Summary: In recent decades, water scarcity has increased considerably in Cuauhtémoc, Chihuahua - the most important apple-growing region of Mexico. Thus, the objective of this research is focused on evaluating growth and development responses in apple rootstocks graf ted with Golden Delicious subjected to four drought cycles, comparing them with the continuous irrigation treatment. Ten rootstocks were evaluated (B.9, M.9Nic29, G.41, G.202, G.890, G.210, G.30, M.7, MM.111 and MM.109) used in the commercial apple orchards in the area, where all the rootstocks were obtained during the 2020 growing season. The planting was carried out in 20-L pots in March 2020 and a substrate composed of compost, soil and sand was used in a ratio of 1:1:1. The recorded variables measured were moisture percentage in the soil, the leading branch growth, leaf water potential, total biomass, and ef ficient water use. The rootstocks B.9 and M.9 Nic29 showed good results in most of the variables studied. Rootstocks with good recovery of leaf water potential af ter recovery irrigation were found. These rootstocks were; B.9, M.9Nic29, MM.111 and G.210. The total biomass was statistically the same in G.30, G.41, MM.111, MM.109, G.202 and B.9. In conclusion, rootstocks tolerate a certain degree of drought and can contribute to improving water use, highlighting B.9.

Resumen: La escasez de agua en la región manzanera más importante de México; Cuauhtémoc, Chihuahua, se ha incrementado considerablemente en las últimas décadas. El objetivo de esta investigación se concentró en evaluar la respuesta en crecimiento y desarrollo de portainjertos de manzano injertados con Golden Delicious, sometidos a cuatro ciclos de sequía, comparándolos con el tratamiento de riego continuo. Se evaluaron 10 portainjertos (B.9, M.9Nic29, G.41, G.202, G.890, G.210, G.30, M.7, MM.111 y MM.109), los cuales son utilizados en las huertas comerciales de manzano de la zona de Cuauhtémoc. Todos los portainjertos se obtuvieron de viveros comerciales durante la estación de crecimiento 2019. La plantación se realizó en macetas de 20 L en el mes de marzo de 2020 y se utilizó un sustrato compuesto por composta, suelo y arena en proporción 1:1:1. Las variables registradas fueron; porcentaje de humedad en el suelo, crecimiento de la rama líder, potencial hídrico de la hoja, biomasa total, y uso eficiente del agua. Los portainjertos B.9 y M.9Nic29 mostraron buenos resultados en la mayoría de las variables estudiadas. Los portainjertos B.9, M.9Nic29, MM.111 y G.210 mostraron buena recuperación del potencial hídrico de la hoja después del riego de recuperación. La biomasa total fue estadísticamente igual en G.30, G.41, MM.111, MM.109, G.202 y B.9. Se concluye que existen portainjertos que toleran cierto grado de sequía y que pueden contribuir a mejorar el uso del agua, destacando B.9.

Abstract Introduction. The parameters of physiological response to drought stress are the result of a combination of slow- or fast-acting attributes. Gas exchange variables are classified as fast-acting and their level of occurrence or impact depends on the interaction between factors such as genotype and the duration, intensity, and phenological stage of stress occurrence. Objective. To identify the levels of physiological response exhibited by Solanum phureja under progressive water deficit stress. Materials and methods. The experiment was conducted between 2019 and 2020 under semi-controlled conditions at the Obonuco Research Center of the Corporación Colombiana de Investigación Agropecuaria. Four potato cultivars were planted, with half of the trial was maintained at field capacity and the other half subjected to water deficit stress by withholding irrigation for 15 days, followed by rehydration. Gas exchange variables, chlorophyll content, and photosynthetic efficiency were evaluated every three days. Results. Significant differences were observed, with maximum gas exchange values in control plants showing 16.67 µmol m-2 s-1 photosynthesis rate (A); 0.34 mol m-2 s-1 stomatal conductance (gs); 5.5 mmol m-2 s-1 transpiration (E), and under stress, 1.17 µmol m-2 s-1 (A); 0.013 mol m-2 s-1 (gs); 0.29 mmol m-2 s-1 (E). Chlorophyll content values ranged between 451.7 and 474.69 mg m-2 with and without irrigation, respectively. Conclusions. Stomatic closure was the earliest response to water deficit, and potato plants showed recovery in gas exchange values after rehydration following stress. Finally, three levels of physiological response were identified: mild, moderate, and severe stress, depending on the intensity and duration of stress, which is useful for future studies and the development of irrigation schedules.

Resumen Introducción. Los parámetros de respuesta fisiológica al estrés por sequía son la conjugación de una serie de atributos de acción lenta o rápida. Las variables de intercambio gaseoso son catalogadas como de respuesta rápida, su nivel de aparición o afección dependen de la interacción entre factores como el genotipo y duración, intensidad y etapa fenológica de ocurrencia del estrés. Objetivo. Identificar los niveles de respuesta fisiológica que presenta Solanum phureja bajo el estrés progresivo por déficit hídrico. Materiales y métodos. El experimento se realizó entre 2019 y 2020, bajo condiciones semi-controladas en el Centro de Investigación Obonuco de la Corporación Colombiana de Investigación Agropecuaria. Se sembraron cuatro cultivares de papa, la mitad del ensayo se mantuvo con riego a capacidad de campo y a la otra parte se le suspendió para inducir estrés por déficit hídrico durante 15 días, luego se rehidrataron; se evaluaron variables de intercambio gaseoso, clorofila y eficiencia fotosintética cada tres días. Resultados. Se presentaron diferencias significativas con los valores máximos de intercambio gaseoso en plantas del tratamiento control con 16,67 µmol m-2 s-1 tasa de fotosíntesis (A); 0,34 mol m-2 s-1 conductancia estomática (gs) 5,5 mmol m-2 s-1 transpiración (E) y en estrés 1,17 µmol m-2 s-1 (A); 0,013 mol m-2 s-1 (gs); 0,29 mmol m-2 s-1 (E). En cuanto al contenido de clorofila, se presentaron valores entre 451,7 y 474,69 mg m-2 con riego y sin riego, respectivamente. Conclusiones. El cierre estomático fue la respuesta más temprana al déficit hídrico, además, las plantas de papa presentaron recuperación de los valores de intercambio gaseoso después del suministro de riego posterior al estrés. Finalmente, se identificaron tres niveles de respuesta fisiológica, estrés leve, moderado y severo, según la intensidad y duración del estrés, lo cual es de utilidad para futuros estudios y planteamientos de calendarios de riego.

