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Productive specialization in Mexico has been significantly shaped by comparative advantages in trade with the United States within the framework of the USMCA (United States-Mexico-Canada Agreement). This paper explores how this specialization has transformed the productive structure, including its technical and organizational foundations, and the evolving standards for labor demand. We argue that Mexico's current specialization in vegetable production is driven by competitiveness that relies on increasingly scarce productive resources, which raises concerns about the sustainability of this productive model. Our analysis reveals that while there has been a notable increase in specialization towards specific agricultural crops, the revealed comparative advantages and the complexity index indicate a focus on low-value activities. This trend contributes to the disarticulation of the regional economy and presents challenges for achieving productive scaling through robust economic development. Furthermore, the rising water stress in key agricultural regions highlights the contradictions inherent in the productive specialization models proposed by classical, neoclassical, and structuralist economic theories. [ABSTRACT FROM AUTHOR]

Contextualization: Water is indispensable for plant development, and its response to water deficit varies according to the species and their growth stages. Knowledge gap: The magnitude of the effect of soil water deficit on the growth of young coffee (Coffea arabica L.) plants evaluated over time is unknown. Purpose: Research was carried out to identify the effect of soil water deficit and, therefore, the sensitivity to drought in young coffee plants. Methodology: The deficit irrigation method was used. Coffee plants of the Cenicafé 1 variety were planted at three months old in cylindrical pots and conditioned for four months in mesh houses at Cenicafé - Planalto. After conditioning, the effect on plants’ growth and dry matter subjected to five ranges of soil matric potential was evaluated over 140 days. Potentials ranged from -20±10 kPa (control) to -1600±100 kPa. Results and conclusions: The results showed that soil water deficit affects the growth of young coffee (C. arabica) plants, which could define C. arabica at this stage as drought sensitive. Plants subjected to the least stress and the extreme drought showed a 30% and 57% decrease in dry matter, respectively. For growth variables, the effect of water deficit was evident in the evaluations at 77, 113, and 140 days of treatment application. In all cases, the results showed differences between the extreme drought and the control of up to 30cm in height and equatorial diameter, 0.9 m2 of leaf area, 132 leaves, 3 branches, and 66 nodes. The mathematical models that explained the effect of drought on dry mass were of the logarithmic type. It was identified that for weather and soil conditions similar to those in the study, young coffee plants begin to deteriorate after 40 days of drought. With a soil matric potential close to -40 kPa, for a time of 120 days, coffee plants can lose 10% of dry mass, and when the potential exceeds -90 kPa there can be further losses in dry matter and decreases in the number of branches between the 77 and 113 days. [ABSTRACT FROM AUTHOR]

In view of the growing scarcity of water for agriculture, the increase in food demand and future drought scenarios posed by climate change, it is essential to design new technologies that contribute to lower water consumption. In this research, high-resolution images have been used to estimate evapotranspiration in rice fields by applying the METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) energy balance model. For this purpose, 5900 m² of crop were monitored under continuous flood irrigation (CF) and 2600 m² under alternate wetting and drying irrigation (AWD), in addition to some plots with lateral filtration. Ten flights were conducted between tillering and flowering phases, five flights with a Matrice 210 UAV equipped with a Parrot Sequoia multispectral camera, and five flights with a Matrice 300 RTK equipped with a H20T thermal camera. Field data were collected from vegetation indices (NDVI and LAI), and readings from a radiometer, to adjust information from multispectral and thermal images, respectively, and to obtain the components of the surface energy balance. Mean values for crop evapotranspiration (ETc) of 6.34 ± 1.49 and 5.84 ± 0.41 mm d-1 were obtained for IC irrigation and AWD irrigation, respectively, obtaining a water saving of 42% with a yield reduction of 14%, providing a guide for proper irrigation management, however, it is suggested to use the model to optimize yield by obtaining critical thresholds for optimal application of AWD in the face of water resource scarcity. [ABSTRACT FROM AUTHOR]

Countries like Mexico make significant efforts to reforest, but the results are not good due to the low survival rates caused by drought and water stress. Therefore, the effect of applying hydrated phenolic foam at plantation moment, on the survival and growth in Pinus leiophylla and Pinus teocote was assessed. Two trials were established, one for each species, with five treatments of different volumes of hydrated phenolic foam. The variables measured were survival, growth in height and diameter. The analyzes showed that hydrated phenolic foam significantly increases survival and height growth in Pinus leiophylla, but not in Pinus teocote. No effect was shown on diameter for any of the species. The application of hydrated phenolic foam at planting moment increase the survival of pine. [ABSTRACT FROM AUTHOR]

