Weeds are an omnipresent and costly problem for farmers in developing countries. They are considered opportunistic and unwanted plants that grow in crop fields, negatively affecting production yield. In Peru, studies on the species diversity and distribution of weeds found in the Andean region are scarce. In this work we contribute to the knowledge of weeds present in crops in the Characato district. To do so, weeds growing next to cultivated plants were collected, herbarium specimens were analyzed to identify them, and the geographic origin of the species was established through specialized bibliography and digital databases. 67 weed species were identified, grouped into 51 genera and 19 families, of which 60 species corresponded to Eudicotyledons and 7 species to Monocotyledons; The Brassicaceae family has the greatest diversity with 9 species, followed by Asteraceae (8), Poaceae (7), Solanaceae (6), Amaranthaceae (5), Fabaceae (4), Plantaginaceae (4) among other families. Of the total reported species, 30 (44.8%) are native and 37 (55.2%) are introduced. Finally, 5 species were found that are globally recognized for their negative impact on agriculture.

Salt stress is one of the main problems that restricts crop production, affecting agronomic performance and fruit quality. Therefore, this research was conducted to identify salinity tolerance in Rubus spp. cultivars at the vegetative stage under in vitro conditions. Nodal segments of the three cultivars were placed in growth and development media supplemented with three levels of NaCl (0, 35 and 70 mM). A completely randomized design with a factorial arrangement was used (Factor A: three cultivars and Factor B: two levels of NaCl and control), with three replications. The cultivar ‘Brazos’ registered an adequate response in shoot height when subjected to simulated saline stress with 70 mM NaCl. The cultivars ‘Tupy’ and ‘Brazos’ registered tolerance to 35 mM NaCl in the variable number of leaves compared to the control. The traits number of leaves and shoot height allowed to identify tolerance to saline stress in the vegetative stage of Rubus spp. cultivars under in vitro conditions.

The performance of avocado (Persea americana Mill) cultivation was evaluated in “type farms” in the department of Moquegua, Peru. A “type farm” is representative of a group of farms with similar socioeconomic and productive characteristics. A “type farm” with avocado, between 6 and 10 years old, was randomly selected for each group of farms, according to the results of the cluster analysis of the characterization of the avocado-producing farms in the department of Moquegua carried out by Bedoya and Julca (2020), reporting five “type farms” (I, II, III, IV and V); where 50 plants were randomly marked in each one. Monitoring was carried out for one season and the physical and chemical characteristics of the soil, presence of diseases, fruit size and yield were evaluated. It was determined that the highest avocado yield was in “type farm” II with the Hass variety (8.1 t/ha); with the Fuerte variety, the highest yield was in the “type farm” V (4.8 t/ha). The Hass variety had larger fruit size and a higher incidence of Lasiodiplodia theobromae; and the Fuerte variety had smaller fruit size and a higher incidence of Phytophthora cinnamomi. In general, the soils are poor in organic matter (0.28-1.66%), with neutral pH and high apparent density (>1.21 g/cc).

Wetland ecosystems play a crucial role in the global carbon cycle due to their high organic matter (OM) content, which makes them important emitters or sinks of soil carbon dioxide (CO2). However, in Peru, studies focused on soil CO2 dynamics are limited. In this context, the present study aimed to evaluate soil carbon dioxide fluxes in the Inner Bay wetland of Puno. Three sampling zones were selected: S1 (in front of Salcedo), S2 (near Espinar Island) and S3 (in front of UNA–Puno). CO2 flux monitoring was carried out during the dry (October 2022) and rainy (January 2023) seasons, using a portable infrared CO2 analyzer (EGM-4–PP Systems), connected to a breathing chamber (SRC-1–PP Systems), the experimental design applied was completely randomized with factorial analysis. The results indicated that soil CO2 emission varied significantly between seasons (p<0.05) and between sampling zones. The highest flux was recorded in S3 during the rainy season, with a value of 0.99 g CO2 m-2 h-1, while the lowest was observed in the same zone during the dry season, with 0.67 g CO2 m-2 h-1. Likewise, it was determined that soil CO2 emission is influenced by environmental factors that vary with the season of the year.

Revaluing Andean foods with high nutritional value is a pending task in the country. This is the case of arracacha, a root also known as the “Andean carrot,” which is rich in starch and easily digestible. The study evaluated the impact of acetylation time (0.5-6 hours) on arracacha starch (Arracacia xanthorrhiza) with acetic anhydride at 120°C on its physicochemical properties. The degree of substitution (DS) was observed to increase over time, reaching a maximum value of 2.91 after 6 hours. The apparent viscosity also increased, reaching 25,483 cP at the end of the process. The water absorption rate was highest in the first hour (25.3%), remaining stable thereafter. In contrast, solubility increased progressively, reaching 16.4% at 6 hours. The swelling power of acetylated starch exceeded that of raw starch, peaking at 35.8% after 2 hours and remaining constant thereafter. The results demonstrate that modifying arracacha starch provides specific technological and functional properties for food applications such as the production of instant soups, a partial substitute in baking, and in the meat industry.

