Michel GIRAUD CTIFL - PowerPoint Presentation

Michel GIRAUDCTIFL (Technical Institute for Fruits & Vegetables) Centre de Lanxade, 24130 Prigonrieux FRANCE Bull’s eye Rot in Europe Recent results of Research and in Experimentation

Centre technique interprofessionnel des Fruits et Légumes Creation : 1952Staff : 270Budget : 23 million € / yearFund : 56% = professional contributions 28% = grants (government, EU) 16% = deliveries, services, Lanxade Center :Staff = 6870 ha + 7000 m2 greenhousesApplied Research and experimentation on pome fruits, walnut, chestnut, kiwi, strawberry, melon, Fruit certification & Virology IPM, Organic

French Apple Production 1 470 000 tons37 000 ha(Agreste, 2017) Apple (and pear growers) are belonging to ANPP (Association Nationale Pomme-Poire) 65% of national apple production is labeled "Vergers Ecoresponsables “ (Global Gap + IPM specifications)

French Apple Production (2017)

Market request and public concern Market 4 residues of pesticides (German market)Residues < 33% MLR (Lidl,…)No postharvest treatment (Casino, filière qualité Carrefour)Green campaignOrganic Zero residue 2018

Market request and public concern The challenge / storage rots 4 residues of pesticides (detected) Pre-harvest : 1 Bellis * + 1 Geoxe * = 3 residues Postharvest : +1 residue Residues < 33% MLR Treatments close to harvest Possible with less susceptible cvs (untreated in pre-harvest) Organic No efficient solution in biocontrol against BER Some scab tolerant cvs are very susceptible to BER (Opal, Topaz, Pinova , Goldrush … Hot water (pre-industrial development) * Bellis = boscalid + pyrachlostrobin * Geoxe = fludioxonil

Bull’s Eye Rot in the world Absent / Quarantine

Species of Neofabrae in EuropeSource : COST 864 – expert meeting, Bergen, Mars 2009, completed by recent literature N. alba N. perennans N. kienholzii

Neofabraea vagabunda Desm. Ross. synonym N. alba (Guthrie) Verkley formerly : Pezicula alba GuthrieAnamorph : Phlyctema vagabunda Desm. = Phlyctaena vagabunda = Trichoseptoria fructigena Usually called in Europe “ Gloeosporium ” Main species in Southern Europe Quiescent pathogen / long term storage

Neofabraea vagabunda

Neofabraea vagabunda False pycnidia : acervuli

Neofabraea perennans / N. malicorticis = formerly Pezicula malicorticis Anamorph : Cryptosporiopsis perennans & C. curvispora = Cryptosporiopsis malicorticis Related to perennial canker Main species in Northern Europe, rare in many countries of south Europe Quiescent pathogen / long term storage

Neofabraea kienholziiNew species, not reported in France Reported in UK, NL, Poland, AmericaSymptoms similar to N. vagabunda, or intermediate with N. perennans (R. Saville, East-Malling, pers.comm.)Artificial inoculation of a british strain(Lanxade, 2016)

International WG Apple Lenticel RotsIncludes Neofabraea and Colletotrichum Last meeting, Liège (Belgium), May 25th, 2019( after the ISHS Postharvest Pathology Conference

Bull’s eye Rot : relative incidence in France Susceptibility level of cvs to BER All regions affected by BER, except Provence-Côte d’Azur (Mediterranean climate)

Low Medium High Gala (group) Red delicious Granny Smith Braeburn Jonagold Idared Joya ® Cripps Red Jazz® Scifresh Antares® Golden Delicious Fuji (group) Elstar Reinettes (all types) Honeycrunch ® Pink Lady® Cripps Pink Pink Lady® Rosy Glow Pinova / Evelina Goldrush ® Opal ® Tentation® Topaz Chantecler Related to : Storage time (long/short) Shape, number lenticels, Harvest date Genetic, … Susceptibility of varieties Updated May 2019, French post- harvest WG

Harvest conidia conidia ? Infection of fruits Storage Rots waste Inoculum Waste disposal , composted ? Cycle ( presumed ) of N. vagabunda No t eleomorphic stage ? Not harvested fruits

N. vagabunda epidemiology : few knowledgeInoculum Dissemination Infection Symptoms Sporulation ? Incubation Latence V International Symposium on Postharvest Pathology – Liège (Belgium) 19-24 May 2019   

1. Inoculum sources in orchard N. vagabunda is known(1) to survive in existing cankers, dead materials, or bark splits It is also known to be unable to make canker naturally on apple tree, unlike N. perennans(1) Several authors Washing artificial cankers (La Morinière ) Evolution and healing of an artificial canker of N. vagabunda during 3 years. Inoculation in May 2013 ( L a Morinière ).

