Late blight resistance management in potato production - The DuRPh approach - Geert Kessel, Jack Vossen, Ronald Hutten, Bert Lotz and Anton Haverkort

Transcription

1 Late blight resistance management in potato production - The DuRPh approach - Geert Kessel, Jack Vossen, Ronald Hutten, Bert Lotz and Anton Haverkort

2 Outline Potato late blight and potato late blight control Phytophthora infestans Best practices The Challenge A Next Level IPM control strategy for potatolate blight The 2014 and 2015 demo trials, a proof of principle

3 Symptoms of potato late blight

4 Potato late blight on a global scale Food security issue 21 million ha globally, losses 5-10 billion

5 Phytophthora infestans in the Netherlands Dutch population ( ) 311 genotypes 652 isolates

6 EU P. infestans population 2013

7 Euroblight 5 Best Practices Hygienic measures (reduction of primary inoculm) Cultural practices (rotation etc.) Use of resistant varieties Fungicides (e.g. weekly) Decision Support Systems Leaflets available from

8 Challenge Develop a durable control strategy for PLB based on host resistance and the principles of IPM P. infestans: Highly adaptive (many R-genes / ai s are overcome) Large numbers of off spring (4 x sp/ha) Highly aggressive Host: R-gene (cassettes) can be overcome

9 A next level IPM strategy for PLB We do NOT spray unless... Preventive strategy Additional components: Host resistance Stacks of R-genes Pathogen population monitoring Virulence to R-genes used Replace cassettes when necessary Switch to low input spraying when necessary Modified components: Fungicides

10 A next level IPM strategy for PLB Pathogen We do NOT spray... unless: The host is present & The Pathogen is present & The weather is suitable for infection (DSS) & The R-gene (cassette) is at risk & Pathogen Monitoring information Host Environment The remaining fungicide protection is insufficient Reduced dose rates on more resistant potato genotypes HR: 25% MR: 50% S: 100%

11 Demo trials 2014 and wet and highly Phytophthora conducive 2015: dry and warm/hot (except 2nd half August) Emergence: 5 July Sprays: 5 Inoculation (Blue13) 4 & 11 August

12 3m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3.5m 7.5m 3m Demo trial 2015 DuRPh: 4x Desiree + R-gene stacks (2 3 genes) Not Sprayed 3m 7.5m 3.75m 7.5m Plot 10 Sto1 Plot 20 Vnt1 A19 Vnt1 A14 Chc1 Onbespoten Blb3 Onbespoten Plot 9 Plot 19 Sto1 A10 Sto1 A16 Blb3 Onbespoten Vnt1 Onbespoten 3m Conventional cultivars 1, 2 or 4 R-genes Sprayed, 25% dose rate Plot 8 Plot 18?? Sarpo mira?? Sarpo Mira 25% Onbespoten Plot 7 Plot 17?? Carolus?? Carolus 25% Onbespoten Plot 6 Plot 16 Blb2 Bionica Blb2 Bionica R2 25% R2 Onbespoten DuRPh: Desiree + Single R-genes Narrow and Broad spectrum Sprayed, 25% dose rate Plot 5 Plot 15 Chc1 A17 Chc1 A17 25% Onbespoten Plot 4 Plot 14 Vnt1 A15 (Cisgeen) Vnt1 A15 (Cisgeen) 25% Onbespoten Plot 3 Plot 13 Blb1 A01 Blb1 A01 25% Onbespoten Sprayed, 100% dose rate Plot 2 Plot 12 Blb3 A03 Blb3 A03 100% Onbespoten Conventional Desiree (Wild type control) Plot 1 Plot 11 R0 Desiree R0 Desiree 100% Onbespoten 7.5m 3.75m 7.5m 3m 4 ruggen 10 ruggen 5 ruggen 10 ruggen 4 rugg

13 Demo trial 2015

14 Severity (%) Severity (%) Severity (%) Severity (%) Demo trials, Results 100 All genotypes, sprayed 100 All Genotypes NOT sprayed jun 26-jun 10-jul 24-jul 7-aug 21-aug 4-sep Date (2014) 0 12-jun 26-jun 10-jul 24-jul 7-aug 21-aug 4-sep Date (2014) 100 All Genotypes sprayed All Genotypes not sprayed jun 26-jun 10-jul 24-jul 7-aug 21-aug 4-sep Date (2015) jun 26-jun 10-jul 24-jul 7-aug 21-aug 4-sep Date (2015)

15 R0 Blb3 Blb1 Vnt1 Chc1 Blb2 + R2 Unknown R3a R3b R4 R8 Sto1 + Blb3 Vnt1 + VChc1 Sto1 + Vnt1 Sto1 + Vnt1 + Blb3 Demo trials, Spray input & Environment 15 Spray input 250 Environmental burden # Sprays TFI Aquatic Organisms Soil Organisms Ground Water R0 Blb3 Blb1 Vnt1 Chc1 Blb2 + R2 Unknown Sto1 + Blb3 Vnt1 + VChc1 Sto1 + Vnt1 Sto1 + Vnt1 + Blb3 0 R0 Blb3 Blb1 Vnt1 Chc1 Blb2 + R2 Unknown Sto1 + Blb3 Vnt1 + VChc1 Sto1 + Vnt1 Sto1 + Vnt1 + Blb3 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 IPM2.0 Desiree A03 A01 A15 A17 Bionica Carolus A10 A19 A16 A14 Desiree A03 A01 A15 A17 Bionica Carolus A10 A19 A16 A Spray Input # Sprays TFI Environmental burden Aquatic Organisms Soil Organisms Ground Water Desiree A03 A01 A15 A17 Bionica Carolus Sarpo mira A10 A19 A16 A14

16 Conclusions Full potential of Host resistance & IPM in PLB control currently not realized... not even close! Ample room for improvement IF host resistance is introduced P. infestans highly adaptive Robust forms of host resistane Monitoring of pathogen adaptation Host resistance should be managed after introduction. It s NOT a silver bulet Fungicides remain an integral part of the control strategy We do not spray unless... Low input spray strategy... 75% Reduction fungicide input