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Copyright of Quaderns de Recerca en Urbanisme is the property of Grup d'Investigacio en Urbanisme and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As irrigation water decreases, crop transpiration also decreases, resulting in an increase in leaf temperature and an increase of the crop water stress index (CWSI). Therefore, in the study, the response of Capsicum to different irrigation regimes was evaluated with periodic measurements of leaf temperature, stomatal conductance and estimation of the CWSI. The treatments consisted of a complete drip irrigation (RO) and deficit irrigation (RD-78 and RD-58) that received 78% and 58% of the complete irrigation, applying a total volume of water of 3363, 2618 and 1956 m³ ha-1 for RO, RD-78 and RD-58, respectively; and obtaining maximum yields of 30.2, 13.9 and 12.9 t ha-1 with CWSI of 0.50, 0.62 and 0.54 in C. bacatum, C. annumm and C. chinense, respectively. The highest stomatal conductance values ranged from 724 to 887 mmol s-1 m-2, with CWSI from 0.1 to 0.3. The CWSI value of 0.3 (soil moisture from 25 to 33%) results in a good indicator of the time of irrigation, and it might be a criterion to be incorporated to save water and improve the management of Capsicum irrigation programs. [ABSTRACT FROM AUTHOR]

Introduction: Beans are most widely cultivated legume in the world. In Mexico it is second most important crop after corn and of basic importance for human consumption. Selection of varieties tolerant to water deficit constitutes a strategy to increase the genetic stability of crops and reduce losses in yield in order to define specific agroecotypes for bean crop. Method: Objective of work was to evaluate four varieties of black beans with horizontal resistance to hydric stress under rainstorm conditions in acid soils in two localities of Northeastern Sierra of state of Puebla. A randomized complete block design with 10 treatments and 5 repetitions was used; variables evaluated were a) survival during phenological cycle of crop and b) potential yield with addition of agricultural lime to soil, during 2019 agricultural cycle. Results: The emergence of the crop was recorded 10 days after sowing (dds), flowering (60 dds) and physiological maturity at 124 dds, in San Juan Acateno of the municipality of Teziutlán and in Pezmatlán of the municipality of Tlatlauquitepec. The Huejonapan and Acatlán bean varieties without lime application, obtained the highest potential yield with 757 and 562 kg ha-1 respectively in the town of San Juan Acateno under rainstorm conditions during the 2019 agricultural cycle. Conclusion: Application of agricultural lime did not have a significant effect on yield of improved varieties, as well as in Michigan regional control; However, highest production was presented in Huejonapan and Acatlán variety without application of agricultural lime during 2019 agricultural production cycle for town of San Juan Acateno in municipality of Teziutlán, Puebla. [ABSTRACT FROM AUTHOR]

Under stressful environments, plants associate with microbiota to adequately fulfill multiple functions. The plant-arbuscular mycorrhizal fungi (AMF) association is one very important by which plants satisfy part of their water and nutritional needs. The knowledge of native AMF is a key factor in the development and application of this biotechnology in crops of socioeconomic importance, such as maize. The objective was to know the diversity of AMF and the extent of mycorrhizal colonization in maize plots in four regions with drought incidence. A significant association is expected between soil properties and spore abundance, species richness, and mycorrhizal colonization. Random sampling was carried out in four regions of the state of Oaxaca (Istmo, Sierra Norte, Mixteca and Valles Centrales) and the relationship of soil physicochemical properties with species richness, spore abundance, and percentage of colonization was analyzed using the redundancy technique. A total of 24 AMF species were recorded, of which Funneliformis geosporum and Rhizophagus intraradices are present in the four regions studied. The association of AMF with roots of maize plants was greater than 60%. The highest spore abundance was recorded in the Sierra Norte region. No significant differences in species richness were observed among regions or by season; however, the Valles Centrales region had the highest diversity index. Concentrations of moisture, total nitrogen, electrical conductivity, and available phosphorus in the soil were correlated (p£ 0.05) with mycorrhizal diversity in the study regions. These findings indicate that the diversity of mycorrhizal fungi in the study plots is high, as well as the levels of mycorrhizal colonization (>60%). In addition, five new genera are reported for Oaxaca. This highlights the need to continue the evaluation of mycorrhizal diversity in the state. [ABSTRACT FROM AUTHOR]

