Introduction: The FAO-56 Penman-Monteith (PM) is one of the most solid and commonly used methods for estimating reference evapotranspiration (ETo); however, it requires meteorological data that are not always available, so an alternative is the use of reanalysis data. Objective: To estimate the error that the NASA-POWER (NP) system data can generate in the ETo of the Comarca Lagunera, Mexico. Methodology: Daily and decadal average ETo were estimated in five different ways. In each case, a different method was used to estimate ETo (FAO-56 PM or Hargreaves and Samani [HS]) and a different meteorological data source (measured, NP data or combination of both). Results: NP data can be used to provide temperature, solar radiation and relative humidity variables, but not wind speed. The NP data overestimate the measured ETo, an RMSE of 1.15 and 0.89 mm∙d-1 was found for daily and decadal periods, respectively. Limitations of the study: A grid error analysis could not be carried out because the number of stations is limited. Originality: The use of reanalysis data to estimate ETo has not been analyzed locally. Conclusion: When measured data are not available, NP data and the HS equation can be used. When using the FAO-56 PM method and NP data, the in situ wind speed must be available.

The vegetation indices (VIs) estimated from remotely sensed data are simple and based on effective algorithms for quantitative and qualitative evaluations of the dynamics of biophysical crop variables such as vegetation cover, leaf area, vigor and development, and many others. Over the last decade, many VIs have been proposed and validated to enhance the vegetation signal by reducing the noise from effects produced either by the soil or by vegetation such as brightness, shadows, color, etc. VIs are commonly calculated from satellite images such as ones from Landsat and Sentinel-2 because of their medium resolution and free availability. However, despite the VIs being fairly simple algorithms, it can take hours to calculate them for an established agricultural area, mainly due to the pre-processing of the images (including atmospheric corrections, the detection of clouds and shadows), size and download time of the images, and the capacity of the computer equipment used. Time increases as the number of images increases. In this sense, the free to use Google Earth Engine (GEE) platform was here used to develop an application called VICAL to calculate 23 VIs map (VIs commonly used in agricultural applications) and time series of any agricultural area in the world with images (cloud-free) from Landsat and Sentinel-2 data. It was found that VICAL can calculate these 23 VIs accurately, and shows the potential of the GEE cloud-based tools using multispectral dataset to assess many spectral VIs. This tool is very beneficial for researchers with poor access to satellite data or in institutions with a lack of computational infrastructure to handle the large volumes of satellite datasets, since it is not necessary for the user writing a single line of code. The VICAL is open-access image analysis platform that can be modified to carry out more complex analysis or adapt it to a specific VI application.

Habanero pepper production was assessed with drip irrigation and plastic mulch, based on two transplanting dates. The objectives of the study were: (i) to evaluate the effect of two transplanting dates and the use of plastic mulch on water productivity and habanero pepper fruit yield under drip irrigation conditions; and (ii) to determine the profitability and economic viability of the product in the regional market. The work was conducted in the municipality of Huimanguillo, state of Tabasco, Mexico, in loam soils classified as Eutric Fluvisol. The Jaguar variety of habanero pepper, developed by INIFAP and possessing better genetic and productive characteristics, was used. Two transplanting dates were studied, (i) 30 January 2013 and (ii) 15 February 2013, with and without plastic mulch. The conclusions were: (i) application of irrigation depths based on crop evapotranspiration (ETc) and plastic mulch transplanted on 30 January increased the fruit yield of the crop and improved the benefit-cost ratio of the production system; and (ii) water use efficiency based on the 30 January transplanting date was 8.68 kg m⁻³ of water applied with plastic mulch, 6.51 kg m⁻³ without plastic mulch, and 3.65 kg m⁻³ for the 15 February transplanting date with plastic mulch.

L a producción de orégano en vivero es una opción para la obtención de plantas de buena calidad para trasplante. El propósito del presente estudio fue evaluar el efecto de cinco sustratos y cinco contenedores en el crecimiento y calidad de la planta de orégano. Los sustratos fueron: mezcla comercial BM2 (turba, perlita y vermiculita, 80:10:10), BM2 + arena de río (1:1), BM2 + arena de río (1.5:1), BM2 + perlita + vermiculita (1:1:1) y mezcla de composta + arena de río (1.5:1). Los contenedores incluyeron charolas de poliestireno expandido (PE) de 200, 128 y 76 cavidades, vaso de PE de 250 cm3 y bolsa de plástico negro de 712 cm3 (calibre 150 μm). Se usó un diseño experimental de bloques al azar con arreglo factorial, con cuatro repeticiones por tratamiento. Los sustratos y el tipo de contenedor afectaron el crecimiento y calidad de la planta. Se observó mayor crecimiento de la planta y mayor área foliar en la combinación bolsa y sustrato BM2. Este mismo sustrato y el contenedor bolsa promovieron el índice de calidad de Dickson más alto. La relación peso seco del vástago y peso seco de la raíz fue mayor en los contenedores de mayor volumen.

La optimización del manejo del agua de riego en las áreas agrícolas es indispensable para una agricultura sustentable y eficiente, esto adquiere mayor relevancia en regiones áridas y semiáridas. Es necesario conocer el requerimiento y la oportunidad de aplicar el agua a los cultivos de importancia y conocer los más eficientes en la conversión del agua a grano y materia seca. El presente estudio tuvo como objetivo determinar modelos de producción bajo diferentes regímenes de riego en dos etapas de desarrollo del maíz (Zea mays L.). Se ensayaron siete tratamientos que corresponden a la matriz de tratamientos San Cristóbal con dos factores de variación: (40 - 40), (40 - 80), (60 - 60), (60 - 100), (80 - 40), (80 - 80) y (100 - 60) de la humedad aprovechable del suelo consumida por el maíz en el periodo de emergencia a inicio de floración y de ésta a madurez fisiológica, respectivamente. Los tratamientos se distribuyeron bajo un diseño experimental de bloques completos al azar con cuatro repeticiones. Las variables evaluadas fueron rendimiento de grano (t ha-1), eficiencia de uso de agua (kg m-3) y el régimen de humedad en el suelo. Los resultados mostraron que el maíz alcanza el mayor rendimiento de grano y eficiencia de uso del agua del orden de 10.3 t ha-1 y de 1.63 kg m-3, al desarrollarse con aproximadamente el 60 y 59 % de la humedad aprovechable consumida del suelo en las etapas vegetativa y reproductiva, respectivamente; además, se encontró que el consumo óptimo fue de 40.3 y 23.2 cm de lámina de agua en las dos etapas estudiadas.