EVALUACIÓN DE SEIS SISTEMAS DE SANGRÍA PARA CUATRO CLONES DE Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg., EN LA ALTILLANURA COLOMBIANA

The rubber yield of four Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. clones was evaluated on the Colombian high plains in the Meta department: ian 873 and rrim 600 (third year of tapping being done) and pb 260 and gt 1 (first year of tapping). Six tapping systems were used, including a combination of different tapping frequencies (d/4 and d/5), Ethephon concentrations (0%, 2.5%, 3.3% and 5%) and a number of applications per year (4 to 8) were also used depending on the clone. The production figures for one commercial year were obtained from assays, using a completely randomblock design (having four repetitions) independently defined for each clone: having on average 4446 g rubber/tree of produce per year for the rrim 600 clone within a system ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 7/y; 2696 g rubber/tree for the pb 260 clone with ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y; 3822 g rubber/tree for the ian 873 clone, ½S, d/4, 6d/7, 10m/12, et 3.3%, Pa 8/y, and 3472 g rubber/ tree for the gt 1 clone, ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y. The highest produce was obtained with a four-day tapping frequency.Este trabajo evaluó el desempeño productivo de cuatro clones de caucho natural (Hevea brasiliensis [Willd. ex Adr. de Juss.] Muell.-Arg.), sometidos a seis diferentes sistemas de sangría, los cuales incluyeron la combinación de dos diferentes frecuencias de sangrado cada cuatro y cinco días (d/4 y d/5) y cuatro concentraciones de Ethefon (0%, 2.5%, 3.0% y 5%) con un número de aplicaciones entre 4 a 8 veces por año. Los ensayos se realizaron en la plantación de la empresa mavalle s.a., ubicada en la altillanura colombiana, bajo un diseño de bloques completos al azar con cuatro repeticiones. Se obtuvieron producciones promedio por año de 4446 g de caucho/árbol para el clon rrim 600 en un sistema ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 7/y; 2696 g de caucho/árbol para el clon pb 260 bajo un sistema ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y; 3822 g de caucho/árbol para el clon ian 873 en un sistema ½ S, d/4, 6d/7, 10m/12, et 3.3%, Pa 8/y, y 3472 g de caucho/árbol para el clon gt 1 bajo una sistema ½ S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y. Se obtuvo la mayor producción en una frecuencia de sangrado cada cuatro días para los clones RRIM 600, gt 1 y pb 260

EVALUACIÓN DE SEIS SISTEMAS DE SANGRÍA PARA CUATRO CLONES DE Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg., EN LA ALTILLANURA COLOMBIANA

The rubber yield of four Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. clones was evaluated on the Colombian high plains in the Meta department: ian 873 and rrim 600 (third year of tapping being done) and pb 260 and gt 1 (first year of tapping). Six tapping systems were used, including a combination of different tapping frequencies (d/4 and d/5), Ethephon concentrations (0%, 2.5%, 3.3% and 5%) and a number of applications per year (4 to 8) were also used depending on the clone. The production figures for one commercial year were obtained from assays, using a completely randomblock design (having four repetitions) independently defined for each clone: having on average 4446 g rubber/tree of produce per year for the rrim 600 clone within a system ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 7/y; 2696 g rubber/tree for the pb 260 clone with ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y; 3822 g rubber/tree for the ian 873 clone, ½S, d/4, 6d/7, 10m/12, et 3.3%, Pa 8/y, and 3472 g rubber/ tree for the gt 1 clone, ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y. The highest produce was obtained with a four-day tapping frequency.Este trabajo evaluó el desempeño productivo de cuatro clones de caucho natural (Hevea brasiliensis [Willd. ex Adr. de Juss.] Muell.-Arg.), sometidos a seis diferentes sistemas de sangría, los cuales incluyeron la combinación de dos diferentes frecuencias de sangrado cada cuatro y cinco días (d/4 y d/5) y cuatro concentraciones de Ethefon (0%, 2.5%, 3.0% y 5%) con un número de aplicaciones entre 4 a 8 veces por año. Los ensayos se realizaron en la plantación de la empresa mavalle s.a., ubicada en la altillanura colombiana, bajo un diseño de bloques completos al azar con cuatro repeticiones. Se obtuvieron producciones promedio por año de 4446 g de caucho/árbol para el clon rrim 600 en un sistema ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 7/y; 2696 g de caucho/árbol para el clon pb 260 bajo un sistema ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y; 3822 g de caucho/árbol para el clon ian 873 en un sistema ½ S, d/4, 6d/7, 10m/12, et 3.3%, Pa 8/y, y 3472 g de caucho/árbol para el clon gt 1 bajo una sistema ½ S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y. Se obtuvo la mayor producción en una frecuencia de sangrado cada cuatro días para los clones RRIM 600, gt 1 y pb 260

