This study evaluated the impact of differential sowing windows and improved weed management strategies on weed dynamics, productivity, and economic viability of direct drum seeded rice (Oryza sativa L.) in the temperate agro-ecosystem of Kashmir. A two-year field experiment was conducted utilizing a split-plot design with two sowing dates (May 10 and June 3) as main plots and six weed management practices as sub-plots. The earlier sowing date (May 10) resulted in significantly enhanced leaf area index, crop growth rate, relative growth rate, net assimilation rate, and grain and straw yields compared to the later sowing (June 3). Among weed management treatments, four mechanized conoweedings (equivalent to weed-free conditions) and sequential application of bensulfuron methyl + pretilachlor (60 and 600 g a.i. ha-1) as pre-emergence followed by 2,4-D (0.75 kg a.i. ha-1) as post-emergence demonstrated superior efficacy in weed suppression and augmentation of crop growth parameters and yield attributes. These treatments also exhibited the lowest weed index and highest benefit-cost ratio. The May 10 sowing, coupled with efficacious weed control measures, significantly reduced weed density and biomass while concomitantly improving nutrient uptake and economic returns. The results indicate that adopting a May 10 sowing date for direct seeded rice, in conjunction with either four conoweedings or the aforementioned sequential herbicide application, can optimize agronomic productivity and economic profitability under the temperate conditions of Kashmir. The study aided in choosing the best sowing window and efficient weed management strategy for attaining higher productivity and profitability of direct seeded rice in temperate conditions.

The yield of pearl millet, a resilient cereal crop crucial for African food security, is severely impacted by the root parasitic weed Striga hermonthica, which requires host-released hormones, called strigolactones (SLs), for seed germination. Herein, we identify four SLs present in the Striga-susceptible line SOSAT-C88-P10 (P10) but absent in the resistant 29Aw (Aw). We generate chromosome-scale genome assemblies, including four gapless chromosomes for each line. The Striga-resistant Aw lacks a 0.7 Mb genome segment containing two putative CARLACTONOIC ACID METHYLTRANSFERASE1 (CLAMT1) genes, which may contribute to SL biosynthesis. Functional assays show that P10CLAMT1b produces the SL-biosynthesis intermediate methyl carlactonoate (MeCLA) and that MeCLA is the precursor of P10-specific SLs. Screening a diverse pearl millet panel confirms the pivotal role of the CLAMT1 section for SL diversity and Striga susceptibility. Our results reveal a reason for Striga susceptibility in pearl millet and pave the way for generating resistant lines through marker-assisted breeding or direct genetic modification.

Striga hermonthica (Sh) and S. asiatica (Sa) are major parasitic weeds limiting cereal crop production and productivity in sub-Saharan Africa (SSA). Under severe infestation, Striga causes yield losses of up to 100%. Breeding for Striga-resistant maize varieties is the most effective and economical approach to controlling the parasite. Well-characterized and genetically differentiated maize germplasm is vital to developing inbred lines, hybrids, and synthetic varieties with Striga resistance and desirable product profiles. The objective of this study was to determine the genetic diversity of 130 tropical and sub-tropical maize inbred lines, hybrids, and open-pollinated varieties germplasm using phenotypic traits and single nucleotide polymorphism (SNP) markers to select Striga-resistant and complementary genotypes for breeding. The test genotypes were phenotyped with Sh and Sa infestations using a 13x10 alpha lattice design with two replications. Agro-morphological traits and Striga-resistance damage parameters were recorded under a controlled environment. Further, high-density Diversity Array Technology Sequencing-derived SNP markers were used to profile the test genotypes. Significant phenotypic differences (P<0.001) were detected among the assessed genotypes for the assessed traits. The SNP markers revealed mean gene diversity and polymorphic information content of 0.34 and 0.44, respectively, supporting the phenotypic variation of the test genotypes. Higher significant variation was recorded within populations (85%) than between populations using the analysis of molecular variance. The Structure analysis allocated the test genotypes into eight major clusters (K  =  8) in concordance with the principal coordinate analysis (PCoA). The following genetically distant inbred lines were selected, displaying good agronomic performance and Sa and Sh resistance: CML540, TZISTR25, TZISTR1248, CLHP0303, TZISTR1174, TZSTRI113, TZDEEI50, TZSTRI115, CML539, TZISTR1015, CZL99017, CML451, CML566, CLHP0343 and CML440. Genetically diverse and complementary lines were selected among the tropical and sub-tropical maize populations that will facilitate the breeding of maize varieties with Striga resistance and market-preferred traits.

