Revista de la Facultad de Agronomía de la Universidad del Zulia

The unwavering resilience of scientific research in Latin America

2025-12-28T23:40:04+00:00

Science in Latin America develops in an environment marked by constant adversity, and empirical research in our region is a living testimony to human strength. From laboratories with infrastructural limitations in South American public institutions to the most advanced innovation centres in Central America, academics have demonstrated an extraordinary ability to forge ahead despite fiscal constraints, brain drain and socio-economic ups and downs. This tenacity goes beyond mere survival: it is a collective effort that redefines what seems possible.

Capsaicin in the control of Spodoptera frugiperda in corn (Zea mays L.) var. Blanco Urubamba

2025-12-26T21:19:00+00:00

Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) causes severe losses in corn (Zea mays L.) crops, which leads to the evaluation of sustainable management alternatives. The objective of this research was to determine the efficacy of capsaicin in controlling S. frugiperda in the corn Blanco Urubamba var. A randomized complete block design with six treatments and three replicates was used: four concentrations of water-soluble capsaicin (6.70; 10.05; 13.40 and 16.75 mL.L^-¹), rocoto pepper extract (Capsicum pubescens Ruiz & Pav. (Solanaceae), 50 g.L^-¹), and an absolute control. Applications were made at 80, 90, 100, 110, and 120 days after sowing (das). The 16.75 mL.L^-¹ dose was the most effective, reducing larval density from 3.12 to 0.13 larvae per plant, and the infestation percentage from 61.12 to 2.78 %, with a control efficacy of 96.69%. Intermediate concentrations (13.40 and 10.05 mL.L^-1) also showed significant effects, with final efficacies of 93.83 and 85.19 %, respectively. T1 had moderate efficacy (78.30%), while T5 recorded the lowest control values (72.86 %), with increasing infestations being observed in the control. In terms of yield, T4 (16.75 mL.L^-¹) produced ears of 16.77 cm in length and 385.13 g in average weight, reaching a yield of 17.12 t.ha^-¹ compared to 9.54 t.ha^-¹ for the control. In conclusion, water-soluble capsaicin, especially at 16.75 mL.L^-¹, proved to be an effective and sustainable alternative for the management of S. frugiperda in corn.

Effectiveness of sex pheromone traps in the integrated management of Planococcus ficus Signoret (Hemiptera: Pseudococcidae) in vineyards

2025-12-28T23:12:58+00:00

Planococcus ficus (Signoret) represents an economically significant pest in viticulture, requiring timely, innovative, and effective control measures. While the application of sex pheromones in vineyards has primarily focused on mating disruption, there is a lack of studies evaluating their use in mass trapping as a management tool for this pest. This study was conducted in a commercial vineyard of the Crimson Seedless variety in Ica, Peru, and the objective was the efficacy of pheromone-baited traps (CINNAFIC®) deployed from postharvest 2020 through postharvest 2021. During this period, a trap density of 15 traps.ha⁻¹ was maintained, resulting in the capture of 16,927 males, with a peak capture rate of 112.20 males.trap⁻¹.week⁻¹ observed during the berry development stage. The greatest control was observed at harvest, with a 59.12 % reduction in the total mealybug population, highlighted by the production of infestation-free, fully exportable grape clusters, compared to 7 % infestation in control plots. Trap deployment limited mating opportunities, significantly altering the population structure by reducing nymphs and ovipositing females in treated plots. These results demonstrate that integrating pheromone traps with cultural practices and timely applications of pesticides and botanical extracts enables effective mealybug control without exclusive reliance on chemical insecticides. It is concluded that pheromone traps constitute a sustainable, effective, and viable tool for the integrated management of P. ficus in vineyards.

