Enhancing the nutritional value of sweet pepper through sustainable fertilization management.

Introduction: The need for healthy foods has become a major concern in our modern world, as the global population continues to grow and environmental challenges intensify. In response to these challenges, researchers have started to explore a range of sustainable solutions, including organic farming practices, precision agriculture, and the development and testing of innovative biofertilizers. Consistent with these ideas come the aim of this study, which sets out to give new insights into the cultivation of two sweet pepper cultivars with economic and nutritional importance in Romania. Methods: Two sweet pepper cultivars (Blancina and Brillant), chemically (Nutrifine®), organically (Orgevit®) and biologically (Micoseed®) fertilized were cultivated over the course of two years (2019 and 2020), between April and October, in high-tunnel, by following a split-plot design with three replications. Production parameters (number of fruits, fruit weight, yield), proximate composition (water content, dry matter, total soluble solids, acidity, ash), the content of phytonutrients (polyphenols, lycopene, ß-carotene, antioxidant activity), phytochemical composition (phenolic compounds) and minerals (macro- and micro-elements) were analyzed in order to determine the impact of fertilization on the quality of sweet peppers. Results: The results showed that the biological and organic fertilizations had a significant positive impact on most of the parameters analyzed, starting with yield and continuing with acidity, phytonutrient content (total phenolic content, lycopene, ß-carotene), antioxidant activity and phytochemical composition (chlorogenic acid, p-coumaric acid, quercetin and isoquercetin). Only in the case of mineral content, the chemical treatment gave better results compared with the organic and biological fertilizers. Conclusion: Overall, this study provides valuable information on the potential of organic and biological fertilizers to enhance the nutritional value of sweet peppers from Blancina F1 and Brillant F1 cultivars, paving the way for subsequent research aimed at achieving superior quality and increased yields.

Comparative Evaluation of Antioxidant Status and Mineral Composition of Diploschistes ocellatus, Calvatia candida (rostk.) Hollós, Battarrea phalloides and Artemisia lerchiana in Conditions of High Soil Salinity.

Natural reserves play a fundamental role in maintaining flora and fauna biodiversity, but the biochemical characteristics of such ecosystems have been studied in an extremely fragmentary way. For the first time, mineral composition and antioxidant status of three systematic groups of organisms, lichens (Diplischistes ocellatus), mushrooms (Calvatia candida and Battarrea phalloides) and wormwood (Artemisia lerchiana) have been described at the territory of Bogdinsko-Baskunchak Nature Reserve (Astrakhan region, Russia), characterized by high salinity and solar radiation, and water deficiency. Through ICP-MS, it was determined that scale lichen D. ocellatus accumulated up to 10-15% Ca, 0.5% Fe, 15 mg kg-1 d.w. iodine (I), 54.5 mg kg-1 Cr. Battarrea phalloides demonstrated anomalously high concentrations of B, Cu, Fe, Mn Se, Zn, Sr and low Na levels, contrary to Calvatia candida mushrooms accumulating up to 10,850 mg kg-1 Na and only 3 mg kg-1 Sr. The peculiarity of A. lerchiana plants was the high accumulation of B (22.23 mg kg-1 d.w.), Mn (57.48 mg kg-1 d.w.), and antioxidants (total antioxidant activity: 68.6 mg GAE g-1 d.w.; polyphenols: 21.0 mg GAE g-1 d.w.; and proline: 5.45 mg g-1 d.w.). Diploschistes ocellatus and Calvatia candida demonstrated the lowest antioxidant status: 3.6-3.8 mg GAE g-1 d.w. total antioxidant activity, 1.73-2.10 mg GAE g-1 d.w. polyphenols and 2.0-5.3 mg g-1 d.w. proline. Overall, according to the elemental analysis of lichen from Baskunchak Nature Reserve compared to the Southern Crimean seashore, the vicinity of Baskunchak Salty Lake elicited increased environmental levels of Cr, Si, Li, Fe, Co, Ni and Ca.