Winter wheat (Triticum aestivum, L.) production in the semi-arid US Northern High Plains (NHP) is challenged by frequent droughts and water-limited, low fertility soils. Composted cattle manure (compost) and cover crops (CC) are known to provide agroecosystem services such as improved soil health, and in the CC case, increased plant diversity, and competition with weedy species. The main concern of planting CC in winter wheat fallow rotation in regions that are more productive than the NHP, however, is the soil moisture depletion. It is unknown however, whether addition of CC to compost-amended soils in the NHP will improve soil properties and agroecosystem health without compromising already low soil water content. The main objective of this study was to assess the effects of four CC treatments amended with compost (45 Mg ha-1) or inorganic fertilizer (IF) (.09 Mg ha-1 mono-ammonium phosphate, 11-52-0 and 1.2 Mg ha-1ammonium sulfate, 21-0-0) on the presence of weeds, soil and plant total carbon (C), nitrogen (N), and biological dinitrogen (N2) fixation (BNF). Mycorrhizal Mix (MM), Nitrogen Fixer Mix (NF), Soil Building Mix (SB), a monoculture of phacelia (Phacelia tanacetifolia Benth L.) (PH), and a no CC control (no CC) were grown in native soil kept at 7% soil moisture in a greenhouse for a period of nine weeks. When amended with compost, MM was the most beneficial (48 g m-2 BNF and 1.7% soil C increase). SB had the highest germination, aboveground biomass, and decreased weed biomass by 60%. It also demonstrated the second highest amount of BNF (40 g m-2) and soil C increase by 1.5%. On contrary, IF hindered BNF by almost 70% in all legume-containing CC treatments and reduced soil C by 15%.

The present study investigates the synergistic impact of earthworms (Eisenia fetida and Eudrilus eugeniae) and microbes during vermicomposting of invasive weed phytomass (Xanthium strumarium and Lantana camara). This study aims introducing an onsite solution for weed control while producing valuable organic manure. Vermitransformation and detailed characterization of mono- (VC1, VC2, VC4, VC5) and polyculture (VC3, VC6) of X. strumarium and L. camara has been reported for the first time employing E. fetida and E. eugeniae. The study achieved 45.16 ± 2.48-76.73 ± 1.37% vermiconvertion rate. The pH, conductivity, and concentration of heavy metals are effectively stabilized. Furthermore, it observed a significant reduction in total organic carbon (TOC) alongside the augmentation of nitrogen, phosphorus, potassium, calcium, and other trace elements (Zn, Ni, Fe). The ash content, humification index, and C/N ratio analysis established the maturity of the vermicompost. The macronutrient enhancement in the vermicompost samples was recorded 1.5- to 2.47-fold for total N, 1.19- to 1.48-fold in available P, 1.1- to 1.2-fold in total K, and 1.1- to 1.18-fold in total Ca. The germination index reveals a significant reduction in phytotoxicity, suggesting the production of mature and suitable vermicompost for agricultural use. Evaluating mono- and polyculture techniques, the research highlights the superiority of E. fetida over E. eugeniae. Further, the earthworm population and biomass have significantly increased by the end of 60-day experimental trial.

Fluorochloridone (FLC) is a chiral herbicide that has four stereoisomers. This study systematically assessed the stereoselectivity of FLC to reveal the selective environmental behavior of its four isomers. Absolute configuration confirmation, evaluation of stereoselective bioactivity toward monocotyledonous and dicotyledonous weeds, toxicity to Danio rerio, and the stereoselective degradation in the potato system under field conditions of FLC were conducted. The four FLC stereoisomers were effectively separated on a superchiral S-AD column. The absolute configurations of the four stereoisomers of FLC were confirmed as (-)-(3S, 4S), (+)-(3S, 4R), (-)-(3R, 4S), and (+)-(3R, 4R)-FLC using single-crystal X-ray diffraction. The activities of the four stereoisomers were in the order of (-)-(3S, 4S)-FLC > (+)-(3R, 4R)-FLC > (+)-(3S, 4R)-FLC > (-)-(3R, 4S)-FLC, and the rate of selective degradation were in the order of (-)-(3R, 4S)-FLC > (+)-(3R, 4R)-FLC > (-)-(3S, 4R)-FLC > (+)-(3S, 4S)-FLC. The toxicity of the isomers were in the order of (-)-(3R, 4S)-FLC > (+)-(3R, 4R)-FLC > (-)-(3S, 4S)-FLC > (+)-(3S, 4R). Based on the results of bioactivity, toxicity, and degradation behavior assessments, the stereoisomer mixture containing (3R,4R)-FLC and (3S,4S)-FLC was concluded to be a better option than racemic FLC for increasing bioactivity and reducing usage.

Photosynthesis system II (PS II) is an important target for the development of bioherbicides. In this study, a series of natural naphthoquinone derivatives containing diaryl ether were designed and synthesized based on the binding model of lawsone and PS II D1. Bioassays exhibited that most compounds had more than 80% inhibition of Portulaca oleracea and Echinochloa crusgalli roots at a dose of 100 μg/mL and compounds B4, B5, and C3 exhibited superior herbicidal activities against dicotyledonous and monocotyledon weeds to commercial atrazine. In particular, compound B5 exhibited excellent herbicidal activity at a dosage of 150 g a.i./ha. In addition, compared with atrazine, compound B5 causes less damage to crops. Molecular docking studies revealed that compound B5 effectively interacted with Pisum sativum PS II D1 via diverse interaction models, such as π-π stacking and hydrogen bonds. Molecular dynamics simulation studies and chlorophyll fluorescence measurements revealed that compound B5 acted on PS II. This is the first report of natural naphthoquinone derivatives targeting PS II and compound B5 may be a candidate molecule for the development of new herbicides targeting PS II.

