1. Phytophthora Blight (Phytophthora capsici) of Peppers in Illinois
M. Babadoost
University of Illinois
Urbana-Champaign, Illinois

2. Chicago

3. (Phytophthora capsici)
Phytophthora Blight
(Phytophthora capsici)
________________________________________
Importance:
Worldwide occurrence
Affects >50 species in 15 plant families
The most important disease of peppers and cucurbits in the US
Causes up to 100% crop losses

4. Phytophthora blight of bell pepper

5. Phytophthora blight on chili Pepper

6. Phytophthora crown infection of peppers

7. Phytophthora blight of, 100% crop losses

8. Phytophthora blight of pepper

9. Phytophthora blight and fruit rot of eggplant

10. Fruit rot of cucurbits (Phytophthora capsici)

11. Phytophthora Blight (Phytophthora capsici) ____________________________________
An oomycete pathogen
Genetic and pathogenic variations
Multi-cycle pathogen
Survival: oospores and mycelium
Favorable conditions: moist & warm

12. Phytophthora capsici

13. Genetic distance
0.0
0.18
0.27
0.36
0.09
0.45
RAPD
group
Pathogenicity
group
Pc1
Pc2-1 A I 70
Pc34-7
Pc34-8
Pc38-12
Pc33-1
Pc33-9
Pc33-5
Pc13 B II
Pc38-13 70
Pc35-10
Pc35-4 58
Pc33-3
Pc34-3 C
III
Pc34-11
Pc36-5 D IV
Pc35-6 58
Pc35-7 E V
Pc24-2
Pc36-7
Pc36-9 57
Pc36-8 F VI
Pc24-4
Pc10

14. Phytophthora Blight of Peppers (Management)
_______________________________
Resistant cultivars
Chemical control
Cultural practices
Red-light treatment

15. Phytophthora Blight of Peppers (Management)
_______________________________
Resistant cultivars
Chemical control
Cultural practices
Red-light treatment

16. Evaluating pepper cultivars for resistance
to Phytophthora capsici

17. Evaluating pepper cultivars for resistance
to Phytophthora capsici

18. Evaluating pepper cultivars for resistance
to Phytophthora capsici

19. Phytophthora Blight Management, 2002.
Resistant pepper cultivars/lines (Field)
__________________________________________________________
Plant survival (%) __________________________________________
CV/Line 11 June 11 July 8 August 22 August ____________ _______ _______ _________ _________
Emerald Isle a 90 a 85 a
Paladin a 92 a 92 a
Reinger a 92 a 92 a
BHN-1P ab 82 a 82 a
Line # a 100 a 100 a
Line # a 92 a 92 a
Line # a 97 a 92 a
Line # a 100 a 100 a
Maxi Bell bc 57 b 57 b
Cal. Wonder c 50 b 50 b

20. Phytophthora Blight Management, 2007.
Resistant pepper cultivars/lines (Field)
__________________________________________________________
Plant survival (%) __________________________________________
CV/Line 15 May 12 June 10 July 14 August ____________ _______ _______ _________ _________
Alliance ab 70 a-d 65 bc
Aristatol ab 80 abc 78 ab
HMX ab 50 d 40 cd
HMX ab 68 bcd 60 bcd
Paladin a 90 ab 83 ab
Polaris b 55 cd 38 cd
Revolution a 85 ab 75 ab
Seigers a 95 a 95 a
Snapper a 83 ab 60 bcd
Cal. Wonder ab 70 a-d 35 d

21. Conclusions _____________________________________
Greenhouse and field trials showed that following bell pepper cultivars are resistant/tolerant to Phytophthora capsici (Illinois Isolates)
Alliance
Aristotle
Emerald Isle
Enza
Paladin
Reinger
Revolution

22. Phytophthora Blight of Peppers (Management)
_______________________________
Resistant cultivars
Chemical control
Cultural practices
Red-light treatment

23. Phytophthora Blight of Vegetables
Phytophthora Blight of Vegetables (Chemical Control) _____________________________________
Since 2000, we have tested more than 40 fungicides for their efficacy for control of Phytophthora capsici

24. Phytophthora capsici –Fungicide Effect/IN VITRO (100 ppm) .
Mycelial Sporangia Zoospore Zoospore
radial formation release germination
growth inhibition inhibition inhibition
Fungicide (mm) (%) (%) (%) __________________________________________________________________________
Acrobat
Aliette
Bravo Ultrex
Cuprofix
Quadris
Ridom Gold/Bravo
Ridom Gold/Copp
Ridom Gold EC
Ridom Gold/MZ
Zoxium
Control ________________________________________________________________________________

25. Phytophthora capsici –Fungicide Effect/IN VITRO (10 ppm) __________________________________________________________
Mycelial Sporangia Zoospore Zoospore
radial formation release germination
growth inhibition inhibition inhibition
Fungicide (mm) (%) (%) (%) ____________________________________________________________________ Acrobat
Bravo Ultrex
Cuprofix
Ridom Gold/Bravo
Ridom Gold EC
Ridom Gold/MZ
Zoxium
Control ______________________________________________________________________________________

26. Phytophthora capsici – Effect of Acrobat (10 ppm) .
Mycelial Zoospore Zoospore
radial release germination
Pathogen growth inhibition inhibition
isolate (mm) (%) (%) _____________________________________________________
Pumpkin
Pumpkin
Pumpkin
Pumpkin
Pumpkin
Pumpkin
Squash
Pepper ______________________________________________________

27. Phytophthora Blight Management ______________________________________
(Chemical Control)
______________________________________
: Spray application
2010: Drip-irrigation delivery

