Osyr: active ingredient to stimulate root growth

Frayssinet’s research into soil organic matter has made it possible to isolate organic molecules of natural origin that act to stimulate plant metabolism. These include OSYR.

OSYR is the active ingredient in the product branded OSIRYL, the first root growth stimulator authorised in France (AMM 1030003) registered on the lists of products that can be used in organic farming. Obtained by depolymerising lignocellulosic compounds, OSYR generates a synergy of resistance and root system boosting actions.

The origin of the OSYR active ingredient

Schéma de l'extraction de la matière active OSYR. Celle-ci est un réel plus pour les biostimulants nutritionnels Frayssinet.




Action mode


OSYR stimulates plant growth and root regeneration through two actions:

– by protecting auxins from oxidative mechanisms

– by strengthening root resistance in stressful conditions.

In situations of stress and nutritional deficiency, the auxins involved in plant physiology (reproduction, growth, flowering, rhizogenesis, etc.) are degraded. This auxin degradation has a negative impact on reproductive mechanisms and crop quality. OSYR has the ability to protect these natural auxins, enabling balanced crop development and resistance to environmental stress.

OSYR has a natural origin, and the activity of its active ingredient is independent of agro-pedo-climatic conditions, giving it constant and regular efficacy.




Test results

The Frayssinet research centre has carried out numerous studies under controlled conditions to characterise the activity of the active ingredient OSYR on vines, arboriculture, market gardening and field seeds.


Field crops


– Improves the emergence and uniformity of seedlings at first growth

test results FC


Résultats d'essais GC


– Stimulates and promotes root development in plants

The application of OSYR by seed treatment shows a significant increase in the root system both under controlled conditions and in field trials.

test results FC



Résultats d'essais GC 1



– Planting

Winegrower – Cénac (33) – Merlot
Applying Osiryl as soon as the vines are planted significantly improves the recovery of the plants, enabling them to store up the nutritional reserves essential for the proper development of young vines from the very first year.



– Stressful condition

Winegrower – Chouilly (51) – Chardonnay
Observations of the rows treated with Osiryl 2 and 5 months later (see photos) show that the young shoots are growing faster (+26%) than the control rows, which are difficult to train on the last wire.






– Apple trees in planting site

Arborist – Sainte-Bazeille (47) – Brookfield on PAJAM1 and Chantecler on NAKB

Osiryl at 20 L/ha has a significant effect on the development of lateral shoots. The applications show a dose effect: on the Brookfield variety, the number of lateral shoots is doubled (+48%) at the dose of 40 L/ha and the general growth of the trees is significantly higher (+15% trunk diameter and +14% terminal shoot length) compared with the untreated controls.



Market gardening


– Lettuce production

Market gardener – Béziers (34) – Batavia blonde
After 4 months of trials, the Osiryl treatment promotes the development of a more efficient root system, providing better nutrition and faster lettuce growth. Osiryl’s action results in an 8-to-12-day earlier harvest and an increase in the weight of batavia plants at harvest.



– Melons under stress

University – Montpellier (34) – Luna
After 38 days of cultivation, under very high pressure from fusariosis, SI plants (inoculated substrate) treated with Osiryl still show better resistance (+15.9% fresh stem weight), with mild symptoms of the disease (26% mottling and yellowing of leaves) compared with SI control plants (42% severe leaf necrosis).
control plants (42% severe leaf necrosis).



Find out more about OSYR in specialised crops