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

Cereals are a fundamental part of the world diet; therefore, their adaptation in different environments due to climate change should be achieved. Studying the modif ications that may occur during plant development is essential, as well as in the quality of the harvested product. Thus the objective of this research is to analyze the effect of water stress on development, growth, production, and agronomic quality of rye crop and harvested grain. For sowing, a completely randomized one-way experimental design was used, where the treatments consisted of three different soil moisture regimes. The variables evaluated at the time of harvest were plant height and number of spikes per linear meter. After harvest, the variables evaluated were spike size and the number of grains it contained, as well as size and color of the grain, weight of 1000 grains, test weight, yield, ash and protein content. An analysis of variance and Tukey’s comparison of means test (P < 0.05) were performed for ash and protein content, and Duncan (P < 0.05 and P ≤ 0.0001) for the rest of the determinations. The results showed that less irrigation did not negatively affect the crop with an appropriate agronomic development, highlighting an increase in the number and size of spikes, an increase in the number of grains per spike, as well as a high yield and protein content of the grain. These values were higher than those reported in previous research, which conf irms that even though rye is considered a winter cereal, it managed to acclimate to soil conditions, decreased water, and high temperatures in the coastal area of Hermosillo, Sonora, México.

The incorporation of biochar obtained from husks, stubble, forest residues, manures, among other residues into the soil can improve the growth of crops. The objective of our study was to evaluate the effect of sugarcane apice biochar (SAB) on the growth of thai basil (Ocimum basilicum var. thyrsiflora) grown in a greenhouse. The treatments consisted of mixtures of biochar and sandy loam soil (v/v) at 0 (control), 7, 14, 21 and 28% concentrations. Plant height, fresh and dry matter, foliar area, SPAD units and the foliar nutrient concentration were evaluated. The use of 7% SAB increased the fresh matter (45.1%), dry matter (35.2%) and foliar area (54.5%). On the other hand, the 21% SAB treatment showed the highest foliar concentration of total-N (44.33 g kg-1), P (9.55 g kg‑1) and Ca (12.61 g kg-1). We conclude that sugarcane apice biochar can be incorporated into the soil as an alternative in the agronomic management of Thai basil.

Riparian vegetation plays an important role in reducing the input of pollutants into water bodies. Water availability in Ecuador is plenty, however, rural areas are without access to quality water and agricultural expansion reduces riparian vegetation. The aim is to assess the quality of the water resource inf luenced by riparian vegetation in the rural area of the canton Mocache in Ecuador. The quantitative method was used. Eight physical, chemical and microbiological parameters were analysed at 12 sampling points with and without vegetation. Concentrations were compared with national (Tulsma) and international, World Health Organization, and United States Environmental Protection Agency (WHO and EPA) standards. We applied two water quality index (WQI), such as Dinius (1978) and NSF (1972). The results indicate a high concentration of total suspended solids in unvegetated areas (52.00 mg L-1) and the water does not meet the EPA standard for agricultural use. Faecal contamination is extremely high, the maximum concentration of faecal coliforms is 1 538.00 NMP.100ml-1in areas with vegetation and 23 493.33 NMP.100ml-1 for total coliforms in sites without f lora. The WQIs showed dif ferences in their quality assessment, Dinius characterized the water as regular to excellent while NSF as poor to regular. The water resources have faecal contamination and represent a risk for human consumption. Likewise, riparian vegetation does not inf luence water quality (P > 0.05).

The disease known as tar spot (Phyllachora maydis) af fects corn (Zea mays). It causes lesions on the leaves that, when progressing, can cause the death of the plant. There are dif ferent methods to assess the progress of a disease in plants. Visual assessment scales are generally used; however, their use is quite subjective. Image processing has been used in recent times as an alternative for the evaluation of plant diseases. This alternative avoids bias and error during evaluations. The objective of this experiment was to use the Leaf Doctor cell phone application as an alternative to the evaluation of the disease caused by P. maydis. For the experiment, a completely randomized block design was used. Three varieties of corn were planted and the level of tolerance to tar spot was evaluated when treated with dif ferent doses of silicon. The most resistant variety to the disease was INIAP-551. The dif ferent doses of silicon do not reduce the disease; however, it was possible to determine an increase in the production of corn in doses of silicon of 252 kg ha-1. The results indicate that the program can be considered as an ef f icient alternative to evaluate the development of the disease known as tar spot due to the high correlation with the visual assessment scale (R2: 0.77-0.94).

Iron (Fe) is an essential trace element for human health and its deficiency affects 1.2 billion people in the world. Agronomic biofortification can mitigate this deficiency as its application in crops improves the biosynthesis of bioactive compounds and promotes their bioaccumulation. Our research aims to evaluate the effect of the foliar application of Fe (FeSO4) on the yield, biosynthesis of bioactive compounds and accumulation in lettuce. For this, five treatments were applied by foliar route: 0, 10, 20, 30 and 35 µM L‑1. At harvest, the nutraceutical quality and the accumulation of Fe in leaves were quantified, as well as the productivity of the lettuce plant. Biofortification with Fe positively modified the biosynthesis of phytochemical compounds and their concentration in lettuce leaves, without affecting the yield. Fe foliar spraying is an alternative to increase the biosynthesis of phytochemical compounds and increase the concentration of this element in lettuce.