El ñame (Dioscorea spp.) es un tubérculo crucial para la seguridad alimentaria en las regiones tropicales. Sin embargo, su producción se ve gravemente afectada por la antracnosis (Colletotrichum spp.), con pérdidas que superan el 80%. Aunque se emplean fungicidas químicos para su manejo, su eficacia en el control es limitada. A pesar de la relevancia del cultivo de ñame, existe una carencia de estudios que evalúen la sensibilidad de los aislados de Colletotrichum causantes de la antracnosis frente a fungicidas de síntesis química. Esta investigación tuvo como objetivo determinar la sensibilidad in vitro de aislamientos de Colletotrichum spp. causantes de la antracnosis del ñame a fungicidas químicos. El ensayo se realizó bajo un diseño completamente aleatorio con un arreglo factorial que incluyó 10 aislados, seis fungicidas y cuatro dosis. Se empleó la técnica de difusión en agar para medir el porcentaje de inhibición del crecimiento micelial y la dosis letal media (DL50) se usó para clasificar la sensibilidad de los aislamientos a los fungicidas. Los fungicidas azoxistrobin, captan y clorotalonil demostraron ser los más efectivos, con una inhibición del crecimiento micelial del 76.8%, 75.5% y 73.2%, respectivamente. Por otro lado, el difenoconazol, mancozeb y benomil tuvieron una inhibición del 52.24%, 41.44% y 29.22%, respectivamente. Además, se observó resistencia de algunos aislados a estas moléculas comúnmente empleadas en campo. Se concluye que el manejo de la antracnosis del ñame debe abordarse bajo un enfoque de manejo integrado, que permita una selección adecuada de los fungicidas.

El precio de venta del litro de leche en la ganadería colombiana presenta baja rentabilidad, por lo cual establecer sistemas silvopastoriles para generar bienes y servicios ambientales es una alternativa para obtener ingresos adicionales. En Pasto-Colombia, se determinó las preferencias de los consumidores en cuanto al portafolio de servicios ambientales, y se identificó la disponibilidad a pagar y a Aceptar un valor adicional por el litro de leche producida en sistemas ganaderos sostenibles, para esto se realizó una valoración contingente; en la cual se encuestaron 100 consumidores y 30 productores para determinar la disposición a pagar o aceptar un pago por mantener o establecer árboles; también se realizó una priorización de los servicios ambientales más relevantes; por último se socializó el valor ponderado para su evaluación por parte de los actores del sistema. Los servicios ambientales más relevantes en la literatura científica fueron Captura de Carbono y Gases de Efecto Invernadero, Biodiversidad, Conservación y fertilidad del suelo, Regulación hídrica y Paisajismo. El 78,7 % de los encuestados manifestaron conocer que la ganadería tradicional afecta negativamente los recursos naturales; el 68 % reconoció la importancia de coberturas forestales en la regulación del clima, En cuanto a la disposición a pagar un valor adicional por litro de leche, más del 80 % de los consumidores y el 100 % de los productores estuvo de acuerdo. Por último, el valor del litro de leche teniendo en cuenta los valores tanto de disposición a dar y recibir, se concertó en $ 68,4 COP.

Los campos magnéticos (CMs) son un factor ambiental necesario para todos los seres vivos. En particular el crecimiento y desarrollo de las plántulas in vitro, los CMs pueden ser una alternativa viable en la propagación in vitro de especies de Rubus spp. El presente trabajo evaluó la influencia de los CMs en la respuesta morfogénica in vitro de plántulas de especies silvestres (ES) de Rubus spp. Se instalaron dos experimentos; el primer experimento evaluó el efecto de intensidad de los CMs sobre la respuesta morfogénica en los segmentos nodales, empleando dos intensidades 100 y 200 mT comparadas con el control (0 mT); el segundo experimento evaluó el efecto de la duración de la exposición del CM de 200 mT en cuatro periodos: 0, 7, 14 y 21 días. Ambos experimentos permitieron identificar el efecto de los CMs en la respuesta morfogénica como la longitud de brotes e inducción de raíces adventicias, siendo las plántulas Z001 las que mostraron mejor respuesta en comparación con las plántulas Z005. Los resultados son importantes porque en futuro podría reducirse la dependencia de las auxinas para la inducción de raíces adventicias en especies de Rubus spp. aportando en la producción sostenible de las plántulas in vitro.

The totora (Schoenoplectus californicus spp. totora) offers multiple functions and ecosystem services. In the Ramsar Site - Uru Uru and Poopó, totora reed beds are the predominant vegetation, and their annual biomass, which is scarcely utilized, generates two problems: part of it is burned, contributing to air pollution, and another part accumulates on the lake beds, increasing sedimentation. Despite its ecological importance and utilization potential, studies on the totora in this Ramsar Site are limited and outdated. This study analyzed its distribution, extent and biomass to promote its management and use. Landsat 3, 5, 7, 8 OLI satellite images were used to calculate the totora reed coverage with the Normalized Difference Vegetation Index (NDVI) between 1979 and 2020, and biomass yield was evaluated at 50 sampling points using the cutting frame method. The results of the multi-temporal analysis indicate fluctuations in the distribution and extent of the totora reed beds in three areas according to the Ramsar Site: Uru Uru Lake, northern Poopó Lake, and the interconnection zone between the two. In 2020, totora reed beds were concentrated in the interconnection zone and Uru Uru Lake, with minimal presence in Poopó Lake. Although the biomass yield per hectare is lower than other Andean wetlands, its total biomass holds significant potential for multiple uses, the most relevant being its use as livestock forage, as it could help mitigate the forage shortage in the region.