Effects of Plant Biostimulation Time Span and Soil Electrical Conductivity on Greenhouse Tomato 'Miniplum' Yield and Quality in Diverse Crop Seasons.

Biostimulants help plants cope with environmental stresses and improve vegetable yield and quality. This study was conducted to determine the protein hydrolysate (PH) effect of three different durations (weekly applications: three, six, or nine times plus an untreated control) in factorial combination with four soil electrical conductivities (EC: 1.5, 3.0, 4.5, or 6.0 mS·cm-1) on yield, fruit quality, and elemental composition of tomato 'miniplum' grown in a greenhouse. Fruit yield was best affected, during the summer, by six and nine biostimulant applications at EC 3.0 mS·cm-1, and in the same season, the six treatments led to the highest fruit number with no difference compared to nine applications; during the winter, the three and six treatments improved the mentioned variables at each EC level. Fruits' dry residue and Brixo were positively affected by biostimulation both in summer and winter. In summer, the 6.0 mS·cm-1 EC led to the highest dry residue and Brixo values, though the latter did not show any significant difference compared to 4.5 mS·cm-1; in winter, the best results corresponded to 4.5 and 6.0 mS·cm-1. A higher beneficial effect of PH on fruit antioxidant status, i.e., lycopene, polyphenols, ascorbic acid levels, and lipophilic (LAA) and hydrophilic (HAA) activity, was recorded in winter compared with summer. Positive correlations between polyphenols and LAA, as well as ascorbic acid content and HAA were found for all EC and PH treatments. Most of the mineral elements tested demonstrated concentration stability, whereas the highest EC decreased P, Mg, Cu, and Se accumulation. The opposite effect was shown by PH application on Se and Mn levels, with P tending to increase. The concentrations of Fe, Zn, and Cu were the lowest under the longest duration of PH supply. These results further confirm the essential role of plant biostimulation in enhancing tomato yield and quality, with a particular focus on the treatment duration.

Effect of Sodium Selenate and Selenocystine on Savoy Cabbage Yield, Morphological and Biochemical Characteristics under Chlorella Supply.

Biofortification of Brassica oleracea with selenium (Se) is highly valuable both for human Se status optimization and functional food production with direct anti-carcinogenic activity. To assess the effects of organic and inorganic Se supply for biofortifying Brassica representatives, foliar applications of sodium selenate and selenocystine (SeCys2) were performed on Savoy cabbage treated with the growth stimulator microalgae Chlorella. Compared to sodium selenate, SeCys2 exerted a stronger growth stimulation of heads (1.3 against 1.14 times) and an increase of leaf concentration of chlorophyll (1.56 against 1.2 times) and ascorbic acid (1.37 against 1.27 times). Head density was reduced by 1.22 times by foliar application of sodium selenate and by 1.58 times by SeCys2. Despite the greater growth stimulation effect of SeCys2, its application resulted in lower biofortification levels (2.9 times) compared to sodium selenate (11.6 times). Se concentration decreased according to the following sequence: leaves > roots > head. The antioxidant activity (AOA) was higher in water extracts compared to the ethanol ones in the heads, but the opposite trend was recorded in the leaves. Chlorella supply significantly increased the efficiency of biofortification with sodium selenate (by 1.57 times) but had no effect in the case of SeCys2 application. Positive correlations were found between leaf and head weight (r = 0.621); head weight and Se content under selenate supply (r = 0.897-0.954); leaf ascorbic acid and total yield (r = 0.559), and chlorophyll (r = +0.83-0.89). Significant varietal differences were recorded for all the parameters examined. The broad comparison performed between the effects of selenate and SeCys2 showed significant genetic differences as well as important peculiarities connected with the Se chemical form and its complex interaction with Chlorella treatment.

Yield, Growth, Quality, Biochemical Characteristics and Elemental Composition of Plant Parts of Celery Leafy, Stalk and Root Types Grown in the Northern Hemisphere.

Celery is one of the major nutraceutical vegetable species due to the high dietary and medicinal properties of all of its plant parts. Yield, growth and produce quality of six celery genotypes belonging to leafy (Elixir and Samurai), stalk (Atlant and Primus) or root (Egor and Dobrynya) types, as well as the distribution of biomass, sugars, mineral elements and antioxidants among the different plant parts, were assessed. Within the celery root type, cultivar Dobrynya resulted in higher yield than Egor, whereas the genotype did not significantly affect the marketable plant part production of leafy and stalk types. Leaf/petiole ratios relevant to biomass, total dissolved solids, sugars, ascorbic acid, flavonoids, antioxidant activity and ash, K, Zn, Fe, Mn, Cu and Se content were significantly affected by the celery type examined. Ash content was highest in the leaves and lowest in the roots. Celery antioxidant system was characterized by highly significant relationships between ascorbic acid, polyphenols, flavonoids, antioxidant activity and Zn. Among the celery types analyzed, the highest values of chlorophyll, Fe and Mn content as well as antioxidant activity were recorded in leaves from root genotypes, which suggests interesting nutraceutical prospects of the aforementioned plant parts for human utilization.

Screening of Chilli Pepper Genotypes as a Source of Capsaicinoids and Antioxidants under Conditions of Simulated Drought Stress.

In many regions of the world, the production of vegetable crops is limited by a deepening water crisis. Drought stress affects productivity and the chemical composition of crops. The variability of drought tolerance between species and cultivars of economically important crops, such as pepper (Capsicum species), requires specific investigations to understand the physiological and biochemical responses to the aftermath of drought. The fruits and leaves of four chilli pepper cultivars were investigated to elucidate the fruits' pungency (Scoville Heat Units, SHU), ascorbic acid content, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, polyphenol content, membrane lipid peroxidation and key protective antioxidant enzyme activity under drought stress (18-28% volumetric water content) as compared to the control (35-60%). Drought increased the chilli pepper fruits' pungency expressed in Scoville Heat Units (SHU) as well as ascorbic acid content, but this relationship was also dependent on genotype and stress duration. 'Jolokia' was marked as most sensitive to drought by increasing content of capsaicinoids and DPPH˙ scavenging activity under stress conditions. Capsaicinoids and Ascorbic acid (AsA) greatly influenced the antioxidant activity of highly pungent chilli pepper fruits, although total phenols played a significant role in the mildly pungent genotypes. Generally, the activities of antioxidant enzymes increased under drought in chilli pepper leaves and fruits, although the intensity of the reaction varied among the cultivars used in the current research. All the investigated biochemical parameters were involved in the drought response of chilli pepper plants, but their significance and effectiveness were highly cultivar-dependent.

Prospects of Arbuscular Mycorrhizal Fungi Utilization in Production of Allium Plants.

The need to improve crop yield and quality, decrease the level of mineral fertilizers and pesticides/herbicides supply, and increase plants' immunity are important topics of agriculture in the 21st century. In this respect, arbuscular mycorrhizal fungi (AMF) may be considered as a crucial tool in the development of a modern environmentally friendly agriculture. The efficiency of AMF application is connected to genetic peculiarities of plant and AMF species, soil characteristics and environmental factors, including biotic and abiotic stresses, temperature, and precipitation. Among vegetable crops, Allium species are particularly reactive to soil mycorrhiza, due to their less expanded root apparatus surface compared to most other species. Moreover, Allium crops are economically important and able to synthesize powerful anti-carcinogen compounds, such as selenomethyl selenocysteine and gamma-glutamyl selenomethyl selenocysteine, which highlights the importance of the present detailed discussion about the AMF use prospects to enhance Allium plant growth and development. This review reports the available information describing the AMF effects on the seasonal, inter-, and intra-species variations of yield, biochemical characteristics, and mineral composition of Allium species, with a special focus on the selenium accumulation both in ordinary conditions and under selenium supply.