Revista de la Facultad de Agronomía de la Universidad del Zulia

Biocontrol of Cosmopolites sordidus using entomopathogenic fungi under laboratory conditions, Ecuador

2025-03-30T22:32:16+00:00

Cosmopolites sordidus known as the black weevil, is an insect pest of economic importance for Musaceae crops such as bananas and plantain, resulting in production losses due to its damage. One of the alternatives for the management of the black weevil is biological control using entomopathogens that regulate the insect populations in Musaceae plantations. The objective of the research was to determine the action of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Verticillium lecanii on adults of the black banana weevil under controlled laboratory conditions. A completely randomized design was implemented with 8 treatments with the application of the entomopathogens individually and in combinations, as well as a control treatment. The results showed that the treatment with the combination of B. bassiana + M. anisopliae showed the best control of the insect pest with 100 % mortality 10 days after inoculation, followed by B. bassiana with 88 % and 24% control with M. anisopliae, while the treatment with the fungus V. lecanii achieved 32 % control of the black weevil. Entomopathogens are an alternative for the management of the insect pest of Musaceae C. sordidus.

Morphological and genetic variability of chili pepper (Capsicum annuum L.) populations from northern of Mexico

2025-04-14T18:02:16+00:00

This study investigated the genetic and morphological variability of five domesticated chili varieties (Árbol, Güerito, Mirasol, Negro and Alcalá) and one wild variety (chiltepín) from Chihuahua, Mexico. Morphological evaluation was carried out according to the International Plant Genetic Resources Institute, combining correspondence analyses and Chi-square tests. Genetic variability was determined using the RAPD technique; a dendrogram was constructed, and genetic diversity among populations was estimated using principal coordinate methods, Shannon index, and permutational multivariate analysis. The morphological analysis revealed significant variations, while the genetic analysis, using the RAPD technique, showed 79.5 % polymorphism, indicating considerable diversity among the varieties. The dendrogram revealed the presence of three groups, highlighting chiltepín as potential ancestor of the domesticated varieties. The study emphasizes the importance of conserving and improving these plant genetic resources.

Multivariate analysis in the characterization of feijoa fruits (Acca sellowiana [O. Berg] Burret) in Tungurahua, Ecuador

2025-04-14T19:26:06+00:00

The feijoa (Acca sellowiana [O. Berg] Burret) is a Myrtaceae native to southern Brazil and northern Uruguay. Its fruits can be consumed fresh or processed into juice, ice cream, wine, liqueurs and others. In Ecuador, feijoa cultivation has been reported since 1980 in the province of Tungurahua. To evaluate the morphological and physicochemical characteristics of feijoa fruits through multivariate analysis, fruits from 18 farms located in Tungurahua, Ecuador were analyzed. A sample of 10 fruits per farm were analyzed in the food processing laboratory of the Tungurahua Higher Technological Institute. Descriptive statistics and multivariate analysis were employed for data evaluation. The fruits exhibited an oboval shape with erect sepals, moderate skin roughness, and white pulp. Fruit diameter ranged from 2.0 to 5.1 cm (CV=17 %), and fruit length ranged from 2.46 to 10.1 cm (CV=16.2 %), indicating variability in fruit size. Fruit biomass ranged from 8 to 133 g, with pulp yields between 4.6 % and 46.2 %. Total soluble solids ranged from 8.0 to 20 °Brix; the pH and titratable acidity (citric acid percentege) averaged 3.5 and 0.50, respectively. Fruit length and diameter showed a high correlation with fruit biomass. PCA identified the formation of three groups of producers, based on fruit size