populations; however, a novel EPSPS Pro-106-His point substitution is probably the primary glyphosate resistance-endowing mechanism. EPSPS in vitro enzymatic activity demonstrated that an 80-fold higher concentration of glyphosate is required in Dgs R to achieve similar EPSPS activity inhibition to that in the Dgs S population. CONCLUSION: This study reports the first global case of glyphosate resistance in D. sanguinalis. This unlikely yet novel transversion at the second position of the EPSPS 106 codon demonstrates the intensity of glyphosate pressure in selecting unexpected glyphosate resistance alleles if they retain EPSPS functionality. © 2022 Society of Chemical Industry.

Screening of secondary metabolites and antioxidant potential of endophytic fungus Penicillium citrinum and host Digitaria bicornis by spectrophotometric and electrochemical methods.

Perennial grasses are hosts to an extremely diverse assemblage of endophytic fungi, but their significance is still underexplored. In the present study, an endophytic fungus was isolated from the aerial regions of Digitaria bicornis (Lam.) Roem. & Schult. and was characterized by morphological and molecular methods (ITS rDNA region), as Penicillium citrinum Thom. The crude extracts of endophytic fungus and host were recovered and evaluated for their antioxidant potential by spectrophotometric and electrochemical methods. The present study was also an attempt to compare the anti-radical power of extracts by spectrophotometric (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), hydrogen peroxide and nitric oxide radical scavenging assay) and electrochemical (cyclic voltammetry) methods and suggested that cyclic voltammetry could be used routinely instead of assaying by more number of spectrophotometric methods. The results indicated that the ethyl acetate extract of P. citrinum and methanolic extract of D. bicornis has potential compounds with antioxidant and other pharmaceutical activities. Nine and 17 antioxidant biomolecules, respectively, in P. citrinum and D. bicornis extracts were detected by OHR-LC-MS and the presence of function group of the bioactive compounds was confirmed by FTIR spectroscopy. Finally, the study also reported that the extracts of P. citrinum and D. bicornis have several bioactive compounds with application in commercial pharmaceutical industries.

Herbicide efficacy in the fall management of Richardia brasiliensis, Commelina benghalensis, Conyza sumatrensis AND Digitaria insularis

Other herbicides, alone or in combination with glyphosate, may be effective in controlling Richardia brasiliensis, Commelina benghalensis, Conyza sumatrensis e Digitaria insularis. Therefore, the aim of this study was to evaluate the efficacy of herbicides, alone or in combination, in the control of these weeds in the off-season. Three composite experiments were conducted by applying herbicides, alone or in combinations. Experiments 1 and 2 were conducted in Palotina, State of Paraná (PR), Brazil. Experiment 3 in Iporã, PR, Brazil. The three during fall 2017 in fallow areas after soybean harvest. The experiment was a randomized complete block design with 4 replications and weed control at 7, 14, 21, 28, 35, and 42 days after application (DAA). The control of R. brasiliensis and C. benghalensis was evaluated in the three experiments, the control of C. sumatrensis, in experiments 1 and 2, while the control of D. insularis was evaluated only in experiment 3. Data were subjected to analysis of variance and F-test (p < 0.05). The treatment means values of experiments 1 and 2 were compared by Tukey's test (p < 0.05), and the treatment mean values of experiment 3 were grouped by the Scott and Knott test (p < 0.05). Some herbicide combinations were effective in controlling R. brasiliensis, C. benghalensis, in a single or sequential application. Herbicide combinations were effective in controlling C. sumatrensis with sequential application. Herbicide combinations in a single application did not provide satisfactory final control (≥ 80%) for D. insularis.

