Revista de la Facultad de Agronomía de la Universidad del Zulia

Autochthonous microorganisms as an alternative for biofertilization of Nicotiana tabacum L.

Lianet Brizuela-Fuentes — 2023-06-27

Tobacco is a crop of economic importance in tropical countries; it generates significant income in small agricultural areas. Within the agrotechnical activities that are carried out on this plant, biofertilization with Autochthonous Microorganisms (AM) represents a viable option for production with low inputs. Therefore, the objective of the research was to determine the biofertilizer effect of AM on black tobacco cv. Havana-2000. The experiment was carried out on a farm located in Los Cayos, Yara, Granma, Cuba, during the period November-February/2021. For this, the yield variables and the components were measured in the field. Statistical processing was performed using ANOVA and principal component analysis. The AM recorded four groups of microbes: bacteria (7x10¹² CFU.mL^-1) Lactobacillus sp. and Rhodopseudomonas sp., the fungi (3x10¹¹ CFU.mL^-1) Trichoderma sp., Aspergillus sp. and Penicillium sp., the yeasts (2x10¹¹CFU.mL^-1) Saccharomyces sp. and Candida sp. and the actinomycete Streptomyces sp. (1x10¹⁰ CFU.mL^-1). In the field, the AM biostimulated between 15 - 82 % of the yield and the components, achieving the best results at the dose of 36 L.ha^-1. Finally, the importance of using AM as an organic alternative for tobacco biofertilization is demonstrated.

Water productivity using furrow and drip irrigation in hybrid maize

José Conde — 2023-07-01

Agriculture is the economic sector that consumes around 70 % of the total water extracted globally, considering itself a victim of its own inefficiency. The present work was oriented to look for irrigation alternatives that allow a greater productivity of water. The trial was carried out at the Faculty of Agricultural Sciences, Technical University of Machala, Ecuador. The amount of water applied to the corn crop through furrow and drip irrigation was evaluated. The treatments were: furrow irrigation, superficial drip irrigation and subsurface drip irrigation at 20 cm. The trial had a surface area of 450 m², in a completely randomized block experimental design with three treatments and three repetitions. The control of the irrigation regime was carried out through tensiometers installed for each treatment. The volume of water applied and the dry grain yield in irrigation by furrows was 3,484 m³.ha^-1 and 9,175 kg.ha^-1, for surface drip irrigation of 1,452 m³.ha^-1 and 10,200 kg.ha^-1, and for subsurface drip irrigation it was 1,237 m³.ha^-1 and 10,181.2 kg.ha^-1. The water productivity for the furrow irrigation treatment was 2.63 kg.m^-3, for surface drip irrigation it was 7.02 kg.m^-3 and for subsurface drip irrigation at 20 cm it was 8.23 kg.m^-3 being the highest productivity.

Study of synergistic effect of combined application of tebuconazole with two biocontrol agents for management of Fusarium crown rot in durum wheat

Abdelmalek Oulmi — 2023-07-18

The in vitro and growth chamber, tests were conducted in order to assess the effects of B. amyloliquefaciens B18 and B. subtilis S8 strains each alone and in combination with tebuconazole against F. culmorum (FC) isolate responsible of Fusarium crown rot (FCR) in durum wheat. The in vitro growth of B18 and S8 strains was unaffected by 30 µg.mL^-1 tebuconazole. The Bacillus strains (at 10⁶ CFU.mL^-1) and tebuconazole, each alone, reduced the mycelial growth, this effect was significantly improved when they were combined (inhibition of more than 92 %). In growth chamber experiments, efficacy against FCR was significantly higher when integrating Bacillus strains and tebuconazole than by either alone; control efficacy of tebuconazole at 30 µg.mL^-1 in combination with S8 and B18 strains reached 90.91 and 95.45 %, respectively. The obtained results indicated that combination of tebuconazole with the biocontrol agents B18 and S8 synergistically improved control efficiency of the fungicide against FCR of wheat.

Effect of microbial consortia on maize yield in Chiapas, Mexico

Lissy Rosabal — 2023-07-26

The use of microbial consortia as biofertilizers allows improving crop productivity and the quality of agricultural soils, by incorporating microorganisms that facilitate the availability of nutrients for plants and change the soil physicochemical conditions. In order to evaluate the effect of microbial consortia on maize yield, inoculums from different environments were used in the maize crop of Villa Corzo and Villaflores municipalities, Chiapas. Six treatments with different consortia were defined: three from agricultural plots and three from mountains “La Frailescana”, “Cerro Nambiyugua” and Biosphere Reserve “La Sepultura”-, and one control, under a randomized block experimental design with four replications. The application of the microbial consortia was made directly to the soil at 20, 40 and 60 days after sowing of the crop. The effect of the consortia on maize yield was determined using a design with nested effects in which the effects of the origin of the microbial consortia were controlled, and the nested treatments in the environments. The association between the physicochemical components of the consortia and the culture yield was evaluated using Pearson’s correlation (p ≤ 0.05). Only the mountain consortiums from “La Sepultura” were the ones that showed maize yield increase. However, both the mountain and plot consortiums have the potential to be used as biofertilizers in maize cultivation, when combined with another source of organic fertilization, such as poultry manure.