This review organizes the existing and current knowledge of the ecophysiology of tropical trees, related to the processes of response to global climate change, with emphasis on water relations, due to the increase in temperature and droughts. The intertropical zone is characterized by a strip with an exuberant biodiversity. Given the current scenario of climate change, the conservation of tropical forests is of vital importance for its intervention in the global carbon cycle, in addition to providing guidelines for carrying out the necessary restoration actions in areas degraded by deforestation, being a source of carbon capture and, in turn, one of the components that will help in mitigating climate change. The methodology of information search was made because of the relevance of the topic, in pertinence with previous and current researches, which contributed solid arguments to the basic understanding of tropical trees ecophysiology. This is a very complex subject and, although there are advances, it is necessary to know the answers and adaptations that trees have developed throughout time. It was inquired to possess in context, the panorama of some species of the tropic, with respect to the mechanisms of survival and the capacity to support drastic changes in its area of distribution. From the review analysis, it can conclude that the knowledge and importance of these studies in the tropical zone is not null. However, more research are needed to know and to understand the behavior of some tropical trees of economic and ecological importance for the society and that, they will be affected by own environmental factors of their geographic region bordering on the extinction. [ABSTRACT FROM AUTHOR]

Copyright of Ingeniería del Agua is the property of Universidad Politecnica de Valencia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Presupuesto y Gasto Publico is the property of Instituto de Estudios Fiscales, Ministerio de Hacienda y Funcion Publica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this work was to evaluate the effect of ridges and nutrition on the phenology and production of eggplant in the middle Sinú Valley, Colombia. The experiment was established in open field conditions in the municipality of San Pelayo (Córdoba) under a factorial arrangement of 2 (With ridges and without ridges) x 3 (organic, chemical, and organic + chemical fertilization) and three repetitions, seedlings of eggplant of the variety C015. During the phenological development of the crop, records of growth and production variables were carried out. The results obtained showed that the use of ridges and fertilization exerts a highly significant effect on early harvest and a significant effect on yield. The combined use of ridges and the application of organic fertilizers reduce the earliness of harvest from 6 to 13 days. On the other hand, the addition of chemical and organic sources with ridges allows to significantly improve the yields, 47.3 t/ha was obtained. The ridges exert a positive effect on the variables foliar area, number of flowers, weight, and diameter of the fruit. Therefore, the use of ridges practices and sources of chemical and organic fertilization allows increasing crop yields and reducing days to harvest. [ABSTRACT FROM AUTHOR]

La investigación se realizó en la Estación Experimental del Zaidín, Granada, España, con el objetivo de evaluar la respuesta fisiológica y bioquímica de la planta de arroz, cultivada en condiciones de anaerobiosis y expuestas a una suspensión de la lámina de agua por un periodo de 15 días en el rendimiento agrícola. Las plantas de arroz (cv. INCA LP-5') se cultivaron en condiciones semi-controladas en macetas plásticas. La suspensión de la lámina de agua se realizó en tres momentos de su desarrollo, a los 30, 40 y 50 días después del trasplante (DDT). Se evaluó el rendimiento agrícola, el número de panículas por planta, granos llenos por panícula y la masa de 100 granos, a los 147 DDT. Se realizó una correlación del rendimiento con la altura de la planta, masa fresca aérea y de las raíces, potencial hídrico foliar, conductancia estomática, contenido foliares de peróxido de hidrógeno y daño oxidativo a lípidos, que se evaluaron a los 122 DDT. Se obtuvo que, el número de panículas por planta y los granos llenos por panícula se favorecieron con la aplicación del estrés hídrico, indicadores que contribuyeron con el incremento del rendimiento agrícola en los tratamientos expuestos a estrés hídrico (30 DDT = 23%, 40 DDT = 20% y 50 DDT = 11%, respecto al testigo). Se encontró que el rendimiento agrícola se correlacionó con la altura de la planta, la masa fresca aérea y de las raíces, el potencial hídrico foliar, la conductancia estomática, los contenidos foliares de peróxido de hidrógeno y el daño oxidativo a lípidos. [ABSTRACT FROM AUTHOR]

