Search Results (71)

The invasive perennial weed Ambrosia confertiflora (Burr ragweed) is widespread across various climatic regions in Israel and neighboring countries. This study examines how temperature affects the development of the plants’ aboveground and underground organs, as well as biomass allocation. We hypothesize that temperature influences how the plant distributes resources, thereby modifying its phenotypic morphology and contributing to its spread. Plants were grown in a phytotron under four seasonal temperature regimes (10–16 °C, 16–22 °C, 22–28 °C, 28–34 °C, N-D, 14 h light). We measured above- and belowground biomass, growth form, leaf size, and the interaction between temperature and apical dominance. Our results show that biomass allocation varies with temperature and developmental stage. During early growth, resources are primarily directed toward shoot development and leaf production. As plants matured, they shifted more resources to underground structures, eventually balancing allocation. At lower temperatures, plants invested more in underground growth while the shoot remained in the rosette form. In contrast, higher temperatures favored aboveground growth. Ambrosia confertiflora demonstrates significant phenotypic plasticity in response to temperature variation, affecting plant height, leaf morphology, and resource allocation in both shoot and underground tissues. Understanding how temperature drives these changes is critical to understanding the spread and ecological impact of this highly adaptable weed. Full article

Organic production systems impose strong environmental constraints on silage maize, yet the relative contributions of genotype, environment and their interaction (G × E) to key performance traits remain insufficiently resolved. This study evaluated six maize cultivars across 11 organically managed environments (location × year combinations) in Poland, assessing weed infestation, plant height, fresh matter yield, dry matter content and dry matter yield. Genotype × environment interaction was explicitly analyzed using AMMI-based models, and cultivar adaptability and stability were evaluated using complementary indices. Environmental effects consistently dominated all traits, explaining 78–91% of total variation, while G × E interactions, though smaller, were significant and altered cultivar rankings. Weed infestation ranged widely across environments, from below 10% to over 90%, and was almost entirely environment-driven. Yield-related traits followed a strong precipitation gradient, with Pawłowice and Śrem showing the highest biomass potential. SM Perseus produced the greatest dry matter yields (13.53 t·ha⁻¹), whereas SM Mieszko combined high dry matter content (37.73%) with outstanding stability. Mega-environment analysis identified distinct adaptive niches, confirming that no genotype performed consistently best across all conditions. These findings close a key knowledge gap regarding cultivar performance under organic management and demonstrate the necessity of multi-environment evaluation that integrates performance, stability and adaptability analyses to support site-specific cultivar recommendations that enhance biomass productivity and silage quality in ecologically managed maize systems. Full article

Plant growth regulators (PGRs) are natural or synthetic substances that control and manipulate plant physiological processes, controlling branching and vegetative growth. Maintaining roadside vegetation through frequent mowing is costly, dangerous, and unsustainable. This narrative literature review proposes a revolution in this management by conducting a systematic literature review on the strategic application of PGRs on roadsides. Practices such as the application of plant growth regulators, the use of native cover crops, and bioengineering techniques with stabilizing species were analyzed. Previous studies have shown that the use of regulators such as mepiquat chloride and paclobutrazol reduces plant height and aboveground biomass, favoring growth control and compacting the plant architecture. The environmental and operational impacts related to vegetation control on roadside strips were also considered. Integrated with LiDAR technology for precise monitoring, this model establishes a new paradigm: smart, safe, and sustainable. Therefore, it is hoped that this compendium will fill a gap in national guidelines by offering an evidence-based protocol guideline for the use of PGR as an alternative to traditional management methods, thus reducing the number of mowing and weeding operations in highway right-of-way areas. Full article

The long-term application of traditional chemical herbicides has caused a significant escalation in herbicide resistance of barnyard grass (Echinochloa crus-galli). As an eco-friendly alternative, biological herbicides demonstrate substantial application potential. Acknowledging the growing herbicide resistance of E. crus-galli, this study aimed to screen target bacteria with inhibitory effects on the growth for bio-herbicide development. By using ungerminated E. crus-galli seeds as the screening substrate, a bacterial strain (BFYBC-8) with potent inhibitory activity was isolated and identified as Brucella pseudorignonensis. Pot experiments revealed that inoculation with B. pseudorignonensis BFYBC-8 significantly suppressed E. crus-galli growth, reducing plant height by 16.7% and root length by 85.1%, while markedly inhibiting biomass accumulation. Fluorescent labeling with green fluorescent protein (GFP) showed that BFYBC-8 successfully colonized the root intercellular spaces of E. crus-galli and extended continuously along the tissue matrix. Additionally, the strain’s supernatant metabolic products exhibited exceptional thermostability: inhibitory activity against E. crus-galli was maintained after thermal treatment at 28 °C, 60 °C, 80 °C, and 100 °C. Crucially, the bacterium displayed no toxicity to agronomically important crops such as rice, wheat, and corn. This study highlights B. pseudorignonensis BFYBC-8 as a promising candidate for bioherbicide development and provides an important reference for applying seed-associated pathogenic bacteria in developing bioherbicides for sustainable weed management. Full article

