The use of elicitors or biostimulants such as salicylic acid (SA) is an emerging novel practice to improve the yield and quality of crops since it plays an important role in the regulation of various physiological and metabolic processes. The objective of this research was to study the effect of the foliar application of SA on the nutraceutical quality and yield of tomato fruits. A completely randomized experimental design with 10 repetitions was used. SA was applied at five doses (0.025 mM, 0.05 mM, 0.075 mM, 0.1 mM, and 0.125 mM) every 15 days through foliar sprays after transplantation, accumulating seven applications through the cycle. The response variables were yield (total fruit weight per plant), fruit parameters (weight, diameter, firmness, and total soluble solids), percentage of weight loss, and nutraceutical quality. The obtained results suggest that the foliar spraying of SA improves the yield and biosynthesis of phytochemical compounds in tomato fruits, compared to control plants. According to the results, it is advisable to use the dose of 0.125 mM of SA since it has a higher content of bioactive compounds without compromising yield.

Tomato fruits are a unique functional food and a natural reservoir of nutrients, antioxidants, vitamins and bioactive compounds that improve nutrition and human health. As an important vegetable throughout the world, tomatoes have attracted the attention of researchers to carry out various strategies to improve the functionality of this food aimed at the prevention of diseases, health and global well-being. An agronomic strategy in this study was to evaluate the influence of the application of "salicylic acid (SA)" on the yield and nutraceutical quality of the tomato crop, produced under hydroponic conditions. A completely randomized experimental design with six repetitions was used. SA at five doses (0.025, 0.05, 0.075, 0.1 and 0.125 mM) and one control were applied every 15 days in the nutritive solution under a hydroponic system on tomato plants. The evaluated variables were yield (total fruit weight per plant), fruit parameters (weight, diameter, firmness, and total soluble solids), percentage of weight loss and nutraceutical quality of tomato. The results obtained indicate that the addition of salicylic acid in nutritive solution increased the yield and biosynthesis of phytochemical compounds in tomato fruits, in relation to the control without application. In conclusion, to obtain a higher nutraceutical quality without affecting the tomato fruit yield, it is recommended to use the average concentration (0.125 mM) of SA.

El tomate es la hortaliza más cultivada y consumida a nivel mundial y frecuentemente sufre diversas tensiones ambientales que afectan su productividad. Como posibles soluciones para mitigar el estrés está el uso de bioestimulantes, en particular, el uso de extractos de algas pardas que afectan positivamente varios procesos fisiológicos y bioquímicos en las plantas. Por lo tanto, el objetivo del presente trabajo fue evaluar el efecto de la aplicación foliar de 17 extractos hidroalcohólicos de Sargassum spp. al 1.5%, más dos tratamientos control (agua destilada y un producto comercial a base de Ascophyllum nodosum) sobre el crecimiento y compuestos antioxidantes de plántulas de tomate, bajo un diseño completamente al azar. Los resultados muestran que el extracto que presentó los mejores resultados fue el EAS7 (160 °C / 30 min / 50% de etanol). Dicho extracto aumentó la altura, diámetro de tallo, materia fresca y seca total de las plántulas de tomate en un 8.67, 32.32, 25.03 y 11.59%, respectivamente, encomparación con el control absoluto (agua destilada). Además, el EAS7 aumentó el contenido de proteínas, glutatión, fenoles totales, flavonoides y capacidad antioxidante (ABTS) de las hojas en un 386.48, 15.92, 22.05, 35.99 y 18.86%, respectivamente, en comparación con el control absoluto. La aplicación de extractos de Sargassum spp. es una alternativa prometedora para mejorar lascaracterísticas agronómicas y antioxidantes del cultivo de tomate.

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Currently, the use of biostimulants in agriculture is a tool for mitigating certain environmental stresses. Brown algae extracts have become one of the most important categories of biostimulants in agriculture, and are derived from the different uses and positive results obtained under optimal and stressful conditions. This study aimed to examine the efficacy of a foliar application of a hydroalcoholic extract of Sargassum spp. and two controls (a commercial product based on Ascophyllum nodosum and distilled water) with regard to growth, the antioxidant system, and the expression of defense genes in tomato seedlings grown in nonsaline (0 mM NaCl) and saline (100 mM NaCl) conditions. In general, the results show that the Sargassum extract increased the growth of the seedlings at the end of the experiment (7.80%) compared to the control; however, under saline conditions, it did not modify the growth. The Sargassum extract increased the diameter of the stem at the end of the experiment in unstressed conditions by 14.85% compared to its control and in stressful conditions by 16.04% compared to its control. Regarding the accumulation of total fresh biomass under unstressed conditions, the Sargassum extract increased it by 19.25% compared to its control, and the accumulation of total dry biomass increased it by 18.11% compared to its control. Under saline conditions, the total of fresh and dry biomass did not change. Enzymatic and nonenzymatic antioxidants increased with NaCl stress and the application of algal products (Sargassum and A. nodosum), which was positively related to the expression of the defense genes evaluated. Our results indicate that the use of the hydroalcoholic extract of Sargassum spp. modulated different physiological, metabolic, and molecular processes in tomato seedlings, with possible synergistic effects that increased tolerance to salinity.