© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Biological control: the case study of Coniothyrium minitans in France France MODULE C11

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Background: sclerotinia nuisibility A common disease occuring intermittently on oil-seed rape – severe epidemics occur only one or twice a decade (2000 et 2006) – sometimes no or very poor epidemics (2003) but a damaging disease with a damage threshold of 10 % of sclerotinia stem rot Stem rot of 0 to 10 % Yield losses < 0.2 T/ha No control Stem rot of 10 to 100 % Yield losses > 0.2 T/ha (0.1 T/ha per 10% of stem rot

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Sclerotinia Life cycle Sclerotia in soil Infected petals on leaves Infected leaves Stem rot Apothecia Fall of petals Favorable climate Favorable climate Sclerotia on stems

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Disease management Chemical control was usually based on protective and systematic spray at early bloom with cheap fungicides  Numerous useless sprays  Development of fungicides resistance, eg carbendazim (in France) But the context is requiring  To reduce the use of fungicides according to their negative environmental effects  To reduce expensive inputs  To justify the use of pesticides according to European regulation

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY IPM solutions on Sclerotinia Sclerotia in soil Infected petals on leaves Infected leaves Stem rot Apothecia Fall of petals Favorable climate Favorable climate Sclerotia on stems BIOFONGICIDE Climatic modelling (rotation and field situation) (field and climate) Risk grid FONGICIDE

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Sclerotinina Resistance on fungicides Efficiency of fungicide against Sclerotinia (french network) Damages Nb trials

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Coniothyrium minitans: an agent of biological control The contact between spores of Coniothyrium and sclerotia are stimulating the germination of spores. C. minitans develops a mycelium that can contaminate the sclerotia Infection of sclerotia Arsenal enzyme => destruction of hyphal cell of the sclerotia Sclerotia becomes flabby and unable to germinate and form apothecia

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Coniothyrium minitans: an agent of biological control Contans ® WG is not used as a chemical fungicide: –To be effective, Contans ® WG should be put in direct contact with the sclerotia  by spraying and incorporation (sensitive to UV) before planting of rapeseed  By spraying on infected crop residues The life of Contans ® WG is approximately 12 months, it should repeat the treatment every year to bring the medium term to reduce the infectivity of the soil.

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Recommandations Contans WG ® : commercial product with Coniothyrium minitans spores –Before the seedling of oil-seed rape:  At the rate of 2 kg / ha.  This practice ensures the destruction of sclerotia surface that reduces the pressure of inoculum (less ascospores to contaminate the flowers of rapeseed) and limit stem attacks of rape. –On infected crop residues:  At the rate of 1 to 2 kg / ha.  Infection of sclerotia by C.minitans helps to reduce the stock of sclerotia in the soil and, consequently, to prevent parasitic pressure later.

© ENDURE, February 2007 FOOD QUALITY AND SAFETY © ENDURE, February 2007 FOOD QUALITY AND SAFETY Conclusion: Response to general principles of IPM Environment: –Reduced quantities of pesticides: general principle 6 –Non chemical measures: general principle 4 Agronomy: –Monitoring and DSS : general principle 2 –Prophylaxis : general principle 1 –Choice of products : general principle 5 –Resistance management: : general principle 7 –Limitation of dose: general principle 6 –Level thresholds : general principle 3