Pinus taeda plantations have been facing declining productivity in South America, especially due to competition for natural resources such as light, water, and nutrients. Competition with spontaneous vegetation in the early years is one of the main constraints on growth and biomass allocation in trees. However, the best method and timing for weed control and its impact on the productivity of Pinus taeda plantations are unknown. This study aims to evaluate whether weed control increases the growth and above-ground biomass production of Pinus taeda plantations in southern Brazil. This study was conducted at two sites with five-year-old Pinus taeda plantations in southern Brazil, with each being submitted to different weed control methods. This study was conducted in randomized blocks, with nine treatments: (i) NC—no weed control, i.e., weeds always present; (ii) PC—physical weed control; (iii) CC–T—chemical weed control in the total area; (iv) CC–R—chemical weed control in rows (1.2 m wide); (v) C6m, (vi) C12m, (vii) C18m, and (viii) C24m—weed control up to 6, 12, 18, and 24 months after planting; and (ix) COC—company operational weed control. The following parameters were evaluated: the floristic composition and weed biomass, height, diameter, stem volume, needle biomass, branches, bark, and stemwood of Pinus taeda. Control of the weed competition, especially by physical means (PC), and chemical control over the entire area (CC–T) promoted significant gains in the growth and above–ground biomass production of Pinus taeda at five years of age, particularly at the Caçador site. The results reinforce the importance of using appropriate strategies for managing weed control to maximize productivity, especially before canopy closure. In addition, the strong correlation between growth variables and the total biomass and stemwood indicates the possibility of obtaining indirect estimates through dendrometric measurements. The results contribute to the improvement of silvicultural management in subtropical regions of southern Brazil. Full article

A two-year field study evaluated biodegradable plastic film (BPF; thicknesses: 0.006, 0.008, and 0.010 mm) versus polyethylene film (PE; 0.010 mm) and no-mulch control on sugarcane yield and weed suppression. Key results demonstrated that 0.010 mm BPF significantly enhanced sugarcane emergence (CV = 5.07% in ratoon), reduced weed biomass by 70%, and increased perennial yield by 3.83% (+5.6 t ha⁻¹), while PE film decreased yield by 3.80%. Regression analysis identified the effective stem number, plant height, and stem diameter as primary yield predictors (R² = 0.996). Logistic models revealed that film mulching duration >119 days was critical for achieving high yields (>122.2 t ha⁻¹) and sustained weed control (R² = 0.81). These findings establish 0.010 mm BPF as an optimal sustainable alternative to PE film for enhancing sugarcane productivity. Full article

Melissa officinalis L. (Lamiaceae) is a perennial plant species widely used in the pharmaceutical and food industries, particularly valued for its sedative properties. This study investigates the impact of synthetic mulch film and planting density as two experimental factors on agronomic performance, raw material quality, and economic efficiency in lemon balm production. The experiment was conducted at three locations in Serbia (L1: Bačko Novo Selo, L2: Bavanište, L3: Vilandrica) from 2022 to 2024, using two planting densities on synthetic mulch film (F1: 8.3 plants m⁻²; F2: 11.4 plants m⁻²) and a control treatment without mulch (C). The synthetic mulch film used was a synthetic black polypropylene film (Agritela Black, 90 g/m²), uniformly applied in strips across the cultivation area, covering approximately 78% of the soil surface. The results showed consistent increases in morphological parameters and yield across the years. Plant height in F1 and F2 treatments ranged from 65 to 75 cm, while in the control it reached up to 50 cm (2022–2024). Fresh biomass yield varied from 13.4 g per plant (C) to 378.08 g per plant (F2), and dry biomass yield from 60.3 g (C) to 125.4 g (F2). The highest essential oil content was observed in F2 (1.2% in 2022), while the control remained at 0.8%. The F2 treatment achieved complete weed suppression throughout the experiment without the use of herbicides, demonstrating both agronomic and ecological advantages. Economic evaluation revealed that F2 generated the highest cumulative profit (€142,164.5) compared to the control (€65,555.3). Despite higher initial investment, F2 had the most favorable cost–benefit ratio in the long term. This study highlights the crucial influence of mulching and planting density on optimizing lemon balm production across diverse climatic and soil conditions, while also underscoring the importance of sustainable, non-chemical weed management strategies in lemon balm cultivation. Full article

