Researchers have tried hard to study the toxic effects of single pollutants like certain antibiotics and nanoplastic particles on plants. But we still know little about how these pollutants interact when they're together in the environment, and what combined toxic effects they have on plants. This study assessed the toxic effects of polystyrene nanoplastics (PS-NPs) and ciprofloxacin (CIP), both individually and in combination, on soybean (Glycine max L.) seedlings by various concentration gradients treatments of PS-NPs (0, 10, 100 mg/L) and CIP (0, 10 mg/L). The results indicated that high concentrations of PS-NPs significantly impeded soybean seedling growth, as evidenced by reductions in root length, plant height, and leaf area. CIP predominantly affected the physiological functions of leaves, resulting in a decrease in chlorophyll content. The combined exposure demonstrated synergistic effects, further intensifying the adverse impacts on the growth and physiological functions of soybean seedlings. Metabolomic analyses indicated that single and combined exposures markedly altered the metabolite expression profiles in soybean leaves, particularly related to amino acid and antioxidant defense metabolic pathways. These results indicate the comprehensive effects of NPs with antibiotics on plants and provide novel insights into toxic mechanisms.

While various studies have attempted to investigate the efficacy of biochars in enhancing plant seedlings, research on the application of biochar specifically for Coffea arabica L. seedlings in drought conditions remains restricted. To reveal the mitigation of biochar in the Coffee. seedlings under drought stress, the impacts of different biochar doses on soil physicochemical, biological, and hydrological parameters, as well as the growth of Coffee seedlings were evaluated. To mimic the effect of drought stress, utilizing three different levels of water holding capacity (20 %, 40 %, and 60 % of WHC) was performed with three different corncob biochar application rates of 1 %, 2.5 %, and 5 % w/w of soil. The results revealed that corncob biochar application increased pH, cation exchange capacity and organic matter. While soil microbial respiration, microbial biomass carbon, and dissolved organic carbon had increased in application biochar 1 and 5 % under both drought and no drought conditions. Corncob biochar at 1 % application rate enhanced the growth and chlorophyll content under drought condition significantly (p < 0.05). However, no statistically significant differences were observed between biochar application and water holding capacity on membrane damage and total soluble sugar content under drought conditions. The relative water and proline content had increased in biochar application at 1 %. Based on these findings, the application of biochar into coffee seedling production systems may help mitigate the adverse effects of water scarcity while promoting long-term soil health and agricultural resilience, particularly in tropical and subtropical highland regions where climate change-induced drought events are becoming more frequent.

To elucidate the mechanism underlying the enhancement of salinity tolerance by tea polyphenols (TPs), we employed seedlings of the wheat cultivar Longchun 30 to explore the individual and combined effects of 150 mM sodium chloride (NaCl) and 25 mg L-1 (25) or 100 mg L-1 (100) TPs on growth parameters, element absorption and transport, as well as polyphenols including anthocyanin metabolism. Compared to the control, treatment with NaCl significantly reduced plant biomass, relative growth rate (by 62%), leaf area (by 61%), AS(K)(+), Na+ levels (by 38%), and AS(Ca2)(+), Na+ levels (by 54%) in wheat seedlings. Conversely, it led to an increase in TSK+, Na+ (by 88%) and TSCa2+, Na+ levels (by 257%). Moreover, the NaCl treatment diminished the antioxidant activity in the in vitro leaf extract, resulting in enhanced reactive oxygen species levels and oxidative damage in wheat leaves. Furthermore, the levels of total polyphenols (by 27%), flavonoids (by 31%), and anthocyanins (by 27%) in wheat leaves were markedly reduced under salt stress. This was accompanied by the down-regulation of the activities of 4-coumaroyl: CoA ligase (4CL), chalcone synthase, chalcone isomerase (CHI), flavanone-3-dioxygenase (F3H), dihydroflavonol reductase (DFR), and anthocyanidin synthase, along with the down-regulation of their gene expression. In contrast, individual TPs exposure resulted in weak, ineffective, or even opposite effects on most of these parameters. More importantly, the addition of TPs partly counteracted salinity-induced changes in these parameters, particularly by increasing total polyphenols, flavonoids, and anthocyanins levels, upregulating the activities of the aforementioned six enzymes, and enhancing the expression of Ta4CL, TaCHI, TaF3H, and TaDFR in wheat leaves under salinity stress. Additionally, the growth-promoting effect of 100 mg L-1 TPs on salinity-stressed seedlings was stronger than that of 25 mg L-1 TPs. Overall, TPs application significantly enhanced the growth of salinity-stressed wheat seedlings by improving K+ and Ca2+ absorption and elevating polyphenols, including flavonoids and anthocyanins levels. Moreover, the accumulation of anthocyanins in salinity-stressed wheat leaves induced by TPs was attributed to the up-regulation of the activities and gene expression of synthesis-related enzymes.

