1. Control Options for Rice
C t l O ti f Ri
Bacterial Panicle Blight
Groth D E 1, Rush M C 2, Shahjahan A K M 2,
Groth, D.E. Rush, M.C. Shahjahan, A.K.M.
Sha, X.1, and Ham, J. 2
LSU AgCenter, 1Rice Research Station, Rayne, LA and
2Department of Plant Pathology and Crop Physiology, Baton
Rouge,
Ro ge LA USA

3. Major Rice Diseases

4. Bacterial Panicle Blight

5. Areas of research
Etiology
Epidemiology
Cultural
C lt l management t
Foliar pesticides
Seed treatments
Disease resistance

6. Etiology
Isolation by plant inoculation
Bacterial species as determined by BioLog
Burkholderia glumae most prevalent
Others identified
– B.
B gladioli
– B. cepacea
– B. pyrrpcinia
py p
Development of a real-time PCR to identify B.
real-
glumae and B. gladioli in green tissues

7. Isolation and identification

8. Epidemiology
B. gladioli found surviving in soil but not B.
glumae
Spread of epiphytic populations limited
during growing season
38 and 40°C for optimum for bacteria
40°

9. Cultural management
Nitrogen management
– Higher N rate more disease
Planting date
– Late planted rice more disease
Exposed to higher temperatures

10. Foliar Applications
Antibiotics
Coppers
Oxolinic A id
O li i Acid
Micro nutrient mixtures
Growth regulators

11. Tested Products In-vitro
In-

12. Foliar Trials
Applied between boot and heading
Various rates ex. Starner 0.35-0.50 lb ai/A
0.35- ai/A
Inoculated and uninoculated t i l
I l t d d i l t d trials
Coppers tend to be toxic
Antibiotics were not very effective
Oxolinic acid (Starner 20WP) best

13. Difficulties with foliar applications
No prediction or scouting methods
Erratic occurrence
Regulatory problems
R l t bl
Cost of preventative sprays
Toxicity of coppers
Increased yields and milling erratic
No h i l
N chemical control i th near f t
t l in the future

15. Scouting and Determining Need
Damage is most severe during periods of
unusually hot weather or unusually hot nights. No
y y g
scouting methods are available and no chemical
control agents are labeled to control bacterial
panicle blight.

16. Seed treatments
Materials tested
– Coppers fungicides
– Antibiotics
– Oxolinic acid
Development of ELISA and PCR t t f
D l t f d tests for
identifying infected seed-lots
seed-
Seed treatments erratic

17. Disease resistance
Screening methods
– Inoculation at boot split and heading
– Bacterial concentration critical ~1x108
CFU/ml
– Too high all susceptible
– Too low all are resistant
– Isolate must produce toxin

20. Inoculation timing - 2 times

21. Rating scale (0-9)
(0-
0 no damage (Immune)
3 20-30% damage (moderately resistance)
20-
6 50-60% damage (susceptible)
50-
9 100% sterility (
t ilit (very susceptible)
tibl )
2 vs 8

22. Disease resistance cont.
Host resistance
– High levels of resistance found (1-3 ratings)
(1-
Nipponbare, LM-1, Jupiter, TeQing, AB647, others
LM-
– Crosses made and populations being evaluated
– Evaluating 6000-8000 inoculated rows/year
6000-
– Evaluate whenever natural disease develops
p
– Screen F3 to F8

23. Panicle Blight Reactions
Very Moderately Moderately
Susceptible Susceptible Susceptible Resistant
CL131 CL161 Catahoula Jupiter
Bengal
g Cheniere Hybrids
y
Trenasse Cocodrie
Neptune CL151
Wells CL171

24. 10 BPB resistant lines, including source
varieties, germplasm, and breeding lines,
are available by request
LM-1
NPB/CCDR
Nipponbare
LM‐1/CCDR
Jup te
Jupiter LR2065/CCDR
/
LM‐1/CCDR CCDR/LR2065
NBP(MCR00‐2190 C93‐137
NBP(MCR00 2190 C93 137 LR2065/CCDR
KATY/CPRS/JA85)

25. Summary
Cultural management ineffective
Chemical control unlikely
Disease resistance main area of effort
Some progress towards developing
diseases resistance including four sources
Request seed from: Don Groth
Rice Research Station
1373 Caffey Road
Rayne,
Rayne LA 70578 USA
dgroth@agcenter.lsu.edu