Nov 16, 2021
Biological stimulant is neither pesticide nor fertilizer, but a substance containing some components and microorganisms. When applied to plants or root circumference, its effect is to stimulate the natural process of plants, but has nothing to do with nutrients. Biostimulants are generally divided into eight categories in the international market, including humic acid, complex organic materials, beneficial chemical elements, inorganic salts (including Phosphite), seaweed extract, chitin and chitosan derivatives, Antitranspirants, free amino acids and other nitrogen-containing substances.
Biological stimulants can promote crop growth, improve nutrient absorption and utilization efficiency, remove heavy metals from polluted soil, reduce soil nutrient loss, improve seed germination rate, induce biosynthesis of plant defensive biomolecules, improve the appearance quality of harvested products, induce tolerance to biological and abiotic stressors, prolong the shelf life of perishable products At present, it has been applied in more than 600 kinds of crops to improve root development, increase crop yield and stimulate plant immune system. Especially for economic crops, the application of biological stimulants has become the just need of crop health protection.
  1. Seaweed extract
Seaweed extract can affect plant disease resistance from abiotic stress and biological stress. In the process of abiotic stress, after the application of seaweed extract, plants absorb effective substances, produce corresponding gene transformation, or synthesize new enzymes to deal with the changes of external environment, and then produce disease resistance. Biological stress is mostly the effective substance in seaweed extract, which directly interferes with the growth of pathogenic organisms, and then makes plants maintain good growth.
2. Plant rhizosphere growth promoting bacteria
Plant rhizosphere growth promoting bacteria (PGPR) can improve plant growth, control plant pathogens, improve plant absorption of nutrients and minerals, enhance plant resistance to various biological stresses and tolerance to abiotic stresses. The common plant rhizosphere growth promoting bacteria are Pseudomonas and Bacillus subtilis.
3. Chitin and its derivatives
Chitin has many beneficial effects, such as promoting plant growth, improving plant nutrition and regulating and improving plant resistance to abiotic and biological stresses. However, due to the hydrophobicity and insolubility of chitin, the single application of chitin is limited. Therefore, various transformations must be considered in order to add value to their beneficial effects on plants through complexation with other compounds or nanofibrosis.
The beneficial activity of chitosan is mainly related to the increased photosynthetic activity, tolerance to abiotic stresses such as drought, salinity and extreme temperature, as well as the increased activity of antioxidant enzymes and the expression of defense genes.
The main activity of oligochitosan is related to the induction of secondary metabolite biosynthesis and the activation of plant innate immunity through signal sensing and transduction, the expression of defense genes and the accumulation of final protective secondary metabolites.
4. Active peptides
Peptides that can regulate the physiological function of organisms are called bioactive peptides. Compared with proteins, active peptides are more easily absorbed and utilized. At the same time, active peptides also have good acid and thermal stability, water solubility and viscosity change slowly with concentration. They can be used as functional factors, especially small peptides with good water solubility, which have good antibacterial and antiviral properties. Eugene et al. (2020) showed that the application of different medicinal plant active peptides could significantly reduce the occurrence of potato late blight at 96h, 120h and 144H after culture.

Dorcas, a leading biotechnology factory in Qingdao, China. As top three manufacturers of seaweed fertilizer in China with more than12 years of experience. We produce seaweed extract, organic granular fertilizer, liquid foliar & vigoroot fertilizer and liquid chitosan fertilizer with biological enzymolysis method. We passed ECOCERT and IMO certification.

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