Revista de la Facultad de Agronomía – Universidad del Zulia

Opuntia cochenillifera (L.) Mill. has a forage potential in arid areas. Because pastures are insufficient to meet livestock's nutritional demands during the dry season, this research aimed to evaluate the effects of sectioning (S), drying (D), and shading (Sh) of cladodes on the propagation of Opuntia cochenillifera (L.) Mill. The S factors (whole cladode and apical, middle, and basal sections), D (pre-drying at room temperature on mesh under shade for 14 days), and Sh (with and without shading under 80 % density raffia mesh), resulted in a combination of 16 treatments, arranged in a split-plot treatment design and a completely randomized experimental design. Percentages of living, rooted, and sprouted cladodes, number of shoots per cladode, and number and length of roots were evaluated 35 days after establishment. An analysis of variance and a means test were applied to determine differences among treatments. An increase in the percentage of rooted cladodes was obtained with the middle, apical, and basal fractions compared to the whole cladode, regardless of the drying process. Prior shading was counterproductive for cladode survival; high environmental humidity, combined with their water content, may have favored the appearance of secondary rots. In general, considering most of the variables evaluated, cladode sectioning without drying emerged as the best technique for asexual propagation of the species, due to the yield of vegetative material and its practicality.

The field of animal feed production it is consider one of the most important areas in livestock production. Given that the livestock sector in Algeria faced many problems, such as water scarcity and the high cost of traditional feed, it is important to find other local sources to overcome those difficulties. This study aimed to determine the content of secondary metabolites, including total phenolic compounds, tannins, and flavonoids, and the antioxidant activities in different parts (leaves, stems, and panicle residues) of ten landraces of sorghum found in the Algerian desert and cultivated in the Bordj Bou Arreridj region of Algeria. The results showed significant differences between the contents of the studied samples, as well as among the three different parts of the plant, namely the leaves, stems, and panicle residues. The total phenolic content ranged from 122.33 to 1344.44 mg EAG.100 g-1, with tannin levels from 4.84 to 927.78 mg EAG.100 g-1, while the flavonoid values ranged from 0.24 to 558.25 mg EQ.100 g-1. The antioxidant activitie also showed a significant variation, with DPPH values between 46.10 and 1481.68 mg AAE.100 g-1, FRAP from 31.76 to 1145.92 mg AAE.100 g-1, and ABTS values ranging from 28.89 to 459.92 mg AAE.100 g-1. These results confirmed that the sorghum plants not only represented a source of primary metabolic compounds such as fibers, starch, proteins, and energy materials used as animal feed, but they could also be utilized as a rich source of phenolic compounds with effective value in the health field.

The peels of Musa acuminata constitute a by-product of interest due to their richness in metabolites that influence important biological activities. The objective of the study was to evaluate the chemical composition of the peels (maturation stage 1) of Musa acuminata AAB (Blue Java), through the application of chemical and physicochemical methods, for their utilization. A comparative study was carried out with a single experimental factor and two independent samples: treatment without antioxidants (ST) and treatment with antioxidants (T). The proximate analysis performed demonstrated the presence of fiber, proteins, and minerals; moreover, it was verified that the application of antioxidants does not alter the nutritional profile. The absence of heavy metals was confirmed, ensuring the safety of the samples. For the identification and structural characterization of specialized metabolites, an HPLC-MS-UV study was carried out, which allowed the identification of 9 flavonoid glycosides in the acetone extracts of the peels. A higher concentration of phenols and tannins (20.21 mg GAE.g-1; 8.36 mg GAE.g-1) was quantified in the samples treated with antioxidants (T) compared to the untreated samples (ST) (6.46 mg GAE.g-1; 1.71 mg GAE.g-1), demonstrating that the application of antioxidants inhibits oxidative degradation and preserves these metabolites. These findings show that the immature peels of Musa acuminata AAB of the Blue Java variety constitute a viable and safe source of phytonutrients and phenols. Additionally, the effectiveness of a treatment with antioxidants was confirmed for preserving these metabolites without compromising their nutritional composition.

Corn is one of the most important species worldwide due to its uses for feeding humans and animals. In Ecuador, the province of Manabí is considered the area with the largest cultivated area nationwide. This work aimed to characterize weeds' floristic composition and predominance in El Junco, Tosagua corn production systems. To estimate the dominance of existing weeds, 10 farms were selected, where thirty random samplings were carried out for each farm using a 0.50 x 0.50 m quadrant. At each sampling point, the existing weeds and their respective identification were counted. In total 39 species were identified, 32 belonging to the Magnoliopsida class (dicotyledons) and 7 to the Liliopsida class (monocotyledons) and grouped into 16 botanical families. The families with the greatest representation were: Poaceae (25,06 %), Euphorbiaceae (18,61 %), Cyperaceae (14,79 %), Asteraceae (9,76 %) and Malvaceae (8,49 %). The most frequent species were Urochloa fasciculata, Euphorbia hirta, Cyperus rotundus, Cyanthillium cinereum, Richardia scabra, Corchorus hirtus and Alternanthera sp. The species U. fasciculata, E. hirta, and C. rotundus obtained the highest dominance values with 3.88, 3.49, and 3.03 % respectively. In this way, we concluded that the Poaceae family, presented the greatest number of weeds in the corn production systems in the El Junco locality. Adequate knowledge of the floristic composition of an agroecosystem will allow the development of appropriate weed management strategies in different commercial corn fields.

Soil acidity severely limits biological activity in high Andean systems, where aluminum toxicity and low pH reduce agricultural productivity and constrain microbial processes. In this context, the effect of calcium carbonate (CaCO₃), applied both individually and in combination with a commercial organo-mineral amendment, was evaluated on soil pH, exchangeable aluminum, and microbial respiration in an acidic soil collected from an agricultural farm located in the mountainous region of Pamplona (Norte de Santander), through a 15 day controlled incubation conducted between March and May 2021. A completely randomized design with four treatments (control, 100 % CaCO3, 50 % CaCO3, and 50 % CaCO3 + amendment) and five replicates per treatment was used, measuring chemical variables and respiration at multiple incubation times; statistical analyses included ANOVA, Spearman correlations, and multiple linear regressions. Results showed that CaCO3 significantly increased pH (up to +0.62 units at the full dose) and reduced exchangeable aluminum only in this treatment, while all amended treatments enhanced microbial respiration, particularly during early stages, with a tendency toward a stronger response in the organic combination. However, multivariate analysis revealed that chemical variables did not independently explain respiratory variability, highlighting the predominance of the integrated treatment effect. It is concluded that liming, especially when combined with organic amendments, corrects chemical acidity and revitalizes microbial activity through systemic effects, with practical implications for the sustainable management of high Andean soils.