RESUMO A salinidade desencadeia uma série de efeitos nocivos na nutrição mineral das plantas, o que causa perda na produção. O objetivo deste estudo foi avaliar os efeitos do uso de água salobra com irrigação por gotejamento por pulso e contínua no acúmulo de nutrientes na cultura de amendoim (Arachis hypogaea). O delineamento experimental utilizado foi o de blocos casualizados sob esquema fatorial (6 × 2), constituído por seis níveis de condutividade elétrica da água de irrigação (CEa: 0,2; 1,6; 2,8; 4,0; 5,2 e 6,4 dS m-1) e dois tipos de manejo da irrigação (por pulsos e contínua) com quatro repetições. Após 63 dias de semeadura, o acúmulo e a exportação de macronutrientes, sódio e cloro foram quantificados. A irrigação por pulso mitigou os efeitos deletérios da salinidade sobre a cultura do amendoim e proporcionou um maior acúmulo de nutrientes pela cultura em relação a irrigação contínua. A ordem decrescente de acúmulo de nutrientes pelas plantas sob irrigação por pulso e contínua foi: K > N > Ca > Mg > P > S. A irrigação por pulso é eficaz para mitigar os efeitos do uso de água salobra na cultura do amendoim. produção Arachis hypogaea. hypogaea . hypogaea) 6 ( 2, 2 , 2) CEa (CEa 0,2 02 0 1,6 16 1 2,8 28 8 4,0 40 4 52 5 5, 64 6, m1 m m-1 repetições semeadura macronutrientes quantificados S 0, 1, 4, m-

ABSTRACT High salinity levels trigger harmful effects on plant mineral nutrition, causing production losses. The objective of this study was to evaluate effects of using pulse or continuous drip irrigation with brackish water on the accumulation and exportation of nutrients in peanut (Arachis hypogaea) crops. A randomized block experimental design with four replications was used, in a 6×2 factorial arrangement consisting of six levels of electrical conductivity of irrigation water (ECw: 0.2, 1.6, 2.8, 4.0, 5.2, and 6.4 dS m-1) and two irrigation regimes (pulse and continuous). Accumulation and exportation of macronutrients, sodium, and chloride were quantified at 63 days after sowing. Pulse irrigation mitigated the harmful effects of high salinity levels on peanut crops and promoted greater nutrient accumulation by plants compared to continuous irrigation. The descending order of nutrient accumulation by plants under pulse and continuous irrigation was: K > N > Ca > Mg > P > S. Pulse irrigation is effective in mitigating the detrimental effects of using brackish water on peanut crops. nutrition losses Arachis hypogaea used 62 6 2 6× ECw (ECw 02 0 0.2 16 1 1.6 28 8 2.8 40 4 4.0 52 5 5.2 64 6. m1 m m-1 continuous. . continuous) macronutrients sodium sowing S 0. 1. 2. 4. 5. m-

RESUMO A salinidade é um dos fatores mais limitantes para a produtividade agrícola, pois afeta tanto as trocas gasosas quanto o metabolismo das plantas. Porém, com o crescimento populacional e a busca constante por alternativas para aumentar a produtividade, a irrigação com águas de salinidade moderada parece ser viável para potencializar a fruticultura no Brasil, especialmente nas regiões semiáridas, onde a maioria das águas tem alta concentração de sal e são as únicas fontes disponíveis para o produtor. Neste contexto, o objetivo deste estudo foi avaliar os efeitos da salinidade da água de irrigação nas trocas gasosas e na qualidade pós-colheita dos frutos do melão amarelo ‘Goldex’ (Cucumis melo L.) nas fases de colheita. Os tratamentos consistiram de duas condutividades elétricas da água de irrigação (CEa - 0,8 e 4,0 dS m-1) e oito etapas de colheita (54, 56, 58, 60, 62, 64, 66 e 68 dias após o transplantio), dispostas em forma de esquema fatorial 2 × 8 e delineamento inteiramente casualizado. Nas condições de salinidade impostas durante as etapas de avaliação, o melão amarelo ‘Goldex’ manteve estáveis suas trocas gasosas básicas. A massa e o número de frutos por planta foram reduzidos pela salinidade da água de irrigação, mas os frutos continuaram classificados como comercializáveis, o que torna a irrigação com água salina até 4,0 dS m-1 uma alternativa viável para a produção de melão amarelo, principalmente em regiões onde há baixa disponibilidade de água de boa qualidade, o que pode potencializar a fruticultura no semiárido. agrícola plantas Porém Brasil semiáridas produtor contexto póscolheita pós ‘Goldex Goldex Cucumis L. L CEa 08 0 0, 40 4 4, m1 m 1 54, 54 (54 56 58 60 62 64 6 transplantio, transplantio , transplantio) casualizado avaliação básicas comercializáveis m- semiárido 5 (5 (

