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.

The current N and P fertilization practices for vegetable crops grown in organic soils are inaccurate and and may potentially damage the environment. New fertilization models are needed. Machine learning (ML) methods can combine numerous features to predict crop response to N and P fertilization. Our objective was to evaluate machine learning predictions for marketable yields, N and P offtakes, and the N/P ratio of vegetable crops. We assembled 157 multi-environmental fertilizer trials on lettuce (Lactuca sativa), celery (Apium graveolens), onion (Allium cepa), and potato (Solanum tuberosum) and documented 22 easy-to-collect soil, managerial, and meteorological features. The random forest models returned moderate to substantial strength (R2 = 0.73-0.80). Soil and managerial features were the most important. There was no response to added P and null to moderate response to added N in independent universality tests. The N and P offtakes were most impacted by P-related features, indicating N-P interactions. The N/P mass ratios of harvested products were generally lower than 10, suggesting P excess that would trigger plant N acquisition and possibly alter soil N and C cycles through microbial processes. Crop response prediction by ML models and ex post N/P ratio diagnosis and N and P offtakes proved to be useful tools to guide N and P management decisions in organic soils.