Biostimulant product types

Seaweed extracts

Extracted from seaweed (e.g. Ascophyllum nodosum). May contain plant growth hormones, trace elements and amino acids.

Humic substances

Extracted from decayed plant or animal material (e.g. humic or fulvic acids).

Phosphite and other inorganic salts

Phosphite products are based on reduced forms of phosphate. These salts do not contain carbon. Phosphite is a commonly used inorganic salt. May stimulate plant defence mechanisms and nutrient uptake.

Chitin and chitosan derivatives

Chitin is an abundant natural polysaccharided derived from the exoskeletons of crustaceans. Chitosan is derived from chitin.

Antitranspirants

Products that reduce transpiration by plants (e.g. abscisic acid and waxes).

Protein hydrolysates and free amino acids

Protein hydrolysates are produced from animal and plant residues. Free amino acids are obtained through enzymatic breakdown of agro-industrial by-products. May support plant metabolism and stress responses and signalling peptides.

Note: Biostimulants derived from mammalian tissue by-products, such as pork and beef materials, might not be acceptable to customers/buyers.

Complex organic materials

Broad range of products that contain material derived from the remains of organisms (e.g. plants).

Silicon-based

Silicon is supplied as a biostimulant in the form of silica or silicate salts.

Plant growth promoting bacteria

Bacteria that potentially benefit plant growth by fixing nitrogen or competing with pathogens. Bacillus, Rhizobium, Pseudomonas, Azospirillum, and Azotobacter species are relatively common in the biostimulant market.

Non-pathogenic fungi

A wide range of fungal species that have no direct pathogenic effect on plants (e.g. Trichoderma spp.)

These root-associated fungi positively interact with plants but do not need a host plant to survive (unlike mycorrhizal fungi).

Arbuscular mycorrhizal fungi

Common type of endomycorrhizal fungus that forms a symbiotic association with plant roots (e.g. Rhizophagus irregularis).

Protozoa and nematodes

Protozoa are single-celled rhizosphere organisms. Nematodes are non-segmented worms.

Several species are available that have no direct pathogenic effect on plants. They selectively graze bacteria and, to a lesser extent, fungi. They may increase the mineralisation of soil nitrogen and enhance root growth.

Microalgae

Mainly single-celled photosynthetic organisms that use sunlight and carbon dioxide to synthesise a wide range of metabolites.