ABSTRACT Salinity is one of the most limiting factors for agricultural productivity, as it affects both gas exchange and plant metabolism. However, with population growth and the constant search for alternatives to increase productivity, irrigation with water of moderate salinity appears to be feasible to enhance fruit cultivation in Brazil, especially in semi-arid regions, where most waters have high salt concentration and are the only available source for the producer. In this context, the objective of this study was to evaluate the effects of irrigation water salinity and harvest stages on gas exchange and post-harvest fruit quality of ‘Goldex’ yellow melon (Cucumis melo L.). The treatments consisted of two electrical conductivities of irrigation water (ECw - 0.8 and 4.0 dS m-1) and eight harvest stages (54, 56, 58, 60, 62, 64, 66, and 68 days after transplanting), arranged in a 2 × 8 factorial scheme and a completely randomized design. Under the salinity conditions imposed during the evaluation stages, the ‘Goldex’ yellow melon maintained its basic gas exchanges stable. The mass and number of fruits per plant were reduced by the salinity of the irrigation water, but the fruits continued to be classified as marketable, which makes irrigation with saline water up to 4.0 dS m-1 a viable alternative for the production of yellow melon, especially in regions where there is low availability of good quality water, which can enhance fruit growing in the semi-arid region. productivity metabolism However Brazil semiarid semi arid producer context postharvest post ‘Goldex Goldex Cucumis L.. L L. . L.) ECw 08 0 0. 40 4 4. m1 m 1 54, 54 (54 56 58 60 62 64 66 6 transplanting, transplanting , transplanting) design stable marketable m- region 5 (5 (

ABSTRACT Custard apple (Annona squamosa L.) is a sensitive fruit crop to salinity. One of the alternatives to minimize the deleterious effects of salt stress is adopting mineral fertilization management practices, promoting increased crop tolerance to salts. Therefore, the objective of the present study was to evaluate NPK doses to mitigate salt stress in custard apple seedlings irrigated with saline wastewater. The experiment was performed in a greenhouse, adopting a randomized block design in a 3 × 5 factorial scheme, corresponding to three irrigation waters (local-supply water of 0.53 dS m-1 electrical conductivity (control); desalination reject of 3.5 dS m-1; fish farming effluent of 3.5 dS m-1) and five proportions of the NPK recommendation (25, 50, 75, 100, and 125% of the fertilization recommendation), with four replicates. The growth, biomass accumulation, and nutrients were evaluated. Irrigation with desalination reject, and fish farming effluent restricted the growth of custard apple seedlings, regardless of the NPK dose used. The ionic homeostasis of seedlings irrigated with desalination reject and fish farming effluent is optimized by fertilization with 50% of the NPK recommendation corresponding to 50, 150, and 75 mg of N, P2O5, and K2O dm-3, respectively. For the production of seedlings irrigated with local-supply water, the dose of 75% NPK, corresponding to 75, 225, and 112.5 mg of N, P2O5, and K2O dm-3, respectively, is recommended. Annona L. L salinity practices salts Therefore wastewater greenhouse scheme localsupply local supply 053 0 53 0.5 m1 m 1 m- control (control) 35 3. 25, 25 (25 50 100 125 recommendation, , recommendation) replicates accumulation evaluated used 150 7 N P2O5 PO P O KO K dm3, dm3 dm 3, dm-3 respectively 225 1125 112 112. recommended 05 0. (control 2 (2 10 12 15 P2O dm- 22 11 (

RESUMO A pinheira (Annona squamosa L.) é uma frutífera sensível à salinidade. Uma das alternativas para minimizar os efeitos deletérios do estresse salino é a adoção de práticas de manejo da fertilização mineral, promovendo o aumento da tolerância da cultura aos sais. Portanto, o objetivo foi avaliar as doses de NPK para mitigar o estresse salino em mudas de pinheira irrigadas com água residual salina. O experimento foi realizado em casa de vegetação, em delineamento de blocos casualizados, em esquema fatorial 3 × 5, correspondendo a três águas de irrigação (água de abastecimento local de 0,53 dS m-1 de condutividade elétrica (controle); rejeito salino da dessalinização de 3,50 dS m-1; efluente de piscicultura de 3,50 dS m-1) e cinco proporções da recomendação de NPK (25, 50, 75, 100 e 125% da recomendação de fertilização), com quatro repetições. O crescimento, acúmulo de biomassa e nutrientes foram avaliados. A irrigação com rejeito salino e efluente de piscicultura restringe o crescimento das mudas de pinha, independentemente da dose de NPK utilizada. A homeostase iônica das mudas irrigadas com rejeito salino e efluente de piscicultura é otimizada pela fertilização com 50% da recomendação de NPK correspondente a 50, 150 e 75 mg de N, P2O5 e K2O dm-3, respectivamente. Para a produção de mudas irrigadas com água de abastecimento local, recomenda-se a dose de 75% de NPK, correspondente a 75, 225 e 112,5 mg de N, P2O5 e K2O dm-3, respectivamente. Annona L. L salinidade mineral sais Portanto salina vegetação casualizados 5 053 0 53 0,5 m1 m 1 m- controle (controle) 350 50 3,5 25, 25 (25 10 125 fertilização, , fertilização) repetições avaliados pinha utilizada 15 7 N PO P P2O KO K dm3, dm3 dm 3, dm-3 respectivamente recomendase recomenda se 22 1125 112 112, 05 0, (controle 35 2 (2 12 dm- 11 (

Resumen En zonas de clima árido y semiárido, la disponibilidad y la calidad del agua son factores críticos para el desarrollo de la agronomía. Para enfrentar el desafío, una alternativa para el aprovechamiento de este recurso es la implementación de técnicas eficientes y sostenibles como el uso de riego por goteo. El objetivo del trabajo fue analizar el comportamiento agronómico del centeno en condiciones desfavorables de agua y temperatura para determinar la efectividad de la estabilidad fenotípica en la Costa de Hermosillo, Sonora, México. Se sembraron dos genotipos de centeno bajo un diseño experimental de parcelas divididas (parcela grande: tres niveles de agua y parcela chica: dos genotipos de semillas obtenidas en ciclos diferentes). Se evaluaron las características agronómicas de la planta, las características fisicoquímicas del grano; y se determinó la significancia entre las distintas variables con un análisis de correlación. El análisis de varianza reveló efectos sobre la altura de la planta, el número de espigas y de granos, tamaño de grano, el peso de mil granos, rendimiento y contenido de proteína del centeno debido a los diferentes regímenes hídricos utilizados. Se obtuvieron entre 219-314 espigas por metro lineal, con tamaño de grano comercialmente aceptable (7.45-7.95 mm largo x 2.18-2.40 mm ancho). También se observaron valores de rendimiento altos (1.72-3.11 t ha-1), así como un excelente contenido de proteína (20.3-22.8%). Estos resultados demuestran que el centeno es un cereal versátil que se adapta a condiciones ambientales adversas como disminución en la cantidad de agua de riego y temperaturas extremadamente altas.

