The effects of zinc oxide nanoparticles on seed germination and seedling growth of Capsicum annuum L. were determined in this research. Total phenols content, total flavonoids, and condensed tannins, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant capacity was determined. Results indicated that treatment with zinc oxide nanoparticles (ZnO-NPs) improved seed germination rate during the first seven days. The seed vigor germination increased 123.50%, 129.40% and 94.17% by treatment with ZnO-NPs suspensions at 100, 200 and 500 ppm, respectively. The morphological parameters tested revealed that ZnO-NPs treatments did not significantly affect plumule development, but they had a significant impact (p ≤ 0.01) on radicle length. Suspensions at 100, 200 and 500 ppm of ZnO-NPs inhibited seedling radicle growth and promoted accumulation of phenolic compounds, with a phytotoxic effect in this organ. Results suggested that zinc oxide nanoparticles influence seed vigor and seedling development and promoted the accumulation of desirable phenolic compounds in the radicle.

Sweet sorghum (Sorghum bicolor [L.] Moench) is a crop that is well known for its high production of biomass and sugars in the stem juice. The objective of this work was to evaluate the productivity of sweet sorghum ‘Roger’ based on the dynamics of sugar production and dry biomass by considering different production methods and plant phenological stages. The experimental design consisted of different tillage and fertilization methods established in a randomized complete block design with a split plot arrangement. Tillage treatments were assigned to the plot using the three levels of minimum tillage, traditional tillage, and traditional tillage that included a subsoil operation. Fertilization treatments were assigned to the subplot using the three levels of organic fertilizer, inorganic fertilizer, and without fertilizer. Data collection was performed at different plant phenological stages from anthesis to physiological maturity. Results showed that evaluated agronomic parameters depended on the phenological stage (P < 0.05) rather than the production methods (P > 0.05). Thus, the distribution and accumulation of sugar by stem internodes was associated with plant phenological components. The highest values of the concentration of total soluble solids (14.89%), juice sugar content (22.91 g), juice sugar concentration (527.46 mg g^-1 DW), dry biomass (60.04%), and dry biomass yield (19.01 t ha^-1) were observed at the physiological maturity stage of the plant.

Energy production from sorghum bioethanol is a way to help decrease climate change and environmental degradation. The objective of this work was to evaluate the agronomic characteristics associated to bioethanol production in experimental genotypes of sweet sorghum. During 2013 and 2014, seventeen sweet genotypes were evaluated in two locations, this locations are situated in northeastern Mexico, under a complete block randomly design with three replications. The three experiments were executed in Estacion Cuauhtemoc, Tamaulipas, in dryland; and two in Marin, Nuevo León, under irrigation. Experimental hybrid Potranca x Keller (p≤0.05) presented the highest values (kg/ha) in: biomass weight (52 125), stem (39 650), panicle (4550), leaf (7700), juice (14 125), and bioethanol (2157 l/ha); it surpassed to the most productive control (Keller) in: 35,7, 32,5, 63,2, 41,6, 32,5, and 36,8%, respectively. It bloomed 6.8 days earlier than variety control. Experimental variety 17-1-1-1 had a minor foliar incidence of diseases in comparison to Keller. In addition, it presented agronomic characteristics similar to control in: biomass weight (44 375 kg/ha), stem (35 438 kg/ha), panicle (2488 kg/ha), leaf (6400 kg/ha), juice (11 750 kg/ha), plant dry weight (19 113 kg/ha), stem dry weight (14 888 kg/ha), bioethanol production (1929 l/ha), °Brix (15,2), days to flowering (80,8) and plant height (224 cm).

El clima extremo como el aumento de la sequía y altas temperaturas han tenido un impacto significativo en el rendimiento de los cultivos. Por lo tanto, es importante identificar caracteres en los genotipos de sorgo que les ayuden a disminuir el impacto de estos factores y les permita ser productivos. El objetivo de este trabajo fue evaluar la tolerancia a calor de un grupo de líneas B y R de sorgo granífero bajo dos condiciones de humedad para seleccionar las mejores líneas tolerantes a calor. Se sembraron 28 líneas experimentales B y R el 30 de agosto de 2017 en Marín, NL, México. El experimento se sembró en un diseño completamente al azar con un arreglo en parcelas divididas y con dos repeticiones El tratamiento de humedad bajo estrés hídrico se aplicó 43 días después de la siembra (DDS) por un periodo de cuatro semanas sin riego. Se tomaron datos de días a floración, daño a la membrana celular a 40 ºC y contenido relativo de agua en hoja (CRA). Los resultados mostraron que el CRA no permitió establecer diferencias entre genotipos, mientras que el tratamiento de calor aplicado a 40 ºC, permitió establecer diferencias y clasificarlos de acuerdo con el porciento de daño causado a la membrana celular, ya que este es uno de los rasgos ampliamente utilizado para seleccionar genotipos tolerantes. Se identificaron como tolerantes al calor los genotipos 20 y 22 y como susceptibles los genotipos 5 y 8.