Background. In Mexico, corn is the most important crop, being an important input with food, economic, political, and social implications. However, intensive cultivation methods, based on chemical ...pesticides, monoculture and synthetic agrochemicals have caused a reduction in soil fertility and crop yields. An alternative, which can help restore soil fertility, increasing organic matter, moisture retention and the load of microorganisms, is mixed fertilizer. Stimulating, in addition, the defense systems of the plants and thus increasing the yield of the crops. Objective. To evaluate some fertilization schemes in Chalqueño maize plants through the measurement of some growth and yield variables. Methodology. A completely randomized block experimental design was established with three repetitions, where four fertilization schemes were evaluated (T1, control without fertilizer input; T2, chemical fertilizer; T3, organic fertilizer; and T4, chemical fertilizer + organic fertilizer) during the crop years 2019-2020. Results. The analyzes showed significant differences (p ≤ 0.05) between the evaluated treatments and years of cultivation. Being the T4 treatment, the one that obtained the best grain yield for the years 2019 and 2020, with values of 5.11 ± 0.05b t ha-1 and 6.57 ± 0.95a t ha-1, while the T1 treatment, recorded 1.59 ± 0.12f t ha-1 and 2.15 ± 0.38e t ha-1, respectively. Implications. With the information generated, it will be possible to implement the best fertilization scheme that provides the corn plants with all the necessary nutrients so that year after year they obtain the best grain yields. Conclusion. Through the results it was possible to demonstrate the negative effect of environmental factors (higher temperature and less rainfall), on the yield of the corn crop during the year 2019, with respect to the best yield result obtained for all the treatments during the year 2020 where a lower temperature and higher rainfall were recorded. Being equally evident the positive effect on the yield when plants were fertilized with the T4 treatment that provided to the corn crop with an adequate dose of moisture and macro and micronutrients.
Agave genera include slow-growing plants with cultural and economic roots dating back to pre-Columbian times in Mexico. Several species have a widespread presence in the country and are cultivated ...and/or used directly from the field to obtain various derived products. Agave salmiana is widely used in the region of the High Valleys of Apan, Hidalgo, Mexico. However, fungal diseases are causing considerable losses to Agave crops. For this reason, fungi strains from maguey plants from Apan, Hidalgo, with “Negrilla” disease symptoms were isolated and identified morphologically and molecularly. The results provide information on a new disease disseminated in A. salmiana plants, which causes symptoms such as black spots on the leaves due to pathogenic fungi of the genera Bipolaris. The morphological and molecular characterization located the phytopathogenic fungus as new isolates of Bipolaris zeae. Finally, the re-isolation of the causal agent of the disease was achieved in all pathogenicity tests, verifying that the symptoms observed in the maguey plants were caused by B. zeae, thus corroborating Koch’s postulates, and constituting the first report of this fungus as a pathogen of A. salmiana in Mexico.
Introducción: Trypanosoma cruzi (T. cruzi), esta clasificado en seis linajes mediante marcadores moleculares de tipificación, que son fácilmente amplificados por técnicas de biología molecular. El ...objetivo del trabajo fue identificar y ubicar geográficamente a los aislados de T. cruzi que infectan naturalmente a los triatominas de los municipios del Estado de Hidalgo a través de la técnica de PCR, que amplifica fragmentos de la región intergénica del gen mini-exón. Método: Se recolectaron 170 muestras de insectos hematófagos en 14 municipios del Estado de Hidalgo, México. El diagnóstico de laboratorio en las muestras de heces y de tejido digestivo de los triatominos, se realizó de manera convencional por microscopia óptica y por la técnica de PCR para determinar la presencia o ausencia de T. cruzi y para la identificación del linaje correspondiente del parásito.Resultados: Se identificaron tres taxones de triatominos: Triatoma dimidiata (87/170), Triatoma mexicana (14/170) y Triatoma gerstaeckeri (7/170). En el 36.47% (62/170) de los especímenes colectados la especie no pudo ser identificada y se clasificaron únicamente como T. spp. Se determinó la presencia del parásito en el 1.76% de los vectores analizados por el método parasitoscópico y en el 11.17% por el método de biología molecular. El total de los parásitos analizados corresponde al biotipo TcI de T. cruzi. En el ecotopo peridoméstico, se encontró la mayor abundancia de triatominos (80.58%) y el mayor porcentaje (10.58%) de infección por T. cruzi.Conclusiones: El vector más importante encontrado en la región en estudio fue Triatoma dimidiata seguido de T. mexicana y T. gerstaekeri y el biotipo con el que están mayormente infectados es el TcI. Los triatominos encontrados se distribuían principalmente en hábitats peridomésticos en los municipios estudiados. Los resultados indican la existencia de riesgo de infección para los habitantes de esas regiones endémicas del Estado de Hidalgo, México.