Abstract In areas with arid and semi-arid climates, the availability and quality of water are critical factors for the development of agronomy. To face the challenge, an alternative for the use of this resource is the implementation of efficient and sustainable techniques such as the use of drip irrigation. The objective of the work was to analyze the agronomic behavior of rye under unfavorable water and temperature conditions to determine the effectiveness of phenotypic stability on La Costa de Hermosillo, Sonora, Mexico. Two rye genotypes were planted under a split plot experimental design (large plot: three water levels and small plot: two genotypes of seeds obtained in different cycles). The agronomic characteristics of the plant, the physicochemical characteristics of the grain were evaluated; and the significance between the different variables was determined with a correlation analysis. The analysis of variance revealed effects on plant height, number of spikes and grains, grain size, thousand grain weight, yield and protein content of rye due to the different water regimes used. Between 219-314 spikes per linear meter were obtained, with a commercially acceptable grain size (7.45-7.95 mm long x 2.18-2.40 mm wide). High yield values (1.72-3.11 t ha-1) were also observed, as well as excellent protein content (20.3-22.8%). These results demonstrate that rye is a versatile cereal that adapts to adverse environmental conditions such as a decrease in the amount of irrigation water and extremely high temperatures.

Irrigation is required to supplement rainfall to enhance the productivity of chickpea in South Africa (SA). However, the dependence on irrigation can be problematic for SA and other countries with limited natural water resources and variable rainfall. Even though access to irrigation water has been identified as one of the challenges faced when planting chickpea in the winter season in SA, irrigation management strategies for chickpea grown on soils differing in texture have not gained considerable research attention. Hence, this study aimed to assess the effects of irrigation levels on dry matter production of chickpea grown on two soils differing in soil texture under greenhouse conditions. The experiment was arranged as a 3 × 2 factorial in a completely randomized design, with 3 irrigation levels (25%, 50% and 75% of the water-holding capacity of soil (WHC)) and 2 soils differing in soil textural class (Loamy sand (LS) soil and sandy loam (SL) soil), replicated thrice. Irrigation level, soil texture and their interaction significantly affected shoot biomass (SBM) and total plant biomass (TBM). Generally, SBM, TBM and root biomass decreased correspondingly with the reduction in irrigation. The 25% WHC significantly reduced the SBM by up to 60% and TBM by up to 56% compared to the 50% and 75% WHC. The SBM and TBM were higher in SL soil than in LS soil. A significantly higher root/shoot ratio (0.45) in the LS soil than in the SL soil (0.16) indicated that the conditions of LS soil encouraged plants to allocate higher proportions of biomass into roots, possibly due to increased competition for soil resources. In conclusion, maintaining soil moisture at 50% WHC ensures better chickpea dry matter production in SL soil.

The Groot Aub (GA) settlement depends entirely on groundwater for domestic purposes and other development activities. Development activities are mainly agriculture, such as animal husbandry, chicken farming and crop farming using irrigation. However, these activities have the potential to contaminate the groundwater system. A total of 87 groundwater samples were collected from the boreholes in the study area during the dry and wet season. Water quality parameters (pH, salinity, total dissolved solids (TDS), electrical conductivity (EC) and hydrochemistry (Na+ > Ca2+ > Mg2+ > K+, and HCO3- > SO4(2-) > Cl-) of 5 boreholes and 1 reservoir tank were analysed. The dominant cations were attributed to cation exchange processes as a coupled exchange of Na+ + K+ replacing Ca2+; and Na+ replacing Mg²+ ions in the rock-water interactions. The HCO3- anion is attributed to underlying rich carbonate rocks in the study area and chemical reactions between groundwater and silicate minerals. TDS ranged from 639.01 to 1 998.96 mg/L. The microbial levels as indicated by heterotrophic plate count (HPC) values exceed the limits imposed by the local Namibian and WHO drinking water regulations. The Piper diagrams showed a mixed water type of mainly HCO3- and SO4(2-)anions and Na+ and Ca2+ > Mg2+ cations. The study shows that the elemental composition of the groundwater is impacted significantly by primarily anthropogenic activities and secondarily geogenic processes. Based on the results of this study it is recommended that a buffer zone be created between human activities and production boreholes to avoid further groundwater contamination.

Abstract The objective of this work was to analyze the relationship between perceptions and agricultural practices in the face of the effects of climate change from the agro-socio-economic context and the hydrological structure in the Cochapata high-altitude ecosystem in Urcuquí-Ecuador. The methodological strategy responds to the qualitative paradigm, case study method. Primary information was collected through landscape reading, interviews, and participant observation. It was found that the territory is occupied by timber industries, whose tree species are characterized by excessive water demand. The sub-paramo is inhabited by peasants in survival conditions who use the land to obtain goods for family sustenance using their labor force. Water distribution is of a hydro-social nature, as it excludes peasants from the right to irrigation and watering. Regarding the effects of the changing climate, the inhabitants perceive heat waves and variations in the rainy season in their daily lives; however, no agricultural practices were found to adapt to the climatic phenomenon. It is concluded that the vulnerability of the ecosystem is not directly related to climate change; it responds to historical failures in the distribution of ecosystem goods such as land and water, to the lack of knowledge of the peasant subject on the part of the state and society, and the excessive extractivism implemented during the last decades.

