Revista de la Facultad de Agronomía de la Universidad del Zulia

Yield and chemical composition of foliage and branches of tropical tree legumes with different trunk diameters

Jorge Oliva-Hernández — 2025-01-09

Erythrina americana Miller and Gliricidia sepium (Jacq.) Walp., are tree legumes presents on livestock farms in the tropical region, mainly on living fences. The goal of the study was to determine the influence of tree legume species (TLS), and of the trunk diameter at base tree (TDB), on production and chemical composition of foliage and branches at a similar regrowth age. The study was conducted in Tabasco, Mexico. Seventy-nine trees were used in a completely randomised design with a 2 X 5 factorial arrangement. The factors were TLS (E. americana y G. sepium), and TDB at 0.20 m height above ground level (D-5: 0.050-0.059 m; D-6: 0.060-0.069 m; D-7: 0.070-0.079 m; D-8: 0.080-0.089 m y D-9: 0.090-0.099 m). The production per tree of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and ash, of foliage and branches were the response variables. The STL x DBT interaction did not affect (P>0.05) the response variables studied in the foliage and branches. In foliage, the TLS and TDB affected the production per tree of DM, CP, ADF, and ash (P<0.01). G. sepium produced a greater amount of DM and the different components assessed than E. americana. An increase in TDB resulted in higher DM production and the components studied in foliage and branches. G. sepium produces foliage with higher CP and lower structural carbohydrate content than E. americana foliage.

Reaction of coffee cultivars to Hemileia vastatrix Berk. & Broome strains in Venezuela, under controlled conditions

Emma Ramírez — 2025-01-18

Coffee rust resistance is of great importance in worldwide coffee crops, since its biotrophic pathogen shows, currently, more than 55 identified races with diverse virulent genes. This work was based on the determination of the reaction of five commercial coffee cultivars inoculated, under controlled conditions, with three strains of Hemileia vastatrix (race XXXIX and pathotypes Hv01ve and Hv02ve) previously identified in Venezuela. Three velvet leaves taken from six selected plants of five cultivars (Caturra, Catuai amarillo, Monteclaro, Colombia 27 y Castillo) were inoculated with 80 μL of a uredospore dilution (5 x 105 uredospores.mL-1), and incubated at 22 °C +/- 2 °C and 12 h light photoperiod. Incubation period, latency period, infection grade, number of initial lesions, number of sporulated lesions, area of lesion, and area of sporulated lesion were the variables used for evaluation. Results showed that number of initial lesion, number of sporulated lesion and area of sporulated lesion allowed to determine the presence of incomplete resistance in Castillo to race XXXIX, Castillo, Catuai and Colombia 27 to Hv01ve, and Monteclaro to Hv02ve, trials also showed possible complete resistance in Monteclaro to race XXXIX and Colombia 27 to Hv02ve. It is suggested that these results should be taken into account when selecting the coffee cultivars to be planted.

Remote sensing applied for the estimation of crop coefficient and detection of forest cover changes

Henry Pacheco — 2025-02-05

With the objective of applying remote sensing techniques for crop coefficient estimation and detection of changes in forest cover, in order to generate information that contributes to the sustainable management of agricultural and forestry resources, a study was conducted based on the theoretical foundations of agriculture 4.0, through the implementation of advanced technologies and intelligent data integration to optimize the entire agricultural production cycle. The methodology adopted includes the capture and processing of multispectral images from satellite platforms and unmanned aerial vehicles (UAVs), in order to obtain geometric and spectral information on various crops. Calculations of spectral indices (NDVI, NDMI, NDWI, Kc) and analysis of forest stand losses were performed using advanced software tools in GIS environment and the Google Earth Engine platform. The drone images made it possible to calculate the NDWI to classify soil moisture in high, moderate and low levels. Satellite images facilitated the identification of relationships between crop evaporation coefficient (Kc) and climatic parameters, as well as the detection of areas with forest losses in the Carrizal river basin. The results suggest strategies for the development of precision agriculture activities, promoting the substitution of conventional practices for sustainable development mechanisms based on geospatial technologies. This study contributes to the literature by demonstrating the application of advanced geospatial technologies to optimize agricultural production and sustainability.