Effect of chitosan on growth and productive parameters in broccoli plants (Brassica oleracea L. var. Calabrese)

Juan Reyes-Perez — 2023-07-26

Biostimulants improve the absorption and assimilation of nutrients by plants, making them more tolerant to biotic or abiotic stress, improving their agronomic characteristics. Natural and biodegradable biostimulants such as chitosan have fungal and bactericidal activities and promote growth and crop yield, this is why, to evaluate the effect of chitosan application on growth and productive parameters of broccoli (Brassica oleracea L.), three concentrations of chitosan (T₁ = 500 mg.L^-1; T₂ = 1000 mg.L^-1; and T₃ = 2000 mg.L^-1) and a control treatment (T₄ = distilled water), were applied by foliar spray when the true leaves unfolded, using a completely randomized design with 30 repetitions per treatment. The variables height of the plant, number of leaves per plant, diameter of the flowering stalk, diameter of the flowering head, length of the flowering stalk, total length of the flowering stalk, fresh biomass of the flowering head, of the root, and of the aerial part, total dry biomass and yield were measured. All the variables increased (P<0.05) as the chitosan dose increased, concluding that the application of chitosan to the broccoli crop is a viable alternative as a substitute for synthetic fertilizers.

Phenotypic stability of forty advanced lines of rice at Babahoyo, Ecuador

Cristina Maldonado — 2023-09-20

The crosses between Oryza sativa L. and O. rufipogon Griff., create a high genetic diversity to develop rice varieties with high yield and phenotypic stability. In the present investigation, forty advanced lines of rice were evaluated in subsidiaries F₅ (dry season) and F₆(rainy season), together with three commercial controls in the town of Babahoyo, Ecuador. A Randomized Complete Block Design (DBCA) was applied with three repetitions, recording morphoagronomic and productive characters. Statistical analyzes were applied and phenotypic stability was determined using the Eberhart and Russell, AMMI, Lin and Binns, PROMVAR models. The average morphoagronomic results were: days to flowering (72), vegetative cycle (98 days), plant height (111 cm), panicle sterility (6 %); the productive variables the results were: tillers per plant (32), panicles per plant (31), panicle length (27 cm), grains per panicle (168) and yield (8,100 kg.ha^-1). The stable lines identified by the models: Eberhart and Russell were 1, 2, 10, 11, 13, 18, 25, 26, 30 and 37; AMMI identified lines 8 and 22; Lin and Binns to lines 2, 12, 18, 27, 37 and 40; and PROMOTE lines 2, 10, 13, 18, 25, 30, 38, 40 and 43; concluding that seven lines (2, 10, 13, 18, 25, 30 and 40) coincided with the applied models except AMMI. The average yield of the lines mentioned in the two seasons was 7,797 kg.ha^-1, higher than the average of the commercial controls that obtained 6,809 kg.ha^-1.

Degradation kinetics of ascorbic acid in peach nectar during thermal processing

Luis Cedeño-Sares — 2023-07-26

Ascorbic acid is a beneficial component for health, but it is degraded during the thermal pasteurization of food products. The aim of this research was to determine the influence of temperature on the thermal degradation of ascorbic acid in peach nectar at 75, 85 and 95 °C, evaluating this effect at 0, 30, 60, 90 and 120 minutes. The degradation of ascorbic acid follows a first order reaction model with rate constants that vary between 5.5 to 10.9 x 10^-3 min^-1. D-Values ranged from 211.28 to 418.73 min, while Z value was 69.4 ^oC. The values of the free energy of inactivation ranged between 112.63 and 117.17 kJ.mol^-1, while for the activation enthalpy the values varied between 25.37 and 25.54 kJ.mol^-1 and the range for the activation entropy was from -249.36 to -250.15 J.mol^-1.K^-1.It can be concluding that the reaction is endothermic and does not occur spontaneously. The knowledge of these values is important not only to explain the loss of ascorbic acid, but also to design and optimize thermal processes aimed at preserving the nutritional quality of peach nectar.

Biokinetic mechnisms of anthocyanins in red fruits produced in the state of Michoacan, Mexico

Jesús Quiroz — 2023-08-28

Berry fruits are a rich source of phytonutrients, especially phenolic compounds such as flavonoids, which have antioxidant properties. Among these fruits, the most cultivated and consumed are those of the genus Fragaria (Strawberries) and Rubus (Raspberries, blackberries, dewberries), which have been widely studied for their beneficial effects on human and animal health. One of the most important bioactive compounds of these fruits are anthocyanins, which have shown potential benefits for health by their antimicrobial, anti-inflammatory and anticancer activity. Therefore, the study of anthocyanins is of great pharmaceutical and nutraceutical interest. The objective of this research is to analyze the biokinetic mechanisms of anthocyanins in Rubus adenotrichos and Fragaria x ananassa produced in the state of Michoacán, Mexico. For this purpose, research strategies that included the extraction and quantification of anthocyanins, as well as bioinformatic tools to understand their biosynthetic pathway in the mentioned fruits were used. The use of informatic platforms allowed to identify the regulatory genes and enzymes involved in the biosynthesis of anthocyanins in R. adenotrichos and F. x ananassa, finding that most are common, with some specific differences, and that there are only a few exceptions, such as the enzymes catechol-O-methyltransferase (OMT), UDP-glucosyltransferase (UGT) and beta-glucuronidase (GUSB), which only occur in Rubus adenotrichos and not in Fragaria x ananassa.

Evaluation of cookies made with bean flour

Blanca Sánchez-Toledano — 2023-09-09

The common bean (Phaseolus vulgaris L.) is a legume rich in protein, carbohydrates, vitamins, and minerals that can be used for food processing. The objective of this study was to evaluate the acceptance of cookies made from bean flour by consumers in Zacatecas, Mexico, for which four formulations of cookies with different combinations of bean flour were prepared. The information was obtained from a sample of 398 consumers over 18 years of age in Zacatecas, Mexico, and was analyzed by multidimensional scaling. In general, the quality attributes relevant to consumers were size, aroma, sweetness, texture, color, consistency, and flavor. Cookie number 873 obtained higher consumer acceptance and its ingredients were 90 % bean flour, 10 % whole wheat flour and walnut. Therefore, the results of this research showed that cookies made from bean flour could be a feasible alternative that allows providing more nutritious food to the Mexican population.