To address the problem of environmental pollution caused by the extensive use of low-density polyethylene (LDPE) mulch film, this study developed a novel sprayable mulch using natural fibers and biodegradable polymers. Urea–formaldehyde resin (UF), strengthened with polyvinyl alcohol (PVA), was used as a modifier to induce beneficial physicochemical structural changes in PVA-modified urea–formaldehyde (PUF) resins. Characterization of these resins was conducted using Fourier transformation infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Preparation of the biodegradable mulch was conducted using Xuan paper waste residue (XP) as an enhancer, with PUF as the auxiliary agent. The resulting film (PUF-XP) was examined for differences in thickness, morphological characterization, and rate of weight loss, and the effects of different covering films on cucumber growth, root development, soil temperature, and weed control were evaluated. Characterization reveals that when the PVA content was 4% (W4UF), the film had the lowest free formaldehyde content (0.26%) and highest elongation at break (5.70%). In addition, W4UF could easily undergo thermal degradation at 278.4 °C and possessed a close-knit, three-dimensional structural network. W4UF was then mixed with paper powder and water in various proportions to produce three mulch films (BioT1, BioT2, and BioT3) that demonstrated excellent water retention and heat preservation and inhibited weed growth by 68.8–96.8%. Compared to no mulching (NM), BioT1 increased both the specific root length and root density, as well as improved the plant height, stem diameter, and total biomass of the cucumbers by 43.5%, 34.1%, and 33.9%, respectively. Therefore, a mass ratio of paper powder, water, and W4UF of 1:30:2 produced a biodegradable mulch film that could be used as an alternative to LDPE, mitigating the environmental pollution rendered by synthetic plastic mulch films and offering the potential for a sustainable agricultural application. Full article

Plant growth analysis provides insight regarding the variation behind yield differences in tested genotypes for plant breeders, but adopting this application solely for traditional plant phenotyping remains challenging. Here, we propose a procedure of using uncrewed aerial systems (UAS) to obtain successive phenotype data for growth analysis. The objectives of this study were to obtain high-temporal UAS-based phenotype data for growth analysis and investigate the correlation between the UAS-based phenotype and biomass yield. Seven different energy cane genotypes were grown in a random complete block design with four replications. Twenty-six UAS flight missions were flown throughout the growing season, and canopy cover (CC) and canopy height (CH) measurements were extracted. A five-parameter logistic (5PL) function was fitted through these temporal measurements of CC and CH. The first- and second-order derivatives of this function were calculated to obtain several growth parameters, which were then used to assess the growth of different genotypes with respect to weed competitiveness and biomass yield traits. The results show that CC and CH growth rates significantly differed among genotypes. TH16-16 was outstanding for its ground cover growth; therefore, it was identified as a weed-competitive genotype. Furthermore, TH16-22 had a higher CH maximum growth rate per day, yielding a higher biomass compared to other genotypes. The CH-based multi-temporal data as well as the growth parameters had a better relationship with biomass yield. This study highlights the application of UAS-based high-throughput phenotyping (HTP), along with growth analysis, for assisting plant breeders in decision-making. Full article

The conversion of aquatic biomass into biochar offers a sustainable strategy for improving soil fertility and mitigating ecological imbalances caused by its rapid proliferation. In this study, Typha angustifolia, a widely distributed aquatic weed, was utilized for biochar production. Three biochar types (TABC400, TABC500, and TABC600) were synthesized through pyrolysis at 400 °C, 500 °C, and 600 °C temperature. It was hypothesized that Typha angustifolia biochar would positively influence the growth and development of okra (Abelmoschus esculentus L.). The results demonstrate that biochar yield subsequently decreases with increasing pyrolysis temperature, with the highest yield at 400 °C temperature (49.03%), followed by 500 °C (38.02%) and 600 °C temperature (32.01%). However, carbon content 67.01 to 83.12%, higher heating value (17.31 to 27.42 MJ/kg), and mineral contents (K, Mg, P, Ca, Fe, Cu, Zn) increase significantly with higher pyrolysis temperature. However, oxygen, hydrogen, nitrogen, bulk density, moisture contents, and volatile context exhibited an inverse relationship with pyrolysis temperature, highlighting biochar stability and its potential for soil amendment. Among the three synthesized biochar, the 4%TABC600 (600 °C) revealed the most substantial improvement in plant height (110.11 ± 4.12 cm), plant dry biomass (6.12 ± 0.41 gm), and chlorophyll contact (39.34 ± 3.33 SPAD values), whereas the 2% and 6% TABC600 demonstrated significant influence on fruit yield (9.11 ± 2.11 gm) and fruit weight (750.44 ± 7.83 g), and chlorophyll contact (32–38 SPAD values). Based on our results, we can conclude that Typha angustifolia biochar prepared at 600 °C (TABC600) has great potential as a biofertilizer, promoting soil fertility and growth and development of crops, particularly for vegetable cultivation such as okra. Full article

