Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Objective: to evaluate the effect of fertigation and granular fertilization to the soil in interaction with the foliar application of a homobrasinolide in Solanum lycopersicum L. Design / methodology / approach: The treatments were Fertigation (F), Fertigation plus brassinosteroids (F+Br), Granular fertilization (FG) and Granular fertilization + brassinosteroids (FG+Bra). A completely randomized design with four replications was used, where one plant of each treatment constituted an experimental unit. The 45-d-old plants were sprayed with 2 mg L-1 of Brasinosteroid CIDEF-4 and subsequently applications were made every 28 d. Plant height and stem diameter were measured 92 d after transplanting, while the yield was obtained by weighing the completely red fruits. An analysis of variance was performed using the GLM procedure and the comparison of means by Tukey (P ? 0.05) with the SAS 9.3 program. Results: Fertigation induced greater tomato plant and reproductive growth compared to granular fertilization with or without the foliar application of homobrasinolide. Treatments with granular fertilizers decreased plant height by 10.36% and 10.45% with respect to fertigation. The yield with granulated fertilization with and without Br correspond to 76.6% and 75.80% of that achieved with Fertirriego with Br. Study limitations / implications: The absence of the stressful environment did not favor the application of the homobrasinolide Findings / Conclusions: Fertigation leads to greater growth and tomato yield under field conditions and the homogeneity of ambient temperatures did not favor the morphological or physiological expression of the homobrasinolide

In southern Veracruz, Mexico, edaphic acidity reduces pineapple development and yield. From July/2018 to January/2019, an experiment was conducted under rainfed conditions to determine the effect of liquid micronized CaCO3 on the edaphic pH and the initial vegetative development of pineapple in acidic soils of Isla, Ver. A randomized block design with four replications and four treatments was utilized: control without liming (T1), application of 2.0 t ha-1 of dolomite (T2), and 10.0 (T3) and 20.0 (T4) L ha-1 of liquid micronized CaCO3. The edaphic pH was measured, before liming and at 30, 60, 90 and 120 days after sowing (das), at depths of 0-5, 5-15 and 15-30 cm, and the biomass (fresh weight of leaves and stem) produced at 60, 90 and 120 das was determined. Up to 90 das, with dolomite, optimal soil pH values ??were reached for pineapple, significantly higher than that of liquid CaCO3 in both doses. At 120 das, with 20 L ha-1 liquid CaCO3, the pH was greater than 5.0 in the three sampled strata, with statistically similar values ??to those of dolomite and higher than those of the low dose of micronized CaCO3 and the control. On this latter date, 1,346 g of plant biomass-1 were produced with 20 L ha-1 of micronized CaCO3, an amount statistically similar to that obtained with dolomite and the low dose of micronized CaCO3 and significantly higher than the control.

Objetive: to measure genetic divergence of Liometopum apiculatum Mayr of three different sites in Mexico based on cytochrome oxidase subunit I.Design/Methodology/Approach: we sampled populations of L. apliculatum (escamol) on three collecting sites: Otumba, Mexico State; Pinos, Zacatecas and Matehuala, San Luis Potosí and compared amplified DNA extracts with NCBI GenBank established molecular taxonomic patterns.Results: we build a two-parameter genetic distance model with the three populations of L. apiculantum that confirms sites connectivity in spite of distance based on the cytochrome oxidase subunit I. These similarities uphold the adaptation of L. apiculatum to adverse climate conditions.Limitations on study/implications: the similarity, based on cytochrome oxidase subunit I, may allow the use of queen ants from different sites in order to enhance the reproduction of ants, but requires acceptability tests of the ant queens.Findings/Conclusions: DNA of L. apiculatum showed a very little genetic divergence on ant nests analyzed. We think of a strategy to enhance Liometopum reproduction activities based on the use of alien queen ants in the needed nests.

