The high content of carbonates (CO32−), bicarbonate (HCO3−), and high pH (>7.5) causes environmental pressure and alkaline stress, impairs plant growth and development, and limits fruit quality by causing osmotic alterations and hindering nutrient absorption. Because of alkaline stress, plants are in an oxidative environment that alters their metabolic processes, impairing their growth, development, and fruit quality. In response to this situation, plants use several mechanisms to cope, including the alteration of osmolytes, induction of transcription factors, signal transduction, hormone synthesis, alteration of the antioxidant system, and differential gene expression. Current knowledge and understanding of the underlying mechanisms that promote alkalinity tolerance in crops may lead to new production strategies to improve crop quality under these conditions, while ensuring food security.

La agricultura mundial se enfrenta a la demanda de alimentaria debido al crecimiento de la población, por otro lado, los cultivos se ven afectados por una serie de factores ambientales. Ante estas problemáticas se han buscado alternativas que puedan frenar los efectos del estrés y mejoren la actividad fisiológica, además de que favorezca en la mejora de la calidad de los frutos. El objetivo de esta investigación fue evaluar el efecto de bioestimulantes en plantas de tomate desarrolladas bajo la condición de campo abierto, se diseñó un experimento bloques al azar. Se aplicó 1g L^-1 de Ca(NO₃)₂ y extractos de algas (Ascophyllum nodosum) (An) a 500mg L^-1 y a 2500 mg L^-1(3 aplicaciones con intervalos de 15 días) vía foliar durante el ciclo del cultivo se tomó variables del tipo vegetativo, variables de calidad de fruto. La aplicación de An obtuvo un incremento significativo en las variables Altura y diámetro de tallo, por otro lado, la aplicación de Ca(NO₃)₂ en combinación con An mejoró de manera significativa la calidad de frutos de tomate. La aplicación de extractos de algas del Ascophyllum nodosum en combinación de un mineral como es el nitrato de calcio de forma foliar, favorece a la activación metabólica de las plantas ayudando a la regulación, mitigando cualquier tipo de estrés que se presente, reflejando así, los efectos positivos que forman parte de una biostimulación generada por el calcio, este elemento mejora la calidad y la firmeza en los tejidos vegetales. El Ascophyllum nodosum es un precursor del metabolismo secundario, puede activar el mecanismo de defensa apoyando a la mitigación del estrés y aumenta las propiedades organolépticas de las plantas.

There is a high supply of industrialized food products that contain many additives, such as colorants. To verify the qualitative consumption of Allura Red in primary schoolchildren, the present cross-sectional quantitative work was established under a retrospective expo facto design. On a school child population (5 - 8 years) from the city of Ramos Arizpe, Coahuila, Mexico, selected in a probabilistic way, a questionnaire applied to qualitatively verify the consumption of said additive. Descriptive and frequency analyses applied to the data obtained, as well as the Mann-Whitney U test and Pearson's X2 test (p≤0.05). The child population evidenced a high consumption of processed products containing Allura Red additive, the intake of jellies and candies (p = 0.025 and p = 0.043, respectively) showed differences between girls and boys. There was a very frequent consumption of "red soft drinks”, dairy - yogurt, oatmeal - flour, and box cereals (61 and 54%, respectively). Likewise, a high association was found between the intake of dairy products - yogurt and cereals (p = 0.008), oats and flour for pancakes and cereal in the box (p = 0.010), as well as consumption of candies and jellies (p = 0.000). High qualitative consumption of processed foods with Allura Red additive was found; it's imperative to reduce the excessive consumption of these products by establishing comprehensive strategies.

Since the fruit of the Capsicum annuum L. var. glabriusculum (Dunal) Heiser and Pickergil (chiltepín pepper) has a low germination rate, we sought to determine whether using an aqueous biochar extract could improve this. Germination tests were performed out in Petri dishes, using wild chiltepín pepper seeds collected in Sonora, México, which were exposed for 24 h to aqueous extracts of coconut shell biochar (CSBA) at different doses (0.05, 0.10, 0.25, 0.50, 0.75, and 1.00%, w/v) and a control comprising deionized water. In addition to quantifying the germination rate, we determined the physical quality, viability, imbibition, electrical conductivity, seed pH, and capsaicin content. The fast green test showed an ideal physical quality (p = 0.5475), an imbibition rate > 65% (p > 0.05), and high viability 98.4% (p > 0.05). The wild chiltepín pepper seeds exposed to the CSBA0.05 and CSBA0.25 treatments increased the percentage germination rate (p < 0.001) to 80.9% and 71.7%, respectively. A higher percentage of normal seedlings resulted from CSBA0.05, CSBA0.10 and CSBA1.00 (p < 0.01), and a greater shoot length was obtained with CSBA0.05 (p < 0.01). The exposure of wild chiltepín seeds to aqueous CSBA for 24 h at low doses (CSBA0.05 and CSBA0.25) increase the germination rate, while CSBA0.05 could enhance early seedling growth.

Vascular wilt caused by Fusarium oxysporum f. sp. niveum (Fon) is the main fungal disease of watermelon crops. Acibenzolar-S-methyl (ASM) is an inducer of plant defenses, which is effective against diseases caused by viruses, bacteria and fungi. In the present study, the effect of ASM on mycelial growth, spore germination and the reduction of the severity of wilting caused by Fon1, as well as its toxicity in watermelon plants was evaluated. The inoculation of the fungus was carried out four days after the application, via irrigation and foliar, of the ASM at concentrations of 15, 20, 30 and 40 mg L-1 in seedlings with two true leaves of the Sugar Baby variety, which does not have Fon resistance genes. In vitro results showed that ASM has a direct effect on spore germination and mycelial growth of Fon1. Also, the application of the defense inducer in watermelon plants significantly reduced (P < 0.05) the severity of wilt caused by Fusarium. The application via irrigation of the defense inducer (15 mg L-1) was more effective than the foliar application, since it reduced the severity of wilting caused by Fon1 in watermelon plants by 100%. The doses of 30 and 40 mg L-1 caused toxicity symptoms, since the plants showed significantly lower height, number of leaves and fresh aerial weight, compared to non-inoculated and untreated plants.

Continuous and excessive use of synthetic fertilizers in food production generates strong pressure on agroecosystems. Therefore, it is necessary to study and standardize alternatives that promote environmental health, such as biochar. Biochar (a blackish solid obtained from the pyrolysis of vegetable waste, food industry waste, animal waste, or water processing waste) is characterized by its high content of mineral carbon, high presence of functional groups, and richness of nutrients such as potassium (K⁺). Its use in soils improves the organic matter content and cation exchange capacity (CEC), which promotes crop nutrition. In addition to describing biochar manufacturing processes, this chapter aims to emphasize its role as a fertilizer, its stimulating effects on the soil microbiome and enzymatic activity, and its positive effects on plant health. Understanding biochar as a biofertilizer can be considered an ecological strategy for food production. However, the agricultural sector must consider the limitations of its production and use as fertilizer.