Growth inhibition of sourgrass as a function of period of darkness after diquat application

Photosystem-inhibiting herbicides, such as diquat, act by inducing oxidative stress. However, oxidative damage impairs translocation, resulting in regrowth of the plants. The aim was to evaluate the effectiveness of diquat in controlling the growth of sourgrass exposed to different periods of darkness after application of the herbicide, as well as to evaluate the photosynthetic activity and the production of reactive oxygen species. Two experiments (field and greenhouse) were conducted by applying diquat (200 g a.i. ha-1) on sourgrass plants at the 3 to 4 tiller stage. The treated plants were subjected to different periods of darkness after diquat application (0, 1, 2, 3, 4, 5, and 6 h), in addition to the control treatment without any application. Growth inhibition and mass evaluations of the sourgrass plants were performed in both experiments, whereas photosynthetic activity and H2O2 accumulation in the leaves were evaluated in the greenhouse experiment. The results showed an increase in the sourgrass growth inhibition with an increase in the period of darkness after application. There was a need for a minimum of 6 h of darkness after diquat application to fully inhibit growth (100%) of the sourgrass, whereas plants that remained in the sun since application exhibited less than 50% inhibition. The increase in the period of darkness after diquat application resulted in a reduction in photosynthetic activity and, consequently, lower accumulation of H2O2. Thus, the maintenance of sourgrass in the dark for at least 6 h enables total control of the growth of the plants, preventing regrowth.

Effect of low glyphosate doses on flowering and seed germination of glyphosate-resistant and -susceptible Digitaria insularis.

BACKGROUND: Herbicide hormesis is characterized by stimulation of various growth and developmental parameters, such as biomass and height, at low herbicide doses. Other possible hormetic effects are earlier flowering, higher seed weight, more seeds, and a shorter plant life cycle, which could favor the propagation of the species. This study tested the early flowering in glyphosate-resistant and -susceptible Digitaria insularis biotypes under treatment with low glyphosate doses. RESULTS: Hormesis caused by low glyphosate doses occurred in all experiments. The hormetic effects were a decrease in time necessary for the formation of inflorescences and increased seed weight and germination speed. Higher glyphosate doses were required for the hormetic effect in the glyphosate-resistant than the -susceptible D. insularis biotype. CONCLUSIONS: Hormesis caused by low glyphosate doses in D. insularis may provide an advantage for the dissemination of this species, helping to alter the weed flora. As the doses that cause stimulation in glyphosate-resistant biotypes are higher than in glyphosate-susceptible biotypes, the selection of resistant biotypes may be favored in glyphosate-sprayed fields, increasing the rate of infestation of glyphosate-resistant biotypes.

Diurnal Variation in Forage Nutrient Composition of Mixed Cool-Season Grass, Crabgrass, and Bermudagrass Pastures.

Warm-season grasses have been suggested as alternative low non-structural carbohydrate (NSC) pasture forages. The purpose of this study was to evaluate nutrient composition and diurnal changes in soluble carbohydrates for the warm-season annual 'Quick-N-Big' crabgrass [CRB; Digitaria sanguinalis (L.) Scop.] and the warm-season perennial 'Wrangler' bermudagrass [BER; Cynodon dactylon (L.) Pers] in comparison to mixed cool-season grass [CSG; 'Inavale' orchardgrass (Dactylis glomerata [L.]), 'Tower' tall fescue (Lolium arundinaceum [Schreb.] Darbysh.), and 'Argyle' Kentucky bluegrass (Poa pratensis [L.])]. Samples were collected at 4-hour intervals over 3 d when each forage reached the boot stage of maturity. Digestible energy was greatest for CSG (2.29 ± 0.34 Mcal/kg) and lowest for BER (2.13 ± 0.34 Mcal/kg), while crude protein was lowest for CSG (16.1 ± 0.29%) and neutral detergent fiber was greatest for BER (60.0 ± 0.41; P ≤ .0008). Non-structural carbohydrates were greater for CSG (17.6% ± 0.26%) compared to BER (10.6% ± 0.26%) or CRB (10.9% ± 0.26%; P < .0001). Overall, NSC was greatest in the afternoon and evening (14.5-14.9 ± 0.60%) and lowest in the early morning (11.2-11.4 ± 0.60%; P ≤ .04), but diurnal variation was most pronounced in CSG versus either Warm-season grasses. Results of this study provide needed data on nutritional composition of CRB and BER and demonstrate that these grasses may serve as pasture forages for horses where NSC intake is of concern. Results also support recommendations for restricting grazing to early morning to limit NSC consumption, particularly in CSG pastures.

