The cultivation of sugar beet (Beta vulgaris L.) for table or horticultural purposes is largely carried out in the conventional way which is characterized by intense mechanization causing soil degradation and high labor costs. New cultivation techniques are being employed in the production of vegetables aiming to ensure improvements in environmental and economic conditions, such as the no-till farming system. Thus, the objective of this work was to evaluate the vegetable classification and physicochemical characteristics of beets from different corn planting densities. The experiment was conducted in the period from October 2018 to June 2019 in the municipality of Nova Laranjeiras (PR). Corn was used as a cover plant and the vegetable used was beet cultivar Early Wonder Tall Top. The experimental design used was in interspersed blocks in unifactorial scheme (corn densities 40, 60, 80, 100 thousand plants/ha and control) with four blocks, with plots 3.60 m long and 1.20 m wide. The parameters evaluated 60 days after planting were: commercial classification (class, group, subgroup, category), length, diameter, mass, pulp firmness, soluble solids, titratable acidity, pH and ratio, phenolic compounds. Of which the variables that were not significant at 0.5 probability were length, category (defects), firmness, subgroup (flesh color), soluble solids and phenolic compounds. It is concluded that high densities of corn as mulch for SPDH of sugar beet crop negatively affect the grade and physicochemical characterization of the products.

Different color-promoting treatments were tested on table grape cv. “Flame Seedlees” to evaluate changes on flavonoids such as anthocyanins and the residual ethylene produced. Treatments were spray-applied at the onset of veraison. The control was Ethrel at 250 ppm (ETH), Salicylic Acid at 100 ppm (AS), Melatonin at 25 ppm (MEL) and 1:1 mixtures of ETH+AS, ETH+MEL and AS+MEL. The trials were conducted in triplicate after harvest, measuring Total Soluble Solids (% TSS), total acidity (% tartaric acid), pH, residual ethylene (ppm) and anthocyanin content (mg∙cm^-2). It was found that treatments ETH, AS, MEL and ETH+AS reached 16% TSS, standing out with lower values ETH +MEL (14.27%) and AS+MEL (15.17%) (p ≤ 0.05). ETH reached 0.83 ppm of residual ethylene, while a sum effect was appreciated in ETH+AS (0.5 ppm) and ETH+MEL (0.35 ppm), but not beneficial as it did not reflect quality characteristics. Only differences (p ≤ 0.05) in anthocyanin content were recorded between ETH (0.019 mg∙cm^-2) and AS+MEL (0.003 mg∙cm^-2). The subjective color of the grape bunches in the field made it possible to relate it to the objective results of the analyses performed. This research provides commercially important information on the substitution of Ethrel by natural compounds such as AS and MEL, as they show similar effects on the quality of “Flame Seedless” table grapes. In addition, these compounds do not have an ethylene residual greater than 0.2 mg/kg.

Knowledge of the presence of heavy metals in soils of agricultural areas is important to prevent their accumulation in cultivated plants. The objective of the present investigation was to evaluate the total concentrations and fractions of heavy metals Cd, Pb, Zn, Fe, Mn, Ni, Cu, Cr and Co in the tobacco-growing area of Pinar del Río, Cuba and their relationship with the physicochemical properties of soil. For the study, 59 samples of three types of soils were collected at 20 cm depth. The pseudo-total concentrations of metals in the soils are low and lower than the prevention values registered for Cuban soils. In general, the heavy metals studied present a high affinity for the most stable fractions of the soil, which means a low risk of transfer to the tobacco crop or accumulation in groundwater. The pseudo-total concentrations of heavy metals were low, below the alert values established for soils in the region. The heavy metals studied were mainly associated with the residual fraction, the second fraction with the highest association with metals was that linked to manganese and iron oxides. The principal component analysis showed that their main source is pedogenetic and that these elements are closely related to cation exchange capacity and calcium content.

Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote the solubilization of insoluble phosphate complexes, together benefiting plant nutrition. The use of these organisms in combination with minerals or rocks that provide nutrients is another alternative to maintain crop productivity. The objective of this work was to combine AMF and S with pyroclastic materials (ashes and pumicites) from the Puyehue volcano and phosphoric rocks (PR) from the Río Chico Group (Chubut) and to evaluate the performance of these mixtures as substrates for potted production of Lactuca sativa. To formulate the substrates, a mixture of Ter-rafertil® with ashes was used as a base. Penicillium thomii was the S and spores of the fungus Rhizophagus intraradices (AEGIS® Irriga) served as the source of AMF. Various combinations of microorganisms and the addition or not of RP were evaluated. The treatments were: (1) substrate; (2) substrate + AMF; (3) substrate + S; (4) substrate + AMF + S; (5) substrate: PR; (6) substrate: PR + AMF; (7) substrate: PR + S, and (8) substrate: PR + AMF + S. There were 3 replicates per treatment. The parameters evaluated were total and assimilable P content in the substrate, P in plant tissue and dry biomass. All of them were significantly higher in the plants grown in the substrate added with PR and inoculated with S and AMF. This work confirms that the S/AMF combination with volcanic ashes from Puyehue and PR from Grupo Río Chico formulated with a commercial substrate promote the growth of L. sativa. Thus, it is possible to increase the added value of geomaterials of national origin.

The detection of urban expansion through digital processing of satellite images provides valuable information for understanding the dynamics of land use change and its spatial relationship with environmental factors. In order to apply or generate effective land-use planning policies, it is essential to have a historical record of the regional distribution of human settlements, an element that is practically non-existent in our country. For this reason, this text aims to determine the urban growth rate during the period 2000–2014 in the state of Hidalgo, Mexico, and to identify potential expansion zones from Landsat images. Six Landsat scenes were used for the spatial analysis of the state urban coverage and their relationship with the road influence area was evaluated. Two maps were obtained as cartographic products: one of urban coverage distribution and another of the municipalities with the greatest expansion, whose areas are located in the Valle del Mezquital region. However, Mineral de la Reforma, Tetepango, Tizayuca and Pachuca de Soto stand out for their growth rates during the study period: 183.44%, 102%, 94% and 68.5%, respectively. In total, the state urban area in-creased 72.3 km² from 2000 to 2014 with an average growth rate of 1.8% per year. Such growth was associated with the areas of influence of important road infrastructure, such as the Libramiento Arco Norte in Hidalgo. Therefore, the Mezquital Valley and the Mexico Basin are considered as potential regions for urban expansion in the state.

Objective: To evaluate the ponticulus posticus according to the skeletal relationship found in strict lateral radiographs at the Centro Dental Docente of the Universidad Peruana Cayetano Heredia during the period 2015–2017, using the classification according to the degree of mineralization described by Selby and Steiner’s skeletal relationship classification. Material and methods: It was performed on digital strict lateral radiographs using a 20-inch screen using the SIDEXIS XG program, observing the degree of mineralization of the ponticulus posticus: without evidence of the bony spicule over the vertebral artery = absent bridge, when spicule formation and/or calcification was noted or evident in the middle of the bridge or incompletely = partial bridge, when the bony arch was evident finished visualizing = complete bridge and the classification of the skeletal relationship by measuring the ANB angle: Class I = 0–4°; Class II = >4° and Class III = <0°: the statistical analysis was done with the SPSS V program.22.0 for Windows using the Chi-square tests. Results: Of the 925 digital strict lateral radiographs evaluated, 283 radiographs were found to present ponticulus posticus and the highest frequency was found in the absent type (69.4%), the partial type (17.1%) and the complete type (13.5%). The ponticulus posticus was present in 25.1% of the female and 38.4% of the male. The skeletal relationship associated with ponticulus posticus was present in Class II (19.1%), Class I (10.4%) and Class III (1.1%). Conclusions: The ponticulus posticus is an anatomical variant present in 30.6% of cases. No statistically significant difference was found between the presence of ponticulus posticus and skeletal relationship or sex.