Pierce disease of grape vine is caused by the bacterium Xyllela fastidiosa. This Slides show how the bacterium can be controlled using avirulent strain of the pathogen.

1. POTENTIAL BIOCONTROLAGENT FOR
GRAPEVINE PIERCE’S DISEASE MANAGEMENT
RUFUS AKINRINLOLA
PLANT PATHOLOGY DEPARTMENT

2. POTENTIAL BIOCONTROLAGENT FOR PIERCE’S DISEASE
MANAGEMENT
Outline
 Pierce’s disease
 Grapevine
 Pathogen and disease cycle
 Biological control
 Conclusion

3.  Pierce’s disease (PD)
PD is a grapevine disease
PD is caused by Xylella
fastidiosa
PD is vector-borne disease
PD is vectored by Insect
vector
PD was first reported in
California 1892

4. PD distribution
PD is endemic in;
• Central America
• Southeastern US
• Southwestern US
• Mexico
Pierce’s disease
https://www.plantmanagementnetwork.org

5. Symptoms:
• Marginal necrosis
• Leaf scorch
• Wilting
• Fruit drying
• Uneven maturation of canes
• Declined vigor
• Delayed bud break
• Death
Economic importance
• Major problem to grape industry
• Wide host range
Pierce’s disease
https://www.plantmanagementnetwork.org/elements/view.aspx?ID=4136

6. Grapevine (Vitis spp)
Economic importance
• Most important fruit crop grown in the world
• Many uses:
Fresh fruit
Dried fruit
Fresh grape juice
Concentrated grape juice
Wine
Distilled liquors
Grapeseed oils
Anthocyanin pigments
Ethanol production
http://www.uky.edu/Ag/CCD/history&uses.pdf

7. Pierce’s disease pathogen
Xylella fastidiosa
• Xylem limited bacterium
• Gram negative bacteria
• First discovered in PD in 1973
• Wide host range: Upto 28 families of monocot

8. Pierce’s disease pathogen
The vectors
• Insect vector called Leafhoppers
• Xylem sap feeding insects
2 families
 Cicadelinae:- sharpshooters
 Cercopidae:- spittlebug
• Vectors have wide host range:
 Woody and Herbaceous plants

9. Xylella fastidiosa survives winter and multiplies primarily in
guts of vector insects and/or in the xylem vessels of their
reservoir hosts and to the least extent in infected grape vines
Nymphs and adults Leafhoppers and froghoppers
can initiate secondary infection within vineyard
orchard as they move from infected to uninfected
susceptible vine trees.
Bacterium multiplies and clogs the
xylem vessels, blocking water flow
from the roots to the leaves
Leaf scotch develops on
infected vine
Adults leafhoppers and sharpshooter pick ups X. fastidiosa
from their survival source and transfer onto the xylem vessel
of healthy susceptible vine (Primary infection).
Winter
Summer
Fall
Spring
DISEASE CYCLE OF
XYLELLA
FASTIDIOSA
Causing Pierce disease
(PD) of Grapevine
(Vitis spp)
Rufus Akinrinlola
PLPT 802
Nymphs
vectors lose
bacterium
cell during
molting
Bacterium
multiplies
and remain
persistent in
adult vector

10. Biological control
Potential biocontrol agent
 Avirulent Xylella fastidiosa strain EB92-1
Mode of Action:
 Cross protection
Biocontrol tests :
 Greenhouse
 Vineyard

11.  Biological control : Methods
EB9-2 strain
Avirulent
antagonistic/
protective
strain

12.  Biological control : Methods
EB9-2 strain
Avirulent
antagonistic/
protective
strain
PD92-8 strain
Virulent/
pathogenic
strain

13.  Biological control : Methods
PD92-8 strain
only
Eb9-2 / PD92-8
strains
Eb9-2 strain
only

14. Biological control : Results
PD92-8 strain
only
EB92-1 / PD92-
8 strains
EB92-1
strain only
No symptom Mild/ no symptom Severe symptom/
death

15. Biological control : Results
Hopkins, D. L. (2005). Biological control of Pierce's disease in the vineyard with strains of
Xylella fastidiosa benign to grapevine. Plant disease, 89(12), 1348-1352.

16. Biological control : Results
Hopkins, D. L. (2005). Biological control of Pierce's disease in the vineyard with strains of
Xylella fastidiosa benign to grapevine. Plant disease, 89(12), 1348-1352.

17.  Biological control : Results
Hopkins, D. L. (2005). Biological control of Pierce's disease in the vineyard with strains of
Xylella fastidiosa benign to grapevine. Plant disease, 89(12), 1348-1352.

18. Biological control : Results
Hopkins, D. L. (2005). Biological control of Pierce's disease in the vineyard with strains of
Xylella fastidiosa benign to grapevine. Plant disease, 89(12), 1348-1352.

19. Conclusion
• Pierce’s disease (PD) is caused by Xylella fastidiosa
• PD is a major problem facing grapes-based industries in California
• Avirulent X. fastidiosa EB92-1 strain is a potential biocontrol agent
• EB92-1 has been tested as positive biocontrol agent both in greenhouse
and vineyard grapevine pierce’s disease
• Research at improving EB92-1 strain application method and
commercialization is in progress.

20. Thanks!