Interceptación de la lluvia en un bosque y en plantaciones de café (Coffea arábica L)

The humid forest vegetable formation was modified by men in order to establish their livings and utilize the soils for diverse cultivations as coffee (Coffea arábica L), which was initially cultivated by handling a somber vegetation, and subsequently leaving it to free solar exposition; these transformations generate changes in the radiation, energy, water and nutriment balance components. The experimental work was carried out in a multistrata primary forest as well as in experimental parcels of coffee under free solar exposition conditions and also under guamo (Inga sp) somber. The better adjustment between rain interception by vegetation and the input precipitation to the ecosystem was obtained by means of a logistic type of the Verhuist function in which differences in all the parameters of the equation, especially in the asintota or maximum interception value as well as the maximum interception rate, accountable for the change in the vegetable cover, were observed. The observed interception rate values for different vegetable cover are within the ranges of the corresponding values found in other studies of tropical zones. It was observed a high variability in the amount of rain measured by the rainmeters located under the trees and a statistical correlation between an observation point and its neighbor was not found.La formación vegetal de bosque húmedo fue modificada por el hombre para establecer sus asentamientos y utilizar la tierra con diversos cultivos como el café (Coffea arábica L), inicialmente con un manejo bajo sombrío y posteriormente a libre exposición solar; estas transformaciones generan cambios en los componentes de los balances de radiación, de energía, de agua y de nutrimento, entre otros. El trabajo experimental se realizó en un bosque primario multiestrato y en parcelas experimentales de café con condiciones de libre exposición solar y con sombrío de guamo (Inga sp). El mejor ajuste entre la interceptación de la lluvia por la vegetación y la precipitación que ingresa al ecosistema se obtuvo con la función de Verhuist de tipo logístico observándose diferencias en todos los parámetros de la ecuación, especialmente en la asíntota o valor máximo y en la tasa máxima de interceptación. Los valores de interceptación encontrados para las diferentes condiciones de cubrimiento vegetativo están dentro de los rangos hallados en otros estudios de las zonas tropicales. La variabilidad encontrada en las cantidades de lluvia observada en los pluviómetros debajo de los árboles es alta y no existe una correlación estadística entre dos puntos de observación próximos. Este estudio presenta las modificaciones en los componentes del balance hidrológico que ocurren por el cambio de cobertura vegetal y demuestra que no se puede considerar un porcentaje promedio fijo en la interceptación de la lluvia por la vegetación

Regionalización de la temperatura del aire en Colombia

The study exhibits a regionalization of the distribution of the air temperature in Colombia that considers the concepts of macroclimate (Inter-tropical convergence zone, ZCIT), mesoclimate (topoclima) at the basin level, and statistical aggregate methods as the Ward method. Integration of the several aggregate criteria allowed to define thirteen regions for the country for which equations for estimating the mean air temperature as a function of altitude were obtained. The results allow to identify four big regions in Colombia: Andean, East (Amazonia and Orinoquia), Atlantic and Pacific. For these four zones, expressions for calculating the mean, the maximum, and the average minimum temperatures as a function of the altitude, are presented.El estudio plantea una regionalización de la distribución de la temperatura del aire en Colombia utilizando conceptos de macroclima (Zona de Convergencia Intertropical, ZCIT), de mesoclima (topoclima) a nivel de cuenca hidrográfica y métodos estadísticos de agrupación por el método de Ward. La integración de los diferentes criterios de agrupación permitió definir para el país trece regiones para las cuales se obtuvieron las ecuaciones para estimar la temperatura media del aire con la altitud. Los resultados obtenidos permiten agrupar a Colombia en cuatro grandes regiones: la Andina, la oriental (Amazonia y Orinoquía), la Atlántica y la Pacífica; para estas cuatro zonas se dan expresiones de cálculo para la temperatura media, la máxima y la mínima media en función de la altitud

Susceptibilidad de Aedes aegypti a DDT, deltametrina y lambdacialotrina en Colombia Susceptibility of Aedes aegypti to DDT, deltamethrin, and lambda-cyhalothrin in Colombia

