The white ball (Guazuma crinita Mart, Meliaceae) as one of the most important species in the Ucayali region due to its rapid growth and increasing market value, makes it a competitive species when choosing species for a program of production of goods and sustainable services, therefore determining the amount of biomass plays a key role for this purpose; In this purpose, the 38 trees of G. crinita at 31 months of age, with an average diameter at the height of the base of 13.33 cm, with a maximum and minimum value of 17.4 and 10.2 cm, respectively, with a standard deviation of 1.80 cm and a variability coefficient of 13%, for an average total biomass of 28.76 Kg, with a standard deviation of 10.07 and a variability coefficient of 35%; It was determined that there is a high relationship between the independent variable diameter at the height of the base (dab) and the total aerial biomass of the trees in the Aguaytia river basin according to the biomass model ~ a*dab^b, which resulted which is predictable with the following formula Bmadab = 0.04253*dab2.5027 with R2 = 0.9397. La bolaina blanca (Guazuma crinita Mart, Meliaceae) es una de las especies más importantes de la región Ucayali por su rápido crecimiento y creciente valor en el mercado, convirtiéndola en una especie competitiva al momento de elegir especies para un programa de producción de bienes y servicios sostenible, por ello la determinación de la cantidad de biomasa cumple un papel clave para este fin; en este contexto, fueron evaluados 38 árboles de G. crinita de 31 meses de edad, con diámetro promedio a la atura de la base de 13,33 cm, con un valor máximo y mínimo de 17,4 y 10,2 cm, respectivamente, con desviación estándar de 1,80 cm y un coeficiente de variabilidad de 13%, para una biomasa total promedio de 28,76 Kg, con una desviación estándar de 10,07 y un coeficiente de variabilidad del 35%; se determinó que en la cuenca del río Aguaytia existe una alta relación entre la variable independiente diámetro a la altura de la base (dab) y la biomasa total aérea de los árboles de acuerdo al modelo biomasa ~ a*dab^b, lo que resultó que es previsible con la siguiente fórmula Bmadab=0,04253*dab2,5027 con R2= 0,9397.

Efficient nitrogen (N) management is crucial for maximizing the growth of young blueberry plants (Vaccinium corymbosum). This study evaluates the effects of the N fertilization form (ammonium, NH₄⁺; nitrate, or NO₃⁻) and application timing on the blueberries’ establishment, N and Ca absorption, and N distribution. The experiment was conducted in the southern hemisphere, in Chile, from October 2023 to January 2024. Six-month-old blueberry cv. Blue Ribbon plants were cultivated in pots. NH₄⁺ and NO₃⁻ were used as full or split-dose applications using the ¹⁵N isotopic dilution technique. Plant leaves, stems, root growth, and biomass, as well as their N and Ca contents, were measured. Our results showed that 90 days after nitrogen application, blueberry plants obtained the lowest biomass in their leaves, stems, and roots when NO₃⁻ was applied in T1 or T1T2. The same pattern was observed for N and Ca contents, hence for N recovery. During the first period (T1) of application, heavy rain (100 mm) was registered over the course of a few days and caused leaching. Therefore, applying nitrate to young blueberry plants cultivated in areas with spring rainfall and low temperatures would not be recommended because the leaching losses and lower growth conditions, such as low temperatures and high precipitation, led to reduced transpiration, resulting in lower calcium and nitrogen contents. These confirm that N fertilization management (form and timing) can ensure a better establishment for young blueberry plants, optimizing their growth and sustainable production by minimizing nitrogen losses.

Los aguajales, son ecosistemas con presencia predominante de aguaje Mauritia flexuosa, aportan importantes beneficios socioeconómicos y ambientales a los pobladores de la Amazonía peruana. Este estudio tiene como objetivo determinar la extensión de aguajales en la región Ucayali, Perú, mediante el método de clasificación supervisada de imágenes de satélite generadas por el satélite de Observación Terrestre LANDSAT 8 a través del sensor OLI-TIRS, correspondiente a la región Ucayali en el año 2017. La extensión de aguajales se ha determinado también mediante la interpretación visual en la combinación de bandas 5 (Infrarrojo Cercano (NIR), con longitud de onda de 0,85 - 0,88 μm), 6 (Infrarrojo de Onda Corta 1 (SWIR 1), con longitud de onda de 1,57 - 1,65 μm) y 2 (Azul, con longitud de onda de 0,45 - 0,51 μm), para la obtención del mapa de aguajales con escala de interpretación de 1:100 000 y con un área mínima de mapeo de 5,00 ha. con lo que determinamos una extensión de 65 120,04 ha de aguajales en la región Ucayali. La identificación de la ubicación y superficie neta de los bosques de aguajales en la región Ucayali permitirá desarrollar estudios futuros sobre sus beneficios potenciales, el manejo y aprovechamiento de los frutos y los servicios ambientales, así como contar con información para una mejor gobernanza en un contexto de cambio climático.