Resumen El objetivo de este trabajo fue analizar la relación entre percepciones y prácticas agrícolas frente a los efectos del cambio climático desde el contexto agro-socio-económico y la estructura hidrológica en el ecosistema de altura Cochapata en Urcuquí-Ecuador. La estrategia metodológica responde al paradigma cualitativo, método de estudio de caso. Se levantó información primaria mediante lectura del paisaje, entrevistas y observación participante. Se encontró que el territorio está ocupado por industrias madereras cuyas especies arbóreas se caracterizan por excesiva demanda hídrica. El subpáramo está habitado por campesinos en condición de sobrevivencia que usan la tierra para obtener bienes de sustento familiar, valiéndose de su fuerza de trabajo. Se evidenció que la distribución del agua es de carácter hidrosocial, pues excluye al campesinado del derecho a riego y abrevadero. Respecto a los efectos del clima cambiante, los pobladores perciben en su cotidianidad olas de calor y variaciones en las temporadas de lluvias, sin embargo, no se encontraron prácticas agrícolas con intención adaptativa al fenómeno climático. Se concluye que la vulnerabilidad del ecosistema no guarda relación directa con el cambio climático, esta responde a las fallas históricas en la distribución de los bienes ecosistémicos tierra y agua, al desconocimiento del sujeto campesino por parte del Estado y de la sociedad, y al excesivo extractivismo implantado durante las últimas décadas.

Abstract Mexico occupies first place in mining exploration in Latin America, a situation that has caused alarm among native peoples because the implementation of extractive projects threatens their vital space. The objective of this paper is to analyze the actions of Corporate Social Responsibility (CSR) of the Ixtaca Project in Ixtacamaxtitlán, Puebla, as well as the strategies of territoial defense undertaken by the communities to stop its expansion. Data was gathered through one survey, one workshop and various interviews conducted in three communities affected by the project. Results discuss three actions of CSR: 1) job offers; 2) investment in community infrastructure; 3) support for social events. Three main defense strategies were identified: 1) collective agreements refusing to sell water to the company; 2) legal litigations in favor of the right to be consulted as native peoples; 3) the strengthening of peasant agriculture thanks to the defense of the ejido, the conservation of irrigation water and the support received from the federal program Sembrando Vida. The paper concludes that, despite the negative impacts of RCS actions, these strategies have proven effective because mining concessions have been cancelled and some families have returned to agriculture.

Resumen México ocupa el primer lugar en exploración minera en América Latina, situación que ha causado alarma entre pueblos originarios dado que el desarrollo de proyectos extractivos representa una amenaza para su espacio vital. El objetivo de este artículo es analizar las acciones de Responsabilidad Social Corporativa (RSC) del Proyecto Ixtaca en el municipio de Ixtacamatitlán, Puebla, así como las estrategias de defensa del territorio desarrolladas por las comunidades para detener su avance. Para obtener información se realizó una encuesta, un taller y varias entrevistas en tres comunidades afectadas por el proyecto. Los resultados destacan tres acciones de RSC: 1) oferta de empleos; 2) inversión en infraestructura comunitaria; 3) apoyo a eventos sociales. Las estrategias de defensa fueron: 1) acuerdos colectivos para negarse a vender agua a la empresa; 2) litigios legales a favor del derecho a la consulta de pueblos originarios; 3) fortalecimiento de la agricultura campesina gracias a la defensa del ejido, la conservación de agua de riego y los apoyos otorgados por el programa federal Sembrando Vida. Se concluye que, a pesar de los impactos negativos de la RSC, estas estrategias resultaron efectivas porque se logró la cancelación de las concesiones mineras y se ha avanzado en la recampesinización de algunas familias.

ABSTRACT Excess of salts in water and/or soil stands out as one of the stresses that compromise the development of crops, including cherry tomato, requiring the use of strategies that reduce salt stress effects, such as foliar application of hydrogen peroxide. Thus, the objective of this study was to evaluate the effect of foliar application of H2O2 on the contents of photosynthetic pigments, growth, and production of cherry tomato under irrigation water salinity. The design used was randomized blocks, in a 5 × 5 factorial scheme, with five values of electrical conductivity of water - ECw (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and five concentrations of hydrogen peroxide - H2O2 (0, 15, 30, 45, and 60 μM). Application of hydrogen peroxide at concentration of 60 μM attenuated the deleterious effects of salt stress on the growth and number of leaves of cherry tomato up to ECw of 3.1 dS m-1. Hydrogen peroxide concentration of 45 μM increased root dry mass, synthesis of chlorophyll b and total chlorophyll under electrical conductivity of water of 0.3 dS m-1 and synthesis of chlorophyll a up to ECw of 0.8 dS m-1. Foliar application of 30 μM reduced the effects of salt stress on leaf, shoot and total dry mass accumulation up to ECw of 3.1 dS m-1. Electrical conductivity of water from 1.41 dS m-1 reduced the production of cherry tomato. andor or crops Thus HO H O H2O pigments salinity blocks scheme 0.3, 03 0 3 (0.3 10 1 1.0 17 7 1.7 24 2 4 2.4 31 3. m1 m 0, (0 15 6 μM. . μM) m1. 1. 0. m- 08 8 leaf 141 41 1.4 (0. 2. ( 14

RESUMO O excesso de sais na água e/ou no solo se destaca como um dos estresses que compromete o desenvolvimento das culturas, dentre elas o tomate cereja, sendo necessário o uso de estratégias que reduzam o efeito do estresse salino, como à aplicação foliar de peróxido de hidrogênio. Assim, o objetivo deste estudo foi avaliar o efeito da aplicação foliar de H2O2 sobre o teor de pigmentos fotossintéticos, crescimento e produção de tomate cereja sob salinidade da água de irrigação. O delineamento utilizado foi o de blocos casualizados, em esquema fatorial 5 × 5, sendo cinco valores de condutividade elétrica da água - CEa (0,3; 1,0; 1,7; 2,4 e 3,1 dS m-1) e cinco concentrações de peroxido de hidrogênio - H2O2 (0; 15; 30; 45 e 60 µM). A aplicação de peróxido de hidrogênio na concentração de 60 µM atenuou o efeito deletério do estresse salino no crescimento em altura de plantas e no número de folhas de tomate cereja até a CEa de 3,1 dS m-1. A concentração de 45 µM de peróxido de hidrogênio aumentou a fitomassa seca de raiz, a sintese de clorofila b e total sob água de condutividade elétrica de 0,3 dS m-1 e de clorofila a até a CEa de 0,8 dS m-1. A aplicação foliar de 30 µM reduziu o efeito do estresse salino no acúmulo de fitomassa seca de folhas, da parte aérea e total até a CEa de 3,1 dS m-1. A condutividade elétrica da água a partir de 1,41 dS m-1 reduziu a produção de tomate cereja. eou ou culturas Assim HO H H2O fotossintéticos irrigação casualizados 03 0 3 (0,3 1,0 10 1 1,7 17 7 24 2 4 2, 31 3, m1 m (0 15 6 µM. . µM) m1. 1. raiz 0, m- 08 8 141 41 1,4 (0, 1, ( 14

