1. 1.1 Introduction to integrated disease management Introduction Effects of control measures on disease progress Effects of control measures within the plant tissue Translocation and deposition of control measures When to apply a control measure? Concluding remarks

2. Plant life cycle Seed germination Seedling establishment Vegetative growth reproductive growth Seed formation Seed dissemination survival

3. Pathogen life cycle spore germination establishment lesion formation reproductive growth spore formation spore dissemination survival

4. Plant and pathogen life cycles seed germination seedling establishment vegetative growth reproductive growth seed formation seed dissemination

5. Monocyclic pathogens Complete only one disease cycle in a growing season (100 - y) QR dy dt Q = amount of initial inoculum R = infection efficacy of the inoculum y = disease intensity (%) t = time Time Disease intensity (%) Time Disease intensity (logit) QR Logit = ln ( ) 100 100-y

6. For monocyclic pathogens All disease plants are infected from inoculum that survived from the previous season Time Disease intensity (%) Previous season inoculum

7. The host is susceptible for a very short tine (smuts) The infecting structures do not disseminate within the same growing season (soil-borne pathogens) The environmental conditions are conducive for infection for a short time (scab) The growth of the pathogen is very slow Pathogens are monocyclic because:

8. Polycyclic pathogens Complete several disease cycles in a growing season r y dy dt (100 - y) r = apparent infection rate y = disease intensity (%) t = time Time Disease intensity (logit) r Logit = ln ( ) y 100-y Time Disease intensity (%)

9. For polycyclic pathogens Time Disease intensity (%) Few plants are infected from inoculum that survived from the previous season Previous season inoculum current season inoculum Most plants are infected from inoculum that was proliferated within the current season

10. The disease triangle host pathogenenvironment

11. The disease pyramid grower pathogen environment host

12. Control measures “Strategic means”: Means that are applied once, and their effect is apparent for a long time (the entire growing season) “Tactical measures”: Means that are applied frequently, and are effective for a relatively short time Chemical Cultural BiologicalGenetic Induced resistance

13. The effects of control measures on disease development Depends on the biology of the pathogen (monocyclic or polycyclic) and on the characteristics of the measure (strategic or tactical)

14. Monocyclic pathogens Complete only one disease cycle in a growing season (100 - y) QR dy dt Q = amount of initial inoculum R = infection efficacy of the inoculum y = disease intensity (%) t = time Polycyclic pathogens r y dy dt (100 - y) r = apparent infection rate y = disease intensity (%) t = time Complete several disease cycles in a growing season

15. Time Disease intensity (logit) Time Disease intensity (%) Polycyclic pathogens Time Disease intensity (%) Monocyclic pathogens Initial disease rate

16. Time Disease intensity (logit) Possible effects of control measures on disease progress Effects on the amount of initial disease Soil treatment Seed treatment Systemic fungicides Crop rotation Certified seeds Sanitation Escape (planting time) Biocontrol agents

17. Time Disease intensity (logit) Possible effects of control measures on disease progress In monocyclic pathogens: on the infection efficacy of the inoculum Polycyclic pathogens: Effects on the apparent infection rate Protectant fungicides Systemic fungicides Genotype resistance cultural measures (e.g., heating, ventilation) Biocontrol measures On the rate of disease development

18. Time Disease intensity (logit) Possible effects of control measures on disease progress On the rate of disease development Effects on the amount of initial inoculum and Systemic fungicidesIntegration of control measures

19. Deposition and translocation of control measures Within treated leaves Within treated plants

20. Deposition and translocation of control measures within treated leaves

21. Mesostemic measure Trans-laminar measure Deposition and translocation of control measures within treated leaves Protectant measure

22. Systemic measure Measures with re-distribution ability Deposition and translocation of control measures within treated leaves

23. Application of a systemic measure to the root system Deposition and translocation of control measures within treated plants

24. Application of a systemic measure to the stem Deposition and translocation of control measures within treated plants

25. Application of a systemic measure to a leaf Deposition and translocation of control measures within treated plants

26. Application of a systemic measure to the foliage of a growing plant Deposition and translocation of control measures within treated plants

27. Necrotic area infected area invaded area Can the control measure reach its target? Biotrophic pathogens Nectotrophic pathogens

28. Integration of control measures Time Combined application Application according to the expected efficacy of each measure Alternated application

29. Combined efficacy of control measures Control efficacy (%) 11+22 exp. Additive 1+2 obs. 1+2 Synergistic obs. 1+2 Antagonistic obs.