Salt stress is a relative concept, excessive sodium ions can inhibit the normal growth and development of mulberry seedlings through osmotic stress, oxidative damage and ion imbalance. Calcium as a second messenger to regulate the process. Therefore, calcium should also be taken seriously in experimental design. The experiment was conducted by setting different salt concentrations (0, 50, 200 mmol L- 1) and exogenous calcium contents (0, 2.5, 5, 10, 20 mmol L- 1) on mulberry seedlings in hydroponics. The effects of exogenous calcium on nutrient accumulation, distribution and stoichiometric characteristics of mulberry seedlings under salt stress were studied. Results showed that salt stress reduced mulberry growth, but exogenous calcium reversed this effect, when the concentration of exogenous calcium was 10 mmol L- 1 the biomass and nutrient accumulation of mulberry seedlings could reach the maximum, and there are significant differences with other treatments (p < 0.05). And salt stress shifted the calcium absorption focus from leaves to trunks. Exogenous calcium mitigation on mulberry stoichiometry under salt stress shows initial decrease then increase, the N: P ratio showed that salt treatment could change the P stress to N stress in mulberry seedlings. Meanwhile, there was a significant positive correlation between the biomass of each organ with C: P and N: P (p < 0.01, 0.001), but a extremely significant negative correlation between the biomass with others stoichiometric ratios (p < 0.001). According to the results of leaf stoichiometric ratio and correlation analysis, the optimum application amount of exogenous calcium in mulberry seedlings under salt stress was 10 mmol L- 1. This research offers a theoretical foundation for salt-alkali soil fertilization and has significant implications for soil salinization management.

Metering device is a main component of vegetable transplanters that could save cost of operation and labour requirement in transplanting. Therefore, a tractor-drawn three-row automatic vegetable transplanter using an inclined magazine-type metering device for cylindrical paper pot seedlings was developed and evaluated in field. Experiments on metering device were conducted at seven forward speeds 1.0, 1.2, 1.4, 1.6, 1.8, 2.0 and 2.2 km/h, to determine the optimal performance speed for 45-day old tomato seedlings. Data on seedling spacing, tilted planting, soil cover, seedling damaged while conveying and feeding and transplanting were recorded and analysed for conveying efficiency (CE), feeding efficiency (FE), transplanting efficiency (TE), overall efficiency (OE) and seedling spacing (SS). The CE, FE, TE and OE were found to be 100, 83.3, 91.7 and 96.7%, respectively, at 1.2 km/h. The SS was ranged from 633 to 651 mm for speed range of 1-1.2 km/h. Based on the optimized values of laboratory studies, a tractor-drawn three-row automatic vegetable transplanter was developed and evaluated in the field. The field performance data revealed that actual field capacity of the machine was 0.11 ha/h at a forward speed of 1.2 km/h, with a 50% field efficiency. The transplanter can transplant per row 33 seedlings/min, compared to 3.7 seedlings/min by manual method. Also, the saving in cost and labour is about 55 and 93.9% as compared to manual method. This transplanter offers efficient transplanting of potted seedlings, ensuring timely operation, labour savings and reduced drudgery compared to conventional practices.

