Update on controlling three bacterial diseases of foliage plants

Material Information

Update on controlling three bacterial diseases of foliage plants
Series Title:
AREC-Apopka research report
Chase, A. R ( Ann Renee )
Agricultural Research and Education Center (Apopka, Fla.)
Place of Publication:
Apopka FL
University of Florida, IFAS, Agricultural Research and Education Center-Apopka
Publication Date:
Physical Description:
3 p. : ; 28 cm.


Subjects / Keywords:
Foliage plants -- Diseases and pests -- Control -- Florida ( lcsh )
Bacterial diseases of plants -- Control -- Florida ( lcsh )
Wildlife damage management ( jstor )
Bacterial diseases ( jstor )
Butterflies ( jstor )
government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )


General Note:
Caption title.
Statement of Responsibility:
A.R. Chase.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
70701662 ( OCLC )


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Copyright 2005, Board of Trustees, University
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Update on Controlling Three Bacterial Diseases of Foliage Plants

A. R. Chase ---.
University of Florida, IFAS' Central Science
Agricultural Research and Education Center ApopP grar
AREC-Apopka Research Report RH-87-1
OCT 14 1987
Bacterial diseases of foliage plants cause serious ,losses every year
in Florida. High temperatures and humidity favor eveldtnot bdfobiact al
diseases making use of pesticides for control more Tftir--tha-under
cool, dry conditions. The only bactericides labeled for use on foliage
plants for control of a bacterial disease are streptomycin sulfate (Agri-
Strep) and copper products such as Kocide 101 77WP cupricc hydroxide).
Although these compounds provide the best chemical control of bacterial
diseases available, their use is commonly limited due to possibility of
phytotoxicity, lack of broad labeling, and relatively poor efficacy. New
compounds are occasionally introduced which may have activity against
bacteria. The following tests were designed to compare the fungicide,
Aliette 80WP (phosetyl aluminum) to cupric hydroxide and some new
bactericides from UniRoyal with cupric hydroxide for control of three
bacteria pathogenic on foliage plants.

All plants were obtained from growers as liners and grown for
approximately 2 months to improve chances of freedom from bacterial
pathogens and pesticide residues. Plants were grown in 4" pots in a
steam-treated potting medium consisting of equal parts of Canadian peat and
pine bark. The medium was amended with 10 Ibs Osmocote 19:6:12, 7 Ibs
dolomite, and 1 lb Micromax per cubic yard after steaming. Plants were
grown on raised benches in greenhouses with temperatures ranging from 65 to
95F and a maximum light level of 1800 ft-c.

The bacterial diseases which were tested were Syngonium blight (caused
by Xanthomonas campestris) on Syngonium podophyllum 'White Butterfly',
Xanthomonas leaf spot (caused by X. campestris pv. hederae) of Schefflera
arboricola (dwarf schefflera), and Pseudomonas leaf spot (caused by P.
cichorii) of Ficus lyrata (fiddle-leaf fig). Plants werg inoculated with a
bacterial suspension of the appropriate pathogen (1 x 10 bacteria/ml) or
treated with water only. A single pesticide application was made 3 days
prior to inoculation and again twice on weekly intervals following
inoculation. Plants were misted (5 sec/30 min from 0800 to 2000 hr daily)
starting 1 day prior to inoculation and continuing until final ratings
approximately 3 weeks after initial pesticide application. Misting was
turned off for 6 hours the day of each pesticide application.

Associate Professor of Plant Pathology, University of Florida, IFAS
Agricultural Research and Education Center, 2807 Binion Rd., Apopka, FL

Aliette was applied at rates from 1.2 to 7.2 g/liter (equivalent to 1
to 6 lbs/100 gallons). Numbered compounds UBI 1820, 1821, and 1825 from
UniRoyal were used at the rates listed in Table 1. Kocide 101 was used at
either 1.8 or 3.2 g/liter (equivalent to 1.5 or 2.7 lbs/100 gallons).

UniRoyal experimental compounds provided moderate control similar to
that achieved with Kocide for White Butterfly infected with X. campestris
and fiddle-leaf fig infected with Pseudomonas cichorii (Table 1). In
contrast, only 1820 at 5.5 g/liter and 1825 atT 7.8 g/iter provided some
control of X. campestris pv. hederae on dwarf schefflera. Aliette failed
to provide control of two of the three bacterial diseases tested (Table 2).
Moderate control of Xanthomonas on White Butterfly was achieved with
Aliette at all rates tested. Kocide provided excellent control of X.
campestris pv. hederae on dwarf schefflera in this trial when used at 1.8
g/liter (Table 2).

Unfortunately, none of the compounds tested gave better control of
these diseases than Kocide 101. Kocide 101 gave good control of
Xanthomonas leaf spot of dwarf schefflera in one trial but not in the
other. Kocide 101 and Aliette gave moderate control of Syngonium blight of
White Butterfly. A combination of the two compounds might provide better
control but should be tested for phytotoxicity prior to general use.
Kocide 101 provided good control of Pseudomonas leaf spot of Ficus lyrata.



Table 1. Efficacy of Kocide 101 or numbered compounds from UniRoyal in
controlling three bacterial diseases of foliage plants.

Mean percentage of foliage area affected
Xanthomonas Pseudomonas
Xanthomonas campestris pv. cichorii
Rate campestris on hederae on on fiddle-
Treatmentz g/liter White Butterfly dwarf schefflera leaf fig

Noninoculated --- 0 ay 0 a 0 a
Inoculated --- 42 c 12 cd 14 c
Kocide 101 1.8 25 b 7 bc 4 ab
Kocide 101 3.2 32 bc 14 d 2 ab
UBI 1820, 1821x 5.5 24 b 6 ab 4 ab
UBI 1825 4.3 34 bc 13 cd 5 ab
UBI 1825 7.8 22 b 6 ab 6 b
UBI 1825 14.6 22 b 12 cd 4 ab

xUBI 1820 was used for dwarf schefflera while UBI 1821 was used for the
other plants tested.
YMeans in the same column followed by different letters were significantly
different at P = 0.05 (Duncan's New Multiple Range Test).
ZFoliar applications were made 2-4 times on weekly intervals with disease
rated 1 week after the final application.

Table 2. Efficacy of Kocide 101 or Aliette in controlling three bacterial
diseases of foliage plants.

Mean percentage of foliage area with symptoms
Xanthomonas Pseudomonas
Xanthomonas campestris cichor i
Rate campestris on pv. hederae on on fiddle-
Treatmentz g/liter White Butterfly dwarf schefflera leaf fig

Noninoculated ---- 0 ax 0 a 0 a
Inoculated ---- 27 c 28 b 17 b
Kocide 101 1.8 NTz 7 a NT
Aliette 80 WP 1.2 NT 18 b NT
Aliette 80 WP 2.4 16 b 20 b 10 b
Aliette 80 WP 4.8 14 b NT 11 b
Aliette 80 WP 7.2 12 b NT 16 b

XNT = not tested.
YMeans followed by a different letter were significantly different at P =
0.05 (Duncan's New Multiple Range Test).
Treatments were applied on 8-20 and 8-27 with disease rated on 9-2-86 for
dwarf schefflera and on 10-9, 10-16 and 10-23 for White Butterfly.

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