ABSTRACT Global solar radiation (Qg) is of paramount importance for several functions, such as photosynthesis and other biological processes, technologies based on solar energy (production of electricity and hot water), estimation of evapotranspiration (irrigation management), and forecast of crops, among other activities, at zero cost. This study aimed to develop a new methodology to estimate the daily and monthly value of global solar radiation based on the power generated by a 10 W photovoltaic solar panel. The methodology performance was assessed by comparing the Qg values estimated by the new method and the Qg values observed in a weather station, and also calculated by the SunDATA software and observed in the NASA POWER system. High r, R2, and Willmott coefficient values (close to 1), a low mean absolute error (MAE) of 0.202 kWh m−2 per day, a low mean bias error (MBE) of −0.146 kWh m−2 per day, a low mean percentage error (MPE) of 3.25%, and a low root mean square error (RMSE) of 0.292 kWh m−2 per day were obtained, confirming the excellent accuracy and reliability of the proposed methodology to estimate Qg. The NASA POWER system and SunDATA software presented similar values for the entire study period compared to the observed data, but not as good as the proposed technique. Thus, the proposed methodology had high performance in estimating Qg. (Qg functions processes production water, water , water) irrigation management, management management) crops activities cost 1 panel station r R2 R close 1, 1) MAE (MAE 0202 0 202 0.20 m2 m 2 m− MBE (MBE 0146 146 −0.14 MPE (MPE 325 3 25 3.25% RMSE (RMSE 0292 292 0.29 obtained data technique Thus 020 20 0.2 014 14 −0.1 32 3.25 029 29 02 0. 01 −0. 3.2 −0 3. −

RESUMO A radiação solar global (Qg) é de suma importância para diversas funções, como fotossíntese e outros processos biológicos, tecnologias baseadas em energia solar (produção de eletricidade e água quente), estimativa da evapotranspiração (manejo da irrigação), previsão de cultivos, entre outras atividades, a custo zero. Este estudo teve como objetivo desenvolver uma nova metodologia para estimar o valor diário e mensal da radiação solar global com base na potência gerada por um painel solar fotovoltáico de 10 W. O desempenho da metodologia foi avaliado pela comparação entre os valores de Qg estimados pelo novo método e os valores de Qg observados em uma estação metereológica, e também pelos valores calculados pelo software SunDATA e os observados no sistema NASA POWER. Altos valores de r, R2 e coeficiente de Willmott (próximos de 1), baixo erro médio absoluto (MAE) de 0,202 kWh m-2 por dia, baixo erro médio da estimativa (MBE) de -0,146 kWh m-2 por dia, baixo erro médio percentual (MPE) de 3,25% e baixa raiz do erro quadrático médio (RMSE) de 0,292 kWh m-2 por dia foram obtidos, confirmando a excelente acurácia e confiabilidade da metodologia proposta para estimar o Qg. O sistema NASA POWER e o software SunDATA apresentaram valores semelhantes para todo o período de estudo em relação aos dados observados, mas os da presente metodologia foram melhores. Assim, a metodologia proposta apresentou alto desempenho na estimativa da Qg. (Qg funções biológicos produção quente, quente , quente) manejo irrigação, irrigação irrigação) cultivos atividades zero 1 W metereológica r R próximos 1, 1) MAE (MAE 0202 0 202 0,20 m2 m 2 m- MBE (MBE 0,146 0146 146 -0,14 MPE (MPE 325 3 25 3,25 RMSE (RMSE 0292 292 0,29 obtidos melhores Assim 020 20 0,2 0,14 014 14 -0,1 32 3,2 029 29 02 0, 0,1 01 -0, 3, -0 -

RESUMEN La menta piperita es una planta medicinal, su cultivo es considerado un interesante rubro de renta, sin embargo, es susceptible al déficit hídrico, siendo ésta la causa principal de los bajos rendimientos de este cultivo en parcelas sin sistema de riego. Con el objetivo de evaluar parámetros productivos y económicos del cultivo de menta piperita con coberturas orgánicas e inorgánicas de suelo que ayuden reducir el déficit hídrico, se llevó a cabo esta investigación en un diseño completamente al azar, compuesto por cinco tratamientos (suelo sin cobertura, mulching negro, mulching blanco, cascarilla de arroz y pasto pacholí) y cuatro repeticiones, totalizando 20 unidades experimentales. Las variables evaluadas fueron: longitud de brotes basales, cantidad de brotes basales y brotes laterales, rendimiento de masa fresca y seca. Adicionalmente, se analizó la rentabilidad de cada tipo de cobertura. Todas las medias fueron sometidas al análisis de varianza (ANAVA) y comparadas por el Test de Tukey al 5%. En cuanto a la longitud de brotes basales, los mejores resultados fueron con la utilización de mulching negro, seguido por el mulching blanco y pasto pacholí; la mayor cantidad de brotes laterales con 16,45 con el mulching blanco, en cambio en la cantidad de brotes basales fue el testigo que presentó una mayor cantidad con 4,15. El mulching blanco presentó mayor rendimiento que el testigo para la masa fresca y masa seca con 1.544 kg ha-1 y 628 kg ha-1, respectivamente. Al analizar la rentabilidad en la masa fresca de la menta piperita, la utilización del mulching blanco fue más factible, mientras que en masa seca se observó una rentabilidad negativa para todos los tratamientos.

