Laminarin

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Chemical Identification | General Product Information | Physical & Safety Data

Chemical Identification

Common Name

Laminarin

General Product Information

Category

Biostimulants > Biostimulants

Activity

Laminarin is an oligosaccharide, more specifically, a beta-glycan with an approximate molecular weight of 4000-5000 Dalton and, therefore, probably not very mobile within the target plant. Laminarin elicits a response from the plant's natural defence mechanisms by mimicking the surface characteristics of the fungal pathogen. The plant responses include thickening of the cell walls with lignin and production of antifungal products such as phytoalexins and pathogen related (PR) proteins.

The product is used as an early season treatment achieving protection against eyespot, mildew and septoria for 40 days following application. Goemar reports that laminarin allows chemical fungicide application rates to be decreased by 25-30% per hectare. However, the product offers only partial protection to the crop and is recommended for use in sequence with conventional fungicides such as triazoles and strobilurins with a maximum interval of 45 days between treatments. The residual activity is reported to be several weeks following treatment.

Field trials in apples (Golden Delicious) in France showed that laminarin was effective in controlling Venturia inequalis though the level of control in mature trees (50%) was less than in young plantings (77%). The optimum timing for treatment was found to be 14 days before infection.

A study reported at the 11th International Cereal Rusts and Powdery Mildews Conference (2004) utilised the occurrence of active oxygen species to indicate the impact of elicitors such as laminarin on defence reactions in wheat. Histochemical techniques were used to observe the presence of H₂0₂ near the fungal appressorial germination tube as indicative of early defence reactions. Other technigues looked at the rate of lipid peroxidation and the autofluorescence of phenolic compounds in papillae and cell walls.

CropUse

CropUses:
wheat

Cereals	40 g ai/ha
Wheat	1L/ha (Iodus 40 formulation)

Physical & Safety Data

Toxicology

Acute oral (rat)

LD₅₀ >2000 mg/kg (male)

Environmental Profile

Rainbow trout _{[96 h]}	LC₅₀ >100 mg/L
Zebra fish _{[96 h]}	LC₅₀ >100 mg/L
Bee _[oral]	LD₅₀ >118 μg/bee
Bee _[contact]	LD₅₀ >100 μg/bee
Selenastrum	E_bC₅₀ >100 mg/L
Daphnia magna	LC₅₀ >100 mg/L