Entomopathogenic potential of thermotolerant microorganisms isolated from infected Dermestes maculatus against Culex pipiens larvae

2025-12-28T23:32:47+00:00

During summer, when temperatures reach extreme records, the inhabitants Sahara seek refuge in oases for shade and water. These ecosystems are characterized by a unique microclimate. Nevertheless, they face serious threats from two arthropod species: venomous scorpions and mosquitoes, which act as vectors of diseases. Chemicals impacting both biotic and abiotic components of the ecosystem, and more critically human health. Chitinolytic entomopathogenic microorganisms were isolated from dust samples collected from the cadavers of the Dermestes maculatus. Chitin extracted from shrimp shells (yield: 16.6 %) served as the sole carbon source in the selective culture media employed for their cultivation. Five strains were obtained: three fungi (Aspergillus flavus, A. fumigatus, Mucor sp.) and two bacteria (Bacillus sp. and Actinomycete). Bioassays against third-instar Culex pipiens larvae showed that Actinomycete (10⁶ CFU.mL^-1) induced 90 % of mortality, followed by A. fumigatus, Mucor sp., and Bacillus sp. (80 %), Data were analyzed using one-way ANOVA and Duncan’s test (p<0.05). Microscopic observations revealed severe larval deformities. These findings confirm the strong larvicidal potential of microorganisms as eco-friendly alternatives to chemical insecticides.

Age-related variation and multivariate analysis of internal and external egg quality traits in ISA Brown hens

2025-12-28T23:06:26+00:00

This study evaluated age-related variations in internal and external egg quality traits in ISA Brown hens raised under semi-arid Algerian conditions. Hens were assessed at two production stages: 5,977 at peak lay (25–30 weeks) and 5,430 at late lay (75–80 weeks). A total of 360 eggs were collected (180 per stage), at a rate of 30 eggs per week, randomly selected at the beginning of each week. Egg weight, shell thickness, shape index, yolk and albumen indices, Haugh units, and yolk color were measured. A one-way analysis of variance (ANOVA) was used to detect age-related differences, Pearson correlation to examine interrelationships among traits, and principal component analysis (PCA) to identify general age-related patterns. Significant differences were observed between the two laying stages. Peak-lay eggs showed superior internal quality, particularly in albumen height and Haugh units, whereas late-lay eggs exhibited greater mass but reduced albumen integrity. Shell thickness and yolk shape remained relatively stable. Correlation analysis revealed stronger trait associations during peak lay, which weakened with advancing age. PCA showed contrasting age-related trends between egg size and internal quality: egg size increased with age, whereas internal quality declined, while shell- and yolk-related traits remained relatively constant. The findings of this study apply to hens up to 80 weeks of age. Further studies covering longer production cycles are recommended to determine whether these patterns persist beyond this period.

Elaboration of “cacho de cabra” chilli canned (Capsicum annum L. Var Longum) in three different coverage media

2025-12-26T21:52:48+00:00

The "cacho de cabra" chili pepper (Capsicum annuum L.) is used in the preparation of a wide variety of foods, primarily consumed in dehydrated, raw, or powdered form to flavor and aromatize dishes. To contribute to the development of different types of products using the "cacho de cabra" chili pepper (Capsicum annuum L. var. Longum) as a raw material, a canned version of this chili pepper was developed, considering the covering medium, the amount of NaCl, citric acid, and spices. Three treatments were proposed for this process. The chemical characteristics, sensory attributes, and safety of the manufactured products were evaluated. Analyses of chemical characteristics (sodium content, total acidity, and pH), sensory attributes (color, flavor, aroma, texture, and overall acceptability), and safety (fecal and total coliforms) were performed after 20 and 40 days of storage. Canned goods prepared with treatment T₀ (water + 2 % NaCl + citric acid) were the most accepted by the panelists, followed by those prepared with treatment T₁ (sunflower oil + spices). Canned goods prepared with treatment T₂ (extra virgin olive oil) were not well-received due to their acidic taste and mealy texture. Significant results were found in all three treatments for sodium content, pH, total acidity, and absence of pathogenic microorganisms.