Successful seed germination and plant seedling growth often require association with endophytic bacteria. Barnyard grass (Echinochloa crus-galli (L.) P. Beauv.) is a main weed during rice cultivation and has frequently been found in drought-prone fields such as cornfields in recent years. To determine whether endophytic bacteria enhance the survival chances of barnyard grass in dryland conditions, endophytic bacteria were collected from barnyard grass seeds. An endophytic bacterial strain, BC-14, was selected and confirmed as Cronobacter dublinensis based on its morphology, physiology, biochemistry, and genomic information. Moreover, C. dublinensis BC-14 secreted IAA in the Luria–Bertani broth up to 28.44 mg/L after 5 days; it could colonize the roots of barnyard grass. After the inoculation with seeds or the well-mixed planting soil, the bacterium can significantly increase the root length and plant height of barnyard grass under drought conditions. When comparing with the control group on the 28th day, it can be seen that the bacterium can significantly increase the contents of chlorophyll b (up to 7.58 times) and proline (37.21%); improve the activities of superoxide dismutase, catalase, and peroxidase (36.90%, 51.51%, and 12.09%, respectively); and reduce the content of malondialdehyde around 25.92%, which are correlated to the drought tolerance. The bacterial genomic annotation revealed that it contains growth-promoting and drought-resistant functional genes. In a word, C. dublinensis BC-14 can help barnyard grass suppress drought stress, promote plant growth, and enhance biomass accumulation, which is helpful to interpret the mechanism of weed adaptability in dry environments. Full article

Rice (Oryza sativa L.) is a crucial crop for employment and agricultural output and heavily reliant on family labor. This study evaluated the effects of nitrogen levels (80, 120, and 160 kg·ha⁻¹) on weed incidence and key agronomic variables, including vegetative growth, yield, and related traits, in Ecuador’s primary rice-growing regions, Guayas and Los Ríos. A split-plot randomized complete block design was implemented using two rice varieties (INIAP-FL-Elite and SFL-11) and three planting densities (20 × 30, 25 × 30, and 30 × 30 cm). Weed incidence was higher in Los Ríos, dominated by grasses (55.28%), while Cyperaceae (46.27%) prevailed in Guayas. The data analysis included non-parametric tests to identify significant treatment effects, debiased sparse partial correlations (DSPCs) to reveal key agronomic interactions, and principal component analysis (PCA) to identify influential traits, ensuring robust and normalized interpretations. Analysis of variance indicated significant effects for all variables, with vegetative growth (VG) most affected (p < 0.001). The number of panicles (NP) and days to flowering (DF) showed significant though less pronounced effects, while the panicle length (LP) and 1000-seed weight (TSB) exhibited moderate responses. The DSPCs highlighted the grains per panicle (GP) and total biomass (SB) as critical variables, with significant correlations between the days to flowering and the tiller count at 55 days (r = 0.750, p < 0.001) and between the vegetative growth and the total biomass (r = 0.678, p < 0.001). PCA explained 58.8% of the total variance, emphasizing the days to flowering, plant height, total biomass, and yield as the most influential traits. These findings underline the importance of integrated nutrient and weed management strategies tailored to Ecuador’s agroecological conditions. Full article

