Examinando por Materia "Peruvian Amazon"

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A multiple-species participatory domestication programme in the Peruvian Amazon: experiences and results to date
(2005-01) Cornelius, J.; Sotelo Montes, C.; Ugarte Guerra, Julio; Weber, John C.; Ricse Tembladera, Auberto
In 1995, the World Agroforestry Centre (ICRAF) and partners initiated a participatory agroforestry domestication programme in the Aguaytía Watershed and Alto Amazonas province of the Peruvian Amazon. The programme, aimed primarily at conservation-through-use of genetic diversity, began with formal, participatory prioritization, leading to selection of four species: bolaina blanca (Guazuma crinita Martius: Sterculiaceae),capirona (Calycophyllum spruceanum (Bentham) Hooker f. Ex Schumann)), guaba (Inga edulis C. Martius: Leguminosae (Mimosoideae)), peach palm (Bactris gasipaes Kunth: Palmae). Open-pollinated seed of each was collected from farmer-selected mother trees, and used in the establishment of a series of seedling seed orchards / progeny tests, the individual blocks of which were dispersed on lands of individual collaborating farmers. Almost ten years later these trials are beginning to produce seed, the Aguaytían famers have organized themselves into a wood and seed producers’ cooperative, the technology developed is being adopted more widely, and genetic results are becoming available. We describe the programme and its results in detail, with special emphasis on its innovative features. Subsequently, we evaluate success to date in relation both to initial objectives and the programme’s response to the evolving local forestry and development environment. Finally, we consider future priorities.
Attack by the mahogany shoot borer, Hypsipyla grandella Zeller (Lepidoptera: Pyralidae), on the Meliaceous trees in the Peruvian Amazon
(Springer, 1992-02-25) Yamazaki, Saburo; Ikeda, Toshiya; Akihiko, Taketani; Vasquez Pacheco, Carlos Salomon; Sato, Takashi
The infestation of meliaceous species by the mahogany shoot borer, Hypsipyla grandella ZELLER, was investigated in plantation areas of the Peruvian Amazon. Damage was particularly great on line plantings and plantings in opened areas. Cedrela odorata was attacked by H. grandella from 0 to 10 times during 16 months, averaging 3 attacks per tree. The upper main stem of trees was more frequently attacked than offshoots or middle stems. First to second instar larvae were mostly found in the offshoot, whereas the older larvae were found most frequently in the upper main stem. Both C. odorata and Swietenia macrophylla sprouted 3 to 5.5 times a year, averaging 3.7 and 4.4 times, respectively. Flushing was concentrated in the rainy season and was rare in the middle of the dry season, resulting in a rapid increase of H. grandella in the former. The attack of Hypsipyla on the main stem triggered sprouting, which seemed to keep the pest density at a certain level in the dry season. The percentage of newly attacked trees per month tended to be slightly higher in C. odorata than in S. macrophylla.
Carbon reserves in coffee agroforestry in the Peruvian Amazon
(Frontiers, 2024-12-11) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Pichis García, Roger; Ordoñez, Luis; García Gonzales, Patricia; Quinteros , Aníbal; Lozano, Andi; Saavedra Ramírez, Jorge; Tuesta Hidalgo, Juan C; Reategui, Keneth; Macedo Cordova, Wilder; Baselly Villanueva, Juan Rodrigo; Marín, César
Secondary forests and coffee cultivation systems with shade trees might have great potential for carbon sequestration as a means of climate change adaptation and mitigation. This study aimed to measure carbon stocks in coffee plantations under different managements and secondary forest systems in the Peruvian Amazon rainforest (San Martín Region).
Carbon stocks in coffee farms and secondary forest systems in the Peruvian Amazon rainforest
(Research square, 2023-09-15) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Ordoñez, Luis; Vallejos Torres, Andi; Mendoza Caballero, Wilfredo; Arévalo López, Luis Alberto; Saavedra Ramírez, Jorge; Macedo, Wilder; Reategui, Keneth; Baselly Villanueva, Juan Rodrigo; Marín, César
Secondary forests and coffee cultivation systems with shade trees might have great potential for carbon sequestration as a means of climate change adaptation and mitigation. This study aimed to measure carbon stocks in coffee plantations under different managements and secondary forest systems in the Peruvian Amazon rainforest (San Martín Region). The carbon stock in secondary forest trees was estimated using allometric equations, while carbon stocks in soil, herbaceous biomass, and leaf litter were determined through sampling and laboratory analysis. The biomass carbon stock in secondary forests was 132.2 t/ha, while in coffee plantations with Inga sp. shade trees it was 118.2 t/ha. Carbon stocks were 76.5 t/ha in coffee with polyculture farming, and the lowest amount of carbon was found in coffee without shade trees (31.1 t/ha). The carbon sequestered by coffee plants in all agroforestry systems examined had an average of 2.65 t/ha, corresponding to 4.63 % of the total carbon sequestered, being the highest stored in the coffee system with Inga sp. shade trees. A higher content of glomalin-related soil proteins (GRSP) was found in coffee without shade trees, with 18.5 mg/g. This is evidence that Inga sp. is the most compatible model of shade system for coffee farms. We recommend the conservation of secondary forests due to the greater biomass and carbon storage, and establishing coffee plantations with Inga sp. shade trees for its integral benefits, such as climate change mitigation.
