Natural biostimulants, such as microorganisms and seaweed extracts, are used in agriculture to improve crop yields with a sustainable approach. However, the interaction effects between different biostimulants have not been thoroughly investigated. The objective of this work was to evaluate the synergistic effects of microorganisms (Glomus intraradices and Azospirillum brasilense) and seaweed extract (Ascophyllum nodosum and Macrocytis pyrifera) on growth, yield and fruit quality of cucumber plants under soilless cultivation. Two doses of microorganisms (0 and 10 spores mL-1 + 106 CFU) and four concentrations of seaweed extract (0, 250, 500 and 2500 ppm) were evaluated. The experimental design used was a randomized complete block design with a factorial arrangement (2 x 4), with four replications per treatment. The results showed that the equatorial diameter of the fruit, yield and titratable acidity improve when applying microorganisms and seaweed extract in combination; however, when applying the two biostimulants the values ​​of plant height, stem diameter, number of leaves, root length, biomass (fresh and dry), firmness, total soluble solids, vitamin C, chlorophyll (a and total) and indices of color (L* and b*) did not exceed those obtained when the biostimulants were applied individually. The combined application of microorganisms and seaweed extract improves cucumber yield, but not vegetative growth and, except for titratable acidity, fruit quality attributes.

Las propiedades mecánicas, químicas, térmicas, ópticas, eléctricas y biológicas de los nanomateriales y nanopartículas hacen posible su aplicación en áreas de la industria: medicina, cosmética, automotriz, higiene personal, electrónica, agrícola y ambiental, entre otras. Para el sector agrícola, desde hace más de dos décadas, la nanotecnología ha sido considerada como una tecnología de avanzada, las investigaciones sobre estos materiales han mostrado el potencial de materiales nanométricos como bioestimulantes del crecimiento, de las características morfológicas y bioquímicas de las plantas. Además, se pueden desarrollar nano productos para el control de plagas, enfermedades, arvenses, entre otros, con la acción combinada de los nanomateriales y los metabolitos de las plantas dando beneficios a favor de la agricultura. Con la información recopilada, se ha demostrado que se continúan investigando los efectos controversiales de la nanotecnología aplicada a la agricultura, pero, sin duda, en los próximos años, con la aparición de nuevos instrumentos, nuevas metodologías y el trabajo multidisciplinario, las futuras investigaciones mostrarán evidencia en la cadena trófica y posiblemente los efectos palpables en el cuerpo humano.

Background. Sustainable agriculture promotes the use of mineral and biological origin inputs that act as plant growth stimulants, such as zinc oxide nanoparticles (NPsZnO) and rhizospheric microorganisms, which have positively intervened in the physiological response of plants, due to their unique properties. Objective. To evaluate the effects of NPsZnO applied via foliar and drench, and of rhizospheric microorganisms on the vegetative growth and biomass of tomato plants. Methodology. The doses of nanoparticles were applied at: 0, 10 and 30 mg·L-1 and in microorganisms 0 and 10 spores·mL-1. The variables evaluated were: plant height, stem diameter, number of leaves, leaf area, root length and volume, and total biomass. Results. It was observed that plant height, stem diameter and number of leaves were higher with the interaction of 10 mg·L-1 of NPsZnO and the microbial consortium. The root length decreased 25.88% with the foliar application of 30 mg·L-1 NPsZnO. Root volume decreased 18.49% with the drench application of 30 mg·L-1 NPsZnO and decreased 29.55% with the foliar application of 10 mg·L-1 NPsZnO. The total biomass increased 15.65% and 28.81%, respectively with the foliar application of 30 mgL-1 of nanoparticles and when 30 mg·L-1 of NPsZnO was applied in interaction with the microbial consortium. Implications. Although root length and volume had a negative effect with the application of NPsZnO, plant height, stem diameter, number of leaves and total biomass structural components for fruit production in tomato plants were promoted by the application of NPsZnO in interaction with rhizospheric microorganisms by generating synergism. Conclusion. The dose of the nanoparticles, the application method and the microorganisms in the substrate showed positive synergism in the growth and biomass of tomato plants.

In recent years, interest in nutrient and nanoscale biostimulant use in agriculture to improve seed germination and crop productivity has increased. Nanoparticle seed priming has improved growth and quality in crops of agricultural value. The following study shows the effect of seed priming on bell pepper RZ F1 (35-71) with zinc oxide nanoparticles (ZnO NPs) with different morphology: spherical and hexagonal. Bell pepper seeds were primed with ZnO NPs at different doses, 50 and 100 mg L-1. The study was carried out in two phases. The first phase consisted of an in-vitro study in a germination chamber (28°C), where early growth variables were assessed: germination percentage, radicle, plumule and hypocotyl length; while the second phase was carried out under greenhouse conditions, where variables such as plant height, stem diameter, dry weight, leaf area, total chlorophyll and phenols were assessed, 45 days after sowing. Seed priming with different morphology ZnO NPs showed a positive influence, 100 mg L-1 dose giving the best results for early growth parameters, as well as for plant height, stem diameter, leaf area, total chlorophyll and phenolic content. These results suggest that ZnO NPs can be considered a promising seed preparation agent to improve germination, early growth parameters, and chlorophyll and phenolic contents.

Huitlacoche or corn smut, Ustilago maydis (DC.) Corda, is a biotrophic fungal pathogenic. The scales that grow in ears of maize, Zea mays L., are used as fresh or raw vegetables. In some regions of Mexico, maize is planted to harvest “huitlacoche”, a crop also susceptible to attack by insect pests that affect its quality. The purpose of this study was to recognize entomofauna in maize ears infected with huitlacoche (corn smut) and identify pest species that attack huitlacoche in five maize hybrids. We collected a total of 515 specimens in four orders, seven families, and 11 species. The orders Coleoptera and Lepidoptera comprised 71.4% of the total number of families, 81.8% of the species, and 99.6% of individuals. The percentage of damaged ears ranged from 47.5 to 65.0%. Species best represented were Cotinis mutabilis (Gory and Percheron), Spodoptera frugiperda (J.E. Smith), Heliothis virescens (Fabricius), and Carpophilus lugubris Murray considered primary pest of huitlacoche because they were present in all maize studied. Shannon-Wiener diversity (0.592 bits per individual) and Simpson (0.302 bits per individual) indices showed less diversity of individuals and moderate species dominance. Greatest richness of species was in hybrids ‘AN388’ and ‘H-318’, each with seven.