From the rich results generated by the combination of psychology and education in universities, it can be seen that the experimental education school that emerged in Europe and the United States in the late 19th century was a purely empirical spirit influenced experimental behavior in education and teaching; He pioneered a scientific educational experimental model, which is a milestone in the development history of education. It first introduces scientific experimental models into educational experiments through psychology, thereby promoting the development of educational experiments towards a scientific and standardized direction. This educational experiment of positivism paradigm, which evolved from the experimental research of psychology, is also the research paradigm advocated by psychological education in colleges and universities after the combination of college psychology and scientific education.

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.