Globally, corn is the most economically important crop, surpassing other cereals of economic importance. However, the tillage methods, monoculture and the abuse of synthetic agrochemicals used in ...Mexico have led to the loss of fertility and soil yield. In this sense, the application of alternative fertilization methods based on chemical fertilizer, organic matter and biofertilizer, applied alone or in combination, can stimulate the defense systems of corn plants and increase their yield. Therefore, in this research, some fertilization schemes were tested on purple corn plants of the Kculli race through the evaluation of some growth and yield variables, as well as the subsequent evaluation of the chemical characteristics of the corn grain produced in each fertilization scheme. The results indicate highly significant differences (
≤ 0.05) between treatments, for the different growth and yield variables studied. Of all the fertilization schemes evaluated, treatment T7 obtained the best grain yield of 6.19 ± 0.07 t ha
, with respect to treatment T1 of 1.02 ± 0.01 t ha
, as well as the highest protein content and starch quality. Being clear the positive effect of the adequate contribution of the macro and micronutrients used exerts on the corn crop in each of the fertilization schemes studied. On the other hand, the analysis carried out on the grains was found within the values reported by other authors.
Fresh fruit is one of the fastest‐growing segments of the agro‐industry. The growing trend has sparked interest in sustainable and eco‐friendly alternatives to preserve fruits’ sensory properties, ...quality, and shelf life. Potential solutions are edible coatings from renewable sources. This paper reports on the evaluation of an edible coating (EC) based on male banana starch (Musa paradisiaca L.) and chitosan on the shelf life and postharvest preservation of guava (Psidium guajava L.) under specific storage conditions (25°C/50% RH). Also, it characterized male banana starch (MBstarch) and evaluates the MBstarch–chitosan film (functional, mechanical, and barrier properties) before applying it to the guava, which was stored at 25°C for 10 days (50% RH). The effect of EC on the postharvest quality of the fruit was evaluated via physicochemical parameters (weight loss, acidity, pH, firmness, and total soluble solids). In conclusion, the MBstarch–chitosan EC to be a suitable preservation alternative for fruit due to its barrier properties. Specifically, it was determined that MBstarch–chitosan EC delays the increase of pH, titratable acidity, and total soluble solids. Moreover, it was efficient in maintaining weight and firmness, improving appearance, and extending the shelf life of fruit by up to 10 days.
Novelty impact statement
Starch isolated from male bananas, a nonconventional source, can be an alternative for manufacturing EC with favorable mechanical and barrier properties. MBstarch/Chitosan EC promotes the postharvest quality (physicochemical parameters) and extends the shelf life of guava by up to 10 days. This EC (MBstarch/Chitosan) can be considered a sustainable ecologic postharvest preservation alternative for the guava fruit.
Vanilla juice has been shown empirically to have antifungal activity against some fungal strains; however, there are no activity reported against Alternaria genre. In this work, the chemical profile ...of vanilla juice was obtained and its antifungal activity against fungal strains from the family Pleosporaceae, isolated from sorghum- and barley-diseased plants, was tested. The strains were identified as Alternaria alternata by their molecular and morphological characteristics. The vanilla juice characterization from Vanilla planifolia pods showed the presence of vanillin, vanillic acid, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, guaiacol, glucovanillin, vanillyl alcohol, and furfural. Vanilla juice showed a fungistatic effect against all A. alternata strains tested in this study and increased the lag time from 50 to 112 h, and no conidia were produced. This result indicates the possible application of vanilla juice as an alternative to control agricultural crops such as barley and sorghum in Mexico.