The objective of this study was to present a methodological tool for the phenotypic evaluation in progeny tests of Guazuma crinita in producer plots of the Aguaytía river basin, Ucayali, Peru, which allows field technicians to standardize the morphological evaluation criteria of trees in forest plantations. Therefore, the phenotypic traits were evaluated for plant height (m), diameter at the height of the base (cm), number of branches, number of rings, stem form, branch orientation, presence and quantity of leaves. The heritability and genetic and phenotypic correlations between traits were also estimated. Therefore, 32 morphological categories were plotted based on the significant correlations (p≤ 0.05) shown between the place of planting, the stem form, the orientation of the branches and the presence of leaves. For the same reason, the progeny showed low morphological patterns, being a low factor of phenotypic variability. It is concluded that the correlations between the biometric and morphological traits evaluated, allowed to validate the phenotypic evaluation procedures of Guazuma crinita progeny tests at 36 months of age.

Arbuscular mycorrhizal fungi (AMF) play an important role in ecological restoration, enhancing the establishment of native tree species and agricultural crops. The present study aimed to determine the diversity and distribution of AMF species in capirona (Calycophyllum spruceanum Benth.) that was planted at different times in areas of the department of Ucayali, Peru. Samples were taken from the rhizospheres of this plant in the localities of Yarinacocha (YC), Curimaná (CM), Irazola (IZ), Alexander von Humboldt (VH) and the AMF species were identified. The YC sampling zone, with one year old plants, recorded the highest number of spores (20 spores per g of dry soil) in relation to the 18 year old plantations at VH, CM, IZ with 4, 4 and 3 spores per g of soil. A total of 45 AMF species were identified, finding the greatest diversity in the VH sampling zone with 21 species, followed by the CM and YC sampling zones with 17 and 16 species, and at IZ having only 13 species. The three families Acaulosporaceae, Diversisporaceae and Glomeraceae together were represented with 11, 14, 12, and 17 AMF species for YC, CM, IZ, VH. The lower species number at YC and IZ corresponded with the higher concentration of phosphorus in the soils. It appears that capirona forms a rapid symbiosis with the native AMF population, and there might be no need to think of a strategy of inoculating seedlings with a commercial AMF inoculum.

El estudio tuvo por objetivo evaluar el efecto de micorrizas arbusculares y abonos orgánicos en el comportamiento vegetativo de Cinchona officinalis en ambientes controlados. La investigación se instaló bajo un diseño completo al azar con arreglo trifactorial (4A: micorrizas x 3B: abonos x 2C: ambientes), contando con 72 unidades experimentales. Las plantas de quina fueron inoculadas en vivero e invernadero con 40 g de micorrizas procedentes de bosques naturales (San Jerónimo, Conila y Leymebamba) y abonadas con 40 g de gallinaza y humus de lombriz. Se encontró que la mortalidad de la quina se dio en el vivero y abonadas con gallinaza, con un 6.3 % en promedio, por su parte, no se reportó mortalidad a nivel de invernadero; respecto a la velocidad de crecimiento, los consorcios micorrízicos SJ y LEY tuvieron mayor efecto, juntamente con la aplicación de humus de lombriz a nivel de invernadero. Se concluye que, resulta factible propagar la quina, inoculando con micorrizas arbusculares autóctonas, potenciando su efectividad en complemento con humus de lombriz, pudiéndose usar como sustrato alternativo y sustituir a la turba de bosque; paralelamente, es indispensable manejar condiciones ambientales (temperatura y humedad relativa), para lograr una alta supervivencia y alta velocidad de crecimiento.