ABSTRACT Peppermint is a medicinal plant, being an interesting income item, however it is susceptible to water deficit, this being the main cause of the low yields of this item in plots without an irrigation system. With the objective of evaluating productive and economic parameters of peppermint with organic and inorganic soil covers, this research was carried out in a completely randomized design, composed of five treatments (soil without cover, black mulching, white mulching, rice husk and patcholí grass) and four repetitions, totaling 20 experimental units. The variables evaluated were: length of basal shoots, number of basal shoots and lateral shoots, yield of fresh and dry mass, cost/benefit profitability of each type of coverage. All means were subjected to the analysis of variance (ANAVA) and the means were compared by the Tukey Test at 5%. Regarding the length of basal shoots, the best results were with black mulching, followed by white mulching and patchouli grass; the greatest number of lateral shoots with 16.45 with the white mulching, on the other hand, in the number of basal shoots, the control had the highest number with 4.15. The white mulching presented a higher yield than the control for the fresh mass with 1,544 kg ha-1 and dry mass of 628 kg ha-1. When analyzing the profitability in the fresh mass of peppermint, the use of white mulching was more feasible and in dry mass they showed negative profitability for white mulching.

The number of people on Earth and human activities are currently taking on frightening proportions with far-reaching consequences for our planet, its biodiversity and ultimately the human race itself. Ten thousand years ago, humans represented 1% of the total biomass of all land vertebrates. The rest was made up by wild animals. Currently, humans, livestock and pets make up 99% of terrestrial vertebrate biomass, while wild animals represent only 1%. It took millennia for the human population to reach the 1 billion mark and that only by 1890. By 1960, however, the world population had grown to 3 billion. Today there are 8 billion people living on our planet. According to Population Matters, the world population will be approximately 10,4 billion by the end of this century, despite the gradual decline in the growth rate in some countries. There is only a 23% chance that the total population growth rate will tail off before 2100. The population of the 47 least developed countries is likely to triple between 2017 and 2100 to around 3 billion. There are currently 62 million people in South Africa. About 67,9% of our population (in 2021) live in urban areas. The South African population grew by 0,87% in 2023. The fertility rate is 2,30 (2023). It is estimated that by 2050 75,5 million people will be living in South Africa, with 8 out of every 10 people living in urban areas, which would significantly increase the pressure on infrastructure. The Global Footprint Network states that humans currently use the resources of 1,75 Earths. If the situation does not improve, by 2050 we would need the equivalent of three Earths to survive. More than 4 billion people will have little or no water by 2050, and South Africa even now has been classified as a "water-stressed" country. Medical science is continually contributing to more babies surviving their entry into the world and to our living increasingly longer. Life expectancy has risen from 46 years in 1950 to 73,2 years in 2023. By 2050 it will be 77 years. What can be done? Empowerment of women is important. Population growth can be curbed to a reasonable extent by giving more girls access to education. This certainly does not mean that girls or women alone should be held responsible for the current population growth, but much more will have to be done about sex education, women's rights will have to be actively promoted and there will have to be better provision and use of contraceptives. Obviously, these issues should be approached and handled with due caution. In this regard, countries such as Thailand and South Korea have, in the recent past, proved that good education may result in lower birth rates. In Africa, women with no education have an average of 5,4 children; women who completed high school an average of 2,7 children and women with tertiary education an average of 2.2. In Nigeria, every year of school attendance by girls cuts the birth rate by a tenth. In addition, intensified efforts to reform economies and societies should be considered. For the sake of the survival of the human species and the sustainability of the Earth, ecological and economic justice and the empowerment ofwomen have to be encouraged. The Millennium Project - a global participatory think tank that was founded in 1996 under the auspices of the American Council for the United Nations University, but which became independent in 2009 and has since grown into a global network of institutions and individuals - aims to improve humankind's prospects for a better future. It recommends, among other things, the following: • Support a policy aimed at improving the survival of children, responsible family planning and educational opportunities for (especially) girls. • Improve methods that will ensure skills and employment opportunities for young people, as well as care and services for the elderly. • Implement the UN's urban agenda. • Create enough smart cities where citizens with urban intelligence can help in eco-smart ways with the necessary improvements in the city. • Increase training in resilience, and improve disaster prediction and management. • Provide guidance for people about urban ecology. • Intensify research and development in saltwater agriculture (halophytes or salt plants) on coastlines to produce food for humans and animals, biofuel and pulp for the paper industry, and to absorb carbon dioxide (CO2). This will ease the pressure on freshwater agriculture. • Improve agricultural and irrigation management. • Invest in precision agriculture and aquaculture. • Reduce food losses from the "farm to the mouth" (one third or 1,3 billion tons of agricultural production is wasted in this way every year). • Establish seaweed to restore wild fish populations along coastlines. The World Bank estimates that 90% of marine life is completely depleted. • Expand the production of insects for animal feed and human diets (insects have a low environmental impact, and 2 billion people already supplement their diet with insects today). • Encourage vegetarianism. Although there are more ways to address these important global challenges, responsible family planning remains one of the most important. This is an extremely sensitive issue for many people (especially in Africa), but if it is not promoted in a humane, informed and responsible way, the sustainability of life on our planet will increasingly come under tremendous pressure in various respects.

