Studies conducted in controlled environments showed that seed priming and foliar treatments with various bioactive substances can stimulate germination, uniform seedling emergence, photosynthesis, and nutrient uptake efficiency and can lead to increased productivity, crop stand, and quality. Only a few studies provide a comparative experimental outlook about the use of the bioactive substances in open-field cultivated canola. The aim of this study was to investigate the effects of seed priming and foliar treatment with ascorbate (AsA), cysteine (Cys), and triacontanol (Tria) on the growth and yield parameters of two canola cultivars rapeseed cultivars (“Factor” and “Hybrirock”) under open-field conditions for three growing seasons under temperate conditions from Central Transylvania. Plant growth and yield parameters were recorded at different plant development stages: in autumn (early vegetative period), in spring, and at harvest. Not all substances that have undergone laboratory testing were successful in the field. Seed priming with 10 ppm Cys and AsA had beneficial effects on the development of seedlings, whereas their foliar application enhanced the number of silique, seed yield, and the oil content of the studied canola cultivars. The effects of Tria were visible on the biometrics parameters only in autumn and spring, and also on the root parameters, but in some cases, 10 ppm Tria had no effect on plants, or even a negative effect could be observed on important parameters for agriculture such as estimated seed yield, seed yield/plant, and oil content. Optimizing treatment and application by determination of the lowest effective concentration, together with the frequency of treatments and persistence effects are crucial for cost-effectiveness.

The Arieş River (Western Romania) represents one of the most important affluents of the Mureş River, with great significance in the Mureş Tisza basin. The environmental quality of the Arieş basin is significantly affected by both historic mining activities and contemporary impacts. Thus, an evaluation of the effects of the main contaminants found in water (organochlorine pesticides—OCPs, monocyclic aromatic hydrocarbons—MAHs, polycyclic aromatic hydrocarbons—PAHs, and metals) on cyanobacteria and plants was performed. Among OCPs, hexachlorocyclohexane isomers, dichlorodiphenyltrichloroethane, and derivatives were detected in plants while admissible concentrations were detected in water. Among MAHs, high levels of benzene were detected both in water and in plants. The levels of PAHs exceeded the allowable values in all samples. Increased concentrations of metals in water were found only at Baia de Arieş, but in plants, all metal concentrations were high. The pH, nitrates, nitrites, and phosphates, as well as metals, pesticides, and aromatic hydrocarbons, influenced the physiological characteristics of algae, test plants, and aquatic plants exposed to various compounds dissolved in water. Considering that the Arieş River basin is the site of intense past mining activities, these data provide information about the impact on water quality as a consequence of pollution events.

A cost-effective enhancement of leafy vegetable yield and health-promoting quality may be achieved by combining moderate stress conditions with the application of bioactive compounds. The aim of this work is to study how salt stress and triacontanol interact with each other in modulating vegetative growth, photosynthetic light use efficiency, carbon dioxide uptake, and chlorophyll and carotenoid pigment content of spinach plants grown under controlled conditions. Besides stimulating metabolic processes related to growth and photosynthetic production, treatments with 1 μM triacontanol once in three days significantly compensate for the deleterious effects of salt stress induced with 250 mM NaCl.

Organic compounds originating from plant metabolism and reaching the environment may inhibit or stimulate germination and early developmental processes of other plants grown in the vicinity. The aim of this study was to investigate the allelopathic interactions of brown mustard with four other aromatic plants (summer savoury, coriander, caraway and common sage). While health-promoting metabolites of brown mustard are thoroughly investigated and the plant receives an increasing interest from cultivators of aromatic and medicinal plants, its allelopathic interactions with other aromatic plants are poorly documented. The experiments were performed in closed germination vessels, under controlled conditions. The influence of the presence or absence of light, as well as of a sufficient or reduced water supply on the co-germination of brown mustard seeds with each of the other four aromatic plants was also evaluated. The presence of brown mustard reduced the germination velocity of caraway, coriander, sage and savoury. It inhibited stem elongation, but stimulated root growth of savoury. Shoot growth of coriander seedlings was enhanced by the vicinity of brown mustard plantlets. Caraway slowed down the germination of brown mustard seeds, but it stimulated root and stem elongation of the seedlings. The presence of savoury enhanced the fresh biomass production of brown mustard. Common sage inhibited root growth, but stimulated stem elongation of brown mustard plantlets. Most of the allelopathic effects were more pronounced under water shortage than under sufficient water supply. Positive interspecific influences on biomass production were, in most cases, more pronounced in the presence of light. The findings may contribute to optimization of brown mustard cultivation in small parcels, in the vicinity of other aromatic plants, some allelopathic interactions being able to stimulate growth and developmental processes in an environmental-friendly and cost-effective manner.

The aim of the study is to evaluate the suitability of a local strain of the microalga Scenedesmus opoliensis in remediation of water pollution with different amounts of chromium(VI), and also to identify new biochemical and physiological markers for a more reliable indication of sustainability and efficiency of bioextraction and phytoaccumulation processes. Quantitative analysis of photosynthetic pigments reveals that the chlorophylls to carotenoids ratio is a sensitive marker of chromium toxicity and of algal metal tolerance on which the remediative capacity relies. From among the chlorophyll fluorescence parameters, the Fv/Fm ratio, related to potential quantum yield of photochemical reactions, indicates that alkaline pH of the medium (8.65-9.15) favors algal vitality as compared to acidic conditions with pH values around 5. The highest extraction rate (91%) is achieved upon exposure of algae for one week to lower chromium concentrations (5 µM) in alkaline water environment, and a longer exposure time does not increase bioaccumulation. These results may directly contribute to optimization of remediation technology for chromium-polluted water, providing new markers and a new algal strain to be introduced in wastewater treatment.

Cultures of Scenedesmus opoliensis P. Richter, used as single-species test systems, were exposed to differently polluted water samples collected from distinct sectors of the Somes River, in order to identify physiological and biochemical markers suitable for a reliable bioindication of changes in the quality of aquatic environments. Algal cultures grown in Bold’s basal nutrient medium were used as control, and another reference consisted of cultures exposed to 25 µM CdCl2. Environmental stress exerted by water pollution induced changes in the antioxidative protection of algal cells. When only small amounts of hydrogen peroxide were generated, the activities of ascorbate peroxidase and of superoxide dismutase were enhanced, while the activity of these enzymes declined when hydrogen peroxide accumulated in cells. Vitamin C content of algal cells increased moderately, but significantly under water pollution. The chlorophylls to carotenoids ratio and net oxygen production decreased, while membrane lipid peroxidation increased in polluted water. Cell density was more affected than dry biomass. From among the parameters of induced chlorophyll fluorescence, potential quantum efficiency and vitality index exhibited the most sensitive changes in accordance with the pollution of aquatic environment. The above mentioned parameters of Scenedesmus opoliensis may be useful biochemical and physiological markers of water pollution.