El tomate es la hortaliza más consumida en el mundo. En Cuba la mayoría de las siembras se concentran en los meses de menores precipitaciones, por lo que se necesita la aplicación de altos volúmenes de agua para el riego. La evolución de la agricultura cubana y los efectos del cambio climático, hace necesario el estudio de las necesidades de agua de los cultivos en cada ambiente, y un nuevo enfoque en su determinación. El presente estudio tiene como objetivo, evaluar diferentes variantes de riego en el cultivo del tomate y su efecto en el rendimiento y calidad del fruto. La investigación se desarrolló en organopónico, mediante ocho tratamientos que oscilaron entre el 10 y el 100% del volumen de agua aplicado diariamente. Se evaluaron descriptores relacionados con los componentes del crecimiento de las plantas, rendimiento y calidad del fruto. La respuesta de las plantas se caracterizó por el efecto inducido debido a los niveles de riego. En los primeros 40 días a partir de la siembra no se apreció diferencias entre los tratamientos. Las necesidades hídricas de las plantas se hicieron evidentes a partir de la floración. En los tratamientos de mayor estrés hídrico la calidad organoléptica del fruto fue superior. Los resultados indican la posibilidad de reducir al 10% el suministro hídrico al cultivo del tomate hasta prefloración y al 60% en las fases siguientes, para obtener frutos de calidad, sin que se afecten los componentes del crecimiento y rendimiento de las plantas. [ABSTRACT FROM AUTHOR]

En la Unidad Científico Tecnológica de Base de los Palacios (UCTB), perteneciente al Instituto Nacional de Ciencias Agrícolas (INCA), se obtuvo un nuevo cultivar de arroz de ciclo medio, 8733 (nominado Sergimar), obtenido mediante métodos biotecnológicos (Cultivo in vitro de anteras), con excelentes características en cuanto a rendimiento de grano, calidad molinera y su resistencia a plagas, así como un buen comportamiento a las condiciones de bajos suministros de agua. Con este nuevo cultivar la UCTB espera favorecer a los productores de arroz del sector cooperativo campesino. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Informacion Tecnica Economica Agraria is the property of Asociacion Interprofesional para el Desarrollo Agrario (AIDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The selection of tolerant varieties of bean to the drought can constitute a strategy that permit minimizing the effect of the hydric deficit on the yield and the quality of the bean grain. The objective of work was to identify more tolerant varieties to the drought, at the farmstead Sabanilla of her CCS "Sabino Pupo", Unión de Reyes. The morphologic characteristic and common bean indicators of yield of eight varieties (CC 25-9 R, BAT 58, Güira 89, CC 25-9 white, CC 25-9 black, Tomeguín, Velazco Largo and BAT 304) were evaluated, in different conditions: four irrigations (drought) and ten irrigations (optimal conditions of humidity). With the results of reproductive index (IR), sensibility index to drought (ISS) and the percentage of losses of the yield (PR) allowed bring to a following conclusion: the varieties more tolerant behavior in the conditions of experimentation where: Tomeguín, BAT 304 and CC 25-9 R and the more susceptible: Velazco Largo and y CC 25-9 black. [ABSTRACT FROM AUTHOR]

Copyright of Revista: Módulo Arquitectura CUC is the property of Corporacion Universidad de la Costa, CUC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AquaCrop is a simulation model designed to look at the productivity of different crops as a response to available water. The goal of the work was evaluate the model prediction capacity to simulate water and fertility stress for the soybean in Red Ferralitic soil. Data were collected from field trials carried out at the experiment station of the Irrigation and Drainage Research Institute in Alquízar, Artemisa province. One of the main results was that yield forecast of soybean as per the model were good, with a value of 0,16 t ha-1 for the square root of the mean square of the error (RMSE), modelling efficiency higher than 0,76 Willmott index (d) of 0,94. Simulation under water stress conditions before flowering showed that yield in the rainy year was 51% higher compared to the dry period, reaching 2,25 t ha-1, with productivity values for biomass and yield that were also higher. During the dry period, soybean submitted to water stress before flowering, showed the most critical period between 30 and 50 days after planting, with 100% inhibition of foliage growth. Soil fertility level had a significative effect on the biomass, yield and soybean productivity. A similar tendency is seen in these variables with reductions of 77%. [ABSTRACT FROM AUTHOR]