Die aantal mense op aarde en hulle/ons aktiwiteite neem tans skrikwekkende afmetings aan met wydlopende gevolge vir ons planeet, biodiversiteit en uiteindelik onsself. Die moderne mens het sy teenwoordigheid op die aarde en die benutting van hulpbronne baie lank as sy onaantasbare reg gesien. Die huidige uitwerking van byvoorbeeld bevolkingsgroei en besoedeling versteur die aarde se natuurlike ritme in so 'n mate dat ons nou nie meer op 'n kitsoplossing kan hoop nie. Die mens se getalle neem teen so 'n tempo toe dat dit nie net nadelig vir die planeet is nie, maar ook vir die mensdom self. Wat kan gedoen word? Bemagtiging van vroue speel 'n belangrike rol. Dit beteken beslis nie dat meisies en vroue alleen vir die huidige bevolkingsgroei verantwoordelik gehou moet word nie. Die bevolkingsgroei kan egter in 'n redelike mate vertraag word deur veral meer meisies toegang tot onderwys en opleiding te gee - asook hul lewensomstandighede te verbeter. Ook sal daar heelwat meer aan seksopvoeding gedoen moet word, vroueregte sal daadwerklik bevorder moet word en daar sal beter voorsiening en gebruik van voorbehoedmiddels moet wees. Uiteraard moet hierdie kwessies met die nodige omsigtigheid benader en hanteer word. In hierdie verband kan onder andere Thailand en Suid-Korea genoem word wat in die onlangse verlede bewys het dat goeie onderwys geboortesyfers laat daal. In Afrika het vroue wat geen onderwys ontvang nie, gemiddeld 5,4 kinders; vroue wat hoërskool voltooi het gemiddeld 2,7 kinders en vroue wat tersiêre studie deurloop het, gemiddeld 2,2 kinders. In Nigerië sny elke jaar wat meisies skool bywoon, die geboortesyfer met 'n tiende. Hiermee saam sal daar ook verskerpte pogings moet wees om ekonomieë en samelewings te hervorm. Ter wille van die mens se voortbestaan en die volhoubaarheid van lewe op aarde moet ekologiese en ekonomiese geregtigheid, en die bemagtiging van vroue aangemoedig word.

Abstract Introduction. The amount of usable water is currently limited due to the deterioration of its sources and indiscriminate use. An alternative to this problem is producing under green houses, where it is possible to obtain better water use efficiency (WUE) by reducing crop evapotranspiration (ETc) without compromising its productive potential. Objective. To evaluate the effect of 3 levels of volumetric moisture content depletion in coir on the vegetative-generative behavior of hydroponic tomato and sweet pepper produced under greenhouse cultivation. Materials and methods. The study was conducted during August to December 2020 and January 2021, at Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. Three treatments were applied: 11, 22 and 32% of water depletion in the substrate. Morphophysiological and reproductive parameters such as: the leaf area (AF), the number of leaves (NH), width (AH) and length of the leaf (LH), the length (LT) and the diameter of the stem (DT), the number of nodes (NN), dry matter (DM), stomatal conductance (gs), crop evapotranspiration (ETc), water use efficiency (WUE), the total yield (Rt), the commercial (Rc) of first (F1), second (F2) and third (F3) and waste fruits (Fd) were evaluated. Results. In the tomato treatments (TT) there was no effect on NH, LT, LH and NN; on the other hand, differences were reported in AH, DT and in MS, with treatment TT11 obtaining the higher values. The sweet pepper (TC), the treatment TC11 was statistically superior to the other treatments in number (NH), width (AH) and length (LH) of the leaf, in number of nodes (NN), production of fresh (MF) and dry matter (MS) and in diameter of the stem (DT), while there were no differences between treatments in stem length (LT). There were no differences in ETc and Rt, for both crops, but there was a difference in the commercial yield once it was divided by quality of fruit, TT11 presented the highest production of first and second fruit quality, while treatment TC11 presented the highest production of first, second and third fruit quality. For both crops, there were significant differences between treatments in terms of stomatal conductance. TT11 and TC11 treatments obtained the highest value of EUA with 37.32 kg.m-3 and 21.46 kg.m-3, respectively. Conclusion. In both crops, treatments with 11 and 22% water depletion showed an adequate balance between vegetative and productive growth, which was reflected in greater production of better quality commercial fruits, less waste and greater WUE.

Resumen Introducción. El uso de agua dulce en agricultura se encuentra limitado debido al deterioro de sus fuentes y su uso indiscriminado. El riego deficitario en agricultura protegida es una alternativa para mejorar la eficiencia en el uso del agua, a través de la reducción de la evapotranspiración del cultivo, sin comprometer su potencial productivo. Objetivo. Evaluar el efecto de 3 niveles de agotamiento del contenido de humedad volumétrica en un sustrato de fibra de coco, sobre el comportamiento vegetativo-generativo de los cultivos de tomate y chile dulce hidropónicos en invernadero. Materiales y métodos. El estudio se realizó en la Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. En ambos cultivos se aplicaron 3 tratamientos con 11, 22 y 32% de agotamiento hídrico en el sustrato, en un diseño experimental en bloques completos al azar. Se evaluaron parámetros morfofisiológicos y productivos tales como área foliar (AF), número de hojas (NH), ancho (AH) y longitud de hoja (LH), longitud (LT) y diámetro del tallo (DT), número de nudos (NN), materia seca (MS), conductancia estomática (gs), evapotranspiración del cultivo (ETc), eficiencia de uso de agua (EUA), rendimiento de fruto comercial (Rc) de primera (F1), segunda (F2) y tercera (F3), fruto de desecho (Fd) y rendimiento total (Rt). Resultados. En los tratamientos en tomate (TT) no hubo efecto sobre el NH, LH, LT y NN; mientras que con TT11 se obtuvieron valores superiores en AH, DT y MS. En chile dulce (TC), el TC11 obtuvo mayor NH, AH, LH, NN, DT y MS que los demás tratamientos; mientras que no hubo diferencias entre tratamientos en LT. En ambos cultivos, no hubo efecto sobre la ETc y el Rt, sin embargo, con 11% de agotamiento se obtuvo mayor producción comercial de F1 y F2 por lo que consecuentemente hubo mayor EUA con 37,32 kg.m-3 y 21,46 kg.m-3, respectivamente. Para ambos cultivos, la gs fue diferente entre tratamientos. Conclusión. En ambos cultivos, los tratamientos con 11 y 22% de agotamiento hídrico evidenciaron un adecuado balance entre crecimiento vegetativo y productivo, que se reflejó en mayor producción de frutos comerciales de mejor calidad, menos desecho y mayor EUA.