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YSY® Yeast ″Papiliotrema terrestris strain PT22AV″ a Novelty Bio Control Agent developed by AgroVenturesqrcode

Feb. 19, 2024

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Feb. 19, 2024

Italy  Italy

YSY<sup>®</sup> Yeast ″<em>Papiliotrema terrestris</em> strain PT22AV″ a Novelty Bio Control Agent developed by AgroVentures

AgroVentures is company with operations in Europe and the USA, developing innovative and low risk bio control agents. In this article we interview Bruno Folchi, AgroVentures’ general manager, a crop protection professional with extensive business development experience in Europe, the Americas and Asia. 

Mr. Folchi, can you explain why AgroVentures is developing a Yeast strain for crop disease control?

Most biological - microbial fungicides are bacteria, such as Bacillus and Trichoderma species, Bacteria primary mode of action is based on the production of active metabolites. These metabolites are chemical compounds with fungicide or antibiotic action. There is a potential risk that such chemical metabolites may trigger future regulatory reviews.

For this reason, we wanted to develop a biological preventative disease control product, without active metabolites and with mode of action based on space competition, bio stimulation and disease resistance induction. At same time we were looking for the best tox and ecotox profile for humans and the environment, while providing a competitive biocontrol solution for the global farming community.

All these criteria were met by the wild yeast Papiliotrema terrestris strain PT22AV, which we called YSY® ″easy″ to reflect its excellent environmental profile and ″easy″ decision mentioned by several panel of consumers, consistently indicating a preference for crops treated with Yeast bio-controls vs alternatives options based on bacteria or virus derivates.

What is YSY® Yeast?

YSY® (easy) is the Trade Name of a naturally occurring yeast, classified as Papiliotrema terrestris, strain PT22AV. We selected this strain from a library of over 100 yeasts strains collected during 25 years of research by UNIMOL (University of Molise) a partner Italian University.

UNIMOL isolated YSY® Yeast from the aerial part of disease resistant plant ecotypes and identified it as the key factor inducing crop disease resistance.

YSY® Yeast, passed all our efficacy and regulatory screening tests, proving its high potential for Use in Biological Agriculture; BioConsortia and IPM (integrated pest management). 

We are therefore patenting and registering its use globally, with YSY® brand name.

What are the target crops and the Pathogens controlled by YSY®?

YSY® Yeast will be registered on a Broad Range of crops mainly Fruits and Vegetables, but with interesting developments on row crops as soon as production costs will benefit from scale economies. 

Application window is very broad, ranging from seed treatment to post harvest.

YSY® is a strong space competitor, therefore can prevent a broad range of pathogens. Primarily necrotrophics fungi, including: Botrytis spp.; Penicillium spp.; Monilia spp.; Stemphilium spp.; Fusarium spp.; Plasmopara spp. . But YSY can also reduce infestation of biotrophics pathogens such as Oidium spp., Phytophtora spp., Pithiums spp., Septoria spp., both by preventing infection and by inducing different levels of systemic resistance. 

In case of most difficult pathogens we recommend integrated pest management with complementary systemic fungicides.

We also see significant potential for certain Bacteria control and as Nematostatic product.

How can YSY® Yeast control Bacteria?

Biocontrol applications at flowering is critical to control several pathogens. Flowers offer ideal development conditions for Yeasts. We discovered YSY® spray at flowering controls both fungal and certain bacterial diseases, such as Erwinia amylovora (pome fruit fire-blight). YSY® efficacy in fire blight is comparable to standard antibiotics but without any russeting implications. Mode of action is on space competition and Induced Systemic Resistance. 

If flowering is a key application stage, how safe is YSY® Yeast on Bees? 

YSY® Yeast thrives on flowers and bees love flowers treated with YSY®

We’ll publish soon a few studies proving YSY® significant pollinators’ attractiveness (eg. up to 3 time vs untreated flowers). Chronic toxicity studies in extreme exposure conditions (massive feed for one full year) proved YSY® is totally safe for bees. 