Despite their overlooked status, weeds are increasingly recognized for their therapeutic value, aligning with historical reliance on plants for medicine and nutrition. This study investigates the medicinal potential of native weed species in Bangladesh, specifically pigments, antioxidants, and free radical scavenging abilities. Twenty different medicinal weed species were collected from the vicinity of Khulna Agricultural University and processed in the Crop Botany Department Laboratory. Pigment levels were determined using spectrophotometer analysis, and phenolics, flavonoids, and DPPH were quantified accordingly. Chlorophyll levels in leaves ranged from 216.70 ± 9.41 to 371.14 ± 28.67 µg g-1 FW, and in stems from 51.98 ± 3.21 to 315.89 ± 17.19 µg g-1 FW. Flavonoid content also varied widely, from 1,624.62 ± 102.03 to 410.00 ± 115.58 mg CE 100 g-1 FW in leaves, and from 653.08 ± 32.42 to 80.00 ± 18.86 mg CE 100 g-1 FW in stems. In case of phenolics content Euphorbia hirta L. displaying the highest total phenolic content in leaves (1,722.33 ± 417.89 mg GAE 100 g-1 FW) and Ruellia tuberosa L. in stems (977.70 ± 145.58 mg GAE 100 g-1 FW). The lowest DPPH 2.505 ± 1.028 mg mL-1was found in Heliotropium indicum L. leaves. Hierarchical clustering links species with pigment, phenolic/flavonoid content, and antioxidant activity. PCA, involving 20 species and seven traits, explained 70.07% variability, with significant PC1 (14.82%) and PC2 (55.25%). Leaves were shown to be superior, and high-performing plants such as E. hirta and H. indicum stood out for their chemical composition and antioxidant activity. Thus, this research emphasizes the value of efficient selection while concentrating on the therapeutic potential of native weed species.

Amaranthus retroflexus L. (redroot pigweed) is one of the most problematic weeds in maize, sugar beet, vegetables, and soybean crop fields in Europe. Two pigweed amaranth biotypes (R1 and R2) from the Czech Republic resistant to photosystem II (PSII)-inhibiting herbicides were analyzed in this study. This study aimed to identify the genetic mechanisms that underlie the resistance observed in the biotypes. Additionally, we also intended to establish the use of chlorophyll fluorescence measurement as a rapid and reliable method for confirming herbicide resistance in this weed species. Both biotypes analyzed showed high resistance factors in a dose-response study and were thus confirmed to be resistant to PSII-inhibiting herbicides. A sequence analysis of the D1 protein revealed a well-known Ser-Gly substitution at amino acid position 264 in both biotypes. Molecular docking studies, along with the wild-type and mutant D1 protein\'s secondary structure analyses, revealed that the S264G mutation did not reduce herbicide affinity but instead indirectly affected the interaction between the target protein and the herbicides. The current study identified the S264G mutation as being responsible for conferring herbicide resistance in the pigweed amaranth biotypes. These findings can provide a strong basis for future studies that might use protein structure and mutation-based approaches to gain further insights into the detailed mechanisms of resistance in this weed species. In many individuals from both biotypes, resistance at a very early stage (BBCH10) of plants was demonstrated several hours after the application of the active ingredients by the chlorophyll fluorescence method. The effective PS II quantum yield parameter can be used as a rapid diagnostic tool for distinguishing between sensitive and resistant plants on an individual level. This method can be useful for identifying herbicide-resistant weed biotypes in the field, which can help farmers and weed management practitioners develop more effective weed control tactics.

Protoporphyrinogen oxidase (PPO, EC 1.3.3.4) has a high status in the development of new inhibitors. To develop novel and highly effective PPO inhibitors, active substructure linking and bioisosterism replacement strategies were used to design and synthesize novel tetrahydrophthalimide derivatives containing oxadiazole/thiadiazole moieties, and their inhibitory effects on Nicotiana tobacco PPO (NtPPO) and herbicidal activity were evaluated. Among them, compounds B11 (Ki = 9.05 nM) and B20 (Ki = 10.23 nM) showed significantly better inhibitory activity against NtPPO than that against flumiclorac-pentyl (Ki = 46.02 nM). Meanwhile, compounds A20 and B20 were 100% effective against three weeds (Abutilon theophrasti, Amaranthus retroflexus, and Portulaca oleracea) at 37.5 g a.i./ha. It was worth observing that compound B11 was more than 90% effective against three weeds (Abutilon theophrasti, Amaranthus retroflexus, and Portulaca oleracea) at 18.75 and 9.375 g a.i./ha. It was also safer to rice, maize, and wheat than flumiclorac-pentyl at 150 g a.i./ha. In addition, the molecular docking results showed that compound B11 could stably bind to NtPPO and it had a stronger hydrogen bond with Arg98 (2.9 Å) than that of flumiclorac-pentyl (3.2 Å). This research suggests that compound B11 could be used as a new PPO inhibitor, and it could help control weeds in agricultural production.