Uranium (U) contamination of rice is an urgent ecological and agricultural problem whose effective alleviation is in great demand. Sphingopyxis genus has been shown to remediate heavy metal-contaminated soils. Rare research delves into the mitigation of uranium (U) toxicity to rice by Sphingopyxis genus. In this study, we exposed rice seedlings for 7 days at U concentrations of 0, 10, 20, 40, and 80 mg L- 1 with or without the Sphingopyxis sp. YF1 in the rice nutrient solution. Here, we firstly found YF1 colonized on the root of rice seedlings, significantly mitigated the growth inhibition, and counteracted the chlorophyll content reduction in leaves induced by U. When treated with 1.1 x 107 7 CFU mL- 1 YF1 with the amendment of 10 mg L- 1 U, the decrease of U accumulation in rice seedling roots and shoots was the largest among all treatments; reduced by 39.3% and 32.1%, respectively. This was associated with the redistribution of the U proportions in different organelle parts, leading to the alleviation of the U damage to the morphology and structure of rice root. Interestingly, we found YF1 significantly weakens the expression of antioxidant enzymes genes ( CuZnSOD, CATA, POD ), promotes the up- regulation of metal-transporters genes ( OsHMA3 and OsHMA2) , ) , and reduces the lipid peroxidation damage induced by U in rice seedlings. In summary, YF1 is a plant-probiotic with potential applications for U-contaminated rice, benefiting producers and consumers.

Introduction As a result of climate change and bark beetle outbreaks in forests, extensive salvage, and sanitary cutting have been undertaken in Europe, resulting in many clear-cuts with coarse stumps. The populations of pine weevils (Hylobius abietis and Hylobius pinastri) are steadily increasing. A high abundance of pine weevils feeding on seedlings typically results in significant economic losses and prolongs the forest establishment period. However, information on these species spatial distribution and habitat selection patterns, necessary for assessing their harmfulness and subsequently accurately estimating their threat to reforested areas, is lacking. To determine which factors influence spatial selection patterns and seedling type preference, this study investigated which clear-cut factors increase pine weevil abundance and which seedling types (species and age) are the most preferred. Methods The experiment was carried out on 20 clear-cuts in the central Czech Republic. We evaluated soil moisture level, average stump distance and diameter, proportion of other conifers, and whether the stumps were mulched. We detected the abundance of pine weevils using pitfall traps. We determined the feeding scar intensity on the first 10 cm of seedling stems on commonly used seedlings for reforestation in central Europe: 1-year-old Scots pine (Pinus sylvestris), European larch (Larix decidua), and 3-year-old Norway spruce (Picea abies), with 1,200 seedlings in total. The individual seedling types alternated in rows. The results were evaluated using generalized linear mixed-effect models (GLMMs). As dependent variables we used total numbers of H. abietis and H. pinastri. The soil moisture level, mulching, proportion of other conifers, average stump diameter, and distance were considered independent variables. Results We found that Norway spruce was the least attractive to pine weevils. We found a higher abundance of H. abietis females in moist clear-cuts, confirming that dry clear-cuts are less suitable for oviposition. Conclusion According to our findings, if foresters want to plant coniferous seedlings, it seems that planting older spruce is a better option than planting larch and pine. These findings provide valuable insights for forest management and reforestation strategies, equipping foresters with the knowledge to mitigate the threat of pine weevils and ensure successful forest establishment.

