Ampelographic Description and Sanitary Analysis of Four Istrian Grapevine Varieties (Vitis vinifera L.)

Istrian Peninsula, one of the five districts within viticultural region of Coastal Croatia, provides great geological-reliefal and climatic diversity and various production conditions. This research studied the autochthonous varieties and their sanitary status in old vineyards. Considering the age of vineyard, ten locations were chosen where four autochthonous varieties ‘Malvasia istarska’, ‘Teran’, ‘Borgonja’, and ‘Pergola velika’ were identified using ampelographic description according to OIV descriptors. Morphological characteristics of chosen varieties were described using OIV parameters and must was chemically analysed (pH value, sugar content, titratable acidity). High intra cultivar variability was found for weight of a single bunch especially for ‘Teran’. There were also differences in sugar content of must particularly for ‘Pergola velika’. Must pH was low for all varieties with predominantly low acidity value. Sanitary status of vines was determined by testing the plant samples for the presence of three grapevine viruses (GLRaV-1, GLRaV-3 and GFLV) using DAS-ELISA. The percentage of infection for GFLV was 55.6% while for GLRaV-1 and GLRaV-3 it was 61.1%. Results showed that some morphological characteristics differ from characteristics described in literature. With purpose of preserving the biodiversity of autochthonous varieties and for future researches, healthy propagation material will be collected and planted in collection field of autochthonous varieties at the Institute of Agriculture and Tourism, Poreč

Modeling water flow and phosphorus sorption in a soil amended with sewage sludge and olive pomace as compost or biochar

Organic amendments are often reported to improve soil properties, promote plant growth, and improve crop yield. This study aimed to investigate the effects of the biochar and compost produced from sewage sludge and olive pomace on soil hydraulic properties, water flow, and P transport (i.e., sorption) using numerical modeling (HYDRUS-1D) applied to two soil types (Terra Rosa and Rendzina). Evaporation and leaching experiments on soil cores and repacked soil columns were performed to determine the soil water retention, hydraulic conductivity, P leaching potential, and P sorption capacity of these mixtures. In the majority of treatments, the soil water retention showed a small increase compared to the control soil. A reliable fit with the modified van Genuchten model was found, which was also confirmed by water flow modeling of leaching experiments (R2 0.99). The results showed a high P sorption in all the treatments (Kd 21.24 to 53.68 cm3 g−1), and a high model reliability when the inverse modeling procedure was used (R2 0.93–0.99). Overall, adding sewage sludge or olive pomace as compost or biochar improved the Terra Rosa and Rendzina water retention and did not increase the P mobility in these soils, proving to be a sustainable source of carbon and P-rich materials

Effect of soil type on pyrethrum seed germination

Pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch. Bip.) is an autochthonous insecticidal plant from Dalmatia (Croatia). It is commercially grown worldwide with a particularly fast expansion in Africa and Australia (Tasmania) and used as a natural insecticide. The study was conducted in Istria, Croatia, in a greenhouse, to determine the effect of soil type on the germination of pyrethrum seeds. The effect of different soil types on the germination of pyrethrum was found to be highly significant. The highest percentage of germination was found on white clay loam (soil type 2), and the lowest on red clay Terra Rossa (soil types 1 and 6). Seed germination was greatly influenced by soil texture, foremost silt percentage, and soil pH. The present study suggests that pyrethrum seed germination is best on slightly alkaline clayey loams with moderate nutrients. Positive correlation was confirmed among germination percentage and silt content and soil pH

Ampelographic Description and Sanitary Analysis of Four Istrian Grapevine Varieties (Vitis vinifera L.)

Istrian Peninsula, one of the five districts within viticultural region of Coastal Croatia, provides great geological-reliefal and climatic diversity and various production conditions. This research studied the autochthonous varieties and their sanitary status in old vineyards. Considering the age of vineyard, ten locations were chosen where four autochthonous varieties ‘Malvasia istarska’, ‘Teran’, ‘Borgonja’, and ‘Pergola velika’ were identified using ampelographic description according to OIV descriptors. Morphological characteristics of chosen varieties were described using OIV parameters and must was chemically analysed (pH value, sugar content, titratable acidity). High intra cultivar variability was found for weight of a single bunch especially for ‘Teran’. There were also differences in sugar content of must particularly for ‘Pergola velika’. Must pH was low for all varieties with predominantly low acidity value. Sanitary status of vines was determined by testing the plant samples for the presence of three grapevine viruses (GLRaV-1, GLRaV-3 and GFLV) using DAS-ELISA. The percentage of infection for GFLV was 55.6% while for GLRaV-1 and GLRaV-3 it was 61.1%. Results showed that some morphological characteristics differ from characteristics described in literature. With purpose of preserving the biodiversity of autochthonous varieties and for future researches, healthy propagation material will be collected and planted in collection field of autochthonous varieties at the Institute of Agriculture and Tourism, Poreč

From Waste to Green: Water-Based Extraction of Polyphenols from Onion Peel and Their Adsorption on Biochar from Grapevine Pruning Residues

