Group Title: CFREC-Apopka research report - Central Florida Research and Education Center-Apopka ; RH-89-7
Title: Aliette 80WP and bacterial disease control
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00066565/00001
 Material Information
Title: Aliette 80WP and bacterial disease control
Series Title: CFREC-Apopka research report
Physical Description: 5 p. : ; 28 cm.
Language: English
Creator: Chase, A. R ( Ann Renee )
Central Florida Research and Education Center--Apopka
Publisher: University of Florida, IFAS, Central Florida Research and Education Center-Apopka
Place of Publication: Apopka FL
Publication Date: 1989
 Subjects
Subject: Xanthomonas -- Control -- Florida   ( lcsh )
Plants, Ornamental -- Diseases and pests -- Control -- Florida   ( lcsh )
Bactericides -- Testing -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 3).
Statement of Responsibility: A.R. Chase.
General Note: Caption title.
 Record Information
Bibliographic ID: UF00066565
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 70552044

Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida




/co




7q9 Aliette 80WP and Bacterial Disease Control I. Xanthomonas
0~__1 .- .i!


L ...


University of Florida, IFAS
Central Florida Research and Education Center Apopka c'&l 2
CFREC-Apopka Research Report, RH-89-7


Bacterial diseases of ornamentals are difficult to control due tbo
unavailability of efficacious and nonphytotoxic bactericides (1). In the
past, plant producers have relied on use of antibiotics such as Agri-Strep
21.2% (streptomycin sulfate) and copper compounds such as Kocide 101 77WP
cupricc hydroxide). New compounds have been tested whenever available but
none have shown activity equal to or surpassing that of the antibiotics or
copper compounds (1). Since 1987, two reports have been published
regarding the potential use of Aliette 80WP for bacterial disease control
(2,3). Aliette 80WP is a fungicide used in the ornamentals industry for
control of pythiaceous fungi (Phytophthora and Pythium spp.), which cause
root rot, stem rot and sometimes leaf blight. This fungicide is unique in
that it can be applied to plant foliage as well as roots for disease
control. Preliminary reports indicated that certain diseases caused by
Xanthomonads could be controlled by preventative sprays of Aliette 80WP at
rates between 1 and 5 lb/100 gal (2,3). The following report summarizes
tests comparing Aliette 80WP and Kocide 101 77WP for controlling some
diseases caused by Xanthomonads. In addition, several trials comparing
Aliette 80WP with other acidic compounds such as phosphorous acid (H3PO,
the breakdown product of Aliette) and vinegar (distilled white vinegar, 5%
acidity) were included.

Fifteen trials employing different ornamentals and pathovars of
Xanthomonas campestris were performed between December 1987 and April 1989.
Rates of each compound are given in appropriate tables. In each trial,
plants were sprayed once prior to inoculation and then on a weekly interval
for a total of 4 applications. Inoculation with a suspension of the
appropriate pathogen occurred 3 days after the initial chemical spray.
Disease ratings consisted of number of lesions per plant.

Xanthomonas leaf spot of Begonia 'Mini Angelwings' (caused by X. c.
pv. begoniae) was not controlled by Aliette but was significantly lower
with applications of Kocide at 1 or 2 lb/100 gal (Table 1). Neither
Aliette nor Kocide provided significant control of Xanthomonas leaf spot of
Hibiscus rosa-sinensis 'Brilliant Red' (caused by X. c. pv. malvacearum)
(Table 1). In contrast, both Aliette (2 or 4 lb/10 gal) and Kocide (1 and
2 lb/100 gal) gave significant control of Xanthomonas leaf spot of
Dieffenbachia maculata 'Camille' (caused by X. c. pv. dieffenbachiae)
(Table 1).

1Professor of Plant Pathology, Central Florida Research and Education
Center Apopka, 2807 Binion Rd., Apopka, FL 32703.


A. R. Chase





) I


Similar tests performed on Ficus benjamin infected with X. c. pv.
fici showed that the 2 lb/100 gal treatment with Kocide gave the Best
control of Xanthomonas leaf spot but the Aliette treatments and the lower
rate of Kocide also gave some disease control (Table 2). Fittonia
verschaffeltii plants infected with X. campestris did not benefit from
Aliette applications and were damaged by the Kocide applications which
resulted in a higher level of disease due to invasion of damaged tissue by
the pathogen (Table 2). One of the best examples of Aliette efficacy was
noted for Xanthomonas leaf spot of Hedera helix 'Brokamp' (caused by X. c.
pv. hederae). Both Aliette and Kocide reduced the number of lesions
significantly (Table 2).

Although a preliminary report (3) described significant control of
Xanthomonas leaf spot of Pilea spruceana with Aliette, more recent trials
did not substantiate this (Table 2). n contrast, excellent control of
Xanthomonas leaf spot of Pilea was achieved with the 2 lb/100 gal rate of
Kocide (Table 2). As indicated by previous reports (2,3), both Aliette and
Kocide give significant control of Xanthomonas blight of Syngonium
podophyllum 'White Butterfly' caused by X. c. pv. dieffenbachiae (Table 2).

