The effect of biostimulants on fruit quality of processing tomato grown under deficit irrigation

Water shortage can be a restrictive factor for the growth and quality of vegetable crops. Considering the alleviating effects of biostimulant application against water stress, this study aimed to investigate the effect of four biostimulant products (protein and amino acids with carboxylic acids (Tr1); protein and amino acids with seaweed extracts (Tr2); humic and fulvic acids with seaweed extracts (Tr3); SiO2 (Tr4); and control (no biostimulants added)) and two irrigation systems (regulated deficit irrigation (RDI)—65% of field capacity and regular irrigation (RI)—100% of field capacity) on quality parameters of processing tomato fruit. Regulated deficit irrigation and biostimulant application increased the energetic value, carbohydrates, and free sugars content, while organic acids showed a variable response to biostimulant use. In terms of tocopherols (α-, β-, γ-, δ-) and carotenoids (lycopene and β-carotene), regular irrigation and biostimulant application negatively affected their content, while Tr3 treatment had a beneficial impact on these lipophilic compounds under RDI conditions. The main fatty acids were palmitic (C16:0) and linoleic (C18:2n6) acids, which increased when plants were treated with Tr3 and Tr1 biostimulants under a deficit regime. Antioxidant activity (assessed by TBARS and OxHLIA assays) and total phenolic and flavonoids content also showed a variable response to the studied factors. In particular, the application of Tr3 and the control treatment under RDI increased the total phenolic content, while the control and Tr3 treatments under the same irrigation regime recorded the highest antioxidant activity. In conclusion, our results indicate that the adoption of eco-friendly strategies such as regulated deficit irrigation and biostimulant application can beneficially affect the quality traits of processing tomatoes.This research has been co-financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH—CREATE—INNOVATE (project code: T2EDK-05281).info:eu-repo/semantics/publishedVersio

Effects of Two Varieties and Fertilization Regimes on Growth, Fruit, and Silymarin Yield of Milk Thistle Crop

Milk thistle is an alternative crop to winter cereals for southern Europe as this species is drought tolerant and its fruits contain silymarin. The aim of this study was to assess the impact of two varieties and fertilization regimes (sheep manure and inorganic fertilizer) on crop productivity. A two-factor experiment was conducted in a randomized split-plot design with three replicates. The varieties were Palaionterveno and Spata, while the fertilization treatments were control, sheep manure, and calcium ammonium nitrate applied at 75 and 125 kg N ha−1. Variety and fertilization significantly affected plants development and productivity, as well as oil and silymarin yield. The use of manure and inorganic nitrogen fertilizer increased rosette diameter, oil and silymarin yield, above-ground biomass, and fruit yield. The influence of inorganic fertilization, regardless of the application dose, was more apparent than organic fertilization. Moreover, variety significantly affected plants growth and silymarin content, as well as silymarin composition. The variety Spata had the greatest silymarin content, reaching 4.40%, and a high silybin B concentration. In conclusion, the selection of a suitable variety is important for achieving high fruit and silymarin yields, while inorganic nitrogen fertilization can maximize the productivity of the milk thistle crop

Seed Germination of Three Milk Thistle (Silybum marianum (L.) Gaertn.) Populations of Greek Origin: Temperature, Duration, and Storage Conditions Effects