OBJETIVOS: Evaluar el estado de susceptibilidad a insecticidas piretroides deltametrina y lambdacialotrina y al organoclorado DDT, e identificar los mecanismos bioquímicos asociados con resistencia en 13 poblaciones naturales de Aedes aegypti recolectadas en localidades de Colombia donde el dengue es un grave problema de salud pública. MÉTODOS: Se recolectaron y criaron en condiciones controladas formas inmaduras de diferentes criaderos naturales del vector para cada localidad. Con la generación F2 se realizaron bioensayos utilizando las metodologías OMS 1981 (papeles impregnados) y CDC 1998 (botellas impregnadas). En las poblaciones con mortalidades compatibles con disminución de la susceptibilidad, se midieron los niveles de esterasas no específicas (ENE), oxidasas de función mixta (OFM) y acetilcolinesterasa modificada (ACEM) mediante pruebas colorimétricas. RESULTADOS: Todas las poblaciones del mosquito evaluadas evidenciaron resistencia al organoclorado DDT. En cuanto a los piretroides, se encontró resistencia generalizada a lambdacialotrina pero no a deltametrina. Los mecanismos bioquímicos de resistencia evaluados permitieron encontrar 7 de 11 poblaciones con ENE elevadas y una población con OFM incrementadas. CONCLUSIONES: Se descarta la resistencia cruzada de tipo fisiológico entre el DDT y lambdacialotrina en las poblaciones de A. aegypti evaluadas. La resistencia fisiológica a lambdacialotrina parece asociarse con el incremento de las ENE. El comportamiento diferencial en los niveles de susceptibilidad y los valores enzimáticos entre poblaciones se asociaron con la variabilidad genética y presión de selección química a nivel local.OBJECTIVES: To assess the susceptibility status of 13 natural populations of Aedes aegypti (collected from sites in Colombia where dengue is a serious public health problem) to the pyrethroids, deltamethrin and lambda-cyhalothrin, and to the organochlorine, DDT, and to identify any biochemical mechanisms associated with resistance. METHODS: Immature forms of the vector were collected from natural breeding spots at each site and then raised under controlled conditions. Using the F2 generation, bioassays were performed using the World Health Organization's 1981 methodology (impregnated paper) and United States Centers for Disease Control and Prevention's 1998 methodology (impregnated bottles). In populations where mortality rates were consistent with decreased susceptibility, levels of nonspecific esterases (NSE), mixed-function oxidases (MFO), and acetylcholinesterase (AChE) were measured using colorimetric tests. RESULTS: All of the mosquito populations that were tested showed resistance to the organochlorine DDT. In the case of the pyrethroids, widespread resistance to lambda-cyhalothrin was found, but not to deltamethrin. Assessing the biochemical resistance mechanisms showed that 7 of the 11 populations had elevated NSE, and one population, increased MFO. CONCLUSIONS: Physiological cross-resistance between DDT and lambda-cyhalothrin in the A. aegypti populations tested was dismissed. Physiological resistance to lambda-cyhalothrin appears to be associated with increased NSE. The differences in susceptibility levels and enzyme values among the populations were associated with genetic variations and chemicals in use locally

Photosynthetic Response of Blueberries Grown in Containers

Recently, there has been increased interest in container blueberry production as a viable alternative to open-field blueberry planting. Container production of blueberries offers numerous advantages, among these, a lack of limitation by suboptimal soil conditions in the open field and the ability to control substrate pH, drainage, and organic matter. The photosynthetic response for three container-grown Southern highbush blueberry (interspecific Vaccinium hybrids) cultivars including ‘Jewel’, ‘Meadowlark’, and ‘Victoria’ and a rabbiteye blueberry (Vaccinium virgatum) ‘Baldwin’, were measured during the spring and summer of 2022. It was hypothesized that the three cultivars evaluated would have different photosynthetic responses. The objective of this study was to determine the photosynthetic activity of different blueberry cultivars during the first year of crop establishment. A series of measurements were conducted every 2 h throughout the day and for different dates using a gas exchange data analyzer on newly matured fully expanded leaves located in the top middle section of the canopy for each cultivar. The response curves showed that net photosynthesis (A) became saturated at moderate light, with saturation occurring at a photosynthetic photon flux density (PPFD) of 1932 µmol m−2 s−1. At this point, the rate of CO2 assimilation was approximately 16.84 µmol CO2 m−2 s−1. No differences in (A) were found among cultivars. Overall, the attained values of photosynthesis provide a strong conceptual basis for understanding the cultivar variation response when grown in containers; therefore, the containerized system may serve as a production system for early fruiting blueberries in Alabama, USA

