Revista Peruana de Investigación Agropecuaria

Characterization of the occurrence and distribution of northern corn leaf blight in the north central of Córdoba for ten years

Roberto Luis De Rossi — 2025-04-20

Northern corn leaf blight (NCLB), caused by the fungus Exserohilum turcicum, is Argentina's most significant corn disease in late planting dates. This study aimed to compile, organize, and analyze a ten-year corn health database to characterize the occurrence and spatial distribution of NCLB in the north-central region of Córdoba. Summary statistics, comparative analyses, multivariate statistics, regression classification trees, and geospatial mapping were applied to evaluate the relationship between crop management variables and final disease severity (FS). High average FS values (≥10%) were recorded in five crop growing seasons, with the highest levels observed in areas near Villa María and Villa María de Río Seco (45% and 62%, respectively). Genotype accounted for the most significant proportion of variation in FS (58.8%; p<0.0001), highlighting the importance of understanding hybrid performance in response to NCLB pressure. Later planting dates were associated with increased FS, and Neutral and La Niña exhibited a higher likelihood of severe disease outbreaks. These findings enhance our understanding of NCLB epidemiology in the region by describing its spatial and temporal dynamics and offering essential information for designing effective disease management strategies for this pathosystem.

Rooting stevia cuttings (Stevia rebaudiana Bertoni) with different natural rooters in Yarinacocha, Ucayali, Peru

Rogger Wagner Peña-Pasmiño — 2025-04-20

The objective was to evaluate the rooting of stevia (Stevia rebaudiana Bertoni) cuttings using natural rooting agents in Yarinacocha, Ucayali, developed at the Instituto Superior Pedagógico Bilingüe de Yarinacocha. The cuttings, 10 cm long, were collected in the morning from plants that had been previously grown in an aquaponic system. A subirrigation chamber was built using materials such as wood and polyethene mica, stone, gravel, and sand were used as an inert substrate. The cuttings, treated with different rooting agents, were placed in this chamber: Rootone, aloe, coconut water, and lentil water. The experiment was evaluated 60 days after installation, analyzing variables related to the development of the cuttings. A Completely Randomized Design was used with four treatments and twenty replications. Tukey's test of averages with a significance level of α = 0.05. The results show that lentil water treatment was the most effective, achieving 61% rooting, as well as the best averages in stem length, number of leaves, number of shoots, root length and number of roots, presenting significant differences with respect to the other treatments, concluding that lentil water is an effective and natural alternative for the rooting of stevia cuttings.

Characterization and classification of high mountain cattle farming systems in Valle del Cauca: foundations for sustainable production

Raúl Andrés Molina-Benavides — 2025-04-20

Cattle farming in Colombia is a key rural activity that transforms vegetation cover, but a lack of knowledge about its practices and benefits limits the transition to sustainability. This study characterized and classified cattle production systems on 15 high mountain farms (2700-3600 ma.s.l.) in La Nevera, Valle del Cauca. Information was collected through surveys (162 questions), forage sampling, and vegetation cover data from the CVC, analyzed using descriptive statistics and QGIS. The results revealed low technological and educational levels among producers, suboptimal reproductive and productive parameters, and a lack of zootechnical records. Two types of systems were identified: one for rearing and fattening, and another for milk production, subdivided by area and animal load. The research concludes that there are threats to the agroecosystems in the area. A vision of sustainable production in the short and medium term is proposed, emphasizing the need for state support for conversion programs that ensure economic viability, social responsibility, and environmental conservation.

Productive behavior of three varieties of lettuce (Lactuca sativa L.) in an aquaponic system in the Yarinacocha district

Marko Antonio Grandez-Cachique — 2025-04-20

The research evaluated the yield of three lettuce varieties (silk, crespa and purple) grown in an aquaponic system in Yarinacocha, Pucallpa, between September and October 2024. Seedlings were planted in seedlings and then transplanted into gravel aquaponic beds, with a spacing of 30 cm x 30 cm. Irrigation was provided by a piping system carrying fish rearing effluent, driven by a 2 HP pump controlled by a timer. Growth and yield evaluations were made every 15 days and at harvest. The results showed that the purple variety presented the most significant plant height, while the silk variety surpassed the others in terms of number of leaves per plant, weight per plant, and yield per hectare. In conclusion, although the purple lettuce grew taller, the silk variety was the most productive in an aquaponic system, yielding the best agronomic results under the evaluated conditions.

Bird diversity at observation sites in the Province of Alto Amazonas, Loreto, Peru

Ronald Rolando Mori-Pezo — 2025-04-20

The Peruvian Amazon is a vast region with an abundance of bird diversity that significantly contributes to ecosystem functioning, making it essential to understand the distribution of these birds. This study aimed to record and analyze bird diversity across various observation sites in the province of Alto Amazonas, Loreto, Peru, between October 2023 and October 2024. Surveys were conducted in nine representative localities using direct and observational methods, as well as playback techniques, supported by digital applications and specialized literature. A total of 157 bird species were identified, belonging to 23 orders and 46 families. Diversity analyses revealed that better-preserved sites, such as Mercedes, exhibited higher diversity and evenness (Shannon index up to 4.02 and Simpson index up to 0.97). In contrast, altered environments, such as the rice fields of La Florida, showed less species diversity but with an abundant population. Species fulfilling key ecological roles—such as pollinators, seed dispersers, and biological controllers—were recorded. Additionally, species of touristic interest, such as the hoatzin (Opisthocomus hoazin) and the horned screamer (Anhima cornuta), were identified. This study provides an essential foundation for future conservation efforts, environmental education, and regional ecotourism planning.