| Material Information
||Euonymus Anthracnose influence of cultivars, shade level and increased disease pressure
||ARC-A research report
||4 p. : ; 28 cm.
||Chase, A. R ( Ann Renee )
Agricultural Research Center (Apopka, Fla.)
||University of Florida, IFAS, Agricultural Research Center-Apopka
||Place of Publication:
||Euonymus -- Diseases and pests -- Florida ( lcsh )
Anthracnose -- Control -- Florida ( lcsh )
Colletotrichum gloeosporioides -- Control -- Florida ( lcsh )
Plants -- Effect of shade on -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
bibliography ( marcgt )
non-fiction ( marcgt )
||Includes bibliographical references (p. 3).
||Statement of Responsibility:
||Florida Historical Agriculture and Rural Life
|Table of Contents
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
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site maintained by the Florida
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Copyright 2005, Board of Trustees, University
< 3 z2- EUONYMUS ANTHRACNOSE INFLUENCE OF
CULTIVARS, SHADE LEVEL AND INCREASED DISEASE PRESSURE
A. R. Chase
IFAS, University of Florida
Agricultural Research Center Apopka
ARC-A Research Report, RH-1983-22
The most serious disease of Euonymus spp. in Florida is anthracnose,
caused by Colletotrichum gloeosporioides. Under severe conditions, which
occur during the summer months on plants grown outdoors, the disease can
cause complete defoliation of infected plants and even death. Control
during the winter and spring months can be accomplished through weekly
applications of one of many fungicides including Daconil and Manzate (1).
The following tests were performed to evaluate the ability of these
chemicals to control anthracnose during the warmer summer months when both
rainfall and temperatures are high and to determine whether or not different
cultivars of Euonymus and different shade levels of the production area
influence severity of anthracnose.
The first test was performed in a shadehouse (50% shade) on ground-
cloth. Plants were grown in 6" plastic pots and irrigated overhead twice
weekly as well as receiving rainfall. Euonymus plants from four cultivars
were included in each of the treatments listed in Table 1 (14 plants per
treatment). Treatments were applied twice on weekly intervals prior to
inoculation with the pathogen and then on weekly intervals for the duration
of the test (5-10-83 to 8-5-83). At the end of the test, the severity of
disease was rated from 1 (no disease) to 5 (lesions on all leaves and stems
Anthracnose control during the summer was less successful than that
attempted during the spring months (1). None of the chemicals tested
provided complete control of the disease, although both Dithane M-45 and
Dithane Z-78 both provided some control (Table 1). Two of the compounds
tested appeared to result in more severe disease than the control treat-
ment, MF-654 and C06054. Disease pressure was obviously quite high as
reflected in the high ratings of all treatments including the noninoculated
The second test was also performed using four cultivars of Euonymus
(Table 2). In this test, plants were placed directly in the ground under
different shade levels including 70, 50 and 30% shade. The plants were
arranged in three rows of twelve plants each for a total of 36 plants per
cultivar for each shade level. Plants became naturally infected over the
period of one year. Ratings of each plant for severity of anthracnose
were recorded on 7-20-83 using the same scale as in the previous test.
Both shade level and cultivar of Euonymus influenced the severity of
anthracnose (Table 2). Disease severity was highest on plants grown under
the highest shade level (70%) compared to plants grown under the medium
and low shade levels (Table 2). Similarly, cultivar type also influenced
the severity of anthracnose, with the Microphylla plants less severely
affected than the three other types tested (Table 2).
These results have further characterized the problems faced by
Euonymus producers during the summer months. The 'Gold Spot' cultivar
is the most susceptible to anthracnose and all cultivars are more suscep-
tible when grown under a high shade (70%). Since complete control was
not achieved during these tests, even with Dithane M-45 or Z-78, cultivar
type and shade level should be considered when planting Euonymus to
minimize the need for fungicide applications and maximize their efficacy.
Chase, A. R. 1983. Some preliminary results on control of Euonymus
anthracnose. Commercial Fern Grower 6(8):1-2.
Table 1. Efficacy of some fungicides for control of
Euonymus anthracnose during the summer.
Treatment lb/100 gal of disease
Water -- 2.6 aby
Water --- 3.4 cd
Manzate 200 1.5 2.9 bc
Dithane M-45 1.5 2.7 ab
Zineb 1.5 2.9 bc
Dithane Z-78 1.5 2.2 a
MF-654 2 oz 4.0 e
C0-6054 7 oz 3.9 de
zDisease was rated from 1 (no disease) to 5 (severe
YMeans were separated using Duncan's New Multiple
Range Test (5% level).
Table 2. Effect of shade level and cultivar type on
severity of Euonymus anthracnose under summer conditions.
Euonymus cultivar 70 50 30
E. japonica 'Microphylla' 2.1 1.4 1.4
E. japonica 'Gold Spot' 2.3 1.6 1.8
E. japonica 'Silver Queen' 2.1 1.9 1.5
E. japonica (green) 2.1 1.7 2.0
z Disease was rated from 1 (no disease) to 5 (severe disease).
This report is not meant as an
endorsement of the products named by either
the author or the University of Florida.