A non-segregated kinetic model is proposed to describe a fermentation process of agro-industrial residues derived via cocoa (mucilage juice) by Pichia kudriavzevii. The novel proposed hybrid model is ...based on a multiple coupling reaction mechanisms (structured) to describe the kinetics of substrate consumption, biomass, carbon dioxide, and ethanol, coupled to an unstructured model for the activity enzyme. The parameters of the kinetic model are estimated by non-linear least-squares curve fitting using the Marquardt-Levenberg algorithm. In addition, numerical simulations were compared with the experimental data via residual graphs. The effectiveness of the model was statistically evaluated using dimensionless efficiency coefficients under different initial conditions. A global sensitivity analysis was applied (Fisher's information matrix). The experimental results of the batch reactor showed a maximum ethanol concentration of 29 g/L, with a yield of 0.48 g-ethanol/g-glucose and a productivity of 0.30 g/L h. The method determined that the cell formation coefficient and the specific substrate consumption rate (
and
) directly influence most of the states of our system. The proposed scheme is particularly suitable to assist in the rational design of cell factory properties or fermentation processes because it can represent the complex biochemistry in more detail and under different initial experimental conditions; the above reveals that the generated model is robust and can be considered for control and optimization purposes.
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•Mechanical milling affects thermal properties at long milling times.•Milling increases amylose content and promotes the formation of elastic gels (Ǵ).•Modified starches show a ...non-Newtonian flow behavior as reofluidizers.•Tan δ shows the modification of starch-generated elastic gels.
This work evaluates the effect of high-energy mechanical milling time (7 levels, 20–80 min) on amylose content, crystallinity pattern, temperature and gelatinization enthalpy, morphology, and rheological properties of chayotextle (Sechium edule Sw.) starch. After 30 min of milling, granular structure was affected, and amylose values were the highest while crystallinity and gelatinization enthalpy decreased significantly. These changes allowed to obtain gels with viscoelastic properties where the elastic character (Ǵ) prevailed upon the viscous modulus (Ǵ́). Native starch showed Tan δ values of 0.6, increased significantly (0.9) after 30 min of milling due to the surge in linear chains (amylose) and loss of granular structure. Native and modified starches showed high dependence on cutting or shear speed, presenting a non-Newtonian behavior (reofluidizers). These results indicate that mechanical grinding is an alternative to obtain modified starches with applications in the food industry.
Globally, corn is the most economically important crop, surpassing crops such as wheat, rice and barley. However, the presence of pathogenic fungi associated with corn, have favoured the appearance ...of diseases that cause economic loss. Therefore, the aim of the present study is to assess the efficacy of treatments in vitro and in vivo with Trichoderma asperellum in controlling the disease severity and the yield reduction in corn plants caused by Fusarium verticillioides and Ustilago maydis. In vitro confrontation experiments demonstrated the high antagonistic capacity of the T. asperellum strains, which is able to reduce the radial growth of the pathogen's colonies from 88.71% up to 100%. In the field experiments treatments 6 and 7, where T. asperellum was confronted with F. verticillioides and U. maydis, showed a significant reduction in the average damage of the disease by 8.3 ± 6.7 and 9.5 ± 3.0, and an increase in their grain yield by 4.43 ± 0.33 and 4.11 ± 0.15 t/ha, respectively. Similarly, the percentage of good ears of 66.75 ± 5.4 and 70.37 ± 5.4, obtained in treatments 6 and 7, was higher than those values obtained in treatments 2 and 3 without Trichoderma confrontation. These results indicate that the selected Trichoderma strains isolated from Zea mays could effectively control these phytopathogenic fungi in field.
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