The aim of the study was to assess the impact of plant extracts from hemp inflorescences (H10-10% and H20-20%), as well as a mixture of extracts from hemp inflorescences, sage, and tansy leaves (M10-10% and M20-20%) on phytotoxicity and selected physiological and biometric parameters of wheat seedlings, as well as the biological activity of soil in a growth chamber experiment. In all experimental combinations, a low phytotoxicity of the extracts was observed in the form of leaf tip yellowing, classified as first-degree damage or its complete absence. The plant extracts and their mixtures, except for the H20 extract, had an inhibitory effect on the development of fungal pathogens, especially Fusarium spp. The H20 extract increased the fresh and dry weight of root seedlings. The tested extracts also had a positive effect on the chlorophyll content in seedlings. The highest chlorophyll concentrations were recorded for the seedlings sprayed with the M20 extract mixture. The applied plant extracts influenced the activity of soil enzymes. The highest activity of catalase and dehydrogenases was observed after spraying seedlings with M20, while the lowest was recorded after applying H10. Of all the tested groups of soil environment compounds included in the Biolog EcoPlates test, carbohydrates and carboxylic acids were most actively utilized. Conversely, amines and amides constituted the group of compounds utilized the least frequently. The present study demonstrated the high effectiveness of plant extracts on wheat seedlings due to their biocidal action against phytopathogenic fungi and increased biological activity of the soil. This research serves as an initial phase of work, which will aim to verify the results obtained under field conditions, as well as assess the biological stability of the extracts.

Electrolytic manganese residues (EMR) and alkali-activated laterite-based geopolymers were used to prepare slow-release fertilizers (SRFs) and the physicochemical properties and Mn release behavior of EMR-laterite-based SRFs (SRFs-LA) were studied. MnSO4 & sdot;H2O in EMR transforms into CaMnSi2O6, MnO2 and (NH4)(2)Mn(SO4)(2)& sdot;6H(2)O after SRFs-LA synthesis. Geopolymers can slow Mn release through ion exchange and can physically encapsulate Mn-containing minerals. Mn release from the SRFs-LA system was primarily influenced by a combination of nonFick diffusion and skeleton erosion. A comparative pot experiment was also conducted between SRFs-LA and SRFs prepared using alkali/acid-activated geopolymers with EMR (SRFs-alGo/SRFs-acGo) to examine the fertilization efficiency of Guizhou white tea seedlings. Compared with Mg(II), Mn(II) not only played a dominant role in the competitive root absorption process from the soil to the interior of seedlings, but also impeded Fe transportation by regulating the expression of citrate transporters. The slow release of Mn from SRFs-alGo and SRFs-LA could benefit tea seedling growth and protein and photosynthetic pigment synthesis, whereas EMR treatments with Mn burst release damaged the antioxidant system owing to the excessive accumulation of reactive oxygen species in leaves. The Mn released from SRFs-acGo may approach the tolerance limit of tea seedlings growth. The order of fertilizer efficiency for young Guizhou white tea seedlings was as follows: SRFs-LA > SRFs-alGo > SRFs-acGo. Moreover, the cost of SRFs-LA prepared using laterite instead of metakaolin as an active silicon-aluminum source could be reduced by approximately $18.7/t.

This study focuses on real-time detection of maize crop rows using deep learning technology to meet the needs of autonomous navigation for weed removal during the maize seedling stage. Crop row recognition is affected by natural factors such as soil exposure, soil straw residue, mutual shading of plant leaves, and light conditions. To address this issue, the YOLOv5s network model is improved by replacing the backbone network with the improved MobileNetv3, establishing a combination network model YOLOv5-M3 and using the convolutional block attention module (CBAM) to enhance detection accuracy. Distance-IoU Non-Maximum Suppression (DIoU-NMS) is used to improve the identification degree of the occluded targets, and knowledge distillation is used to increase the recall rate and accuracy of the model. The improved YOLOv5s target detection model is applied to the recognition and positioning of maize seedlings, and the optimal target position for weeding is obtained by max-min optimization. Experimental results show that the YOLOv5-M3 network model achieves 92.2% mean average precision (mAP) for crop targets and the recognition speed is 39 frames per second (FPS). This method has the advantages of high detection accuracy, fast speed, and is light weight and has strong adaptability and anti-interference ability. It determines the relative position of maize seedlings and the weeding machine in real time, avoiding squeezing or damaging the seedlings.