Copyright of Investigación Agraria is the property of Investigacion Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of Azofert® on bean plants on the relative water content and the pigments concentration under two irrigation regimes was evaluated. The experiment was carried out in the light room of the Department of Plant Physiology and Biochemistry of the National Institute of Agricultural Sciences, San José de las Lajas, Mayabeque. The varieties CC-25-9R and Tomeguín-93 were used. In each case, Azofert® was applied, with a dose of 200 mL per 50 kg of seed at the time of sowing and as controls were used treatments without the application of this product. The irrigation treatments consisted of applying 100 and 50 % of the maximum moisture retention capacity. A completely randomized design was used. Ten plants were selected at random for each treatment to evaluate fresh leaf mass, saturated mass, fresh leaf mass, relative water content and concentration of photosynthetic pigments. The results showed that the bean plants are affected when subjected to a soil moisture deficit and the inoculation with Azofert® was able to attenuate the effects of water deficiency. The relative water content decreased significantly in both varieties when humidity is reduced. The chlorophyll b content was affected in both varieties when subjected to water stress conditions. The content of carotenoids in the CC-25-9R variety had a significant increase in water stress conditions. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Achieving an efficient use of irrigation water in rice cultivation, not only responds to the management of irrigation, also depends on the response of the plant to physiological and biochemical level of it, to adapt and recover from the water deficit and to complete its biological cycle. The experiment was carried out at the Zaidín Experimental Station, Granada, Spain, under semicontrolled conditions in plastic pots, with 'INCA LP-5' rice plants, which were cultivated under anaerobic conditions and exposed to water deficit, the suspension of the water lamina at three stages of its development, at 30, 40 and 50 days after transplantation (DAT) for a period of 15 days and evaluated after the recovery period at 122 DAT. In general, plants recovered from the water stress to which they were exposed during their vegetative phase, which was evidenced through increased water potential and stomatal conductance, also increased the content of hydrogen peroxide and oxidative damage to lipids. In addition, a direct relationship was found between these variables (hydric potential - stomatal conductance and hydrogen peroxide - oxidative damage to lipids). These variables indicated that plants exposed to water stress at 30 DAT, showed a higher recovery state than those exposed to 40 and 50 DAT, response may influence crop yield. [ABSTRACT FROM AUTHOR]

Humic acids (AH) were extracted and isolated from bovine manure vermicompost, and they were partially characterized using UV-vis and / FT-IR. They were sprinkled foliarly at 32 days after germination coinciding with the start-up phase tillage in rice cultivation (Oryza sativa L.) under conditions of irrigation and water deficit. Three concentrations of AH (30, 34 and 38 mg L-1) were used, in addition to a control treatment without application. Specifically in the active tillering stage, the effect of foliar application of AH under irrigation conditions and water deficit was evaluated in indicators such as: plant height, dry mass in the root section, peroxidase enzyme activity (POX) and content of soluble proteins. The results indicated positive effects of the AH on the biochemical - physiological indicators evaluated in the vegetative phase, with effects on the dry mass in the radical part up to 40 % higher than the control, observing evidence of a possible protective effect against the water deficit by the AH. It was concluded that a possible response could be the mimetic action of AH with the abscisic acid hormone (ABA), producing equivalent effects to this. [ABSTRACT FROM AUTHOR]

The increase of atmospheric CO2 can influence the growth of vegetation causing stomatal closure, changes in the wateruse efficiency, or a fertilization effect that leads to greater growth. However, the response of vegetation depends on the environmental conditions and physiology of each species. The objective of this study was to evaluate the composition of carbon and oxygen isotopes (Δ13C and δ18O), the net discrimination of 13C (δ13C), the growth rate in basal area (IAB) and the intrinsic water-use efficiency (iWUE) of Taxodium mucronatum Ten. (Montezuma baldcypress) over the last 100 years in three regions of central Mexico. The hypotheses were: 1) the physiological response of T. mucronatum Ten. to climatic variation is different among regions; 2) changes in the growth rate in basal area and physiological variables of the Montezuma baldcypress tree suggest that fertilization effects took place in the last century. The regions under study were: Estado de México (MEX), Querétaro (QRO), and Morelos (MOR), with 600, 750, and 1038 mm rainfall. Nine trees per site were sampled to build a common chronology. In the growth rings, Δ13C and δ18O were analyzed to estimate discrimination (δ13C), internal CO2 concentration (Ci), and iWUE in the last century. The data were analyzed as samples repeated over time with variable spacing. The difference between sites was tested with a multivariate analysis of variance (MANOVA) and contrasts tests. The Δ13C on wood and Ci varied according to the moisture regime in MEX and MOR. In the past five decades, δ18O increased by 4 ‰ and the average annual temperature (AAT) increased from 1.2 to 1.4 °C. Since 1950, δ13C decreased by 1.1 ‰ and iWUE increased by 50 %. The increase in Ca, iWUE, and AAT was related to the IAB decrease in MEX site, and a slight IAB increase in QRO and MOR, indicating a different CO2 fertilization effect depending on the moisture gradient. [ABSTRACT FROM AUTHOR]

