Starting from the fact that the principles of agro-ecology become fundamental principles for the development of a green economy, especially in the context of current climate change, the effective capitalization of the ecological conditions of an agricultural area is one of the main objectives of agricultural science and practice. Identifying and formulating adaptive technological solutions can guide any producer to capitalize different climate and soil conditions. The sandy soils in Southern Oltenia offer less favourable ecological conditions, and the cultivation of watermelons is now profitable enough for such conditions. Growers are, however, interested in getting the most productive yields, early and profitable, even under the conditions of climate change. The current paper quantifies the grafting of watermelons in the conditions of the sandy soils of Dăbuleni, with poor soil supply, with meteorological drought phenomena and agricultural drought risk, in terms of quality and quantity of production under the climatic conditions in 2015-2017. The results, correlated with the climatic conditions, recommend the cultivation of grafted watermelons, offering the producers in the area a niche of ecological adaptation, ensuring the resistance of plants to abiotic, thermo-hydric stress factors, and improving the resistance to low temperatures, heat and drought.

Sorghum bicolor L. Moench is a herbaceous annual C4-type plant, with a high ecological plasticity because it can be grown in tropical, subtropical, temperate and semi-arid regions, harnessing soils with reduced natural fertility, from the category of sandy soils. Studies on 5 sweet sorghum hybrids studied under psamosols in southern Oltenia highlight a bioenergy potential in the milk-wax phase of the grain, ranging from 60847.4-89338.65 Mcal / ha, with a maximum in the hybrid Shaşm 2, which achieved a distinctly significant difference in production, compared to the average production of hybrids. The results recorded in sugar sorghum production were positively correlated, significantly distinct with leaf index determined during the flowering of the plants (r = 0.9854**).

Research into the cultivation of watermelons began many years ago. At the beginning, at RDSPCS Dăbuleni, the study of as many varieties and hybrids as possible was considered, in order to determine which ones find optimal conditions for growth and development on sandy soils and which meet the demands of the constantly changing market. Another important concern in the research activity at RDSPCS Dăbuleni was related to the obtaining of extra-early and early productions. In the traditional culture, established by direct sowing, mulching the soil with polyethylene ensured a production increase of 5.2 t/ha, 0.9 t/ha representing extra-early production, and in the seedling culture, by mulching the total production increased by 7.2 t/ha, and extra-early production increased by 2.3 t/ha compared to the non-mulched crop. Plant grafting, regardless of cultivar, rootstock and protection method, showed resistance to the attack of Fusarium oxysporum, even when crop rotation was not respected, but did not influence the attack of foliar pathogens (Alternaria cucumerina and Colletotrichum lagenarium).

The advanced homozygous tomato lines (L-13, L-10/9 and L-10/52) were subjected to an analysis of the variability of the main quantitative characteristics of the fruit (fruit weight, fruit height and diameter, shape index , pericarp thickness and soluble dry matter). The recorded biometric data were statistically processed, the average of the analyzed character (x‾), the standard deviation (s), the coefficient of variability (s%), the degree of dispersion (k = x‾ ± s) and the frequency of the individuals in the variability range ( f%). The statistical analysis of the recorded data showed that the three tomato lines are uniform in terms of variability of the main characters, the coefficient of variability having small and medium values for most of the characters analyzed, and represent a valuable material for the improvement of this species in sandy soil conditions.

The pedo-climatic conditions specific to sandy soils in southwest Oltenia determine differences in performing different phenophases of growth and development of plants, both between varieties and in the physiological behavior of the same variety under different yield conditions. Therefore, at the Dăbuleni Research and Development Station for Plant Culture on Sands, research was carried out on some physiological, biochemical and production processes at five varieties of bell peppers cultivated in the open fields and solar. Determinations of photosynthesis, foliar transpiration, the biochemical composition of fruits, quantity, and quality of bell pepper production were performed. The physiological and biochemical processes studied were influenced by the environmental conditions specific to each cultivation method, but also by the studied variables. Of the 5 varieties studied, the best results on the biochemical composition of the fruits were recorded at the Artim variety (8.83% total dry substance, 4.60% soluble dry substance, 0.19% acidity, 3.80% carbohydrate and 36.96% vitamin C). The production was between 15,387 t / ha for open-field plants and 108,574 t / ha for plants grown in the solar, the differences between the two cultivation methods being statistically assured as distinctly significant.