Heavy metals like cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn), resulting from anthropogenic activities, are elements with high persistence in nature, being able to accumulate in soils, water, and plants with significant impact to human and animal health. This study investigates the phytoremediation capacity of Silphium perfoliatum L. as a specific heavy metal hyperaccumulator and the effects of Cu, Zn, Cd, and Pb on some physiological and biochemical indices by growing plants under floating hydroponic systems in nutrient solutions under the presence of heavy metals. One-year-old plants of S. perfoliatum grown for 20 days in Hoagland solution with the addition of (ppm) Cu-400, Zn-1200, Cd-20, Pb-400, and Cu+Zn+Cd+Pb (400/1200/20/400) were investigated with respect to the control. The level of phytoremediation, manifested by the ability of heavy metal absorption and accumulation, was assessed. In addition, the impact of stress on the proline content, photosynthetic pigments, and enzymatic activity, as being key components of metabolism, was determined. The obtained results revealed a good absorption and selective accumulation capacity of S. perfoliatum plants for the studied heavy metals. Therefore, Cu and Zn mainly accumulate in the stems, Cd in the roots and stems, while Pb mainly accumulates in the roots. The proline tended to increase under stress conditions, depending on the pollutant and its concentration, with higher values in leaves and stems under the associated stress of the four metals and individually for Pb and Cd. In addition, the enzymatic activity recorded different values depending on the plant organ, its type, and the metal concentration on its substrate. The obtained results indicate a strong correlation between the metal type, concentration, and the mechanisms of absorption/accumulation of S. perfoliatum species, as well as the specific reactions of metabolic response.

There is an increasing interest in developing natural methods to replace the current chemicals used for maintaining postharvest quality of citrus fruits. The essential oil antifungal activity of mint (MEO), basil (BEO), and lavender (LEO) acting as the vapor-phases was tested against Penicillium digitatum. The minimum doses with fungistatic and fungicidal effect, in vitro, acting as the vapor-phases, were set up. The minimum fungicidal dose was 300 μL for BEO and 350 μL LEO, while for MEO only minimal dose with fungistatic effect was reached. The IC50 values were calculated and used (v/v) for testing preservation of lemon fruits, in close space enriched in vapor oil. For this purpose, the following two independent in vivo experiments were carried out: experiment 1, inoculated lemons with P. digitatum stored without chemical treatments 7 days, at 22 ± 2 °C, at two concentrations (C1—IC50 equivalent; C2—half of C1); and experiment 2, the non-inoculated lemons kept under the same conditions and concentrations of EO vapor served to evaluate the lemon quality properties. The results showed that antifungal protective effect was provided in the order of LEO-C1 > BEO-C1 > MEO-C1 > BEO-C2 > MEO-C2 > LEO-C2. The quality indicators like weight loss, pH, and firmness were not negatively influenced.

Romania has a wide variety of local landraces and heirloom genotypes. Our study aims to assess the performance of twenty halotolerant tomato landraces, collected from areas with medium and high levels of soil salinity, in terms ofthe accumulation of antioxidant compounds in fruits and to cluster them according to their nutraceutical components. The tomatoes used in the study were harvested once they had attained full ripeness and then analyzed for lycopene (Lyc), ascorbic acid content (AsA), total phenolic content (TPC), and total antioxidant capacity (TAC). The results revealed major differences between genotypes in terms of nutraceutical values. According to principal component analysis, the tomato landraces were grouped into five clusters, characterized by different proportions of compounds with antioxidant activity. The high/moderate nutritional values of Lyc, TAC, TPC, and AsA were obtained from varieties taken from local lands with high soil salinity, over 6.5 dS m⁻¹. These findings support the idea that metabolites and secondary antioxidants are involved in the process of stress adaptation, thereby increasing salinity tolerance in tomatoes. Our results show that there are tomato landraces with a tolerance of adaptation to conditions of high soil salinity and provide information on their ability to synthesize molecules with antioxidant functions that protect plants against oxidative damage.

This paper presents the development of a cost-effective automatic system for greenhouse environment control. The architectural and functional features were analyzed in the context of the realization of a controlled-environment agricultural system through all its stages: installation, deployment of the software, integration, maintenance, crop control strategy setup and daily operation of the grower. The proposed embedded platform provides remote monitoring and control of the greenhouse environment and is implemented as a distributed sensing and control network integrating wired and wireless nodes. All nodes were built with low-cost, low-power microcontrollers. The key issues that were addressed include the energy-efficient control, the robustness of the distributed control network to faults and a low-cost hardware implementation. The translation of the supervisory growth-planning information to the operational (control network) level is achieved through a specific architecture residing on a crop planning module (CPM) and an interfacing block (IB). A suite of software applications with flows and interfaces developed from a grower-centric perspective was designed and implemented on a multi-tier architecture. The operation of the platform was validated through implementation of sensing and control nodes, application of software for configuration and visualization, and deployment in typical greenhouses.

Soil salinity is one of the best known stress factors of plants that can lead to crop yield reduction. Therefore, it is important to identify new tolerance varieties of plants that can grow on saline soils. We have studied the influence of salt on five different tomato varieties from the Western region of Romania and compared them with a commercial hybrid and found that one of them (Rudna) is a very salt-tolerant variety (up to 200 mM NaCl). The assimilation rates and stomata conductance of water vapour are affected by salinity but some of the local varieties of tomato exhibit quite good tolerance. We found that all plants under salinity stress emit (Z)-3-hexenol (a C6, green leaf volatile) and the emission of all terpenes increased in proportion to the salt concentration. The emission of three terpenes, (Z)-beta-ocimene. 2-carene and beta-phellandrene, have been quantitatively correlated with salt concentration.