Grindelia covasii is an endemic species of the Lihue Calel Sierras. In this semiarid enviroment soil water availability is a limiting factor for seedling establishment. This greenhouse experiment evaluated the growth and survival of juvenile G. covasii plants by exposing four plant sizes (G=large, M=medium, and P=small plant sizes) to three irrigation levels, simulating high (Rf), moderate (R7) and low soil water availability (R14). Plant growth and physiological measurements were taken during the experiment. Results showed that growth parameters were affected by increasing waterstress. Leaf senescence was high under severe water limitation (R14) with larger individuals showing highest drought tolerance. No changes were observed in resource allocation from aboveground parts to roots in response to water stress. Survival was also affected by reduced water availability, with smaller plants being the most affected. The lower tolerance of juvenile stages of G. covasii to severe water stress observed in this experiment, suggest that this species would require moist conditions for successful seedling establishment. This study provides useful information regarding G. covasii recruitment. [ABSTRACT FROM AUTHOR]

To evaluate the effect of FitoMas-E on the performance of the chickpea, in conditions of drought stress, was the objective of this investigation. An experiment was conducted in the Intensive Garden "Río de Guisa" in the municipality of Guisa during the period from November to February 2014. Four treatments were applied, distributed in a randomized block design with three repetitions, on a "Pardo mullido grisaceo" soil, comparing the application of FitoMas-E under two soil moisture regimes, with and without water stress. The yield of grain and its components were evaluated at the time of harvest maturity, to analyze the responses of these variables to the treatments applied. An analysis of variance was performed using the statistical package STASTISTICA version 8.0 for Windows and the means of the treatments were compared using the Tukey Multiple Range test. The variables that showed a greater response to the treatments imposed were the number of legumes per plant, number of seeds per plant, the mass of 100 seeds and the yield of grain, which ranged between 0.9 and 0.93 t ha-1 for the treatments 2 and 4 respectively. The results obtained in this research showed that the chickpea crop achieved the best productive indicators when the plants were under water stress conditions and received the application of FitoMas-E. [ABSTRACT FROM AUTHOR]

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Controlled deficit irrigation (CDI) is a management strategy where water is applied according to the crop phenological stages. As a result, different irrigation management conditions can produce significant changes in production, fruit quality and the reduction in the applied total water volume. The objective of this research was to evaluate the effect of CDI on the production and quality of kiwi (Actinidia deliciosa) Hayward, in Chile. During the production cycles from 2009 to 2012 four water restriction periods were applied: 1) from 10 d to 30 d before flowering, 2) when fruits reached 60 % of their final weight, 3) when fruits reached more than 70 % of the final weight, and 4) when fruits reached more than 80 % of their final weight. The results of each restriction period were compared with a control treatment which had a 100 % evapotranspiration replacement. The experimental design was completely randomized in blocks with four replicates per treatment. The experimental unit was of three rows of seven plants each. Treatment means were compared by the Tukey test (p⩽0.05). Throughout the study, soil moisture, water status of the plant, applied water volume, fruit development and uniformity were measured. The main results were the decrease of water volume and its associated costs of pumping between 24 and 60 % compared to the control treatment; the applied CDI showed significant differences (p⩽0.05) on the size in the evaluated years. With CDI there was good uniformity in 24.2 % of the fruits without effects on productivity (p>0.05). [ABSTRACT FROM AUTHOR]

To objective of evaluate the response of two cultivars of chickpea (Nac-29 and Nac-5 HA) under different soil moisture conditions, field research was carried out in productive teaching plot of the University of Granma. Sowing was carried out on November 22, 2014. Two treatments were used: T1 (Control) and T2 (varieties of chickpea in water stress) with three replicates, distributed in a randomized block design with split plot arrangements (The large plots corresponded to the two moisture conditions and the small plots to varieties). The variables were: length and diameter of pods, number of grains per plant, number of grains per pods, weight of 100 seeds and agricultural yield. The results obtained were statistically processed using the STATISTICA version 8.0 for Windows program and in case of significant differences, a variance analysis was performed using the Tukey Multiple Range test. The results showed that, with the cultivation of the chickpea, better results are obtained when the plants are subjected to water stress conditions. [ABSTRACT FROM AUTHOR]