Effect of the application of a biofertilizer on the yield of forage oats (Avena sativa L.) in the southern Durango, Mexico

Oscar Aguirre-Córdova — 2025-02-23

It is a priority to identify more efficient ways to fertilize crops without harming the soils. Biofertilizers obtained from the anaerobic digestion of manure can emerge as an ecological alternative in crop production. This study aimed to evaluate the yield and nutritional characteristics of oats (Avena sativa L.) fertilized with different doses of biofertilizer (Biol) through foliar application. In southern Durango, Mexico, four doses of Biol were applied: 0, 220, 440, 660 and 880 L.ha^-1, corresponding to treatments T1, T2, T3, T4, and T5, respectively, using a completely randomized block design. The crude protein (CP) content was similar among treatments (p>0.05); Meanwhile, neutral detergent fiber (NDF), acid detergent fiber (ADF), and phosphorus (P) decreased with the maximum doses of Biol (p<0.05). Regarding in vitro dry matter digestibility (IVDMD) differences were found (p<0.05). Fresh weight (FW) and dry weight (DW) yields increased with the higher doses of Biol, achieving higher values of 25.50 and 7.05 t.ha^-1, respectively. Additionally, the application of the biofertilizer Biol increased oat yield and improved some nutritional values of the forage. These results suggest that Biol is a viable alternative to the use of chemical fertilizers, promoting sustainable agriculture and contributing to the mitigation of the negative environmental impact generated by chemical fertilizers.

Extraction of K+, Ca2+, Mg2+, Na+ in saline soil by mono or multi-germ sugar beet

Sergio Valdivia — 2025-02-23

Approximately 33 % of surface of irrigated valleys in Peruvian northern coast, has a bad drainage or salinity problem. Sugar beet has good yields in those soils (90 t.ha^-1). The objective of present work was to know if in those soils there is a relationship between soil K, Ca, Mg, Na, and its extraction by sugar beet, and if they contribute with crop salinity tolerance. Experiment was made in Chicama valley, with randomized complete block design, ten treatments: five multi-germ cultivars, five monogerm; six replications. In each plot five soil sub-samples were taken, mixed in the field making one sample per plot, and available K, Ca, Mg, Na analyzed. Sugar beet extractions of those elements were evaluated in buried dry bio mass (roots) and aerial (leaves + crowns). Sugar beet mono or multi-germ did not absorb more K, Ca, Mg, Na if their quantity augmented in soil; for that is not an efficient soil “reclamator”. K and Na contributed to sugar beet salt tolerance, Ca could give salt tolerance, Mg had any action in salt tolerance. In those soils where there are large amounts of CaCO₃, Ca was absorbed with low or high available Ca soil amounts. Na contributed to salt tolerance because it was “included”. Mono or multi-germ showed no differences “including” nutrients.

Influence of the K+/Ca2++Mg2+ ratio in the yield of zucchini (Cucurbita pepo L.)

Rolando Rueda-Luna — 2025-02-24

Zucchini (Cucurbita pepo L.) is a widely cultivated vegetable that plays a significant role in global food production. Its yield and nutritional composition are influenced by various agronomic factors, including the availability and balance of essential nutrients. Among these, the cationic ratio of potassium (K⁺), calcium (Ca²⁺), and magnesium (Mg²⁺) in the nutrient solution is critical for plant growth and productivity due to their interactive effects on absorption and transport. The objective of this study was to evaluate the impact of different K⁺/Ca²⁺+Mg²⁺ ratios on the yield and mineral composition of zucchini leaves. The experiment was conducted under greenhouse conditions using a factorial design with two commercial varieties (Zuchinni Gray and Ambrosia) and five nutrient solutions with different cation ratios (K⁺/Ca²⁺+Mg²⁺; 0.2, 0.6, 1.0, 1.4, and 1.8). Plants were grown in polyethylene containers filled with red tezontle substrate. The results showed that Ambrosia exhibited a higher total yield compared to Zuchinni Gray. The K⁺/Ca²⁺+Mg²⁺ ratios of 1.4 and 1.8 significantly increased total production, while the ratio of 1.4 enhanced calcium absorption. However, no significant differences were observed in potassium and magnesium content in the leaves. These findings highlight the importance of optimizing the cationic balance in the nutrient solution to improve zucchini productivity and mineral composition.

Methane production and nutritional content from the diet consumed by grazing cattle

Elizabeth García

It is a high priority to account for methane emissions from cattle grazing grasslands in order to evaluate the strategies for mitigating GHG emissions in livestock. The aim of this study was to evaluate in vitro ruminal methane production and nutritional content of the consumed diet by bovines grazing an open medium grassland in atypical dry and rainy periods in the semi-arid region of the state of Durango, Mexico. Four rumen fistulated bovines were subjected of an ad libitum graze under a repeated measure design. Chemical analysis showed that DM, OM, NDF and ADF increased in rainy period (p<0.05). Otherwise, CP, EE, phosphorus contains and IVDMD increased in dry period (p<0.05). Ruminal fermentation parameters as pH and volatile fatty acids as acetic, propionic and butyric, showed no changes among periods (p>0.05). However, ammonia increased in rainy period (p<0.05). Moreover, gas production kinetics only showed differences in lag phase (p<0.05); whereas, maximum gas production and production constant rate showed no changes among periods (p>0.05). Likewise, methane production showed no changes among both periods (p<0.05). As conclusion, it is observed that nutritional quality of the consumed diet by bovines grazing and open medium grasslands in dry and rainy periods presents acceptable protein values (8-10 %). In addition, phosphorus contents are higher than the minimum requirements for growing bovines. Furthermore, methane production was not affected by dry and rainy periods.

