Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Lettuce is one of the most widely consumed vegetables globally. China is the leading producer of this crop, followed by the United States, which produces 3.3 million tons per year, with 90% of production concentrated in the south-western region, primarily in the states of California and Arizona. Various studies indicate that nitrogen fertilizer application rates between 363 and 470 kg ha-¹ achieve the highest yields in loose-leaf and ‘iceberg’ lettuce cultivation. However, of this application rate, only 40% of the nitrogen is absorbed by the crop, while the remainder is lost through leaching processes. This issue is compounded by the indiscriminate use of irrigation rates, which vary according to climatic conditions, ranging from 0.45 m ha-¹ in Colombia to 2.0 m ha-¹ in California. These two factors contribute to groundwatercontamination and increase production costs. The objective of this study was to evaluate, in terms of yield, two different irrigation rates and three nitrogen fertilization levels using a split-plot design arranged in a randomized complete block with four replicates. The variables analysed included NDVI index, chlorophyll content, stomatal conductance, sap nitrate concentration, yield, and dry biomass weight of lettuce. The results show no statistically significant differences in yield based on the different irrigation rates and nitrogen fertilization levels, suggesting that a change in the current technological package for this crop is feasible, allowing for the application of the treatment with the lowest irrigation rate (0.62 m ha-¹) and lower fertilization (94 kg ha-¹).

The production of Musa spp. AAA (banana) generates significant foreign exchange globally. For this reason, its cultivation requires tools that ensure healthy and robust plants from the early stages of development. This research aimed to evaluate the ef fect of Bacillus spp. and Trichoderma spp. on the development of banana seedlings (Musa spp. AAA) in the nursery stage. The study was conducted at Quinta Herrera, located at km 23.2 of the Quevedo – Ventanas road. Species of Trichoderma isolated from the Microbiology Laboratory at the Technical State University of Quevedo and microorganisms from two commercial products were studied. The treatments applied at the soil level were: T1: T. asperellum, T2: T. yunnanense, T3: T. asperellum + T.  yunnanense,  T4:  B.  subtilis,  T5: T. harzianum,  T6:  B. subtilis +  T. harzianum,  andT7: Absolute control. The trials were set up using a completely random design. The results showed that, with the combined application of B. subtilis + T. harzianum, the banana seedlings experienced significantly greater growth compared to the other treatments, with an average of 17.54 cm af ter 6 weeks of evaluation, and a pseudostem thickness of 12.50 mm during this period. Leaf emission was similar across all treatments; however, the development of the leaf area was greater in T6, which reached 1517.52 cm² at 20 weeks of seedling age. Finally, the combined application of the two native Trichoderma strains resulted in greater root development, with longer roots (32.93 cm) and consequently higher fresh and dry root weight, with averages of 367.93 g and 145.84 g, respectively. In conclusion, T6 (B. subtilis + T. harzianum) is recommended for improving the development of banana seedlings in the early or vegetative phenological stage under greenhouse conditions.  

Climate change is a global phenomenon, its repercussions disrupt the functioning and integrity of ecosystems. The most marked impact of climate change is water stress, hence the importance of plant selection studies and their strategies based on the availability of water in the soil. The current study aimed to establish how the xylem water potential (Ψ) in three native shrubs, such as Condalia warnockii (Rhamnaceae), Flourensia cernua (Asteraceae), and Larrea tridentata (Zygophyllaceae), is influenced by soil water content, air temperature, relative humidity, and rainfall. The study was carried out in an area located the municipality of Galeana, state of Nuevo Leon. Using a Scholander pressure bomb, the Ψ were estimated at 15-day intervals between June 3 and November 18, 2018, in four dif ferent plants per species at 06:00 h (predawn) and 14:00 h (midday). At the wettest period, Ψ oscillated from -1.13 to -4.27 MPa (C. warnockii) at predawn. In contrast, at midday, L. tridentata and C. warnockii achieved the highest (-1.46 MPa) and lowest (-3.75 MPa) Ψ values, respectively. Soil water content at dif ferent soil depths, and relative humidity were significantly and positively correlated with Ψ at predawn of C. warnockii and F. cernua; whereas air temperature was correlated with F. cernua and L. tridentata at midday F. cernua and L. tridentata maintained high values in Ψ at predawn and midday under water stress conditions, so these species may be considered as drought tolerant species.