29. Phytophthora Blight – Management, 2007 (Chemical Control, 7-Day)
_________________________________________
Plant Survival (%) _________________________
Treatment (1S,7F) 15 May 10 July 14 August
Control b 35.0 a
Ra, Ra+Ko+Sil a 65.0 a
Om, Om/Ra+Ko+Sil ab 45.0 a
Ma, Ma ab 57.5 a
Re, Re+Ko+A a 70.0 a
Fo, Fo+Ko/Ta+Ko a 45.0 a __ A-90=Activator-90; Ko=Kocide-3000; Ma=Maestro; Om=Omega; Ra=Ranman; Sil=Silwet; Ta=Tanos

30. Phytophthora Blight – Management, 2010
(Chemical Control, 7-Day: Drip Irr. Delivery)
_________________________________________
Plant Survival (%) _________________________
Treatment (D, F) 14 May 11 June 9 July
Control c 10.0 e
RG/RS/RGC/PO (7) ab 70.0 a
RG/RS+AD/RGC (7) ab 55.0 a-d
ZO/ZO(D)+ZO(F) (8) ab 65.0 ab
ZO/ZO(D) (8) ab 60.0 a-c
RG/RG(D)+ZO(F) (8) ab 52.5 a-d AD=Actigard; PO=presidio; RG=Ridomil Gold EC; RGC= Ridomil Gold Copper; RS=Revus; ZO=Zampro525SC.

31. Effective Fungicides No fungicide is effective with heavy rainfalls
Fungicides for Control of Phytophthora capsici
__________________________________________________________
Effective Fungicides
** Cyazofamid (Ranman 400SC)
** Captan (Maestro 80DF)
* Dimethomorph (Forum 4.16SC )
** Famoxadon + Cymoxanil (Tanos 50WDG)
* Fluopicolide (Presidio 4SC)
** Mandipropamid (Revus 2.09SC)
* Mefenoxam (Ridomil G. EC 4SC, R. G. Copper 65WP)
Phosphorous acid (ProPhyt) – inconsistent results
(Zampro 525SC) – further studies needed
No fungicide is effective with heavy rainfalls

32. Fungicides for Pumpkin Phytophthora
___________________________________________
Name FRAC Code
Copper (Kicide, Cuprofix) M
Cyazofamid (Ranman 400SC) 21
Dimethomorph (Forum)
Famoxadon + Cymoxanil (Tanos) 11, 27
Mandipropamid (Revus)
Mefenoxam (RG EC, RG Copper)
Fluopicolide (Presidio)
Phosphonates (ProPhyt, …..) 33

33. Phytophthora Blight of Peppers (Management)
_______________________________
Resistant cultivars
Chemical control
Cultural practices
Red-light treatment

34. Phytophthora Blight of Peppers (Management)
__________________________________
Cultural practices
Crop rotation
Host range of the pathogen
Survival of the pathogen in soil

35. Phytophthora Blight Management
(Host Range: 36 Crops and 9 Weed Species) ___________________________________________
Host________________ Non-Host____________.
Cantaloupe Cucumber Gourd Corn Pigweed Soybean
Eggplant pepper Beet Broccoli Kale Cabbage
Pumpkin Squash Radish Crabgrass Basil Chive
Zucchini Watermelon Turnip Sandbur Celery Dill
Honeydew Swiss-chard Carrot Wheat Water hemp Barley
Spinach Nightshade Onion Cocklebur Lamb’s-quarters
Green bean Lima bean Tomato Mustard Cauliflower
Velvet-leaf Snow pea Tobacco Parsley Puncture vine

36. Phytophthora Blight of Peppers (Management)
___________________________________________
Survival of Phytophthora capsici in soil
- 5,000 oospores/ g soil
- 4 soil type X 3 depths (2, 10, 25 cm) for 4 years

37. Oospore survival in soil
100
5,000 Oospores/g soil
Depth:
60.6
% Oospores recovered
16.7
10.1
0.9
0.4
0.06
0.04
0.004
0 Day
1 Day
3 Month
6 Month
12 Month
24 Month
30 Month
36 Month
48 Month
Oospore survival in soil

38. Germination of oospores recovered
5,000 Oospores/g soil
Depth:
53.2
47.2
% Oospores germinated
30.0
20.8
15.5
7.6
2.7
2.5
0.0
0 Day
1 Day
3 Month
6 Month
12 Month
24 Month
30 Month
36 Month
48 Month
Germination of oospores recovered

39. Conclusions
(Cultural Practices: Cropping Rotations) _____________________________________
3 years crop rotations with non-host plants and effective weed control is necessary for managing Phytophthora blight (P. capsici)

40. Phytophthora Blight of Peppers (Management)
_______________________________
Resistant cultivars
Cultural practices
Chemical control
Red-light treatment (Induced Resistance)

42. Natural Light
Red Light

44. Phytophthora Blight Management (Red-Light Treatment, ) - Greenhouse ____________________________________
Grow seedling under red light ( = ~ 650 nm) for 4 weeks – resistance induced
______________________________________________
Seedling death (%)
___________________
Red-light
Natural light
_________________________________________

45. Phytophthora Blight Management (Red-Light Treatment) - Field __________________________________
Inconsistent results in the fields

46. Managing Phytophthora Blight Recommended practices
_______________________________________________________
Recommended practices
Plant resistant cultivars
≥3 years of effective crop rotations
Grow on raised beds
Avoid using contaminated water
Fungicide applications (7-day, alternate)
Tolerant cultivars with fungicides

47. Acknowledgements ____________________________________ Researchers:
D. Tian: Graduate Student
S. Z. Islam: Post-Doc Res. Associate
C. Pavon: Graduate Student
A. Jurgens: Academic Professional
Financial Support
USD – NCR – IPM
USDA – NCR – SARE
IDOA
Chemical Companies: BASF, DuPont, Syngenta, ISK, Cerexagri

48. QUESTIONS