Allelic frequencies of genes associated with productive traits in western Mexican boars

Miguel Ayala-Valdovinos — 2025-01-09

The ESR1, PRLR, and RYR1 genes have previously been associated with traits of productive interest. The objective of this study was to determine the allelic frequencies of genes associated with productive traits in boars from pig farms in western Mexico. A total of 140 boars of six breeds, Duroc, Hampshire, Landrace, Piétrain, and Yorkshire, and Yorkshire/Landrace crosses were sampled. The pigs were genotyped via polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. The two alleles of the ESR1 gene were identified in the six breeds, but only BB homozygotes were recognized in Yorkshire pigs (0.2) and their crosses (0.05). The A and B alleles of the PRLR gene were distinguished in all the breeds studied, recognizing a considerable variability in the allele frequencies. Due to the allelic diversity and its effects evidenced in previous publications, it is suggested to evaluate the association of each genotype with the reproductive parameters to be improved in order to determine which genotype is more relevant in each population. In the RYR1 gene, the mutant allele causing PSS was found in all the breeds studied, which can generate pigs with PSE meat. It is recommended that the selection of boars of any breed to be used as breeders includes a genotyping test. Knowing the genotypes in boars can be used as a way to select better breeders.

Antioxidant activity and physicochemical properties of mango nectar with pitahaya

Jorge Vera — 2025-01-09

Currently, mixed fruit nectars are generating greater consumer interest due to their potential contribution of nutrients and exotic flavors. The objective of the study was to evaluate the antioxidant activity and physicochemical properties of mango nectar (Mangifera indica L.) made with various levels of pitahaya (Hylocereus undatus). A completely randomized experimental design was used. The test consisted of the formulation of three treatments (10, 20, and 30 % pitahaya flesh (pf) and a control). Physicochemical, functional, microbiological, and sensory parameters were evaluated. Analysis of variance and Dunnett and Kruskal Wallis mean comparison test were applied at 5 % significance. The results showed that the levels of pitahaya flesh significantly influenced the response variables of pH, viscosity, soluble solids, density, turbidity, antioxidant activity, and total phenols, on the contrary, the colorimetry parameters (L, a, b) presented a p> 0.05. Regarding sensorial acceptability, a p < 0.05 was determined in the attributes of texture, consistency, and flavor, while color and smell were not significant (p>0.05). The treatments under study met the physicochemical and microbiological requirements established in the NTE INEN 2337 standard. It was shown that the addition of 30 % of pf improved the content of total phenols in mango nectar up to 0.537 ± 0.00 mg Gallic Acid Equivalent.mL^-1. The nectars had a yellow color with a greenish hue and bright luminosity. The treatment T3 was considered the best at the organoleptic level in texture, consistency, and flavor.

Production of a distilled mango drink: volatile compounds and heavy metal

Bruno Giménez-López — 2025-01-09

The optimization of processes for the production of fruit distillates is essential to ensure high product quality, comply with current regulations, and promote the development of the agro-industrial sector. The objective of this study was to evaluate the physicochemical properties of a mango distillate (Mangifera indica L.), varieties Kent and Alphonso, in order to optimize its production process, the fruits underwent controlled fermentation and subsequent distillation, during which volatile compounds and heavy metals were analyzed. The results showed significant differences between both varieties in terms of the concentration of ethyl acetate and furfural, which influence the sensory profile of the distillate. Methanol concentrations and other harmful compounds remained within regulatory limits. However, the copper concentration exceeded the limit allowed by the Peruvian Technical Standard (5 mg.L^-1), while zinc levels remained within safe parameters according to the WHO. This study demonstrates that, with adjustments in process control, mango distillate has the potential to be a high sensory quality product suitable for commercialization.

Physical properties of french fries made with quinoa and opuntia-peel flours

Roenfi Guerra — 2025-01-09

A large part of the world population consumes fast food on a regular basis. Most of these menus are accompanied by french fries. Their consumption does not represent a major nutritional contribution, and the frying process incorporates a considerable amount of oil into the french fries, increasing the risks of diseases such as obesity. The objective of the present work was to evaluate the physical and textural properties of a potato chip substitute made by extrusion technology with the incorporation of flours of a nutritious cereal such as quinoa and prickly pear peel in its formulation. Color and porosity were evaluated by image analysis. Texture by mechanical compression tests with an Instron universal testing machine and oil absorption rate by a modified compression method. Sticks of a potato substitute were obtained and fried by immersion in oil at 180 °C in the same way as a commercial pre-fried product. The firmness of the sticks (4.5 N) is 30 % higher than the commercial product, while the oil absorption rate (6.25 %) of the products obtained is three times lower. This phenomenon could be due to the fiber content present in the prickly pear peel flour and protein content in the quinoa flour. It is concluded that is possible to elaborate products similar to traditional and commercial potato chips, so that, without altering the consumption habits of the population, it can allow the intake of healthier foods.

