| Material Information
||Two foliar diseases of Euonymus SPP.
||ARC-A research report
||2 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 )
Foliage plants -- Diseases and pests -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
bibliography ( marcgt )
non-fiction ( marcgt )
||Includes bibliographical references (p. 2).
||Statement of Responsibility:
||Florida Historical Agriculture and Rural Life
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
DISEASES OF EUONYMUS SPP.
2 1j, A. R. Chase
University of Florida IFAS
i.F.A.S.-Univ nf F i ltural Research Center-Apopka
..S--- U----i. of F A Research Report RH-82-17
Some of the newer crops in the cut foliage industry are Euonymus spp.
There are two foliar diseases which have been described on euonymus;
Colletotrichum leaf spot (also called anthracnose), and Phytophthora aerial
Colletotrichum leaf spot is the most common disease of Euonymus spp.
in Florida and is caused by Colletotrichum gloeosporioides. The disease was
first described on E. fortunei cultivars 'Emerald 'n Gold' and 'Gaiety' in
commercial woody ornamental nurseries in New England in 1980 (2). Leaf
spots start as light brown 1/32 1/16 inch wide areas with reddish margins.
When weather conditions are hot and rainfall is high, these leaf spots
enlarge to 1/4 1/2 inch wide and have concentric rings of light and dark.
In addition, the shoot tips of infected plants can be severely infected and
leaf abscission is common giving these plants a blighted appearance. Although
this disease has only been reported on E. fortunei it also occurs on several
cultivars of E. japonica (Table), grown for cut foliage production in Florida.
Newly rooted cuttings appear to be especially susceptible to Colletotrichum
leaf spot which can even kill them if preventative measures are not initiated
rapidly. Use of maneb, mancozeb, and chlorothalonil are reported to
completely protect euonymus from Colletotrichum leaf spot (2). Labels of
these products should be consulted to verify safety (with respect to
phytotoxicity) on euonymus as well as rates and intervals of applications.
A second foliage disease of Euonymus sp. is Phytophthora aerial blight
caused by an unidentified species of Phytophthora. This disease was first
described in California in 1981 on E. japonica cultivars in woody ornamental
nurseries (1) (Table). Disease occurs first on shoot tips during the
rainy season and appears as a slightly brown, wilted condition. The tissue
then dries out and becomes a dark brown. Infection gradually advances down
the stem until the entire shoot is killed. Phytophthora aerial blight of
euonymus has not been reported in Florida. However, many other foliar blights
caused by Phytophthora spp. occur in Florida and growers should watch for this
disease on euonymus. If Phytophthora aerial blight is diagnosed, several
fungicides may be used which successfully control Phytophthora spp., including
ethazole and metalaxyl. Since the pathogen lives in the soil, special care
should be taken to treat soil as well as foliage of the plants. As always,
consult pesticide labels prior to use to insure safety (with respect of
phytotoxicity), rate, and interval of application.
Table- Known susceptibility of some Euonymus species and cultivars to two
foliar diseases. No euonymus are known to be resistant to either
Species Cultivar Disease
Col etotrichum Phytophthora
fortunei Emerald Gold +
japonica Aureo-marginata +
Gold Spot + +
Non-variegated + +
Silver King +
Silver Queen + +
1. Keim, R., L. J. Klure, and G. A. Zentmyer. 1981. A foliage blight
of euonymus caused by Phytophthora. California Agriculture 35(5,6):16-17.
2. Mahoney, M. J. and T. A. Tattar. 1980. Identification, etiology, and
control of Euonymus fortunei anthracnose caused by Colletotrichum
gloeosporioides. Plant Disease 64:854-856.