Front Cover

Group Title: ARC-A research report - Agricultural Research and Education Center - RH-83-15
Title: Attempts to control Erwinia Blight of Philodendron selloum with some unusual compounds
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066514/00001
 Material Information
Title: Attempts to control Erwinia Blight of Philodendron selloum with some unusual compounds
Series Title: ARC-A research report
Physical Description: 4 p. : ; 28 cm.
Language: English
Creator: Chase, A. R ( Ann Renee )
Agricultural Research Center (Apopka, Fla.)
Publisher: University of Florida, IFAS, Agricultural Research Center-Apopka
Place of Publication: Apopka FL
Publication Date: 1983
Subject: Philodendrons -- Diseases and pests -- Control -- Florida   ( lcsh )
Bacterial diseases of plants -- Control -- Florida   ( lcsh )
Bactericides -- Testing -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: A.R. Chase.
General Note: Caption title.
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00066514
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 71261557

Table of Contents
    Front Cover
        Front Cover
        Page 1
        Page 2
        Page 3
        Page 4
Full Text


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

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida


A. R. Chase, -
University of Florida, IFAS
Agricultural Research Center-Apopka
ARC-A Research Report RH-83-15

Erwinia blight is a serious bacterial disease in Florida which severely
affects Philodendron selloum. Production of this plant under shadehouse
conditions can be very difficult since there are few bactericides available
for foliage plants and none exist which completely control Erwinia under wet
conditions. Chemical suggestions for bacterial disease control include use
of streptomycin sulfate (such as Agri-Strep), copper compounds (such as Kocide
or Copper Count N) and combinations of copper compounds and a maneb product
(such as Manzate 200 or Dithane M45). In addition, new materials are sometimes
suggested as possible controls for bacterial diseases. Two such compounds
which have been recently investigated by some growers are vinegar and Kilol
DF-100 (which has an extract from grapefruit seed as the active ingredient).
The purpose of this report is to provide the results from tests involving these
materials, as well as others listed previously for control of Erwinia blight of
P. selloum.

Treatments are listed for each test (Tables 1-4), including the rate and
date of application. Table 1 lists results for a test involving vinegar used
in a 1:10 dilution. Plants did not respond well to this treatment and developed
white marginal necrosis (burning) after a single application. Since plants were
relatively small the phytotoxicity may have been due to their sensitivity;
larger plants were used in subsequent tests. However, even at this relatively
low rate of vinegar bacterial blight was not controlled. In contrast,
Agri-Strep provided good control of the bacterium in this test.

Higher rates of vinegar were employed in the second test to determine the
best rate for bacterial disease control (Table 2). The results of this test
were similar to those of the first. None of the vinegar treatments provided any
degree of control while the level of phytotoxicity increased as vinegar

concentration increased. Disease level appeared highest on inoculated plants
sprayed with the highest rate of vinegar. This may have been due to
creation of wounds by the vinegar which allowed more entry of the bacterium
in the plant.

The third test was performed to evaluate the recommended rates of some
bactericides, including Kilol DF-100, for control of Erwinia blight. In this
test the only chemical application which gave good disease control was
Agri-Strep (Table 3). Overall, Kilol treated plants were as badly infected
with Erwinia as inoculated control plants. Vinegar did not appear to control
disease to any acceptable degree in this test.

The final test evaluated use of higher rates of Kilol. No treatments
were successful in controlling the bacterial blight (Table 4). There was a
general trend toward fewer total lesions as the concentration of Kilol
increased immediately after inoculation, but this trend rapidly disappeared
within one week as additional applications of the products were made.

It is possible that Kilol DF-100 or vinegar could affect a different
bacterial disease of foliage plants, but these tests indicate that it is
unlikely. Both compounds caused phytotoxicity on P. selloum and should be
tested carefully on other plants for safety as well as efficacy. A separate
test showed that vinegar was very toxic to Xanthomonas infected ivy and
provided no control of this bacterial disease. Recommendations for bacterial
disease control remain: 1) use pathogen-free stock plants and propagation
materials; 2) keep the plant foliage as dry as possible; and 3) apply copper,
copper plus maneb or streptomycin sulfate for chemical control as needed.

Mention of trade names in this article does not imply endorsement by either
the author or the University of Florida of these compounds over others which
have similar activities.

Table 1. Effect of vinegar and some bactericides on severity of Erwinia
blight of Philodendron selloum.

Treatment Rate Number lesions/plant

Water b
noninoculated 0.0 a
inoculated -- 3.2 b
inoculated 10% 4.2 b
inoculated 4.5 g/gal 0.2 a
inoculated 200 ppm 0.2 a
aTreatments were applied on 4-18 and 4-23.
bMeans were separated with DNMRT (5%).
CPlants were inoculated on 4-20.

Table 2. Effect of high rates of vinegar on Erwinia

blight on Philodendron

Rate/ No. leaves without No. leaves with
Treatment gal lesions/plant phytotoxicity/plant

noninoculated -- 5.4 0.0
inoculated 2.7 0.0
inoculated 10% 2.0 0.5
inoculated 20% 2.2 0.7
inoculated 40% 1.1 0.8
aTreatments were applied on 4-20 and 4-24.
bPlants were inoculated on 4-21.

Table 3. Effect of several bactericides, vinegar and
severity of Erwinia blight of Philodendron selloum.

Kilol DF-100 on

Rate/ No. leaves without No. leaves
Treatment gal Erwinia/plant standing/plant

noninoculated -- 7.7 a 7.7 a
inoculated -- 0.7 d 1.9 d
inoculated 20% 3.1 c 4.2 bc
inoculated 4.5 g 3.1 c 4.1 bc
inoculated 6.8 g/4.5 g 3.3 c 3.9 c
inoculated 200 ppm 5.0 b 6.0 ab
Kilol DF-100
inoculated 0.2 ml (50 ppm) 1.1 d 2.4 cd
aTreatments were applied on 6-7, 6-10 and 6-13.
bMeans were separated with DNMRT (5%).
CPlants were inoculated on 6-8.

Table 4. Effect of high rates of Kilol DF-100 on severity of-Erwinia
blight of Philodendron selloum.

Rate/ No. leaves without No. leaves
Treatment gal Erwinia/plant standing/plant

noninoculated 12.4 a 12.4 a
inoculated 2.6 bc 7.6 b
inoculated 0.2 ml (50 ppm) 2.6 bc 7.2 b
inoculated 1.0 ml (250 ppm) 2.2 bc 7.5 b
inoculated 5.0 ml (1250 ppm) 1.9 c 6.4 b
inoculated 200 ppm 3.6 b 7.8 b
plants were sprayed on 6-20, 6-23, 6-27 and 6-30.
bMeans were separated with DNMRT (5%).
CPlants were inoculated on 6-24.

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