We are developing YSY® use on almonds in California, to reduce bee mortality from conventional fungicide applications. It is estimated that over 60% of all USA commercial bees hives are moved to California to pollinate almond flowers in a very hostile environment for their survival. YSY® may help US almond growers to increase bee pollination efficiency, while reducing bees mortality and add value to their crops with a ″Bee Safe″ certification.

How can a Yeast contro Nematodes and Soil Borne Diseases?

Papiliotrema terrestris″ in Latin means: ″Soil Borne Vibrating Butterfly″. With such an auspicious name we were not surprised to confirm YSY® Yeast high adaptability in soil, where it excels in controlling both nematodes and soil borne diseases, in an environmentally friendly way.

Performance on Nematodes is superior to any other biocontrol tested and comparable to several established chemicals. It also controls root rots diseases such as rhizoctonia and pythium while adding superior bio-stimulation and yield increase.

Mode of action is based on different and complementary levels of space competition, bio stimulation and resistance induction. In case of nematodes we identified a set of mode of actions, which we are patenting globally.

YSY® Yeast is not only a soil disease bio control agent, but also an efficient soil conditioner. 

PT22AV is a saprophytic fungal strain, effectively metabolizing organic and mineral compounds, resulting in increased availability of soil nutrients, root and plant stimulation.

Extensive Metagenomics studies indicate that PT22AV soil application generates significative reduction of broad range of fungal plant pathogens, while showing consortia synergies with beneficial microbes.

What are the critical application stages for YSY® Yeast?

YSY® Yeast can be used in any plant growth stage on a preventative disease control program. For aerial applications, its advantages are quite evident at flowering, where it attracts and protects pollinators while inducing disease resistance. Pre harvest use also has high potential, where YSY can contribute to reduce chemical residues by over 95% and prolong post harvest shelf life of fruits and vegetables.

For soil borne diseases and nematodes, best application is at seedling drenching or seed/plant transplant, followed by bi weekly uses depending on level of infestation.

Can YSY® Yeast be used in integrated pest management?

We believe a Microbic fungicide should not only fit in Biological agriculture, but should be a good partner for chemical fungicides in IPM (integrated pest management). On this regard YSY® is compatible in tank mix with most fungicides and given its preventative and anti-resistance performance, could be a biological alternative when Multisite Fungicides are restricted by regulatory decisions.

Why YSY® Yeast should be used as an alternative to other microbial bio-controls?

It is good practice for farmers to have multiple bio control options with different mode of action. YSY® difference vs other microbials is that it does not produce any active or toxic metabolite; it is a potent and safe pollinator attractant; has superior bio stimulation; no phytotoxicity risk and leaves treated crops surface shiny due to abundant protective exa-polysaccharides production. Consumer perception should also be more favorable for a Yeast treated crop.

Does YSY® Yeast meet Global Sustainability and Green New Deal targets?

LCA (life cycle analysis) showed YSY® has an extremely favorable carbon foot print profile, with over 5 times reduction of CO2 emission per treated surface vs alternative chemical fungicides. This may double with an activation technology able to decrease YSY® use rate. Additionally we developed a zero waste production process, where we recycle all fermentation by products into potent bio stimulants, thus meeting all criteria for circular agriculture.

What is the experimental base supporting YSY® Yeast performance?

We have over 140 field trials in multiple crops, pathogens, geographies. We are planning to add over 60 trials in 2024. Here some performance examples from YSY® Yeast GEP regulatory trials, performed over the last 3 years:

Efficacy evaluation of YSY – PT22AV on Strawberry against Grey Mold (Botrytis cinerea) in open field conditions 


At the final evaluation, 47.8% of fruits in the untreated plots were infected with B. cinerea. Eight applications of YSY-PT22AV at 1 kg/ha achieved higher efficacy than organic reference B. amyloliquefaciens at 2500 g/ha for 10 applications. PT22AV showed equivalent efficacy of two applications of the chemical standard (Ciprodinil+Fludioxonil 800 g/ha) at label rate. The strategy with 6 applications of PT22AV at 1 kg/ha combined with one applications of chemical standard at 800 g/ha provided the best control against grey mold.

