Update On An Antimicrobial Field
Trial To Control Citrus HLB
Dr. Charles A. Powell
Dr. Muqing Zhang
Dr. Yongping Duan
IRREC-IFAS, University of Florida
Jan. 2016
Field Trial
Split-Plot factorial A+BC design with 4 replicates in three young
red grapefruit groves in St. Lucie County
A: 12 Chemicals, including SDX, PCY, CARV, Silver nitrate,
Silver phosphite, Aliette®, Mycoshield®, Firewall®, ZS, VA, WATER
(NEGATIVE CONTROL) and PEN (POSITIVE CONTROL). Three
foliar sprays applied by handgun at 1 gallon per tree on three
growth flushes. Penicillin applied via trunk injection.
B: Heat Treatment applied to ½ of the trees (125-128F for 30
seconds in June).
C: Foliar nutrition (N, P & K w/ Micros) applied to ½ of the
treatment trees at each growth flush.
Pre-Treatment HLB Disease Severity
Grove B
Grove E
Grove P
Grove 2
Grove 3
Effectiveness of Antimicrobials against Las
Fruit Drop in the Treated Trees
ALIETTE WDG
APPLICATION
COMPOUND
RATE
FRUIT
DROP
ALIETTE
WDG
(Aluminum 5 pounds per Decrease
tris (O-ethyl acre in 100
phosponate)) gallons water
EPA
COST/ACR REGISTRATION
registration
E
STATUS
264-516
$183
No more than
20 pounds per
year on
bearing citrus
Firewall 50WP
COMPOUND
Firewall 50WP
(Streptomycin
sulfate)
APPLICATION
RATE
11 ounces per
acre in 100
gallons water
FRUIT
DROP
No change
EPA
Approved
80990-3
COST/ACRE
$93
REGISTRATION
STATUS
Section 18 Emergency
Exemption for Citrus
Canker Management.
Maximum 22 ounces
per year.
Mycoshield
APPLICATION
RATE
FRUIT
DROP
COMPOUND
EPA Reg. No COST/ACRE
Mycoshield
200 ppm (1
(Oxytetracycli
pound) in 100
$45
ne calcium
gallons water
complex)
Increase
55146-97
REGISTRATION
STATUS
No current
label for
citrus
Silver Nitrate (SN) and Silver Phosphite (SP)
COMPOUND
Silver
Foliar
APPLICATION
RATE
FRUIT DROP
1.75 liters
per acre in
100 gallons
water
EPA
Decrease Approved
REGISTRATION
COST/ACRE
STATUS
50 USD
Fertilizer
Registration
Agricultural antibiotics (VA and ZS)
APPLICATION
COMPOUND
RATE
FRUIT DROP
VA
Validoxylamine A 200 ppm per
Decrease;
&
acre in 100
ZS
Zhongshengmyxin gallons water
Increase
EPA
No
REGISTRATION
COST/ACRE
STATUS
Registration
80-120 for crop use
in China and
USD
Japan
Essential oils (Carv and Pcy)
COMPOUND
Carvacrol
&
P-cymene
APPLICATION
REGISTRATION
RATE
FRUIT DROP
EPA
COST/ACRE
STATUS
500 ppm per
Listed on the
acre in 100 Decrease 2009-0237 50-80
US TSCA
gallons water
inventory
USD
Antibiotics (PEN and SDX)
COMPOUND
PEN
SDX
APPLICATION
REGISTRATION
RATE
FRUIT DROP
EPA
COST/ACRE
STATUS
500 ppm for
Registration
PEN in one
for animal
liter
decrease Approved 80 USD
use
100 ppm for
Registration
SDX,per acre
for animal
in 100 gallons
use
water
decrease Approved 120 USD
Future Activities
• Field trial will be continued through 2016
• Fruit quality data will be completed in
Feb. 2016
• Optimization of the application rate and
dosage of the treatments.
P22 (SN)
April, 2015
Dec, 2015
P64 (ALI)
April, 2015
Dec, 2015
P82 (OXY)
April, 2015
Dec, 2015
CK, without any treatment
PEN
ALI
PCY
SP
Mycoshield
SDX
Contacts
TIM GAVER
FIELD TRIAL MANAGER
UF/IFAS/IRREC
2199 S. ROCK RD., FORT PIERCE, FL34945
EMAIL: [email protected]
TEL: 772-201-6066