The Effect of Botanical Extracts Obtained through Ultrasound-Assisted Extraction on White Head Cabbage (Brassica Oleracea L. Var. Capitata L.) Seedlings Grown under Controlled Conditions

Abstract

This research presents the possibility of using innovative botanical extracts as biostimulants of plant growth to improve plant nutritional value, growth, and development. It is important to increase agricultural production but this process should be carried out in a sustainable way, without causing risks for both the environment and consumers. For this reason, we have focused on the use of 14 natural raw materials and ultrasound assisted extraction for the production of biostimulants. Results proved that higher plants can be used to obtain valuable products for the application in modern horticulture and agriculture. For instance, extract based on Urtica dioica L. showed the highest biostimulatory properties: in the group sprayed with 0.1% extract cabbage seedlings were longer by 31%, while with 1.0% extract of Polygonum aviculare L. roots were longer by 72% than in the control group treated with water. Extracts based on Equisetum arvense L. (0.5%) and Urtica dioica L. (leaf) (0.1%) increased the fresh weight of sprouts by 113% and 112%, respectively. The highest root weight was observed in groups treated with Equisetum arvense L. (0.5%), Polygonum aviculare L. (0.5%), and Urtica dioica L. (leaf) (2.5%)—heavier by 207%, 206%, and 205%, respectively. Most of biostimulants increased the content of pigments involved in photosynthesis (e.g. 156% more chlorophyll for 0.1% Hypericum perforatum L. extract), decreased the content of polyphenols (e.g. 47% less for 2.5% Trifolium pretense extract), and showed a varied impact on antioxidant activity. There is an increasing interest in botanical extracts due to their high content of biologically active compounds and wide variety of application possibilities.

Field-Scale Evaluation of Botanical Extracts Effect on the Yield, Chemical Composition and Antioxidant Activity of Celeriac (Apium graveolens L. Var. rapaceum)

“…The up-to-date published literature concerning the use of natural raw materials for the production of bio-products is summarised in Table 7 . Furthermore, an interesting aspect of this research is the possibility to compare the results obtained in the field trials with previously published findings, that concerned germination tests performed under laboratory conditions [ 14 , 15 ]. In these tests, the effect of examined extracts (obtained through ultrasound assisted extraction) on the growth and chemical composition of white head cabbage seedlings was evaluated.…”

“…The raw materials used for the production of botanical extracts were selected based on our previous studies [ 14 , 15 ]. Seven sources (candidates) of bioactive compounds were chosen: St. John’s wort ( Hypericum perforatum L.) (herb) (marked as: Hp H), giant goldenrod ( Solidago gigantea Ait.)…”

“…For the determination of the content of chlorophyll a + b (mg·100 g −1 fresh weight, FW) and carotenoids (µg·100 g −1 FW) [ 14 , 15 , 83 ], the freshly collected celeriac leaves (0.4 g) were comminuted to a smooth paste in a mortar with a few drops of acetone (80%), pinch of sand and calcium carbonate. Then, the mixture was filtered using Schott filter and vacuum pump, quantitatively transferred to a volumetric flask (50 mL) and filled up with the solvent.…”

“…The measurements (in four replicates) of absorbance (663, 645, and 470 nm) were made immediately after preparing the solutions with the use of portable visible spectrophotometer (HACH DR1900, Berlin, Germany). The formulas for the calculations are presented in our previous study [ 14 , 15 ].…”

“…rapaceum ). The raw materials (herb of St. John’s wort, leaves of giant goldenrod, flowers and leaves of common dandelion, flowers of red clover, leaves of nettle and roots of valerian) were chosen based on our previous studies conducted under laboratory conditions [ 14 , 15 ]. Celery root was chosen as a model plant because both roots and leaves are edible, are low in calories and carbohydrates and can be consumed fresh or processed [ 16 ].…”