Efficacy evaluation of YSY – PT22AV on Tomato against Soil borne disease (Pythium spp.), in greenhouse


YSY-PT22AV at 1 kg/ha applied six times every week from transplant, achieved best efficacy against Pythium spp.,  comparable or superior B. amyloliquefaciens at 3 L/ha for eight applications and Thricoderma asperellum – Thricoderma gamsii at 2500 g/ha for two applications.YSY-PT22AV at 1 kg/ha applied six times every week from transplant, achieved best efficacy against Pythium spp.,  comparable or superior B. amyloliquefaciens at 3 L/ha for eight applications and Thricoderma asperellum – Thricoderma gamsii at 2500 g/ha for two applications.

Efficacy evaluation of YSY – PT22AV on Tomato against Nematodes (Meloydogine spp.) in greenhouse conditions


At final evaluation, 60% of the plants of untreated plots were infected with nematodes. Eight applications of YSY-PT22AV at high doses (1 kg/ha) achieved satisfactory nematocidal efficacy and were equivalent to two applications of the chemical standard Fluopyram at label rate. 4 applications of PT22AV at high dose (1 kg/ha) combined with two applications of Fluopyram provided the best nematodes control. The bio-stimulating effect of YSY-PT22AV increased commercial yield by almost 20% compared to the standard reference.

Efficacy evaluation of YSY – PT22AV on Pome fruits against Fire Blight (Erwinia amylowora) in open field


The trial was carried out in open field conditions in Connecticut (USA). At final assessment, 37.38% of control flowers showed fire blight disease symptoms. Both YSY® at full dose and YSY at lower dose with a specific Activator (Booster) resulted in symptons reduction compared to un-treated control. YSY® efficacy was comparable to the reference product the antibiotic streptomycin, while YSY® did not show any russeting symptom.

Efficacy evaluation of YSY – PT22AV on Rice Blast (Pyricularia oryzae) open field in Italy


At harvest, 31.1% of untreated plots showed symptoms of P. oryzae in rice ears area. 3 applications of YSY-PT22AV at 1 kg/ha and YSY-PT22AV at half rate activate with YSY specific activator, showed efficacy superior to 8 L of comparable bio control standard and comparable to two applications of the best chemical standard Pyraclostrobin applied at 1 l/ha.

Attractiveness of Papiliotrema terrestris strain PT22AV (YSY®) on honey bees


Syrup consumption: In all the time intervals (0-24h, 24-48h and 48-72h) and in all the three repetitions we observed a clear preference of the bees towards the syrup containing the PT22AV. This evident trend was statistically confirmed in all the cases and the statistical significance was almost always high (p<0.01).

Bio stimulant action of Papiliotrema terrestris strain PT22AV (YSY®) on Strawberry



Numerous experiments in field and growth chamber condition, confirm bio-stimulating action of YSY-PT22AV when applied to soil, superior than commercial standard tested (eg. Radifarm). YSY-PT22AV stimulates plant root development and increases number of flowers. Strawberry commercial production increased by 20% on average.

Scientific Article on YSY® use to control  Plum Brown Rot in Biological and Biocontrol Integrated Pest Management Strategies and Incidence and Fungicide Residues in Fruits 


When can we expect YSY® launch on market?

We anticipate full market launch in Europe and the USA in 2026 with multiple crops and pathogens in user label. 

We generated a solid regulatory dossier, which we already applied in the European Union early 2023. USA application is planned in 1st Quarter 2024 for 2 different formulations.

We are planning 2025/26 registration applications in Brazil, Mexico, India, China, Japan, Korea. 

We expect fast track registrations in most markets, with possible emergency registrations from 2024, considering YSY® favorable regulatory profile and the high interest expressed by farming associations for certain uses where YSY has superior performance vs other biological alternatives (eg. bee attraction and protection; fire-blight control; soil borne diseases and nematodes control).

What is AgroVentures distribution model? Any partner in China?

We will distribute product via companies interested to develop their own bio control portfolio.  We are receiving indications of interest from major industry players and national distributors.  Zhejiang Tide CropScience Co., LTD., a sister company of AgroVentures, is our Partner for YSY® development in China.

image.pngAgroVentures contacts:

email: service@agroventures.eu; Web: www.agroventures.eu  

Source: AgroVentures


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