Modeling the Budbreak in Peaches: A Basic Approach Using Chill and Heat Accumulation

Phenological shifts in peaches have been observed over the last few years due to the fluctuation of the seasonal climate conditions experienced during dormancy, affecting orchard management practices and influencing production and harvest dates. This study aimed to model the vegetative and floral budbreak of selected peach cultivars. Three peach cultivars, including “Rubyprince”, “Harvester”, and “Red Globe”, were considered in this study based on the representation of the early, early-mid, and mid-seasons. The prediction of the budbreak in peaches was assessed using different models that integrate the combination of chill and heat requirements. Models used include the Weinberger model, the modified Weinberger model, Utah, the dynamic model, and the growing degree model. The accumulation of chill varies according to the season evaluated. A model that considers both chill and heat accumulation is presented for each cultivar. Budbreak as an indicator of dormancy completion was established for each cultivar. The outcome of this study is to determine the amount of chilling accumulation and thermal time required to mark the beginning of the budbreak in selected cultivars with a model that predicts the duration of the dormancy. These results are valuable information that can be used for crop management practices and support the mitigation of cold damage during this critical period of crop development

Predicting Floral Bud Progression for Three Peach Cultivars

The prediction of floral bud progression in commercial peach cultivars promotes knowledge about the adaptability of cultivars to the climatic conditions in a specific location under a climatic variability context. Phenology is relevant to improving the scheduling of cultural practices in peach orchards. This research aimed to predict the floral bud progression of three peach cultivars: ‘Harvester’, ‘Red Globe’, and ‘Rubyprince’. Floral bud progression was assessed using one-year-old shoots collected from an orchard located at the Chilton Research and Extension Center, Alabama. Samples were evaluated under laboratory and growth chamber conditions. We recorded the flower developmental stages daily to identify the transition among stages. Daily temperature records were used to estimate the heat requirement in terms of Growing Degree Days (GDD). After dormancy release, samples needed between 23 to 39 and 37 to 42 days to reach the petal fall stage for season 1 and season 2, respectively. In terms of heat requirements, cultivars needed between 425.5 to 721.5 and 684.5 to 777 GDD to end flowering. A logistic curve was adjusted to describe the growth of the different floral stages over time. The results are key to supporting peach growers in crop management practices such as orchard establishment, irrigation, fertilization, freeze and frost protection, and pollination under climate variability scenarios

Caracterización y obtención de cepas mejoradas de hongos entomopatógenos.

IP 2251-12-330-95Incluye también Etapa 3.aislamientos de Beauveria bassiana de una coleccion de hongosentomopatogenos de Cenicafe / Beatriz Elena;Valdes Duque, Patricia Eugenia Velez Arango. -- En: Revista colombiana deentomologia. -- vol. 24, no. 1-2;(ene.-jun. 1998); p.61-66. -- ISSN 01200488 -- Analisis delavariabilidadgenetica del hongo entomopatogeno;Beauveria bassiana con marcadores RAPD / Ana Milena ValderramaF., Marco Aurelio Cristancho A., Bernardo;Chaves C. -- En: Revista colombiana de entomologia. -- vol. 26,no. 1-2 (ene.-jun. 2001); p. 25-29. -- ISSN;01200488 -- Estandarizacion de una metodologia para obtener cultivos monoesporicos del hongo Beauveria;bassiana / Maria Nancy Estrada V., Patricia E. Velez A., JuanCarlos LopezN. -- En: Cenicafe : revista del;Centro Nacional de Investigaciones de Cafe. -- vol. 48, no. 1(ene.-mar. 1997); p. 59-65. -- ISSN 01200488 --;detection of Beauvericin from the entomopathogenic fungus: Beauveria bassiana / J.W.V. Arboleda, F.B. Deldago;and A.J. Valencia. -- En: International Colloquium on Invertebrate Pathology and Microbial Control (ICIPMC),;Annual Meeting of the SIP, International Conference on BacillusThuringiensis (ICBt). (8, 25, 6 : 2002 Aug.;18-23) -- ARTICULO(S) EN REVISTA: Actividad enzimatica dehongosy su patogenicidad sobre Hypothenemus hampei;/ Fernando Delgado Blandon, Yamel Lopez Forero, Elsa MariaGiraldo Cardozo. -- En: Revista manejo integrado de;plagas. -- No. 60 (2001); p. 43-49 -- Actividad lipoliticay proteoliticade Beauveria bassiana y Metarhizium;anisopliae y su relacion con la patogenicidad sobre Hypothenemushampei (Coleoptera: Scolytidae) / Elsa Maria;Giraldo Cardozo ... [et al.]. -- En: Revista colombiana deentomologia. --vol. 27, no. 1-2 (ene.-jun. 2001);p. 61-65. -- ISSN 01200488 -- Caracterizacion de aislamientosdeBeauveriabassiana y Metarhizium anisopliae;de la coleccion de Cenicafe / Patricia E. Velez A... [et al.].-'- en: Revista colombiana de entomologia. --;vol. 25, no. 3-4 (jul.-dic. 1999); p. 191-207. -- ISSN 012488'-- Caracterizacion bioquimica cualitativa de;Colombiana de Entomologia, Socolen (28 : 2001 ago. 8-10 :Pereira, Colombia) -- [s.l. : s.n.], 2001 -- p. ; 28;cm. -- Avances en el estudio de la toxina beauvericina producidapor el hongo Beauveria bassiana patogenico a;Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae) / JorgeWilliam Arboleda V., Fernando Delgado B. -- En:;Congreso de la Sociedad Colombiana de Entomologia, Socolen(28:2001 ago.8-10 : Pereira, Colombia) -- [s.l.;: s.n.], 2001 -- p. ; 28 cm. -- Biologia de Phymastichus coffeaLasalle (Hymenoptera: Eulophidae);endoparasitoide de la broca del cafe, en tres altitudes diferentes de la zonacafetera colombiana / Fernando;Cantor R. ... [et al.]. -- En: Congreso de la Sociedad Colombiana de Entomologia, Socolen (28 : 2001 ago. 8-10;: Pereira, Colombia) -- [s.l. : s.n.], 2001 -- p. ; 28 cm.--Produccion de anticuerpos policlonales para;deteccion de Beauvericina del hongo entomopatogeno Beauverianabassiana /Jorge W. Arboleda V., Fernando;Delgado B., Arnubio Valencia J. -- En: Congreso de la SociedadColombianade Entomologia, Socolen. (29 : 2002;jul. 18-19 : Monteria, Colombia) -- [s.l. : s.n.], 2002 --p.;28 cm. --Polyclonal antibodies productions to;Caracterizacion de cultivos monoesporicos del hongo Beauveriabassiana / Maria Nancy Estrada Valencia,;Patricia Eugenia Velez Arango, Esther Cecilia Montoya Restrepo.'-- en: Cenicafe : revista del Centro Nacional;de Investigaciones de Cafe. -- vol. 48, no. 4 (oct.-dic. 1997);p. 217-224. -- ISSN 01200275 -- Esporulacion,;germinacion y patogenicidad de aislamientos monoesporicosde Beauveria bassiana / Maria Nancy Estrada Velez;... [et al.]. -- Cenicafe : revista del Centro Nacional deInvestigacionesde Cafe. -- vol. 50, no. 1;(ene.-mar. 1999); p. 5-23. -- ISSN 01200275 -- Caracterizacionenzimaticay patogenicidad de aislamientos de;Beauveria bassiana sobre la broca del cafe / Beatriz ElenaValdes D., Patricia Eugenia Velez Arango, Esther;Cecilia Montoya Restrepo. -- Cenicafe : revista del CentroNacional de Investigaciones de Cafe. -- vol. 50,;no. 2 (abr.-jun. 1999); p. 106-118. -- ISSN 01200275 -- Evaluacion en campo de un aislamiento de Beauveria;bassiana seleccionado por resistencia a la luz ultravioleta /Sandra Patricia Tobar H., Patricia Eugenia Velez;Arango, Esther Cecilia Montoya Restrepo. -- En: Revista del Centro Internacional de Investigacion de Cafe. --;01200275.;PONENCIA(S) EN CONGRESO: Transformacion de Beauveria bassianacon la proteina verde fluorescente y proteasas;de Metarhizium anisopliae / Carmenza E. Gongora B. -- En:Congreso de la Sociedad Colombiana de Entomologia,;Socolen (28 : 2001 ago. 8-10 : Pereira, Colombia) -- [s.l.: s.n.], 2001 -- p. ; 28 cm. -- Taller con;caficultores experimentadores para evaluar Beauveria bassianaenel control de Hypothenemus hampei (Ferrari);(Coleoptera: Scolytidae) / Francisco Javier Posada Florez...[et al.]. --En: Congreso de la Socieda