1. Oilseed rape in the rotation Faye Ritchie, ADAS Rosemaund January 2012

2. What drives rotations? Economics – best margins Soil type (tradition) – what crops can be grown well (and sold) Pest and disease control – especially soil-borne organisms Weed control Politics – set-aside requirements etc Biodiversity Fertility building – especially organic systems Other problems – weather, late harvest, crop failure

3. Rotational issues WOSR yields – rotation – rooting Soil-borne disease threats – and interventions - principles - examples Other disease issues Conclusions

4. Impact of previous cropping on winter oilseed rape yields HGCA project 2922 – led by Ron Stobart, NIAB-TAG Trial location; NIAB-TAG Morley farm, Norfolk four replicate trial drilled on large plots variety Winner (used for the entire trial series) General agronomy prophylactic inputs consistent with local best practice Trial establishment (ideal) OSR cv Winner, typically drilled in early September 1st wheat cv Brompton, typically drilled in the second half of September 2nd (and later) wheat cv Brompton, typically drilled in mid October

5. Project treatment listing Rotation Year 1Year 2Year 3Year 4Year 5Year 6Year 7Year 8Description 1WOSRWW WOSR6 year gap 2WWWOSRWW WOSRWW WOSR2 year gap 3WW WOSRWW WOSR4 year gap 4WW WOSRWW WOSR3 year gap 5WOSR continuous WOSR 6WOSRWWWOSRWWWOSRWWWOSRWWalternate WOSR 7WOSRWW WOSRWW WOSRWW2 year gap 8WWWOSRWWWOSRWWWOSRWWWOSRalternate WOSR

6. OSR Rotational position and yield (t/ha) (Mean of 2006 – 2011 data)

7. Decline in OSR yield and rotational frequency (Mean of 2006 – 2011 data)

8. WW Rotational position and yield (t/ha) (Mean of 2006 – 2011 data)

9. Yields and outputs (average data) DescriptionOSR £300/t WW 125/t OSR £350/t WW 150/t OSR £400/t WW 150/t OSR £400/t WW 200/t OSR1 in 3 (1 st WW; 10.10 t/ha, 2 nd WW 8.96 t/ha, OSR; 3.36 t/ha) 1070127413231663 Alternate WW / OSR (WW; 10.08 t/ha, OSR; 2.81t/ha) 1052124813181570 NB Data for longer rotations not provided by this project

10. Key messages Results clearly highlight rotational impacts on crop performance yield penalties with associated financial implications from close rotations Results to date demonstrate reduced early vigour volunteers issues (crop competition or early season disease) other disease problems (eg stem canker) potential reduction in (cumulative) flowering period evidence that closer rotations are impacting on components for yield and yield drivers (seed development and rooting) Potential pathogens e.g.Olpidium brassicae and Pyrenochaeta sp. are being investigated TSB funded research is starting to examine management options

11. Rooting of OSR - Effects of June rainfall on yield at Boxworth Where rooting is limited, yield is likely to be linked to rainfall

12. Rooting at depth improved particularly by metconazole PGR in spring and correlated with yield ADAS Boxworth 2005

13. Metconazole effects on rooting Rooting data from 6 field trials Applications from pre-green bud (GS3,1) to late green bud (GS3,6) Spring applications increased root length density from 0.48 to 0.60 cm/cm 3 (40-100cm depth) Estimated additional water uptake of 6-9 mm Estimated additional yield in dry year of 0.22 – 0.34 t/ha

14. Risk of drought affecting yield Rainfall for 1986-2008 5 regions 3 soil types On heavy & medium soils the risk of drought was 1 yr in 2 to 1 yr in 3 With metconazole the risk of drought was 1 yr in 5

15. Soil-borne diseases and rotation Pathogen increases in a susceptible crop and then declines under non- susceptible crops. Use extended rotations so that pathogen population declines to below threshold for economic damage. Many soil-borne pathogens are capable of long-term survival – interventions are required as long crop rotations may be impractical (>10 years) Where is threshold?

16. Changes in Verticillium populations in relation to potato crop in 2003. No decrease in 6yr rotation March 2003 14.8 cfu/g January 2009 12.5 cfu/g Potato Council Project R/328

17. Soil-borne oilseed rape diseases – severe clubroot

18. Sclerotinia surveys WOSR England 1986- 2011 CropMonitor data

19. Products stretched in 2010 by late flowering infection (early June) - Herefordshire

20. Responses c. 1 t/ha from all products, Herefordshire 2010

21. SkleroPro Infection model Criteria: Minimum requirements 7ºC and 80% RH for 23hr Use to identify infection events in England Koch et al., 2006

22. Fungicide persistence 3 weeks – needed 2 sprays in 2010 Sklero Pro infection events AFD

23. Sclerotinia and rotations Higher risk where OSR grown in short rotations or in rotations with other susceptible crops - Peas, potatoes, carrots and other veg crops Sclerotia are long-lived if buried deeply. Fungicides very effective (for a soil-borne disease)

24. Verticillium wilt (V. longisporum) symptoms – can we manage this disease threat?

25. Verticillium wilt First confirmed in UK in 2007 Pathogen is Verticillium longisporum – specific for crucifers (mainly brassicas) – first described 1997 Important in other parts of Europe with up to 50% yield loss

26. Disease cycle of OSR verticillium wilt Plant debris or soil from nearby infested fields How much inoculum are you producing?

