Investigating the toxicological effects of aged nanoplastics (NPs) in soil is critical, as UV irradiation may exacerbate their ecological toxicity by altering surface properties and enhancing interactions with the soil. Here, we investigated the effects of different concentrations of pristine and aged polystyrene (PS) and carboxylpolystyrene (PSC) NPs on lettuce and soil properties. Both pristine and aged NPs inhibited pigment synthesis and lettuce growth. The maximum growth inhibition rates of leaf (root) biomass were 10.2 % (23.4 %) and 32.7 % (45.3 %) for pristine PS and PSC (50 mg center dot L- 1) and 26.7 % (35.9 %) and 43.1 % (57.8 %) for aged PS and PSC (50 mg center dot L- 1), respectively. NPs induced excessive reactive oxygen species (ROS) production in the leaves and roots, antioxidant defense mechanisms, and oxidative damage, which was more pronounced with aged NPs. ROS accumulation gradually increased with aging time and concentration of NPs, which inhibited photosynthesis and decreased biomass. At the same aging duration, exposure to either pristine or aged NPs significantly reduced soil pH. Compared to the control, neither pristine nor aged NPs altered the composition of dissolved organic matter, whereas aged PSC induced a significant increase in the intensity of soluble microbial byproducts; this was attributed to differences in soil acidity and alkalinity. Low concentrations of pristine and aged NPs increased the Chao 1 index in soils, exhibiting hormesis, and altered relative microbial abundances. Pristine and aged PS/ PSCs promoted microbial oxidative phosphorylation, carbon fixation pathways in prokaryotes, and the tricarboxylic acid cycle. The results provide critical insights into the impacts of NPs on plant and soil microbial growth.

Carrot (Daucus carota) is an important crop grown in Canada and globally. Fresh market carrots have strict cosmetic requirements to command full value at Grade A and are frequently downgraded for irregular shape, size, or pest damage. Organic farming presents challenges for nutrient management, soil health and pest control, which may be mitigated with cover cropping. A 3-year field experiment was conducted on a commercial organic farm to 1) test the effects of six preceding-year cover crop treatments compared to a weedy fallow control on carrot yield and quality, wireworm damage, reasons for downgrading, and populations of plant parasitic nematodes, and 2) characterize within-farm spatiotemperal variability in production to identify strategies to improve and stabilize economic return. Carrot yield (42-55 Mg ha-1), quality (39-92% Grade A) and market value (183-221 $1000 Canadian dollars ha-1) varied drastically across years, and blocks within years (<= 20% differences), but cover crops had no impact on these metrics. The dominant reasons for downgrading were morphological, affecting 7-74% of carrots each year and varying with cover crop only once, where carrots following buckwheat (Fagopyrum esculentum) had fewer shape flaws. Nematodes had no relationship to cover crop or any carrot metric and wireworms damaged only 2% of carrots across all three years. This study found virtually no effect of cover crop species composition on next year's carrots on this farm, and that the farmer-collaborators can optimize their operation by improving crop establishment across space and time, reducing morphological flaws, and seeking higher value for downgraded produce.

Genera Pseudomonas and Xanthomonas include bacterial species that are etiological agents of several diseases of major vegetable crops, such as tomato, pepper, bean, cabbage and cauliflower. The bacterial pathogens of those genera may cause severe crop damage, leading to symptoms like leaf spots, wilting, blights, and rotting. These plant pathogens can affect propagation materials and spread rapidly through plant tissues, contaminated soils, or water sources, making them challenging to control using conventional chemical products alone. Biopesticides, such as essential oils (EOs), are nowadays studied, tested and formulated by employing nano- and micro-technologies as innovative biological control strategies to obtain more sustainable products using less heavy metal ions. Moreover, there is a growing interest in exploring new biological control agents (BCAs), such as antagonistic bacterial and fungal species or bacteriophages and understanding their ecology and biological mechanisms to control bacterial phytopathogens. These include direct competition for nutrients, production of antimicrobial compounds, quorum quenching and indirect induction of systemic resistance. Optimisation of the biocontrol potential goes through the development of nanoparticle-based formulations and new methods for field application, from foliar sprays to seed coatings and root inoculation, aimed to improve microbial stability, shelf life, controlled release and field performance. Overall, the use of biological control in horticultural crops is an area of research that continues to advance and shows promising potential. This review aims to provide an in-depth exploration of commercially accessible biocontrol solutions and innovative biocontrol strategies, with a specific focus on the management of bacterial diseases in vegetable crops caused by Pseudomonas and Xanthomonas species. In this article, we highlighted the advancements in the development and use of EOs and other BCAs, emphasizing their potential or shortcomings for sustainable disease management. Indeed, despite the reduced dependence on synthetic pesticides and enhanced crop productivity, variable regulatory frameworks, compatibility among different BCAs, and consistent performance under field conditions are among the current challenges to their commercialization and use. The review seeks to contribute valuable insights into the evolving landscape of biocontrol in vegetable crops and to provide guidance for more effective and eco-friendly solutions against plant bacterial diseases.