Milk thistle besides being a highly competitive weed is cultivated as a medicinal plant, and the seeds of which have been clinically utilized in several disorders caused in liver. The present study aims to evaluate the effect of duration and storage conditions, population, and temperature on seed germination. The experiment was conducted in Petri dishes with three replications and three factors: (a) wild populations of milk thistle (Palaionterveno, Mesopotamia, and Spata) originating from Greece, (b) duration and storage conditions (5 months at room temperature, 17 months at room temperature, and 29 months in the freezer at −18 °C), and (c) temperature (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, and 30 °C). All three factors significantly affected germination percentage (GP), mean germination time (MGT), germination index (GI), radicle length (RL), and hypocotyl length (HL) and significant interactions among the treatments were noted. In specific, no seed germination was recorded at 5 °C, while the populations showed higher GP and GI at 20 °C and 25 °C after 5 months of storage. Prolonged storage negatively affected seed germination although, cold storage mitigated this effect. Moreover, higher temperatures reduced MGT and increased RL and HL with the populations reacting differently in storage and temperature regimes. The results of this study should be taken into consideration when proposing the appropriate sowing date and storage conditions of the seeds used as propagation material for crop establishment. Moreover, the effects of low temperatures such as 5 °C or 10 °C on seed germination as well as the high decline rate in germination percentage over time could be utilized in the design of integrated weed management systems thereby indicating the importance of the sowing time and the suitable crop rotation system to weed control

Optimization of the yield, silymarin content and composition, and other quality characteristics of seeds in wild populations of Silybum marianum (L.) Gaertn. by controlling nitrogen fertilization

Milk thistle (Silybum marianum (L.) Gaertn.), is an annual or biennial plant that is considered a common weed in cultivated and undisturbed areas. However, this species is cultivated in many European countries as its seeds, which contain silymarin, have significant commercial value as they are utilized in the pharmaceutical industry. The present study aimed to evaluate the effects of different milk thistle populations and nitrogen fertilization on the growth, yield, and quality characteristics of the crop. Field and pot experiments were conducted during three growing seasons. The two-factor field experiment was carried out in a randomized split-plot design with three replicates. Population with two treatments (Paleonterveno and Mesopotamia) during the growing season 2018-2019 and three treatments (Paleonterveno, Mesopotamia, and Spata) during the seasons 2019-2020, 2020-2021 was the whole-plot factor. Fertilization, with six treatments (control, conventional nitrogen fertilizer applied at 7.5 and 12.5 kg N/decare, stabilized nitrogen fertilizer applied at 7.5 and 12.5 kg N/decare, manure) was the sub-plot factor. Digested manure was applied at a rate of 1300 kg/decare. Calcium ammonium nitrate (26-0-0, N-P2O5-K2O) and ammonium sulfate (26-0-0 (+13S), N-P2O5-K2O) with nitrification inhibitor DMPP were used. The field experiments showed useful results about the effects of population and nitrogen fertilization on milk thistle crop. The highest values of height, rosette diameter, and dry weight were recorded in Spata, while the lowest values of chlorophyll concentration were recorded in this population. Moreover, seed yield ranged from 72.65 to 199 kg/decare and was significantly affected by genetic material and Paleonterveno was the most productive population during the first and third growing season. In terms of seed quality characteristics, the highest oil content was recorded in Mesopotamia, while the maximum content (4.03-4.44%) and yield of silymarin (4.24-5.24 kg/decare) were observed in Spata that there were high values of silybins A and B. The use of conventional and stabilized nitrogen fertilizer significantly increased growth traits, yields parameters, and seed yield compared with control and the use of manure, while fertilization did not affect the oil and silymarin content of the seeds and did not alter the silymarin compounds. However, both inorganic and organic fertilization led to greater oil and silymarin yields, owing to the higher seed yields. In particular, the use of nitrogen fertilizers at a rate of 12.5 kg N/decare increased silymarin yield by up to 40,78%. In general, the application of nitrogen fertilizers at a rate of 12.5 kg N/decare more strongly affected plants growth than the lowest rate, while there were no differences between the two types of fertilizers when they were applied at equal doses. In conclusion, the selection of population is important for achieving high yields and nitrogen fertilization can maximize the productivity of the milk thistle crop.Το γαϊδουράγκαθο (Silybum marianum (L.) Gaertn.), είναι ένα ετήσιο ή διετές φυτό που θεωρείται κοινό ζιζάνιο τόσο σε καλλιεργούμενες όσο και σε ακαλλιέργητες εκτάσεις. Ωστόσο, πλέον καλλιεργείται σε πολλές Ευρωπαϊκές χώρες καθώς οι σπόροι του, οι οποίοι περιέχουν σιλυμαρίνη, έχουν σημαντική εμπορική αξία διότι χρησιμοποιούνται για την παραγωγή φαρμακευτικών προϊόντων. Σκοπός της διατριβής ήταν να διερευνηθεί η επίδραση γηγενών πληθυσμών και της αζωτούχου λίπανσης στην ανάπτυξη, την απόδοση και τα ποιοτικά χαρακτηριστικά του σπόρου. Πραγματοποιήθηκαν πειράματα στον αγρό και σε φυτοδοχεία σε τρεις καλλιεργητικές περιόδους. Στα πειράματα αγρού ακολουθήθηκε το πειραματικό σχέδιο των υποδιαιρεμένων τεμαχίων με 2 παράγοντες, 3 επαναλήψεις. Κύρια τεμάχια (1ος παράγοντας): γενετικό υλικό-γηγενείς πληθυσμοί με 2 επεμβάσεις την περίοδο 2018-2019 (Παλαιοντέρβενο, Μεσοποταμία) και 3 επεμβάσεις τις περιόδους 2019-2020, 2020-2021 (Παλαιοντέρβενο, Μεσοποταμία, Σπάτα). Υποτεμάχια (2ος παράγοντας): 6 επεμβάσεις λίπανσης (μάρτυρας, συμβατικό αζωτούχο λίπασμα σε επίπεδο 7,5 και 12,5 μονάδων N/στρ, σταθεροποιημένο αζωτούχο λίπασμα σε αντίστοιχα επίπεδα, οργανική λίπανση-κοπριά). Η «χωνεμένη» κοπριά εφαρμόστηκε στη δόση των 1300 κιλών/στρ. Χρησιμοποιήθηκαν τα λιπάσματα ασβεστούχος νιτρική αμμωνία (26-0-0, N-P2O5-K2O), νιτροθειϊκή αμμωνία (26-0-0 (+13S), N-P2O5-K2O) με αναστολέα νιτροποίησης DMPP. Τα αποτελέσματα του πειράματος ανέδειξαν χρήσιμα συμπεράσματα για την επίδραση των πληθυσμών και της αζωτούχου λίπανσης στην καλλιέργεια του γαϊδουράγκαθου. Για τα χαρακτηριστικά ύψος, διάμετρος της ροζέτας και ξηρό βάρος, οι μεγαλύτερες τιμές καταγράφηκαν στα Σπάτα, ενώ η συγκέντρωση της χλωροφύλλης α και β ήταν μικρότερη στο συγκεκριμένο πληθυσμό. Ακόμη, η απόδοση σε σπόρο που κυμάνθηκε από 72,65 έως 199 kg/στρ επηρεάστηκε σημαντικά από το γενετικό υλικό και το Παλαιοντέρβενο ήταν ο παραγωγικότερος πληθυσμός κατά την πρώτη και τρίτη καλλιεργητική περίοδο. Όσον αφορά τα ποιοτικά χαρακτηριστικά του σπόρου, η μεγαλύτερη περιεκτικότητα σε έλαιο καταγράφηκε στη Μεσοποταμία, ενώ η μέγιστη περιεκτικότητα (4,03-4,44%) και απόδοση σε σιλυμαρίνη (4,24-5,24 kg/στρ) παρατηρήθηκε στα Σπάτα όπου καταγράφηκαν και υψηλές τιμές στις σιλυβίνες Α και Β. Η εφαρμογή του συμβατικού και του σταθεροποιημένου λιπάσματος αύξησε τις τιμές των παραμέτρων ανάπτυξης, τα συστατικά της απόδοσης, την απόδοση σε σπόρο συγκριτικά με το μάρτυρα και την κοπριά, ενώ δεν επηρέασε την περιεκτικότητα των σπόρων σε έλαιο, σιλυμαρίνη και τα συστατικά της σιλυμαρίνης. Ωστόσο, τόσο η ανόργανη όσο και η οργανική λίπανση οδήγησαν σε υψηλότερες αποδόσεις σε έλαιο και σιλυμαρίνη, λόγω των αυξημένων αποδόσεων σε σπόρο. Πιο συγκεκριμένα, η εφαρμογή των αζωτούχων λιπασμάτων σε επίπεδο 12,5 μονάδων Ν/στρ αύξησε την απόδοση σε σιλυμαρίνη έως 40,78%. Γενικά, η εφαρμογή των αζωτούχων λιπασμάτων σε επίπεδο 12,5 μονάδων Ν/στρ επηρέασε περισσότερο την ανάπτυξη και την παραγωγικότητα του φυτού συγκριτικά με το χαμηλότερο επίπεδο αζώτου, ενώ δεν καταγράφηκαν διαφορές μεταξύ των δύο τύπων λιπασμάτων όταν εφαρμόστηκαν στην ίδια δόση. Συμπερασματικά, η επιλογή πληθυσμού είναι σημαντική για την επίτευξη υψηλών αποδόσεων και η αζωτούχος λίπανση μπορεί να συμβάλει στη μεγιστοποίηση της παραγωγικότητας της καλλιέργειας του γαϊδουράγκαθου

Cultivation Practices, Adaptability and Phytochemical Composition of Jerusalem Artichoke (Helianthus tuberosus L.): A Weed with Economic Value

The Jerusalem artichoke (Helianthus tuberosus L.) is a perennial weed that is cultivated for bioethanol production or pharmaceutical purposes, as its aerial parts and tubers contain several chemical compounds. This review summarizes important data on the effects of the main cultivation practices (e.g., the planting density and pattern, weed management, fertilization, irrigation, genotypes and harvest) on tuber yield and quality. The most widespread method for the propagation of the Jerusalem artichoke is planting the tubers directly in the field, with a plant density of about 33,000–47,000 plants ha−1. Weed management is based on herbicide application, mechanical cultivation and hand hoeing, while the nutrient requirements are low, and irrigation relies on weather conditions. For instance, under Mediterranean semi-arid conditions, the crops are irrigated from June to September. In addition, the harvest time depends on the genotype and the purpose of cultivation, which is an important consideration for obtaining a high-quality product. In conclusion, Jerusalem artichoke yield and quality depend on several factors, and this plant, due to its high productivity, constitutes a promising crop with numerous uses

Effects of Post-Emergence Herbicides and Period of Johnsongrass (<i>Sorghum halepense</i> (L.) Pers.) Control on Growth and Yield of Sunflower Crops

Sunflower is an important industrial crop since it is grown all over the world for oil production, while Johnsongrass (Sorghum halepense (L.) Pers.) is characterized by great competitiveness and can severely impair plant growth and crop productivity. Thus, a two-year field experiment was conducted to evaluate the impact of Johnsongrass control practices on plant growth, seed yield, and oil content of sunflower crop. The results indicated that Johnsongrass competition negatively affected sunflower growth and productivity as the lowest values of height, dry biomass, seed, and oil yields were recorded at the weed-infested treatment, followed by the weed infested for 30 days after sowing. All the other treatments had a positive effect on vegetative and yield parameters. Moreover, fluazifop-p-butyl, quizalofop-p-ethyl, and the combination of fluazifop-p-butyl and imazamox effectively controlled Johnsongrass. Specifically, in 2020, the lowest dry weight of Johnsongrass was observed in the plots where fluazifop-p-butyl + imazamox were applied. Thus, the results of this study clearly showed that the use of the above-mentioned herbicides can improve the seed and oil yield of a sunflower crop by managing Johnsongrass, while the competition of this rapidly growing weed for a short period of 30 days can significantly reduce crop yield