Vegetation removal, soil erodibility, and rain erosivity trigger the movement of soil particles and eventually the formation of gullies. To minimize the impacts of soil erosion, conservation and restoration dams are of ten constructed using stone, wood, or other materials aimed at slowing the movement of soil particles and promoting water infiltration. The performance of these dams was evaluated by estimating the volume and weight of retained soil retained in micro-watersheds with pine-oak forests in Durango, Mexico. Soil density and volume data were obtained to determine the weight of the sediments, as well as the volume of trees found in the catchment area of the check dam. An analysis of variance test with the Monte Carlo permutationtechnique was applied to evaluate the ef fectiveness of the dam construction material in retaining sediments, organic matter content, and carbon. Quantile regression analysis was performed to analyze the relationship between sediment weight and tree vegetation. Results indicate no significant dif ferences in sediment retention, but there are dif ferences in the amount of retained organic matter and carbon content according to the type of construction material. Wooden dams were the most ef fective compared to stone dams. The weight of retained soil has an inverse relationship with the volume of trees. Sites with higher tree vegetation density tend to better protect the soil and reduce the amount of sediment deposited in the dams. These results can help develop forest management plans compatible with less soil degradation.

Among the options for improving Capsicum annuum L., fertilization increases nutrient availability. The objective was to evaluate eight bell pepper genotypes with two study factors: 1) greenhouse, 2) open field. The fertilization sources applied as treatments were: 1) solarized manure, 2) vermicompost, 3) poultry manure, and a control with Steiner solutions. The results show a significant difference between genotypes and fertilizers, mainly expressed in growth. Fruit weight for genotype 1 with cow manure or poultry manure, genotype 5 with cow manure or vermicompost and genotype 6 with chicken manure showed the best interactions with 81.5, 118.96, 75.63, 82.7 and 81.49 g. Therefore, there was a significant difference in the response of the genes involved in the control of the characteristics to fertilizers.  

Phosphorus (P) availability in the soil is a limiting nutrient for biomass production in agroecosystems developed in Andosols. Nonetheless, it remains unknown how soil structure af fects the storage and availability of this nutrient. Thus, this research aimed to evaluate the role of soil structure in phosphorus availability using Olsen P as a chemical indicator of availability. Undisturbed and disturbed soil samples were collected following a grid pattern under naturalized and sowed pastures that reflected two dif ferent soil structures (untilled and tilled, respectively). The untilled soil showed higher variability and a higher concentration of Olsen P (5-27 mg kg-1) than the tilled soil (14 mg kg-1).Undisturbed samples collected in cylinders showed that Olsen P continues to increase af ter removing the soil from the cylinder, sieving the sample, and re-extracting Olsen P, resulting in three times the amount of Olsen P found in disturbed samples collected before the experiment. The methodological approach used in this research allowed to highlight the role that soil structure plays in the availability of P over time to improve the ef ficiency of nutrient utilization.

The Ejido Puente Negro is characterized by the economic activities of farming and agriculture, despite having extensive periods of drought. Access to groundwater through dug wells is one of the main alternatives to meet the living needs of its inhabitants. However, poor practices have resulted in groundwater degradation, compromising phreatic mantles. The generation of treatment methods results in a good option to supply the population and ensure its quality. However, it is essential that residents are informed and have suf ficient knowledge to implement these practices. The present work shows a physicochemical study of groundwater from dif ferent wells located in the Ejido. A kinetic analysis of the desorption of sulfides was also carried out, concluding that their natural desorption is suf ficient to reduce more than 70% of their concentration in a period of 6 days. Additionally, the geology of the area is assessed in search of possible influence on groundwater contamination. Finally, a social study is presented about contaminated groundwater, the health implications involved in its consumption, and the understanding of purification and reuse processes.

