The Effect of Plant-Derived Biostimulants on White Head Cabbage Seedlings Grown under Controlled Conditions

Abstract

The aim of this study was to investigate the potential of using natural raw materials that have not been used for the production of biostimulants of plant growth. These products can effectively contribute to overcome the challenge posed by the increasing demand for food. Ultrasound assisted extraction (UAE) was chosen to prepare innovative biostimulants. The expected outcome of this research was to generate products that show beneficial effects on white head cabbage growth, development, and nutritional quality. The results proved that higher plants (mugwort, calendula, purple coneflower, chamomile, basil, giant goldenrod, comfrey, dandelion, and valerian) can be successfully used for the production of biostimulants. For example, products based on common dandelion showed the highest biostimulating activity. In a group treated with 2.5% flower extract, cabbage shoots were 37% longer, whereas in a group treated with 0.5% leaves extract, roots were longer by 76% as compared with a control group treated with water. Biostimulants based on common mugwort (at a dose of 0.5%) and common dandelion (root) (at a dose of 1.0%) increased the mass of cabbage shoots and roots by 106% and 246%, respectively. The majority of biostimulants increased the content of photosynthetic pigments (chlorophyll and carotenoids) and decreased the content of polyphenols. Botanical extracts also showed varied impact on the antioxidant activity of cabbage. Taking into account the benefits for a wide scope of applications, it is expected that the utilization of these types of products should increase in the future. These products can play a key role in sustainable agriculture.

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

“…In our previous article [71] we have conducted research on 12 biomasses, whereas in this article we performed a second series of tests for 14 another medicinal plants popular and easily available in Poland, which have never been tested as a raw material to receive biostimulants of plant growth. The time of the raw materials collection were adjusted to the plant growth stage that exhibits the highest level of active constituents.…”

“…The deionised water was used as a solvent. The methodology of extracts production is presented by Godlewska et al [71]. The dried and milled raw materials were stirred with deionised water (1:20).…”

“…In the germination tests, 25 seeds of white head cabbage (cultivar 'Socrates F 1 ', Syngenta) were placed on the filter paper in Petri dishes which were put on the Jacobsen apparatus (Laborset, Lodz, Poland) [71]. For the experiment a completely randomized design was used.…”

“…The absorbances (663, 645, and 470 nm) were measured in three replicates using UV-Vis spectrophotometer (HACH DR1900). The exact methodology and calculation formulas are described in our research [71]. The greenness index of five cotyledons from each Petri dish was measured in three replicates using chlorophyll meter SPAD 502 Plus (Konica Minolta, Europe).…”

“…The concentrations of total phenolic compounds (TPC) in cabbage seedlings were made in accordance to the Folin-Ciocalteu method presented by Jałoszyński et al [72] with modifications [71]. The fresh, grounded plants (2 g) were sonicated with 20 mL of 80% aqueous methanol for 15 minutes and centrifuged (10 min, 4500 rpm).…”