Biostimulant Substances for Sustainable Agriculture: Origin, Operating Mechanisms and Effects on Cucurbits, Leafy Greens, and Nightshade Vegetables Species

Abstract

Climate change is a pressing matter of anthropogenic nature to which agriculture contributes by abusing production inputs such as inorganic fertilizers and fertigation water, thus degrading land and water sources. Moreover, as the increase in the demand of food in 2050 is estimated to be 25 to 70% more than what is currently produced today, a sustainable intensification of agriculture is needed. Biostimulant substances are products that the EU states work by promoting growth, resistance to plant abiotic stress, and increasing produce quality, and may be a valid strategy to enhance sustainable agricultural practice. Presented in this review is a comprehensive look at the scientific literature regarding the widely used and EU-sanctioned biostimulant substances categories of silicon, seaweed extracts, protein hydrolysates, and humic substances. Starting from their origin, the modulation of plants’ hormonal networks, physiology, and stress defense systems, their in vivo effects are discussed on some of the most prominent vegetable species of the popular plant groupings of cucurbits, leafy greens, and nightshades. The review concludes by identifying several research areas relevant to biostimulant substances to exploit and enhance the biostimulant action of these substances and signaling molecules in horticulture.

Silicon fertilization counteracts salinity-induced damages associated with changes in physio-biochemical modulations in spinach

“…Salinity affects growth, ion homeostasis, imbalance of nutrients, and physiological, chemical, and molecular processes of plants which are directly responsible for plant development [ 13 , 14 ]. Saline conditions affect the nutrient uptake (Ca, K, Mg) resulting in inferior quality of products due to the enhanced concentration of toxic elements that ultimately result in membrane leakage, metabolic and ionic disturbances in spinach [ 15 – 18 ]. In leafy vegetables, salinity stress enhances bioactive leaf pigments, phenolics, flavonoids, polyphenols, and antioxidant activity [ 19 ].…”

“…Salt tolerance of vegetable crops can be enhanced by applying certain nutrients (e.g., silicon, zinc, boron, potassium) and organic acids (e.g., salicylic acid, humic acid, aspartic acid). The application of biostimulant substances controls abiotic stress and improve the growth of plant by improving physiological, catabolism/anabolism, and molecular reactions [ 18 ]. Silicon (Si) is the second most abundant element in the earth’s surface and it accumulates in plant cells [ 24 ].…”

Leafamine®, a Free Amino Acid-Rich Biostimulant, Promotes Growth Performance of Deficit-Irrigated Lettuce

“…In order to mitigate these negative effects, many research works have been focused on the use of plant biostimulants because they represent a commonly used environment-friendly strategy [39]. Lettuce is widely considered to be an ideal plant model for evaluating the protective effect of biostimulants on vegetative growth [14,40]. In line with this, we characterized the effects of Leafamine ® , a free amino acid-rich biostimulant, on the physiological performance of lettuce plants grown under two contrasting water regimes (well-watered and water deficit) for 38 days.…”

Hydraulic Efficiency of Green-Blue Flood Control Scenarios for Vegetated Rivers: 1D and 2D Unsteady Simulations

“…It is crucial to highlight that the outcomes of the present study refer to a single riparian vegetation species (common reed beds), while, in a more realistic perspective, the combined effect of two or more species represent a source of uncertainty which inevitably propagates in the vegetative Manning's n hydraulic roughness coefficient associated with each simulated cross-section, quantitatively varying in a wider range of values. Thus, this uncertainty could be reduced by implementing more complex and rigorous numerical analyses, obtained by coupling high-performance computational fluid dynamics (CFD) models [49][50][51][52][53] and simulations [54][55][56][57][58][59][60][61] with the most advanced remote sensing techniques of fluvial hydraulics, agro-forestry and land use governance interest [62][63][64][65][66][67][68][69][70][71].…”