Climate, carbon, and soil stability: a key link in coffee-growing landscapes of the Peruvian Amazon
(Frontiers Media S.A., 2026-04-14) Romero Chávez, Lorena Estefani; Hermoza Ayme, Nilton Alexander; Chuchon Remon, Rodolfo Juan; Aldava Pardave, Uriel; Arroyo Isuiza, Rosa Karen; Solórzano Acosta, Richard Andi; Vallejos Torres, Geomar
Introduction: Coffee cultivation in the Central Peruvian Amazon, one of the country's most important production regions, faces increasing challenges from soil degradation and climate change impacts. This study aimed to evaluate the influence of the altitudinal gradient on soil organic carbon (SOC) stocks and soil erodibility (K index) in coffee-growing systems. Methods: Three altitudinal zones were established for sampling (0–20 cm depth): zone 1 (900–1200 m.a.s.l.), zone 2 (1201–1400 m.a.s.l.), and zone 3 (1401–1600 m.a.s.l.). Within these zones, physical and chemical soil properties were analyzed, and SOC and soil erodibility (K index) values were calculated. Results: The results revealed a direct and statistically significant relationship between altitude and carbon sequestration capacity. Zone 3 exhibited the highest SOC (63.19 t·ha⁻¹) and organic matter (OM) content (5.49%), compared with zone 1 (37.56 t·ha⁻¹). This difference is attributable to the climatic conditions at higher elevations, characterized by greater precipitation and lower temperatures. Structural equation modeling (SEM) indicated that increasing altitude enhances SOC (b = 0.42), which in turn improves the soil structural stability index (SI) (R² = 0.87) and reduces the K index (b = –0.38). Overall, the findings demonstrate that organic carbon acts as a key mediator between topography, soil texture, and susceptibility to erosion. The altitudinal gradient thus represents a major controlling factor influencing the health and structural stability of coffee soils. Discussion: These results highlight the need to implement site-specific soil management practices, emphasizing intensive conservation strategies in low-altitude coffee-growing systems to mitigate accelerated erosion and ensure long-term production sustainability under changing climatic conditions.
Integrated multivariate analysis of morphological and yield traits in native Capsicum chinense ecotypes grown in acidic soils of the Peruvian Amazon
(Frontiers Media S.A., 2026-04-15) Díaz Chuquizuta, Henry; Manrique Gonzales, Luis Fernando; Sánchez Ojanasta, Martín; Cuevas Gimenez, Juan Pablo; Martínez Zapata, Boris Guillermo; Flores Sinti, Geiner; Kerry Tanchiva, Juan Jose; Vallejos Torres, Geomar
Introduction: The comprehensive characterization of native Capsicum chinense ecotypes represents a strategic priority for genetic improvement, germplasm conservation, and the sustainable use of Amazonian crops. The objective of this study was to evaluate morphological, phenological, and productive variability among 12 ecotypes from the Peruvian Amazon by integrating multivariate análisis and machine learning with soil physicochemical characterization. Methods: The research was conducted on acidic tropical soils with low organic matter content and limited availability of exchangeable bases, conditions representative of degraded Amazonian agroecosystems, which enabled the assessment of soil–plant interactions and their influence on phenotypic expression and crop yield. Results: The results revealed a broad, well-structured range of phenotypic variability, with fruit diameter, fruit length, fruit weight, and seed weight identified as the primary morphological determinants of yield and adaptive capacity under low-fertility soil conditions. Principal component analysis indicated that four components explained more than 70% of the total variance, primarily associated with productivity, fruit morphometry, and phenological traits. Cluster análisis identified groups with high internal consistency, while linear discriminant analysis validated the phenotypic structure, achieving a classification accuracy of 91.8%. The ecotypes JEB-028 and LAG-022 exhibited superior productive performance, whereas BAL-012 and YUR-001 demonstrated greater phenotypic stability under restrictive soil conditions. Discussion: Overall, these findings confirm the strategic value of native Amazonian germplasm and underscore the importance of integrating edaphic diagnostics into genetic selection programs and into strategies for the sustainable management and restoration of degraded agricultural soils in the Amazon.