Two trials comparing efficacy of three acidic compounds were conducted
on Xanthomonas blight of Anthurium 'Amazonia' caused by X. c. pv.
dieffenbachiae and Xanthomonas leaf spot of H. helix 'Brokamp' (ivy) caused
by X. c. pv. hederae. The pH of each spray solution was recorded prior to
application. Although Aliette gave about 50% control of Xanthomonas blight
of Anthurium, neither phosphorous acid nor vinegar gave significant disease
control (Table 3). In contrast, all three acidic compounds gave a moderate
degree of control of Xanthomonas leaf spot of ivy (Table 3). The solution
pH's of the various compounds indicate that pH is not the only factor
involved in the activity of Aliette (Table 3). The longevity of the leaf
surface pH effect due to applications of Aliette may exceed that achieved
with the phosphorous acid or vinegar on some plants.

Tests performed to evaluate the pH sensitivity of Xanthomonads
indicate that while some strains are more sensitive than others this cannot
completely explain the differences in efficacy responses (Table 4). Only
strains of X. c. pv. dieffenbachiae from syngonium were consistently more
sensitive to low pH than the other Xanthomonads (data not shown).

Aliette significantly reduces disease severity of various diseases
caused by Xanthomonads, although not all of those tested. The degree of
control is approximately equal to that achieved with Kocide, which has been
the best compound for controlling some Xanthomonas diseases of ornamentals
(1). Aliette applications prior to symptom development and rates similar
to those labeled for control of pythiaceous fungi should give the best
response.


-2-








References


1. Chase, A. R. 1986. Effect of experimental bactericides on three
bacterial diseases of foliage plants. Journal of Environmental
Horticulture 4:37-41.

2. Chase, A. R. 1987. Effect of fosetyl aluminum on severity of two
Xanthomonas leaf spot diseases. Proc. of Symposium on Aliette. Pages
81-86.

3. Chase, A. R. 1987. Update on controlling three bacterial diseases of
foliage plants. Foliage Digest 9(8):1-2.


Table 1. Comparison of Aliette 80WP
Xanthomonas leaf spot on Begonia,


and Kocide 101 77WP for control of
Dieffenbachia and Hibiscus.


Mean number lesions per plant
Treatmenta lb/100 gal Begonia Dieffenbachia Hibiscus

Noninoculated -- 0 ab 0 a 0 a
Inoculated --- 73 c 36 d 64 b
Aliette 80WP 2 76 c 20 bc 76 bc
Aliette 80WP 4 78 c 17 bc 112 c
Kocide 101 77WP 1 50 b 28 cd 76 be
Kocide 101 77WP 2 39 b 14 b 64 b

aTreatments were applied once 3 or 4 days prior to inoculation and repeated
weekly for a total of 3 applications.
Numbers in the same column followed by the same letter were not
statistically different (DNMRT, P=0.05).


-3-











Table 2. Comparison of different rates of Aliette 80WP and Kocide
Xanthomonas leaf spot diseases of foliage plants.


101 77WP for control of


Mean number lesions per plant
Treatmenta lb/100 gal Ficus Fittonia Hedera Pilea Syngonium

Noninoculated 0 ab 0 a 0 a 0 a 2 a
Inoculated -- 29 d 25 b 47 c 65 c 28 c
Aliette 80WP 1 -- 22 b -- 63 c 18 b
Aliette 80WP 2 20 c 23 b 16 b 81 c 14 b
Aliette 80WP 4 17 c 24 b 16 b 65 c 14 b
Aliette 80WP 8 -- 23 b -- 79 c 15 b
Kocide 101 77WP 1 12 bc -- 24 b 30 b 20 b
Kocide 101 77WP 2 4 ab 38 d 10 ab 7 ab 17 b
Kocide 101 77WP 4 -33 c 17 ab 15 b
Kocide 101 77WP 8 -- -- -- 8 ab 13 b
Aliette + 2 +
Kocide 2 -- 35 cd -

aTreatments were applied once 3 or 4 days prior to inoculation and repeated weekly for a total
of 3 applications.
bNumbers in the same column followed by the same letter were not statistically different
(DNMRT, P=0.05).









Table 3. Effect of acidic compounds on Xanthomonas leaf spot of Anthurium
and Hedera.

Mean number lesions per plant
Treatmenta lb/100 gal Anthurium solution pH Hedera solution pH

Noninoculated -- 0 ab 7.4 0 a 7.4
Inoculated --- 15 c 7.3 39 c 7.4
Aliette 80WP 2.5 8 b 4.0 15 b 4.4
Aliette 80WP 5 --- -- 13 b 4.3
Phosphorous 0.25 12 bc 3.3 22 b 3.4
acid (H3PO )
Phosphorous 0.5 -- -- 13 b 2.6
acid (H3PO, )
Vinegar 1 gal 13 bc 4.5 --
(5% acidity)
Vinegar 2 gal --- 11 ab 4.1
(5% acidity)
Vinegar 4 gal --- 13 b 3.8
(5% acidity)

"Treatments were applied once 3 or 4 days prior to inoculation and repeated
weekly for a total of 3 applications.
Numbers in the same column followed by the same letter were not
statistically different (DNMRT, P=0.05).


Table 4. In vitro pH growth studies for Xanthomonads.

Pathovar Minimum pH
Begoniae (from begonia) 4.75
Dieffenbachiae (from dieffenbachia) 4.75
Dieffenbachiae (from anthurium) 4.75
Dieffenbachiae (from syngonium) 5.75
Fici (from ficus) 4.75
'"iTtonia" (from fittonia) 4.75
Hederae (from ivy) 5.00
Malvacearum (from hibiscus) 4.75
"pilea" (from pilea) 4.75




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs