The effects of climate change projected for 2050 to 2079 relative to the 1968–2014 reference period were evaluated using 39 CMIP5 models under the RCP8.5 emissions scenario in the Guayas River basin. The monthly normalized precipitation index (SPI) was used in this study to assess the impact of climate change for wet events and droughts from a meteorological perspective. The GR2M model was used to project changes in the streamflow of the Daule River. The climate projection was based on the four rigorously selected models to represent the climate of the study area. On average, an increase in temperature (~2 °C) and precipitation (~6%) is expected. A 7% increase in precipitation would result in a 10% increase in streamflow for flood periods, while an 8% decrease in precipitation could result in approximately a 60% reduction in flow for dry periods. The analysis of droughts shows that they will be more frequent and prolonged in the highlands (Andes) and the middle part of the basin. In the future, wet periods will be less frequent but of greater duration and intensity on the Ecuadorian coast. These results point to future problems such as water deficit in the dry season but also increased streamflow for floods during the wet season. This information should be taken into account in designing strategies for adaptation to climate change.

En este estudio se generó el modelo de regresión múltiple para predecir el rendimiento del cultivo de papa (Solanum tuberosum) en Ecuador, utilizando el registro anual de la producción de las Encuestas de Superficie y Producción Agropecuaria para el periodo 2002-2019. Las variables independientes consideradas, fueron la superficie sembrada con semillas comunes, mejoradas y certificadas, prácticas de cultivo, volumen de venta y superficie sembrada, perdida y cosechada.  Los resultados evidencian que el rendimiento se ve influenciado por cinco variables independientes como son:  semilla mejorada, riego, aplicación de fertilizantes, helada y otros. El modelo de regresión múltiple presenta un buen ajuste con un coeficiente de determinación de 0,86, un RMSE de 1,014 ton/ha y un MAE significativamente bajo (0,024 ton/ha), el cual ayuda a verificar el arreglo del modelo. Por otra parte, la evaluación del incremento del rendimiento (p≤0.01) reveló tasas de crecimiento promedio anual entre 0,87 y 2,07% para las provincias de Tungurahua (0,87%), Pichincha (1,26%), Chimborazo (1,54%), Carchi (1,71%), Cotopaxi (1,91%) y Bolívar (2,07%). La predicción del rendimiento del cultivo de papa en Ecuador se centra principalmente en la influencia de los factores climáticos y tecnologías de cultivo. Es importante que las acciones políticas permitan que los agricultores tengan acceso al crédito y favorezca el uso de tecnologías de manejos del cultivo como el riego, fertilización y controles fitosanitarios.

The objective of the present study was to determine the general combinatorial aptitude (GCA), specific combinatorial aptitude (SCA) and heterosis in inbred lines of yellow maize and its crosses for, the yield of grain, height of plant and ear and days to male and female flowering. Six inbred lines from CIMMYT, their direct crosses and four controls were evaluated at UNALM during 2016-2018, under a 5 x 5 lattice design with four repetitions. The effects of GCA and SCA were calculated using method II, model I of Griffing. Heterosis was measured based on the mean and best parent. Heterosis was measured based on the mean and best parent. The combined analysis of years showed significance (p ≤ 0.01) in: genotypes by years for days to male and female flowering; GCA for years for days to male flowering and SCA for years for days to female flowering. The effects of ACG for grain yield were significant in lines CML 229 and CML 428, for plant height, precocity, ear and precocity CML 487 line highlighted. The effect of ACE was superior in the cross CML 453 x CML 486 for the grain yield character. Heterosis was higher for the grain yield in the CML 229 x CML 453 and CML 453 x CML 487 crosses. The GCA / SCA relationship evidenced effects of additive genes on plant height, days to male and female flowering, therefore, for grain yield and ear height, non-additive effects governed.

The assessment of ecological flow is a great challenge, which has important implications in the protection of aquatic ecosystems and socio-economic development of an area. The Tennant-Montana method provides the ability to determine ecological flows considering the relationship between aquatic habitat conditions and the average annual flow of a channel. This research presents an estimat∫e of the ecological flow at 10, 30 and 60% of the average flow and trends of the Cebadas River located in the central Andes of Ecuador through a hydrological approach during the period 1966 to 2015. The results allowed to determine an average annual flow rate of 20,768 m3/s and identify a period of avenues (May-September) and a period of dry (October-April). Long-term trend analysis using linear regression and Spearman Rho's test determined that the flow rate has remain Zvirtually unchanged for 50 years and for decade periods. The selected ecological flow was 30% of the seasonal average with values of 6.22 m3/s and 8.32 m3/s for the dry and avenue period respectively. The hydrological variability of the Cebadas River was considered because it is a restrictive factor for the development of the different aquatic species. Flow rates at 30% flow could ensure adequate development and conservation of the aquatic habitats of the Barley River while ensuring a sufficient supply of water for food security. Keywords: Cebadas River, ecological flow, trends, tennant. Resumen La evaluación del caudal ecológico es un gran desafío, que tiene importantes implicaciones en la protección de ecosistemas acuáticos y desarrollo socioeconómico de una zona. El método de Tennant-Montana provee la capacidad de determinar caudales ecológicos considerando la relación entre las condiciones del hábitat acuático y el flujo anual medio de un cauce. Esta investigación presenta una estimación del caudal ecológico al 10, 30 y 60% del caudal medio y tendencias del río Cebadas ubicado en los Andes centrales del Ecuador mediante un enfoque hidrológico durante el periodo de 1966 al 2015. Los resultados permitieron determinar un caudal promedio anual de 20.768 m3/s e identificar un periodo de avenidas (mayo- septiembre) y otro de estiaje (octubre-abril). El análisis de tendencias a largo plazo mediante la regresión lineal y el test de Spearman Rho determinaron que el caudal se ha mantenido prácticamente sin cambios durante 50 años y para los períodos decadales. El caudal ecológico seleccionado fue al 30% de la media estacional con valores de 6.22 m3/s y 8.32 m3/s para el periodo de estiaje y avenida respectivamente. Se consideró la variabilidad hidrológica del río Cebadas porque constituye un factor restrictivo para el desarrollo de las diferentes especies acuáticas. Los caudales al 30% de flujo podrían asegurar un desarrollo y conservación adecuada de los hábitats acuáticos del río Cebada y al mismo tiempo garantiza un suministro suficiente de agua para la seguridad alimentaria. Palabras claves: río Cebadas, régimen fluvial, tendencias, tennant.