Native entomopathogenic nematodes from Peru control Spodoptera frugiperda, a major pest of Zea mays in the Peruvian Amazon
(MDPI, 2026-03-09) Fachin Ruiz, Grecia; Córdova Sinarahua, Deyvis; Romero Chávez, Lorena Estefani; Alvarado Ramírez, Jaime; Quesquen Lopez, Cesar; Flores García, Eybis; Koch Duarte, Christian; Cerna Mendoza , Agustín; Vásquez Bardales, Joel; Corazon Guivin, Mike
This study evaluated entomopathogenic nematodes (EPNs) isolated from a cacao agroforestry system in the Peruvian Amazon, focusing on their molecular characterization and efficacy against Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae. Thirteen EPN isolates were obtained from 50 soil samples using the Galleria mellonella baiting technique. Mortality assays revealed significant differences among isolates at 24, 48, and 72 h, with isolates 11N-A4 and 8N-B1 being the most virulent, achieving maximum mortalities of 100% and 96.3% at 72 h, respectively. Median lethal time (LT50) values indicated rapid action of these isolates on G. mellonella larvae, with 33.3 h for 11N-A4 and 32.4 h for 8N-B1. Molecular identification using ITS, D2-D3 (LSU), and COI markers confirmed the isolates as Heterorhabditis sp. (11N-A4) and Heterorhabditis amazonensis (8N-B1). In bioassays with S. frugiperda larvae, both EPNs exhibited dose- and time-dependent mortality. H. amazonensis showed rapid action, reaching 100% mortality at the highest dose (60 IJs/larvae) within 48 h, whereas Heterorhabditis sp. displayed a gradual, sustained increase, attaining 91% mortality at 72 h. Median lethal dose (LD50) and LT50 values reflected the efficiency of both isolates, with Heterorhabditis sp. achieving lower LD50 at later stages and shorter LT50 at low-to-intermediate doses. These findings highlight the potential of Heterorhabditis sp. and H. amazonensis as effective biocontrol agents adapted to local conditions and represent the first report of H. amazonensis in Peru. Further studies under field conditions are required to confirm their suitability for incorporation into integrated pest management strategies in the Peruvian Amazon.
The conversion of forests to agricultural croplands significantly depletes soil organic carbon reserves, total nitrogen, and available potassium, reaching critical thresholds in the Peruvian Amazon
(Frontiers Media S.A., 2025-09-19) Solórzano Acosta, Richard Andi; Cruz Luis, Juancarlos Alejandro; Chuchon Remon, Rodolfo Juan; Romero Chávez, Lorena Estefani; Lozano, Andi; Gaona Jimenez, Nery; Vallejos Torres, Geomar
Introduction: Land-use change from primary forests to agricultural croplands can degrade soil quality by depleting soil organic carbon (SOC), total nitrogen (STN), and soil-available potassium (SAK). The magnitudes and thresholds of these losses in the Peruvian Amazon remain insufficiently quantified. Methods: We assessed six land-use systems—two primary forests and four croplands (coffee, cocoa, oil palm, camu camu)—collecting 72 surface soil samples (0–20 cm) from 12 subplots per system using pit sampling. SOC, STN, and SAK were measured with standard laboratory procedures and compared across land uses. Results: The humid primary forest (WE–PF) had the highest nutrient status (SOC 118.99 t C ha⁻¹; STN 0.35%; SAK 181.83 mg kg⁻¹). The lowest values occurred in croplands, especially camu camu (SOC 23.93 t C ha⁻¹; STN 0.08%). Forest-to-cropland conversion was associated with average reductions of 58.98% (SOC), 59.49% (STN), and 59.66% (SAK). Among crops, coffee showed the smallest deficit (18.04%), whereas camu camu showed the largest SOC deficit (30.92%). Discussion: Converting forests to croplands critically depletes SOC, STN, and SAK, indicating substantial nutrient losses and concomitant deterioration of soil quality. These findings support conserving primary forests and promoting agroforestry and soil-restorative practices to mitigate degradation in the Peruvian Amazon.