Irrigation District 025, located in northeastern Mexico, faces adverse climatic conditions characterized by a dry climate and insufficient rainfall for optimal agricultural development. This situation has been exacerbated by Climate Change (CC), which has significantly reduced agricultural yields. Our study, classified as empirical with an associative strategy, aimed to evaluate the economic impact of water stress on agricultural production using three key indicators: the Economic Value of the Water Footprint (HHvalor), Irrigation Supply Efficiency (ESRhh), and Agricultural Production Value (Vp). The non-experimental methodology included theanalysis of water footprints, water productivity, current irrigation conditions, and agricultural and hydrometric statistics, associated with two scenarios: an ideal scenario without water stress (Baseline, LB) and a scenario with water stress (Real Condition, RC). Meteorological data were generated using WXGEN and processed with FAO’s CROPWAT 8.0 software to calculate irrigation requirements for the main crops. The results showed that the highest economic impact of water stress was obtained with HHvalor ($ 798 110 647.64), followed by ESRhh ($ 215 410 806.25) and Vp ($ 72 341 989.32), with an average impact of $ 361 223 351.00. The main limitations of the study included the lack of directly measured meteorological and physiological data for the crops. Nevertheless, the developed indicators and methodology provide effective tools to quantify and mitigate economic losses resulting from water stress, contributing to more efficient water management in agriculture. In conclusion, our main finding was that HHvalor allows for a comprehensive assessment of the economic impact of water stress on irrigated agricultural production, as it incorporates both the water footprints of crops and their intrinsic economic value.

The use of beneficial microorganisms and the application of liquid compost enriched with silicon constitute sustainable agroecological practices in rice (Oryza sativa) cultivation. The objective of this research was to evaluate the ef fect of agroecological practices and the use of silicon on the variables days to flowering and percentage of sterility of the panicle in the INIAP-14 rice crop in clay loam soil, at the State Technical University of Quevedo (UTEQ), Ecuador. The treatments evaluated consisted of T1= control without application; T2= Buf fago® insecticide (0.5 L ha-1); T3=, strain Ag, at 1×109 CFU mL-1; T4= liquid compost enriched with potassium silicate (K4SiO4)  (10  L  Azotobacter chroococum  ha-1);  T5=  Metarhizium  anisopliae,  strain  45 (1. 2 L ha-1) and T6= combination of A. chroococum + liquid compost enriched with K4SiO4 and M. anisopliae, in a completely randomized design with four replications. The analysis of variance showed significant dif ferences for both days to flowering and percent sterility. The results showed that treatment T6 presented the lowest significant values in days to flowering (72.8 days) and percentage of panicle sterility (9.0%) according to the Scott and Knott test. A non-linear sigmoidal relationship was found by Hill’s model between days to flowering and the percentage of panicle sterility, which indicates that for this cultivar and in these soil and climatic conditions, the lengthening of days to flowering increases the percentage of panicle sterility, suggesting that the application of A. chroococum + liquid compost enriched with K4SiO4 and M. anisopliae could be ef fective in decreasing the percentage of sterility of the rice panicle, thus increasing the yield of the crop developed with bioinputs accepted in agroecological practices.

The surface area of irrigated potatoes harvested in Mexico is 68 000 ha, of which 64% are irrigated and 36% rainfed with an average yield of 27.4 Mg ha-1 and an economic impact of 11 000 million pesos per year, placing this crop among the five main ones in the country. In the last 10 years, the use of fixed sprinkler systems has increased exponentially, mainly in northwestern irrigation districts. Nonetheless, a lack of scientific information exists on their ef fect on yield, quality, and irrigation water use. Therefore, the objective of the present research is to determine the ef fect of Naan Dan 5022 (A1) and Xcell Wobbler Senninger (A2) sprinklers on water yield, quality and use in Fiana variety of potato crop. The study was performed in Sinaloa, Mexico,  on  a  representative  soil  of  the  area,  establishing  three  treatments  (T)  in  a strip of land of 0.12 ha: T1 (A1) sprinkler and T2 (A2) sprinkler. The variables measured were operating pressure, irrigation depth, irrigation uniformity, application ef ficiency, biomass, Normalized Dif ference Vegetation Index (NDVI), yield and tuber quality; the last three variables were subjected to an analysis of variance and a mean test. The estimated yield for the best treatment was 42 Mg ha-1 using Xcell Wobbler sprinkler. At the end of this project, the use of Xcell Wobbler sprinkler is recommended due to its operation reliability at lower pressures and, in general, adapting to specific operating demands of the study area and improving potato crop production in the northern state of Sinaloa.