Salinity stress hampers plant growth and crop productivity. The growth and yield of coriander are severely affected by soil salinity. A pot experiment was performed to investigate the effectiveness of zinc and iron foliar application along with spray adjuvants under salinity stress. The single foliar application of micronutrients was carried out under normal and saline conditions (7 dS m-1) at the vegetative growth stage (21 days after germination). The results showed an increase in plant biomass, relative water content, antioxidant activities, and zinc and iron concentrations in coriander. The shoot dry biomass was significantly improved by 107 and 203%, respectively, in both control and saline conditions where zinc + iron + adjuvant was applied. The same treatment combination reduced the membrane damage, increased antioxidant enzyme activity, and improved gas exchange attributes (27% increase in photosynthesis rate compared to the control) and mineral contents in coriander plants under saline conditions. The application of zinc and iron was beneficial in mitigating salinity stress in coriander plants, and their effectiveness was increased by the addition of spray adjuvants.

Lead (Pb) contamination in rhizosphere soil inhibits seed germination and impairs ATP generation, causes lipid peroxidation, damages DNA molecules, and increases reactive oxygen species (ROS) formation, leading to decreased chlorophyll synthesis and plant growth. Using PGPR in combination with organic amendments has emerged as an eco-friendly and sustainable biological approach to reducing heavy metal toxicity in vegetables. In view, lead-tolerant Bacillus sp. strain N18 was evaluated along with compost to ameliorate lead toxicity in tomatoes under lead-contaminated soil conditions. The test soil was spiked with different concentrations of Pb (0, 400 and 600 mg kg- 1) and placed for 72 h for equilibrium before filling the plastic jars. Five 20-day-old tomato plants were transplanted in each jar and harvested after 40 days of transplantation. Results showed that plant height and root length were significantly improved by 11 and 49% over the control, while SPAD value was enhanced by 31% due to the combined use of Bacillus sp. strain N18 and compost under 600 mg kg- 1 of lead. The lead in root and shoot decreased by 6 and 13% compared with the un-inoculated control under 600 mg kg- 1 of Pb. The combination of Bacillus sp. strain N18 and compost also improved the enzymatic and non-enzymatic antioxidant systems by decreasing the proline contents, superoxide dismutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity and peroxidase (POX) activity. It is concluded that the combined use of lead-tolerant Bacillus sp. strain N18 and compost effectively ameliorated the lead toxicity in tomatoes grown under Pb-contaminated soil conditions. The integrated use of Bacillus sp. N18 and compost showed the potential for improving tomato growth and physiology under Pb-contaminated soils and decreasing the Pd uptake in tomato plants by stabilizing it in the root zone. This approach can be explored as a good strategy for growing vegetables, especially tomatoes, in Pb-contaminated peri-urban areas.

The adoption of protected cultivation techniques has significantly enhanced vegetable productivity in India, by offering numerous advantages such as extended growing seasons, increased yield and better control over environmental conditions. Growing crops under protected cultivation has multifaceted benefits; however, the adoption of sequential cropping pattern in these closed structures has led to the prevalence of soil borne pathogens, nematodes and pest incidence, which became a major hindrance to the sustainable agriculture. Continuous cultivation of crops without adequate rotation or sanitation measures in the same soil creates a conducive environment for pest and disease proliferation. Prevalence of nematode infestation is particularly concerning as they pose a serious threat to the yield and quality of agriculture production. Nematodes, such as root-knot nematodes and reniform nematodes, can survive in the congenial conditions of higher temperatures and humidity present in the protected cultivation structures. Nematode infestations can cause significant damage to the root systems of plants, leading to reduced water and nutrient uptake, stunted growth and lower yields and symptoms like chlorosis, wilting and stunting will appear after the significant damage. This review discusses the key nematode species affecting crops under protected cultivation, their impact on crop health and productivity, their ecological interactions and various integrated management strategies. Integrated management strategies, including biological, chemical and cultural practices, are essential for mitigating the menace caused by the plant parasitic nematodes. Cultural practices such as crop rotation and soil solarisation, chemical treatments with nematicides, Biological control using biocontrol agents and natural predators, are all part of a comprehensive strategy to manage nematode populations effectively and sustain the productivity of protected cultivation systems.