Objetive: The objective of this work was to assess the effect of bull breed on sperm quality after thawing semen. Design/methodology/approach: 10 plastic straws of 0.5 ml of frozen semen from three different breeds of bull were used, which were purchased from a commercial company. The bull breeds used were Charolais, Brahman and Simbrah. The straws were thawed at 37 ° C for 40 seconds. Immediately afterwards motility, viability and acrosmosomal integrity (NAR) were assessed. Results: The results were for motility 75.0, 87.5 and 85.0%; for viability 74.5, 74.5 and 72.5%; and for NAR 97.1, 96.9 and 96.9% for the Charolais, Brahaman and Simbrah races, respectively. Limitations/implications: The straws used were obtained from a commercial company dedicated to the sale of frozen bovine semen. Findings/conclusions: The three bull breeds showed good sperm quality after thawing, which can be recommended to be used in artificial insemination without any problem.

A constant growth in the population, as well as a demand for natural resources and the climate change effect have lead to the seek of new feedstuffs sources which may satisfy the nutritional requirements of productive ruminants and contributing to the reduction of greenhouse gases (GHG) in the livestock activity. In this way, industrial wastes and agricultural shears have been subjected of many researches worldwide. Likewise, the use of aquatic macrophytes as forage sources in ruminants feeding emerges as an option. Additionally, the implementation of forest livestock systems has resurged as a real alternative in the battle against the erosion in arable lands. Regarding to the latter, this literature review recommends the use of agricultural shears, industrial wastes, and other feedstuffs sources as a sustainable alternative in the reduction of GHG in livestock systems as a contribution to the mitigation of the climate change effect.

Objective: To evaluate the bird diversity in the El Llano region in Aguascalientes, central part of the Mexican Altiplano, a region that has been transformed into grasslands and agricultural areas. Design/methodology/approach: From January 2010 to March 2012, a bird fauna inventory was carried out through transects with counting points within different areas with different land use in the region. Results: A total of 166 bird species were recorded, the greatest species richness was terrestrial (136), and the rest were of aquatic and underwater habits (30). Of the total species, seven are listed under some risk status and two are endemic to Mexico. Limitations on study/implications: There are other habitats around this region that can also serve as areas of movement and shelter for birds and have not yet been studied. Findings/conclusions: The greatest diversity was observed in thickets, nopal orchards and yuccas patches, and oak forest. Bird diversity recorded in this region suggests that this area represents an important source of food resources, nesting area by resident species, as well as a transit site for migratory species.

Objective: To evaluate the antihypertensive activity of peptides extracted from nixtamalized and non-nixtamalized creole corn (blue and red) zein from the Estado de México. Design / methodology / approach: Bioinformatic tools, such as the NCBI database, were used to search for primary sequences of the maize zein protein. The methodology included a prediction of peptides with antihypertensive activity through various bioinformatic servers. Inhibitory activity was determined by percentage regression. Statistical analysis was performed to assess possible significant differences using the Tukey test (p <0.05). Results: The following peptides were found by in silico hydrolysis: IFSILMLLA, LSACVLDATI, TASVCENPTL, LPLSPLLFQQ, SPALSLVQSL, LSPYSQQQQF, PFSQLATAY, LPFYQQFSAN and PAAFYQQHII that showed inhibition activity. The results showed that the GH (grade of hydrolysis) was higher in blue corn (13.96 ± 0.02) than in red corn (10.38 ± 0.79) without nixtamalization, while, with the nixtamalization process, this parameter was also higher in blue corn (10.52 ± 0.57) than in red corn (8.96 ± 0.01). Study limitations / implications: The enzyme used for hydrolysis generates oligopeptides that may not be as closely related to the angiotensin-converting enzyme. Findings / Conclusions: In vitro antihypertensive activity of unhydrolyzed blue corn zein showed a lower percentage of ACE inhibition compared to unhydrolyzed red corn. Trypsin hydrolysis only increases ACE inhibitory activity in blue corn at a concentration of 0.3 mg / mL without nixtamalizing.