27. Use resistance in varieties LSD 10.2

28. Improving verticillium management – 2012 actions Monitor crops pre-harvest – how much verticillium is present? Found in all regions - more in south and east Consider variety choice Be prepared to extend rotations to at least 1 in 4

29. Rotations – spatial implications If crops are grown in short rotations, new crops will be close to the previous year’s stubble and subject to spore transfer from crop residues and volunteers. Disease gradients can be steep for some diseases (eg Phoma leaf spot).

30. Light leaf spot – high risk for 2012

31. Light leaf spot in spring has been increasing for the last 6 years

32. Regional light leaf spot risk 2010/2011 2011/2012 Source: http://www3.res.bbsrc.ac.uk/leafspot/forecast/Default.htm Increased risk Similar risk

33. Large yield benefits from varieties with good light leaf spot resistance (KWS data 2010 N Yorks)Castille 4.19 Cuillin 4.84 LSD =0.2

34. HGCA Light leaf spot control not easy - 2011 LSD = 0.47

35. HGCA Light leaf spot fungicides and yield, N Yorks 2011 Treated yield 4.97 v untreated 4.39 P<0.001

36. Implications for light leaf spot control High risk in 2012 Better yield performance where second treatments applied in February Control difficult – need to use more resistant varieties. Product and dose differences were identified - prothioconazole gave best economic performance in first HGCA project; tebuconazole and flusilazole still performing well Concerns about azole resistance Highly resistant varieties – Palace, Cuillin, Cracker, Catana

37. Conclusions Rotations are driven by economics Disease problems can emerge on short rotations but solutions are available to manage many of them. New diagnostic tools should help quantify problems in future and guide management decisions.

38. Thank you Visit www.hgca.com/diseasecontrol for more information

39. Oilseed Rape Update on new RL varieties and disease management Paul Gosling Research & KT Manager (Agronomy) 39

40. 40 Recommended list new additions for 2012

41. 41 VarietyTypeRegionBreeder Marko*SRH-DSV DK CamelotWOpen pollinatedE/WDEKALB DK ExpowerWRHE/WDEKALB ThorinWRH semi dwarfE/WLSPB PalaceWRHUKLSPB ArtogaWRHNorthLimagrain CrackerWRHSp UKLSPB Oilseed rape * The spring OSR list is descriptive

42. Spring varieties 42 MarkoDelightTamarin RH Conv Gross output[109]101102 Oil content[44.5]43.943.4 Lodging[8]88 Shortness of stem[4]66 Earliness of maturity[3]76 New Yield

43. 43 Winter varieties

44. Seasonal variation in oilseed rape E/W yields (controls & new) 44 Average yield gain worth £140/ha based OSR @ £350/tonne

45. Restored hybrid varieties DK ExpowerPR46W21 E/W gross output105109 Lodging[7]8 Stem stiffness79 Shortness of stem66 Earliness of maturity65 Phoma stem canker[9]5 Light leaf spot64 DK Expower contains the RLM7 resistance gene giving good resistance to Phoma Resistance New 45

46. Conventional varieties DK CamelotDK Cabernet E/W gross output 106108 Lodging [7]8 Stem stiffness 79 Shortness of stem 87 Earliness of maturity 64 Phoma stem canker 66 Light leaf spot [5]5 DK Camelot is an earlier maturing variety Agronomy New 46

47. Semi-dwarf RH - East/West ThorinDK Sequoia E/W gross output104101 Lodging[8]8 Stem stiffness99 Shortness of stem98 Earliness of maturity56 Stem canker[5]6 Light leaf spot65 Thorin is a high yielding semi dwarf variety with short stiff stems Yield Agronomy New

48. Clubroot resistant RH CrackerMendel E/W gross output9794 Lodging8[8] Stem stiffness89 Shortness of stem66 Earliness of maturity66 Stem canker45 Light leaf spot95 Cracker provides growers with a combination of light leaf spot resistance and clubroot resistance Yield Resistance New 48

49. 49 New information on disease management

50. Clubroot 50 RD-2007-3373 Management of clubroot (Plasmodiophora brassicae) in winter oilseed rape RD-2008-3525 Brassicas: Further Development of “in field” tests for resting spores of clubroot and the development of clubroot control based on detection Diseased Healthy