Chemical study of the macrophyte duckweed (Lemna minor L.)

José Vera — 2024-12-19

Duckweed (Lemna minor L.) has attracted considerable attention in the scientific field due to its nutritional contribution and capacity to phytoremediate waters. Therefore, the objective of the study was to analyze the chemical composition of the macrophyte (Lemna minor) from natural environments. Chemical compounds and Weende composition were determined from the plant, and the fresh weight gain was observed in different types of water (deep well and bovine slurry), waters that were subjected to physical-chemical analysis. The chemical analysis of the macrophyte resulted in the presence of 1.42 mg.g^-1 of total chlorophyll; 2.35 mg.kg^-1 of ascorbic acid; tannin content less than 2.50 mg.kg^-1; 45.34 mg.kg^-1 of phenols; also the presence of alkaloids, phenols and reducing sugars in the chemical screening. The Weende analysis indicates a composition of: 89 % of dry matter, 30 % of crude protein, 4 % of gross energy, 3.2 % of ether extract, 15 % of ashes, 32 % of nitrogen-free extract and 10 % of fiber. The fresh weight gain of Lemna minor obtained in water contaminated with bovine slurry increased significantly 13 g.day.m³ and 5 g.day.m³ in deep well water. The physical-chemical properties of the water improve their quality 16 days after treatment with this aquatic plant with respect to the initial analysis. This macrophyte exhibits remarkable phytoremediation properties to absorb, metabolize and stabilize various pollutants effective in the purification of contaminated waters.

Review of microclimate mapping methods in forestry

Manuel Sánchez-Chero — 2024-12-25

The study of microclimates provides a several benefits that imply their importance to reduce the effects of climate change, so the mapping of microclimates emerges as an alternative for their identification and conservation. The objective of this review is to identify the techniques used in microclimate mapping. The methodology used was an exploratory review in databases such as Science Direct, Springer and IEEXplore, which determined that there is a shortage of works related to microclimate mapping, since only 19 works met the inclusion requirements of the review. It was determined that the main objective of the microclimate mapping focused on the tree canopy, the height and density of the forest structures and their effects on the climatic factors that comprise them. On the other hand, the microclimate mapping methods identified were divided into photogrammetric methods and laser scanning methods, where most of the studies were based on obtaining aerial data, either by drones (UAV, UAS, RPA, RPAS) or airplanes as in the case of airborne LiDAR technologies. It was concluded that there is little research on microclimate mapping, so the forestry scientific community is exhorted to employ the different methodologies for objectives of great impact on the environment such as the prediction of forest fires and the monitoring of forest restoration after these fires.

The development status of rice iron-coated wet direct seeding technology in Japan

An Hao — 2025-02-05

This review examines the development and potential of iron-coated wet direct seeding technology in Japanese rice cultivation, emphasizing its role in mitigating labor shortages and enhancing the sector's competitiveness. The technology, which has been rapidly adopted, improves seedling emergence, reduces seed drifting, and minimizes damage from birds and rodents by increasing seed weight and hardness. Comprising cost-effective materials such as iron powder and calcium sulfate, the coating process is both straightforward and economical. While some studies report a modest 5 % reduction in yield relative to transplanting, others suggest comparable or even improved yields. The technology offers significant advantages in reducing labor input, lowering production costs, and improving seedling establishment, positioning it as a promising solution not only for Japan but also for other rice-producing regions facing similar challenges.

Use of plant extracts for the protection of the plantain bunch (Musa AAB) against insects, Sucre municipality, Zulia State

Juan Nava — 2024-12-18

Plantain producers from the Sucre municipality of Zulia state, Venezuela, have expressed concerns about improving or maintaining the quality of the bunch, seeking to protect it from damage caused by insects, thus harming its appearance for marketing. It was proposed to evaluate the effect of aqueous plant extracts from the 100 % water-plant organ mixture for the protection of the plantain bunch. A completely randomized experimental design was used with 5 treatments and 20 repetitions. The treatments were: T1: cluster without product application; T2: cluster sprinkled with garlic bulb extract (Allium sativum); T3: cluster sprinkled with hot pepper fruit extract (Capsicum spp.); T4: bunch sprayed with lemongrass (Swinglea glutinosa) leaf extract and T5: bunch sprayed with eucalyptus (Eucalyptus spp.) leaf extract. The variable that was studied was: bunch fruits without damage from insect attack. T2 and T3 presented a higher percentage of fruits without insect damage (94 and 96 % respectively), with better quality in the bunch for commercialization.