Evaluation of the chemical, antinutritional and antioxidant properties of composite flour comprising native and modified acha (digitaria exilis stapf) flour supplemented with mango kernel seed and soy cake flours.

Gluten-free flours that are nutritionally balanced with appropriate functional characteristics were developed by supplementation of native and modified acha flours with protein, dietary fiber and antioxidants-rich mango kernel and soy cakes flours. Acha flour was subjected to chemical and enzymatic modifications. The proximate, mineral compositions, bioactive and antinutrients properties of the composite flours were evaluated. The water content of the composite flours with native and chemically modified acha flour was between 7.62 and 9.30%, while that of enzymatic acha flour was between 10.12 and 10.79%. However, samples made with 20 and 30% incorporated mango kernel flour had around 13 and 19% increase in the protein content respectively, others including sample with enzymatically modified acha flour had lower protein content. On the other hand, all samples with enzymatically modified acha flour had between 83 and 100% increase in fibre content. The Na/K ratio of all the samples were less than one, as nutritionally required. Samples with enzymatically modified acha flour had best total flavonoid (0.03-0.77 mgGAE/g), total phenol (2.35-11.99 mgTAE/g) and DPPH radical scavenging activities (58.29-94.02%) contents. In addition, samples with enzymatically modified acha flour had the least antinutritional values. Although all the samples had values that were significantly (p ≥ 0.05) different, the samples had significant protein, dietary fiber, minerals and antioxidants contents, while the antinutritional contents were well lower than the standard.

Discovery of ortho-Alkoxy Substituted Novel Sulfonylurea Compounds That Display Strong Herbicidal Activity against Monocotyledon Grasses.

In the present study, we have designed and synthesized a series of 42 novel sulfonylurea compounds with ortho-alkoxy substitutions at the phenyl ring and evaluated their herbicidal activities. Some target compounds showed excellent herbicidal activity against monocotyledon weed species. When applied at 7.5 g ha-1, 6-11 exhibited more potent herbicidal activity against barnyard grass (Echinochloa crus-galli) and crab grass (Digitaria sanguinalis) than commercial acetohydroxyacid synthase (AHAS; EC 2.2.1.6) inhibitors triasulfuron, penoxsulam, and nicosulfuron at both pre-emergence and postemergence conditions. 6-11 was safe for peanut for postemergence application at this ultralow dosage, suggesting that it could be considered a potential herbicide candidate for peanut fields. Although 6-11 and triasulfuron share similar chemical structures and have close Ki values for plant AHAS, a significant difference has been observed between their LUMO maps from DFT calculations, which might be a possible factor that leads to their different behaviors toward monocotyledon weed species.

Relative Traffic Tolerance of Warm-Season Grasses and Suitability for Grazing by Equine.

Warm season wear-tolerant turfgrasses, such as those used on golf courses and athletic fields, may be valuable forages on equine operations because of their potential to remain viable during heavy hoof traffic. Crabgrass may also be suitable as it thrives in conditions where other grasses have limited success. The objective of this study was to assess the relative traffic tolerance and nutritional composition of five warm-season (WS) turfgrass cultivars of bermudagrass and zoysiagrass and one WS forage-type crabgrass. All cultivars were established by seed in replicated monoculture plots. Simulated hoof traffic treatments consisted of either none, one, or two passes of a Baldree Traffic Simulator. Traffic was applied weekly for 6 weeks in the summer of 2016 and 2017, with each treatment period followed by a 4-week rest period. Plots were assessed for compaction, biomass, and persistence before and after treatment and rest periods. Nutritional composition was assessed throughout the growing seasons. Soil compaction increased as treatment level increased for all cultivars (P < .0001). There was no effect of treatment on cultivar persistence. Biomass available for grazing was increased in year 1 by the application of LOW traffic treatment (P = .0193). Both bermudagrass and zoysiagrass cultivars showed promise for use in areas of heavy traffic on equine operations, however, zoysiagrass cultivars were more suitable as they were highest ranking in relative traffic tolerance, moderate in yield, and low nonstructural carbohydrates (<12% NSC). Future on-farm studies evaluating bermudagrass and zoysiagrass to determine ideal stocking rate, management methods, and persistence under grazing are warranted.