Objective: The objective of this work was to evaluate the nutritional quality of larvae of the white worm (Agathymus remingtoni) of the maguey lechuguilla (Agave lechuguilla). Design/methodology/approach: Samples of A. remingtoni larvae, were collected from stems and leaves of wild maguey lechuguilla that grows in hills of the community of San Francisco, Municipio de Epazoyucan Hidalgo, Mexico. Proximal analysis was performed and content of calcium and phosphorus were determined on larvae samples.   Results: The larvae of A. remingtoni had a protein content of 33.69% on a dry basis, and 12.05% on a wet basis. Other results obtained were as follows:  ethereal extract 15.97%, dry matter 35.76%, humidity 64.24%, ash 0.82%, crude fiber 0.85%, free extract Nitrogen 6.07, Calcium 0.40%, Phosphorus 0.56%. Limitations/implications: During: In the literature review carried out, no reports were found on the nutritional quality of the white worm (Agathymus remingtoni) of the maguey lechuguilla (Agave lechuguilla). Findings/conclusions: Agathymus remingtoni larvae have excellent nutritional content, which makes them an alternative source of protein, fat, calcium and phosphorus for human and livestock feeding. Keywords: Agave lechuguilla, white worm, food, nutritional composition.

Objective: Evaluate the antioxidant and quelating activity of Vicia faba protein hydrolysates. Design/methodology/approach: Bean seeds of the San Pedro Tlaltizapan variety, purchased from the Institute of Agricultural, Aquaculture and Forestry Research of the State of Mexico (ICAMEX) were used. A protein substrate was prepared for enzymatic hydrolysis by alkaline extraction of the protein, followed by isoelectric precipitation from the defatted flour, the concentrate obtained was named CP. Subsequently, enzymatic hydrolysis of the PC was carried out with a sequential pepsin-pancreatin system and the degree of hydrolysis was determined. Finally, the antioxidant and chelating activity of protein hydrolysates was determined. Results: The defatted bean flour presented 18.6g of protein / 100g sample. While the concentrate obtained with this flour presented 62.7g of protein / 100g of sample. The protein increase in the concentrate was 3.4 times showing a significant difference (p?0.05) with the defatted bean flour. The total hydrolysis time was 90 min (45 min for each enzyme in the case of the sequential system). The highest GH obtained with the sequential system was 16% at 45 min. On the other hand, the chelation percentage of these hydrolysates was less than 25%. Limitations on study/implications: The protein concentrate of Vicia faba was not free of phenolic compounds, so this would be a limitation in the degree of hydrolysis and consequently in the chelating and antioxidant activity. Findings/conclusions: The protein hydrolysates of Vicia faba obtained through the sequential pepsin-pancreatin system present good antioxidant activity by the various methods studied, showing that when pancreatin is added to the system, these activities improve, since hydrolysates are active, they could be used as functional ingredients in food products.

Objective: To evaluate the effect of starter feed consumption on the post-weaning productive response of calves of the dual-purpose system. Design/methodology/approach: Ten calves with an average live weight at birth of 34.5 ± 4.8 kg were distributed in two treatments: CM = calves fed milk + Taiwan grass (Pennisetum purpureum) weaned at seven months of age; CMS = calves fed milk + Taiwan grass + starter feed, weaned at 90 days. A completely randomized design with five repetitions per treatment was used, the experimental phase was made from birth to one year of age. Starter feed intake, live weight (LW), daily weight gain, (DWG), rump height (RH), withers (W), length (L) and thoracic perimeter (TP) were evaluated in the periods of one to three months old, four to seven and eight to 12. Results: The consumption of starter feed from one to three months was 482.33 g calf-1 d-1 and from four to seven months 1895.0 g calf-1 d-1; the LW, RH, W, L and TP at seven and 12 months was greater in CMS (P <0.05), the DWG was greater in CMS (P <0.05) in the period of four to seven months. Study limitations/implications: Milk consumption was not measured, it could affect DWG in the period of one to three months. Findings/Conclusions: Starter feed consumption allowed calves to be weaned at three months of age with the highest response in LW and zoom measurements at seven and 12 months. Key words: Beef cattle, ruminal development, zoom measurements.