Performance was analyzed in the first plantain harvest cycle, with different levels of rainfall presented in the growing stages. One hectare of the crop was established with an average population of 2,450 plants / ha in thirteen farms, under similar management conditions; taking weekly precipitation data. Farms were distributed in four groups using analysis of hierarchical clusters according to productivity variables. Group 4 obtained the lowest yields due to the high rainfall accumulated during all the stages of development of the crop, followed by group 2, where the low precipitation six weeks before flowering (55.13 mm), affected the fruit filling. On the other hand, groups 1 and 3 produced the largest quantities of boxes (1067.75 and 953.00 respectively). The productivity of each group was determined by the accumulated precipitation in different phenological stages of the crop. [ABSTRACT FROM AUTHOR]

The most highlighted physiological response of plants to water stress by drought is the synthesis of the plant hormone Abscisic Acid (ABA). A solution to environmental changes is to achieve a better efficient use of water. For this reason, predicting the magnitude of ABA signaling may have considerable importance in agroecology; in addition, will allow the optimization of irrigation techniques in arid zones that need crops that limit the use of this natural resource. The most specific and reliable methodology for quantification of the enzyme is the indirect competitive type Enzyme-Linked Immunosorbent Assay (ELISA). For this reason the present study used this technique in order to establish a reproducible and accessible protocol that determines concentrations of ABA. The methodology included the evaluation of different antibodies, antigen and media concentrations. Results show that optimal conditions that allowed the highest sensitivity and reproducibility are: converage ABA-BSA conjugate 300 ng / ml, MAC 252 (monoclonal antibody specific for ABA) to 1:80 000, antirat IgG 1: 2000 and PNPP substrate in 1 mg / ml. Linear equations obtained gave R² values in a range of 0.95-0.99 as well as significant differences between the positive and negative controls. [ABSTRACT FROM AUTHOR]

In the last decades, breeding programs for Eucalyptus species in Chile have mainly focused on increasing productivity and adaptation. However, little is known about how droughts and climate change may influence physiological responses that determine tree growth. Evaluating leaf-level physiology may be important to predict survival of eucalyptus genotypes under severe water stress. This study assessed net photosynthesis (AN), stomatal conductance (gs), transpiration (E) and instantaneous water use efficiency (WUEi) in Eucalyptus globulus, E. nitens, E. badjensis, E. smithii and E. globulus x E. nitens and E. camaldulensis x E. globulus hybrids genotypes under increasing water stress conditions. Survival of each genotype was related to the observed physiological responses at -0.03 MPa, -1.5 MPa and -2.5 MPa soil water potentials. Higher plant survival was observed on genotypes with reduced water loss due to stomatal adjustment under water deficit, and on genotypes that could maintain initial photosynthetic rates under increased water deficit despite reductions in stomatal conductance. A negative relationship between plant survival and gas-exchange parameters suggests that photosynthesis rate, under high water availability (-0.03 MPa) and moderate water deficit (-1.5 MPa), may be a useful indicator for early selection of genotypes at sites under water limitations. [ABSTRACT FROM AUTHOR]

Drought is the main cause of low productivity in field conditions, and like most of methods to counter; they are costly and unaffordable for low-income farmers, the plant breeding has found the most economical option to increase or stabilize the common bean production under drought conditions. Therefore, the main objective of this research was to obtain bean lines derived from inter- gene pool crosses, in order to select lines tolerant to water stress. In the F5:6 generation, the top 54 elite lines in terms of performance and favorable agronomic traits, from 492 harvested lines. In addition, they were coded as DAB lines (Drought Andean Bean). These 54 elite lines were evaluated in yield trials in two conditions of drought, being able to elucidate the DAB 18, 49 DAB, DAB 52 and DAB 3 lines, showed a higher performance with a range of 2506.2 to 2682.3 kg. ha -1 in the two drought conditions evaluated, which brings genotypes with traits of importance to be multiplied and distributed to farmers, in addition to obtaining parental lines to generate new plant breeding programs to improve drought tolerant lines. [ABSTRACT FROM AUTHOR]

