Physicochemical analyses of plant biostimulant formulations and characterisation of commercial products by instrumental techniques

Abstract

Background:The objective of this study was to develop instrumental protocols for evaluating physicochemical characteristics of plant biostimulant/biofertiliser formulations. Six formulations (Rygex, Algavyt, Ryzoset, Manek, Ecoryg and Algavyt Zn/Mn) containing algal/plant extracts, humic and amino acids, lipids and inorganic components were assessed for particle size distribution and zeta potential (ZP) by dynamic light scattering (DLS) and gross compositional differences by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Results:The six commercial formulations were assessed by mung bean root and wheat leaf senescence bioassays to determine auxin-and cytokinin-like activities. Among them, Rygex, Manek and Ecoryg showed significant auxin-like activities compared to the other formulations. Only Manek showed very low cytokinin-like activity. In combination, the four instrumental techniques highlighted gross differences in the particle sizes, ZP and compositions of the products, and provided key results on the physicochemical characteristics of the formulations including potential stability of the products. Conclusion:The three techniques (TGA, FTIR and Py-GC/MS) require no sample preparation beyond drying of the materials. The activities of the plant growth hormones have been compared to show advantages of the growth hormone bioassay methods for selecting better formulations.

Characterization of Biostimulant Mode of Action Using Novel Multi-Trait High-Throughput Screening of Arabidopsis Germination and Rosette Growth

“…Recently, the global biostimulant market has grown rapidly and, to satisfy crop requirements, many companies are actively introducing various innovative products and ingredients ( Calvo et al, 2014 ; Sharma et al, 2014 ). However, in general, the raw materials used by the biostimulant manufacturers exhibit considerable compositional variations which may impact on the composition and concentration of major components ( Povero et al, 2016 ; Sharma et al, 2016 ). The origin of biostimulants is diverse, and can range from single compounds to complex matrices with different groups of bioactive components that have only been partly characterized ( du Jardin, 2015 ).…”

Potential of three microbial bio-effectors to promote maize growth and nutrient acquisition from alternative phosphorous fertilizers in contrasting soils

“…The plant growth-promoting effect of BEs is based on different mechanisms, for example, the control of plant pathogens either by stimulation of the plant's defense mechanisms or by microbial antagonism [11,13]. Some BEs induce plant growth by stimulating the plant's own hormone production such as auxins or cytokinins [13,14], or by producing directly hormone-like compounds [15]. Regarding P acquisition, some BEs are associated with increased phosphatase activities in the soil [16][17][18] and have also shown the ability to liberate P from soil particles [9,16,19,20] and from P-recycling fertilizers [21,22].…”

Evaluation of antioxidant activity and total phenol content of Gracilaria bursa-pastoris harvested in Nador lagoon for an enhanced economic valorization

“…On the other side, some authors have found other special bioactive compounds such as alkaloids, terpenes, bromophenols, phlorotannins, ascorbic acid, tocopherols, and carotenoids, in algae which have antioxidant potential [8][9][10][11][12][13]. These observations suggest that these bioactive compounds can have strong antioxidant properties.…”