Possible source of inoculum in the environment : hedges ?Source:Farr & Rossman Fungal Databases http://nt.ars-grin.gov 22 species / 3 hedges in 2014 Few collected spores : 1-3/ rain

Cankers Apple Leaf litter Mummies Weeds N. vagabunda is abundantly present on necrotic tissues of apple and pear : mummies , cankers and dead leaves, and also on necrotic tissues of other plant species present on the orchard floor such as various weeds and grasses N = no data

2. Dissemination : spore flying in orchard12.7% 20% Spore flying is not the only way of dissemination

2. Dissemination : sporulation in orchard2 peaks of sporulation (Bompeix, 1973) cv. Pinova Pear cv. Bosc Artificial cankers

2. Dissemination : washing by rain Anti-rain plastic protection cv. Rosy Glow, planted 2014 When avoiding rain, infection by N. vagabunda is drastically reduced Rain is playing a major role

3. Fruit infection processInfection occurs mechanically by rain, washing bark, to the fruitIncidence of the shape of lenticels (susceptibility of cv.) and of their receptivity (related to fruit maturity) Germination of several spores in the lenticel : anastomosis of mycelium and haustoria : short incubation, and then become latent.From Gilbert Bompeix, Marta Mari (pers. comm.) Neri et al. 2019

V International Symposium on Postharvest Pathology – Liège (Belgium) 19-24 May 2019

Incidence of temperature on spore germination Observation of germination of conidia in free water, in Petri dishes, no replicate, each in a climatic chamber

3. How to study the incidence of climatic parameters on N. vagabunda ?Artificial inoculation Needs no infected fruits prior to inoculation Impossible in oceanic climate Natural infection Windows / covering trees (La Morinière Experimental Station, Loire Valley , trials in progress ) My method : Selected picking fruits before / after a rain event and store 6-7 months (trials from 2006, 3 cvs )

Example : 2015, cv. Goldrush Few rain , poor effect Receptivity of lenticels

N. vagabunda potential on Tentation® (2006-2014) Significant reduction of N.vagabunda infection potential after a dryer period Infection may occur before 1 month before harvest Survival of conidias in lenticel ?

Incidence of rainfall on N. vagabunda (2006-2016)Tentation® 2006-2014 and Goldrush 2012-2016Storage 6-7 months Assessment of incidence of one (rainy) period on BER : % of increasing fruit infection potential 0% : no effect <5% : few effect, not significant 5-10% : significant effect >10% : high incidence

Research : climatic data having an incidence on BER infectionBest correlated parameters:Rain durationWetness duration when associated with rainWetness > 5 hoursCumulative degree-days during wetnessData collected during 9 years (2006 – 2014) in Tentation® orchard To be checked / continued with other varieties (Pink Lady,…)

N. vagabunda Infection potential for Tentation® (Lanxade 2006-2014) The level of receptivity of lenticels is an important parameter having incidence on infection rate

How to assess the infection risk by Neofabraea alba in orchard?RainQuantity and duration: enough for a best washing of the treesWetness associated with this rain eventMinimum 4-5 hoursIncidence of temperature Cool temperature (Tmini<10°C) favorable to sporulation (ref. Marta Mari, CRIOF Bologna) Warmer temperature (20-25°C) optimal for infectionMaturation of fruits before harvest: Relation ethylene (data from Italy)Receptivity of lenticels Volatile organic compounds (Neri et al., 2019)No infection without rain, and in dry periodSusceptibility of varieties

N. vagabunda ControlEfficacy of chemicals, alternatives and biocontrol Pre-Harvest FludioxonilBoscalid+pyrachlostrobinefluazinam + tebuconazolMethyl-thiophanate* Captan, dithianonCopper Sulfur , lime sulfur Myco -Sin : >3 traitments Boni- protect ( Aureobasidium pullulans ) Phosphites Laminarin Calcium chloride K bicarbonate Post- Harvest Thiabendazole * Pyrimetanil / thermofog 1-MCP ( secondary effect ) Yeasts (all types) * e xcept if resistant strains

Hot Water commercial machines : by dippingXeda (France) Burg Machinefabriek (NL) Inconvenient : max 20 bins /hour

Hot Water commercial machines : drencher Austria : hot water + cooling (stop heat damages) 40 bins (13 T) / hourCost = 0.025 € / kg Treatment of Austrian organic apples, from 2011 France : new machine made by Crovara (MAF- Roda group) : 2018 Recycling system for water 2 bins / treatment Prototype : no conveyor belt

Hot water in practiceTemperature / exposure time : Efficacy against N. vagabunda : >50°C / 2-3 mn Susceptibility to heat damage of cvs  adapt temperature for: Golden Delicious : 48°C / 2-3 mn  poor efficacy (50%) Pinova : 50°C / 3 mn  80-90% efficacy Topaz : 52°C / 2 mn  90-95% efficacyDipping is better for efficacy than drencher (contact points between fruits) Drencher is better for work in chain Hot water is efficient against N. vagabunda , N. perennans, Phytophthora, Colletotrichum acutatum , Monilia fructigena , Phacidiopycnis , Cladosporium , superficial scald Variable with Neonectria ditissima No effect on Penicillium expansum , Mucor , Rhizopus Unknown : storage scab

Incidence of some storage technics on N. vagabundacv. Tentation®Storage 7 months + 10 days in Reg.Atm.cv. Pink Lady®Harvest : 28.10.2009 + Storage 6 m. ILOS (0,5% O 2 then ULO)

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