The "omics" technologies are novel tools that facilitate the study of microbial communities in different ecosystems, particularly the biological soil crust, also called biocrust. These technologies include genomics, transcriptomics, proteomics, metabolomics, and metagenomics, which are used to analyze the diversity and functions carried out by microorganisms through the study of their biomolecules and metabolic pathways. Among the microorganisms that inhabit the biocrust are the cyanobacteria, which are a group of phototrophic bacteria responsible for important processes in the soil, such as the fixation of atmospheric nitrogen, organic carbon, chlorophyll and phycobilin synthesis, as well as the production of exopolysaccharides to improve soil stability and fertility. Therefore, the objective of this review is to explore the diversity and role that these microbial communities play in the biocrust, particularly cyanobacteria, highlighting studies conducted using omics technologies. The knowledge generated in recent years through omics technologies has demonstrated the limited coverage of traditional molecular techniques, resulting in an underestimation of the real diversity of microbial communities. In addition, there has been an improvement in the understanding of the ecological processes developed by the microorganisms for the benefit of the biocrust, as well as the individual and collective functional capacities, which will serve as a baseline to propose important strategies to solve the problem of soil degradation.

Zucchini is a vegetable of great agricultural and social relevance in Mexico, hence, the implementation of alternatives such as the use of products of biological origin, can contribute to the improvement and increase of profits in this crop. The objective of this study was to determine the effect of chemical and biological fertilization on the growth, yield, and profitability of the zucchini crop. The study was established under irrigation in Tlayacapan, Morelos, Mexico, where seedlings of Italian zucchini variety Adelita were transplanted. The treatments consisted of the application of seaweed extract [Ascophyllum nodosum (L.) Le Jolis] and Rhizophagus irregularis (Błaszk., Wubet, Renker & Buscot) C. Walker & A. Schüßler (2010) to the soil mixed with chemical fertilizers. A random complete block design with four repetitions was used. To evaluate crop growth and leaf area dry matter per plant was recorded, with which the growth rate of the crop, absolute growth rate, crop yield, weight, diameter, and length of the fruit were determined. In addition, an economic analysis was performed to determine the profitability of each treatment. Overall, it was observed that the application of 100% chemical fertilization promoted the largest leaf area, fresh plant weight, dry matter, absolute growth rate, crop growth rate, yield, and fruit weight in zucchini cultivation, which caused improved profitability. Fertilization with seaweed complemented chemical fertilization and generated a better response in the variables evaluated compared to R. irregularis.

Heavy metals can be found in agricultural soils, absorbed and accumulated by crops, representing a public health risk. This research aimed to study the influence of agricultural practices on the concentration of heavy metals cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) in lettuce irrigated with treated water and determined the level of risk to human health. Four treatments were evaluated: (1) Flood irrigation without mulch and compost; (2) Drip irrigation without mulching with compost; (3) Drip irrigation with mulch without compost; (4) Drip irrigation with mulch and compost. The detected concentrations of Cd, Cr, Pb and Zn in the edible part of lettuce exceeded the maximum permissible levels in vegetables established by the European Union reference. In the case of Cd, it showed a high capacity to be transferred from the soil to the plant, which represents an even greater health risk. The agronomic practices of drip irrigation, using water from a wastewater treatment plant, plastic mulch and organic fertilizer slightly reduce the concentration and transfer rate of Cd, Cr, Cu, Pb and Zn in the edible part of lettuce, promoting an increase in biomass production, which in turn affects the dilution of heavy metals in plant tissues.

Studies on species natural distribution are necessary to determine the effect of social and environmental conditions on spatial distribution. The objectives of this research were to know the natural distribution of pine species considered at risk by Mexican laws and identify the possible association between these categories and socio-environmental factors (marginalization, soil degradation and forest productivity). For this purpose, a database was created on location and socioeconomic characteristics of the pines created from various sources. The independence between the risk categories of the pines and the socio-environmental factors was evaluated by means of a contingency analysis, which considers a chi-square statistics test. Of the 20 listed pine species, a total of 2480 records were obtained. Highly marginalized areas recorded 4.48%, high 26.21%, medium 18.47%, and low 50.85%. Thirteen species are found on degraded soils; 55.79% of the records are in a moderate situation, 37.76% light, 6.22% strong, and 0.21% extreme. Production, areas recorded 65.89% (of the total species), 30.81% in Conservation and 3.31% in restoration. The chi-square statistics test showed that the proportions of pine species in danger of extinction ─and in special protection─ are not the same in the different types of forest zoning, as well as in the different degrees of marginalization and soil degradation.

Nutrient solutions with balance in ion ratios, proportions and concentrations optimize nutrient use ef f iciency and crop yield. The objective of this study is to evaluate under greenhouse conditions three percentage ratios Mg2 + (20, 30 and 40/100) and three of NO3- (40, 60 and 80/100) and their combination on the mineral composition, nutrient use ef f iciency (EUN) and the yield of cucumber (Cucumis sativus cv. Poinsett 76) developed in hydroponics. The experimental design was completely randomized with a factorial arrangement of 32 treatments and six replicates. The variables evaluated were mineral composition of leaves, stems and fruit, ef f iciency in the use of nutrients, and weight, diameter, length, number, and yield of fruit. The results were analyzed with the analysis of variance (ANOVA) and the means were compared with Tukey’s test (P ≤ 0.05). The superior yield was with the combination 20/100 Mg2+ and 60/100 NO3-, higher ratios of Mg2+ (40 and 60/100) and NO3- (80/100) reduced yield 33.4%, 30.7% and 20.6%, respectively, and decreased the ef f iciency of Mg and N, compared to 20/100 Mg2+ and 60/100 NO3-. The 60/100 Mg2+ ratio increased the nutrient concentration of Mg in the fruit, but decreased yield.