Evaluation of three pinto bean varieties under drought and irrigation in Durango, Mexico. The aim of this study was to identify the behavioral response in growth and physiology on three bean varieties under irrigation and drought. The study was conducted in 2014 at the experimental campus from the Autonomous University of Chapingo, Regional University Unit of the Arid Zones, Durango, Mexico. A randomized block design with three replications in a split plot arrangement was used. The plots were the soil moisture contents: favorable, near to Field Capacity (FC: 22-26%) and unfavorable, near to Permanent Wilting Point (PWP: 16-20%); subplots were varieties of beans: Pinto Centauro, Pinto Americano, and Pinto Saltillo. The variety Pinto Centauro had the greatest plant height (10.2 cm), vegetation cover (155.1 cm2), and dry matter production per plant (5.2 g) and, physiologically, it showed an outstanding water use efficiency (15.8 μmol CO2: μmol H20). The variety Pinto Americano was the most stable in growth and development when changing from the favorable moisture condition (CC) to the hydric stress condition (PWP), which makes it more viable under restrictive water availability conditions, but also more susceptible to root rot, associated to soil pathogens. [ABSTRACT FROM AUTHOR]

The present work was carried out with the aim of evaluating drought stress tolerance in 28 germplasm accessions of tomato (Solanum L. section Lycopersicon subsection Lycopersicon) ex situ preserved in Cuban collections as well as identifying the most tolerant accessions to be used in plant breeding programs. Thus, crop fruiting percentage was evaluated at the optimal period and under drought conditions (stressful period), which was used to calculate stress criteria: stress susceptibility index (SSI), geometric mean productivity (GMP), mean productivity (MP), stress tolerance index (STI), fruiting index (FI), harmonic mean (HARM), fruiting stability index (FSI), drought tolerance index (DI), stress susceptibility percentage index (SSPI), relative drought index (RDI), sensitivity drought index (SDI), modified stress tolerance indices (MSTI) and abiotic tolerance index (ATI). Accessions were classified according to their drought stress tolerance at plant level based on fruiting percentage, whereas the relationship among tolerance indices was evaluated by Biplot analysis. At the evaluated germplasm, there were accessions with high tolerance indices and fruiting percentages under stressful and non-stressful environments. This indicates that ex situ preserved germplasm in Cuba has tolerant accessions which can be used in breeding programs, in order to obtain adequately-performing cultivars or hybrids under these conditions. [ABSTRACT FROM AUTHOR]

In the locality of El Espinal, Tolima, the effect of water stress on leaf water potential and gas exchange of plants three clones of cacao (Theobroma cacao L) was evaluated. The experiment was established in a split plot design in randomized block arrangement. The main plot was four levels of available soil water, subplot grafted seedlings to three months of three clones with five repetitions. The results showed highly significant differences (P <0.01) in content of soil water, but no differences between the materials evaluated. The loss of water in the soil decreases leaf water potential (Ψf) and causes stomatal closure altering gas exchange and vapor pressure deficit (DPV) accentuates mainly at noon with increasing evapotranspiration. The magnitude of impact of water deficit depends on climatic variations throughout the day. The climatic variables that affect plant development, are temperature and relative humidity in the form of DPV. Net photosynthesis and growth of cocoa seedlings are physiological variables very sensitive to excess and especially to water deficit. [ABSTRACT FROM AUTHOR]

It was evaluated the tolerance to hydric stress in 14 cultivars of Chenopodium quinoa Willd. “quinua", by determination of Permanent Whithered State and desiccation tolerance (DHL50). Also, it was determinate the correlation between the response to hydric deficit with the changes in the concentration of compatible solutes (carbohydrates, betaine, proline) and soluble proteins. Plants of three months old with 8 true leaves were exposed to hydric deficit by 6 days. The evaluation of cell damage allowed to select the 14 cultivars in resistant, tender and with response between both, showing significant differences (p<0.05). Two cultivars were selected by its response to hydric deficit, Blanca de Juli (resistant) and Kamire (tender) by determination of DHL50 after of treatment with solutions of PEG (8000) at different concentrations in contrast to control without PEG. From this plants were obtained slides of leaves, and these slides were exposed to different concentrations of PEG to finally to evaluate the cell damage by release of electrolytes. The cultivar Blanca de Juli had shown the major level of tolerance and Kamire the minor level. The concentrations of carbohydrates, betaine and soluble proteins were incremented significatively (p<0.05) in the resistant cultivar. Proline was incremented in Blanca de Juli, but decreased in Kamire (tender), but this change not was significative. [ABSTRACT FROM AUTHOR]

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)