Mikania micrantha (“mile-a-minute” weed) is a global invasive alien weed that can cause severe damage to agroforestry ecosystems and significant agricultural losses worldwide. Although chemical, manual, or mechanical control methods are widely used to control M. micrantha, RNA interference (RNAi)-based biocontrol methods have rarely been reported for this species. The MONOPTEROS (MP) gene, encoding an auxin response factor, plays an essential role in embryonic root initiation in Arabidopsis thaliana. In this study, we identified the MP gene from M. micrantha via orthologous gene analysis. A total of 37 MP orthologous genes was identified in 4 plants, including 9 MP candidate genes in M. micrantha, 13 in Helianthus annuus, 6 in Chrysanthemum nankingense, and 9 in Lactuca sativa. Phylogenetic analysis revealed that an MP candidate gene in M. micrantha (Mm01G000655, named MmMP) was clustered into one clade with the MP gene in A. thaliana (AtMP). In addition, both MmMP and AtMP contain a B3-DNA binding domain that is shared by transcription factors that regulate plant embryogenesis. To study gene function, dsRNA against MmMP (dsMmMP) was applied to the roots of M. micrantha. Compared with those of the controls, the expression of MmMP was reduced by 43.3%, 22.1%, and 26.2% on the first, third, and fifth days after dsMmMP treatment, respectively. The dsMmMP-treated plants presented several morphological defects, mostly in the roots. Compared with water-treated plants, the dsMmMP-treated plants presented reduced developmental parameters, including root length, number of adventitious roots, root fresh and dry weights, plant height, and aboveground biomass. Additionally, safety assessment suggested that this dsMmMP treatment did not silence MP genes from non-target plants, including rice and tomato; nor did it inhibit root growth in those species. Collectively, these results suggest that MmMP plays an important role in root development in M. micrantha and provides a potential target for the development of species-specific RNAi-based herbicides. Full article

The economic significance of hemp (Cannabis sativa L.) as a source of grain, fiber, and flower is rising steadily. However, due to the lack of registered herbicides effective in hemp cultivation, growers have limited weed management options. Plant height, biomass, and canopy architecture may affect crop–weed competition. Greenhouse experiments conducted at the joint Clemson University Coastal Research and Education Center and USDA-ARS research facility at Charleston, SC, USA used 27 hemp varieties, grown under controlled temperature and light conditions. Weekly plant scans using a digital multispectral phenotyping system, integrated with machine learning algorithms of the PlantEye F500 instrument, (Phenospex, Heerlen, Netherlands) captured high-resolution 3D models and spectral data of the plants. Manual and scanner-based measurements were validated and analyzed using statistical methods to assess plant growth and morphology. This study included validation tests showing a significant correlation (p < 0.001) between digital and manual measurements (R² = 0.89 for biomass, R² = 0.94 for height), indicating high precision. The use of 3D multispectral scanning significantly reduces the time-intensive nature of manual measurements, allowing for a more efficient assessment of morphological traits. These findings suggest that digital phenotyping can enhance integrated weed management strategies and improve hemp crop productivity by facilitating the selection of competitive hemp varieties. Full article

As one of the dominant species of the alpine grassland on the Qinghai–Tibet Plateau, the activities (e.g., gnawing, burrowing, and grass storage) of plateau pikas (Ochotona curzoniae) directly alter the plant community structure of the grassland ecosystem and affect livestock production and greenhouse gas emission. In order to investigate the effects of rodent isolation (RI) on plant community structure and greenhouse gas emission in the alpine grassland of the Qinghai–Tibet Plateau, we established plots of rodent isolation and rodent activity (i.e., the control sample (CK)) in the 14th village, Seni District, Nagqu City in May 2018. From July 2019 to September, the numbers, sizes, and total damaged area of effective holes; the height, coverage, and aboveground plant biomass; and the methane (CH₄) and nitrous oxide (N₂O) emissions of the alpine grassland were monitored by the quadrat survey method and static closed-chamber method. The results show that the invasion and tunneling of Ochotona curzoniae resulted in the destruction of alpine grassland measuring 0.064 m² per square meter, while the rodent isolation plots showed that 97.9% of the alpine grassland remained unaltered; such unaffected land implies that the economic income of herdsmen could increase by 140 CNY hm⁻². The rodent isolation plots also show that the height and proportion of grasses and sedges in the alpine grassland increased, while the proportion of poisonous weeds decreased. Moreover, the rodent isolation plots also showed a significantly increased coverage of aboveground biomass (p < 0.05), although species richness showed no significant effect based on the Shannon–Weiner, Simpson, and Pielou indices (p > 0.05). The soil uptake of CH₄ and N₂O was 204.99 ± 50.23 μg m⁻² h⁻¹ and 4.48 ± 1.02 μg m⁻² h⁻¹ in the rodent isolation plots, significantly higher by 465.75% and 3001.4% relative to the rodent activity plots, respectively (p < 0.05). Therefore, the establishment of rodent isolation areas can effectively alleviate the degree of damage to alpine grasslands in the short run and slow down the greenhouse gas emission rate to some extent. However, excessive rodent control may also have negative effects on grassland ecosystems, so more attention should be paid in future studies to determining the disturbance threshold of plateau pika in this area. These results provide theoretical guidance for rodent control, grassland protection, and ecological environment management on the Qinghai–Tibet Plateau. Full article