30. Calculation of combined efficacy of control measures - Step 1 Control efficacy (%) 12 1+2 obs. A = control efficacy of #1 B = control efficacy of #2 A+B (obs.) = observed control efficacy of 1+2 Abbott formula E (exp) = A + B - (A*B)/100 1+2 exp. A+B (exp.) = expected control efficacy of 1+2

31. SF = E (obs) / E (exp Control efficacy (%) 1+2 exp.obs. SF = Synergy factor E (obs.) = Observed control efficacy of 1+2 E (exp.) = Expected control efficacy of 1+2 Calculation of combined efficacy of control measures - Step 2

32. Combined efficacy of control measures Control efficacy (%) 1+2 exp. obs. SF = 1 additive Control efficacy (%) 1+2 exp. obs. SF > 1 synergistic SF = Synergy factor Control efficacy (%) 1+2 exp. obs. SF < 1 antagonistic

33. Combined efficacy of control measures Treatment Disease severity (%) 1 2 1+2 Control 20 30 15 80 Abbott formula E (exp) = A + B - (A*B)/100 E (exp) = 75+62.5 - (75*62.5)/100=90.6% control efficacy of #1 = 100-(20/80)*100= 75% control efficacy of #2 = 100-(30/80)*100= 62.5% control efficacy of 1+2= 100-(15/80)*100= 85% E = 100-(t/c)*100

34. Combined efficacy of control measures SF = E (obs) / E (exp E (obs.) = Observed control efficacy of 1+2 E (exp.) = Expected control efficacy of 1+2 E (obs.) = 85% E (exp.) = 90.6% SF = 85 / 90.6 = 0.93 SF < 1antagonistic reaction

35. When to apply a “tactical” control measure? Effects of the environment on the pathogen Effects of the control measure on the pathogen’s life cycle Effects of the host on the pathogen

36. grower pathogen environment host When to treat? Effects of the environment on the pathogen

37. spore germination establishment lesion formation reproductive growth spore formation spore dissemination When to treat? Effects of the environment on the pathogen

38. Environmental factor Time Disease intensity (%) Rain Periods of high relative humidity High or low temperatures Hail Sand storms Environmental factors

39. When to treat? Effects of the environment on the pathogen spore germination establishment lesion formation reproductive growth spore formation spore dissemination Time Disease severity (%)

40. When to apply a “tactical” control measure? Effects of the environment on the pathogen Effects of the control measure on the pathogen’s life cycle Effects of the host on the pathogen

41. control measure pathogen environment host When to treat? Effects of the control measure on the pathogen

42. When to treat? Effects of control measures on the pathogen’s life cycle spore germination establishment lesion formation reproductive growth spore formation spore dissemination Protectant fungicides, biocontrol agent, heating, ventilation

43. spore germination establishment lesion formation reproductive growth spore formation spore dissemination Mesostemic fungicides, biocontrol agents, genotype resistance When to treat? Effects of control measures on the pathogen’s life cycle

44. spore germination establishment lesion formation reproductive growth spore formation spore dissemination Systemic fungicides, biocontrol agents When to spray? Effects of fungicides in the pathogen’s life cycle

45. spore germination establishment lesion formation reproductive growth spore formation spore dissemination Curative fungicides, heating, ventilating, light filters When to treat? Effects of control measures on the pathogen’s life cycle

46. spore germination establishment lesion formation reproductive growth spore formation spore dissemination Eradicative fungicides, biocontrol agents, ventilation, heating When to treat? Effects of control measures on the pathogen’s life cycle

47. When to apply a “tactical” control measure? Effects of the environment on the pathogen Effects of the control measure on the pathogen Effects of the host on the pathogen

48. When to treat? Effects of the host: age-related resistance Time Host resistance Time Disease intensity (%) grower pathogen environment host

49. Concluding remarks Application of control measures should be based on: The biology of the pathogen (monocyclic, polycyclic) The possible activity of the control measure (protectant, mesostemic, translaminar, systemic) The relationships between the host, the pathogen and the environment: effects of the environment on the pathogen effects of the control measures on the pathogen effects of the host on the pathogen

50. The disease pyramid pathogen environment host man woman