Onion peels (OP) are rich in bioactive compounds with a plethora of benefits for human health, but this valuable material is often wasted and underutilized due to its inedibility. Likewise, grapevine pruning residues are commonly treated as agricultural waste, but biochar (BC) obtained from this material has favorable characteristics as an adsorbent. This study investigated the potential of BC in removal of targeted polyphenolic compounds from OP extracts. The OP extracts were obtained adhering to green chemistry principles using deionized water amplified by three methods: maceration (MAC), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). The extraction efficiency on the polyphenolic profile and antioxidant capacity was investigated with different extraction temperatures and solid-to-liquid (s/l) ratios. For further analysis, UAE at 90 °C with an s/l ratio of 1:100 was used due to higher polyphenolic compound yield. The BC adsorption capacity of individual polyphenols was fitted with the Langmuir and Freundlich isotherm models. Quercetin-3,4′-diglucoside obtained the highest R2 coefficient in both models, and the highest qmax value. The optimum conditions in the dosage experiment suggested an amount of 0.5 g of BC using 3 g/L extracts. The studied BC showed a high affinity for targeted phytochemicals from OP extracts, indicating its potential to be applied for the green adsorption of valuable polyphenolic compounds

Determination of the Variability of Biophenols and Mineral Nutrients in Olive Leaves with Respect to Cultivar, Collection Period and Geographical Location for Their Targeted and Well-Timed Exploitation

The interactive effects of cultivar, collecting period, and geographical location on the content and composition of biophenols and macro and micronutrients in olive (Olea europaea L.) leaf were investigated. Leaves of six cultivars were collected at three periods in two locations in Croatia. The leaves of Istarska bjelica cultivar had the greatest biophenol (oleuropein) potential, especially those sampled in January and in March at the location of Pag. All the cultivars yielded leaves with the highest concentration of biophenols in March, which coincided with the pruning period. Except for high oleuropein concentration in Istarska bjelica, flavonoids were found to be most useful for differentiating olive leaves according to cultivar. Verbascoside turned out to be the most potent differentiator of collecting periods, while phosphorus and zinc turned out to be most useful for differentiating locations. Despite different agroecological conditions at the two locations, cultivar exhibited a significant effect on olive leaf nutrient composition, which was certainly causally related to that of the biophenols. The results obtained showed that it is possible to plan more well-timed and efficient exploitation of biophenols from olive leaf based on the knowledge about the interactive effects of the three studied factors

Effect of sewage sludge derived compost or biochar amendment on the phytoaccumulation of potentially toxic elements and radionuclides by Chinese cabbage

This study set out to evaluate the effect of using sewage sludge-derived compost (SSC) or biochar (SSB) as a soil amendment on the phytoaccumulation of potentially toxic elements, PTE (Cd, Cr, Cu, Ni, Pb, Zn) and natural radionuclides (238U and 232Th) by Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) in terra rossa and rendzina soils, which are the two common soil types in Croatia. The experiment consisted of a greenhouse pot trial using a three-factor design where soil type, sludge post-stabilisation procedure and amendment rate (12 and 120 mgP/L) were the main factors. At harvest, the concentrations of analytes in the substrate, leaves and roots were measured, from which the edible tissue uptake (ETU) and concentration ratios (CR) were determined. Also, the average daily dose (ADD) and hazard quotient (HQ) were determined to assess the health risk, as well as soil contamination factor (CF). The results showed that neither adding SSC nor SSB affected the soil loading at the rates applied, suggesting a low risk of soil contamination (CF ≤ 1). The ETU of Cd, Cu, and Zn were 0.0061, 1.23, and 0.91 mg/plant from compost-amended soil and 0.0046, 0.78 and 0.65 mg/plant for biochar-amended soil, respectively. This difference suggests that their ETU was higher in compost-amended soils than in soils treated with biochar. The CR data indicate that the bioavailability of Cu (CR of 5.30) is highest at an amendment rate of 12 mgP/L, while for Zn (CR of 0.69), the highest bioaccumulation was observed with an amendment rate of 120 mgP/L. Translocation of Cr, Ni, Pb and 238U to the leaves was limited. Overall, the HQ (<1) for Cd, Cu and Zn in the edible parts confirmed that consuming Chinese cabbage does not threaten human health. Similarly, the daily intake of 232Th remained below the limit (3 μg) set by ICRP, suggesting no radiological risk. Finally, although the amendment rate, which was 10-times the amount stipulated in Croatian regulation and the CR ranged from 0.007 to 5.30, the precautionary principle is advised, and the long-term impact of sewage sludge derived compost or biochar on different plant groups (incl. root vegetables) at the field-scale is recommended. [Display omitted] •Sewage sludge compost or biochar amendment did not result in soil contamination.•Biochar amendment reduced Cd, Cu and Zn edible tissue uptake relative to compost use.•No evidence of phytoaccumulation of Cr, Ni, Pb and 238U in Chinese cabbage leaves.•Levels of Cd, Cu, Zn and 232Th in the edible tissues does not pose a health risk