There has been a growing concern on the health effect of edible plants growing near/on/within the vicinity of dumpsites. This study investigated two edible vegetables: Amarathus hybridus and Talinum triangulare (Jacq) grown in the vicinity of a major informal dumpsite of electronic waste in Nigeria. The levels of polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and heavy metal concentrations in the vegetables were measured. The health risks of consuming the vegetables were assessed using the hazard index (HI), lifetime cancer risk (LCR), estimated daily intake (EDI), and hazard quotient (HQ). Using the Ames Salmonella fluctuation test on Salmonella typhimurium (TA100 and TA98) and the SOS chromo test on Escherichia coli (PQ37), the mutagenicity and genotoxicity of the vegetables were evaluated. The two vegetables have elevated levels of heavy metals, PBDEs, PCBs, and hazardous PAHs. Compared to A. hybridus, , T. triangulare was more contaminated. The amounts of organic constituents and heavy metals in the vegetables correlated favorably. The levels of the HQ, HI, and LCR were above the suggested guideline values, indicating a significant risk of both carcinogenic and non-carcinogenic consequences, particularly in children. The two vegetables were mutagenic even at 50 % concentration in the Ames test. This was corroborated with SOS-chromo test results showing that the two vegetables were indeed genotoxic. This study demonstrated the harmful effects of growing food crops close to dumpsites; therefore, sufficient measures should be implemented to stop farmers and individuals from utilizing dirt from dumps as fertilizer or from planting in soil that has been used as a dump in the past or present.

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.

Plant parasitic nematodes (PPNs) are acknowledged as a paramount factor which limits the production of staple crops and vegetables. Preferred standard control method had been the use of synthetic nematicides. However, owing to the undesirable consequences of the residual effect of nematicides in the environment, the need for alternative approaches becomes pertinent and this has prompted investigation into the nematicidal potential of extracts from Lawsonia inermis for practicable application on lettuce plants infected with Meloidogyne incognita in field experiments. The leaves of L. inermis were collected and divided into four parts for separate extraction and these were compared with the standard nematicide carbofuran individually. The essential oil (EO) was significantly more potent than the other extracts from L. inermis . There was no significant difference between plants treated with carbofuran and EO. The fractions were significantly better than crude methanol and ethanol extracts of L. inermis. Reproduction of M. incognita on lettuce plant roots was considerably reduced by utilization of L. inermis extracts. Notably higher vegetative growth was observed in treated lettuce plants. The IR, 1 H-NMR and 13 C-NMR spectral data analysis confirmed the presence of sesquiterpenes in the chromatographic fraction. The GC-MS profile indicated phytol as the major constituent of the EO. The results obtained from this study indicates that extracts from L. inermis could be a viable option in the management of M. incognita damaging lettuce in dependable vegetable production.

Bacterial wilt (BW) is a soil-borne disease that leads to severe damage in tomato. Host resistance against BW is considered polygenic and effective in controlling this destructive disease. In this study, genomic selection (GS), which is a promising breeding strategy to improve quantitative traits, was investigated for BW resistance. Two tomato collections, TGC1 (n = 162) and TGC2 (n = 191), were used as training populations. Disease severity was assessed using three seedling assays in each population, and the best linear unbiased prediction (BLUP) values were obtained. The 31,142 SNP data were generated using the 51K Axiom array (TM) in the training populations. With these data, six GS models were trained to predict genomic estimated breeding values (GEBVs) in three populations (TGC1, TGC2, and combined). The parametric models Bayesian LASSO and RR-BLUP resulted in higher levels of prediction accuracy compared with all the non-parametric models (RKHS, SVM, and random forest) in two training populations. To identify low-density markers, two subsets of 1,557 SNPs were filtered based on marker effects (Bayesian LASSO) and variable importance values (random forest) in the combined population. An additional subset was generated using 1,357 SNPs from a genome-wide association study. These subsets showed prediction accuracies of 0.699 to 0.756 in Bayesian LASSO and 0.670 to 0.682 in random forest, which were higher relative to the 31,142 SNPs (0.625 and 0.614). Moreover, high prediction accuracies (0.743 and 0.702) were found with a common set of 135 SNPs derived from the three subsets. The resulting low-density SNPs will be useful to develop a cost-effective GS strategy for BW resistance in tomato breeding programs.