51. Clubroot distribution RD-2007-3373 50% of Scottish samples 54% of English samples 51

52. Effect on yield 52

53. Clubroot persistence 53 Modelled from Swedish data

54. Field trial results - RD-2007-3373 54 Factor / SiteAberdeen WarwickshireHerefordshire 2008/ 2009 AberdeenShropshire 2007/20082008/ 20092009/2010 2007/2008 Clubroot epidemic Very low all season Low all seasonLow in autumn and medium in spring Moderate in autumn and severe in summer Very severe from early on Autumn conditions Cool and drier than average Cool and very wet, early frosts Dry at sowing Early winter WetWet, coolWet, warmer Soil treatment effect NoYes No Variety effectNo Yes - pH pre trial6.86.66.56.16.66.5 Calcium pre trial (mg/l) 18572407172099921271720 Clubroot severity pre trial (bioassay) 22.67.111.38324.635

55. Project conclusions Clubroot can cause significant yield loses in OSR even crop failure. Neither varietal resistance or soil amendments offer complete and reliable control. The risks of clubroot increase when brassicas are grown in short rotations (less than 1 in 5?) Preventative action with lime will be beneficial in managing this disease where pressure is low. Varietal resistance is likely to be very successful initially but will be eroded in short rotations. 55

56. Topic sheet 56

57. Oilseed Rape 2012 and beyond New RL varieties showing increased yield and improved agronomic characteristics Watch for signs of clubroot - consider management options

58. Thank you 58

59. Oilseed Rape Update on new RL varieties and disease management Paul Gosling Research & KT Manager (Agronomy) 59

60. 60 Recommended list new additions for 2012

61. 61 VarietyTypeRegionBreeder Marko*SRH-DSV DK CamelotWOpen pollinatedE/WDEKALB DK ExpowerWRHE/WDEKALB ThorinWRH semi dwarfE/WLSPB PalaceWRHUKLSPB ArtogaWRHNorthLimagrain CrackerWRHSp UKLSPB Oilseed rape * The spring OSR list is descriptive

62. Spring varieties 62 MarkoDelightTamarin RH Conv Gross output[109]101102 Oil content[44.5]43.943.4 Lodging[8]88 Shortness of stem[4]66 Earliness of maturity[3]76 New Yield

63. 63 Winter varieties

64. Seasonal variation in oilseed rape E/W yields (controls & new) 64 Average yield gain worth £140/ha based OSR @ £350/tonne

65. Restored hybrid varieties DK ExpowerPR46W21 E/W gross output105109 Lodging[7]8 Stem stiffness79 Shortness of stem66 Earliness of maturity65 Phoma stem canker[9]5 Light leaf spot64 DK Expower contains the RLM7 resistance gene giving good resistance to Phoma Resistance New 65

66. Conventional varieties DK CamelotDK Cabernet E/W gross output 106108 Lodging [7]8 Stem stiffness 79 Shortness of stem 87 Earliness of maturity 64 Phoma stem canker 66 Light leaf spot [5]5 DK Camelot is an earlier maturing variety Agronomy New 66

67. Semi-dwarf RH - East/West ThorinDK Sequoia E/W gross output104101 Lodging[8]8 Stem stiffness99 Shortness of stem98 Earliness of maturity56 Stem canker[5]6 Light leaf spot65 Thorin is a high yielding semi dwarf variety with short stiff stems Yield Agronomy New

68. Clubroot resistant RH CrackerMendel E/W gross output9794 Lodging8[8] Stem stiffness89 Shortness of stem66 Earliness of maturity66 Stem canker45 Light leaf spot95 Cracker provides growers with a combination of light leaf spot resistance and clubroot resistance Yield Resistance New 68

69. 69 New information on disease management

70. Clubroot 70 RD-2007-3373 Management of clubroot (Plasmodiophora brassicae) in winter oilseed rape RD-2008-3525 Brassicas: Further Development of “in field” tests for resting spores of clubroot and the development of clubroot control based on detection Diseased Healthy

71. Clubroot distribution RD-2007-3373 50% of Scottish samples 54% of English samples 71

72. Effect on yield 72

73. Clubroot persistence 73 Modelled from Swedish data

74. Field trial results - RD-2007-3373 74 Factor / SiteAberdeen WarwickshireHerefordshire 2008/ 2009 AberdeenShropshire 2007/20082008/ 20092009/2010 2007/2008 Clubroot epidemic Very low all season Low all seasonLow in autumn and medium in spring Moderate in autumn and severe in summer Very severe from early on Autumn conditions Cool and drier than average Cool and very wet, early frosts Dry at sowing Early winter WetWet, coolWet, warmer Soil treatment effect NoYes No Variety effectNo Yes - pH pre trial6.86.66.56.16.66.5 Calcium pre trial (mg/l) 18572407172099921271720 Clubroot severity pre trial (bioassay) 22.67.111.38324.635

75. Project conclusions Clubroot can cause significant yield loses in OSR even crop failure. Neither varietal resistance or soil amendments offer complete and reliable control. The risks of clubroot increase when brassicas are grown in short rotations (less than 1 in 5?) Preventative action with lime will be beneficial in managing this disease where pressure is low. Varietal resistance is likely to be very successful initially but will be eroded in short rotations. 75

76. Topic sheet 76

77. Oilseed Rape 2012 and beyond New RL varieties showing increased yield and improved agronomic characteristics Watch for signs of clubroot - consider management options

78. Thank you 78