Viruses are estimated to be responsible for approximately 50% of the emerging plant diseases, which are difficult to control, and in some cases, there is no cure. It is essential to develop therapy practices to strengthen the management of these diseases caused by viruses in economically important crops. Metal nanoparticles (MeNPs) possess diverse physicochemical properties that allow for them to have a wide range of applications in industry, including nanomedicine and nano-agriculture. Currently, there are reports of favorable effects of the use of nanoparticles, such as antibacterial, antifungal, and antiviral effects, in animals and plants. The potential antiviral property of MeNPs makes them a powerful option for controlling these histological agents. It is crucial to determine the dosage of NPs, the application intervals, their effect as a biostimulant, and the clarification of the mechanisms of action, which are not fully understood. Therefore, this review focuses on discussing the ability of metal nanoparticles and metal oxides to control viruses that affect agriculture through an exhaustive analysis of the characteristics of the particles and their interaction processes for a possibly beneficial effect on plants.

Due to low yields, organic agriculture cannot satisfy the global demand for food, although it can provide products of higher nutraceutical quality. The objective of this research was to incorporate vermicompost leachates (VCLs) into an irrigation system during tomato (Solanum lycopersicum cv. Rafaello) cultivation to evaluate their effects on the lycopene, β-carotene, and phenolic content of tomatoes and on the physical and chemical soil variables. To evaluate the effects of VCLs, three types of substrates were used to create VCLs: mushroom waste (MSHW), leaf-cutting ant waste (LCAW), and cow compost (CC). A total of 0.1 L of leachate per plant was added as a supplement to a nutrient solution (NS) and applied once weekly, twice weekly, or every fifteen days to three different treatments for each leachate. All VCLs had a positive effect on the production of lycopene; the best results were obtained by the application of the MSHW (78 mg kg -1 fresh weight). The VCL decreased the presence of ions phytotoxic to plants by 99% and improved the soil structure by increasing the amount of organic matter and the hydraulic conductivity. However, the VCL had no effect on the physiological variables. The results support the use of leachate from CC via fertigation twice a week at a dose of 0.1 L plant -1 because it increases lycopene content by 67%.

The tomato fruit is rich in bioactive compounds with antioxidant activity, the levels of which can vary over time in response to biotic and abiotic factors, including the application of elicitors. We investigated the effects of foliar spray of methyl jasmonate (MeJ), salicylic acid (SA), nitric oxide (NO), and hydrogen peroxide (H 2 O 2 ) on tomato plants every 15 days until the end of cultivation. We measured the levels of bioactive compounds, antioxidant activity, and physiological parameters in three distinct trusses. With the exception of plant length, the elicitors had no effects on physiological parameters, whereas they did have an effect on lycopene content, bioactive compound levels, and antioxidant activity in the three sampled trusses. A strong correlation between bioactive compounds and antioxidant activity was found for the elicitors, particularly MeJ. Our results indicate that certain bioactive compounds and their antioxidant activities vary not only between trusses but also based on the specific elicitor used.

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One of the factors determining success in tomato production is plant nutrition. The diagnosis and recommendation integrated system (DRIS) is a tool used to obtain fertilizer recommendations. The objective of this study was to determine DRIS indices using petiole sap analysis (PSA) and compare them with those obtained using leaf analysis in two tomato cultivars grown under greenhouse conditions. A complete randomized design with eight treatments and 60 plants per experimental unit was used. To determine whether employing PSA with the DRIS methodology can provide a reliable diagnosis of fertilization, doses of some elements, such as N, P, or K, were reduced by 30% and supplied to two tomato cultivars, namely, Cid and Moctezuma. The indices for PSA-DRIS and DRIS were estimated. R2 values greater than 0.84 were obtained for the relationships between the leaf concentrations and petiole extract (PE) concentrations of some elements in both tomato cultivars. The PSA-DRIS method detected 62.5% of the cases of deficiency identified via DRIS. The PSA-DRIS method is a low-cost way to rapidly fertilize recommendations in tomato.